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Sample records for consciousness related neural

  1. Consciousness related neural events viewed as brain state space transitions

    PubMed Central

    2008-01-01

    This theoretical and speculative essay addresses a categorical distinction between neural events of sensory-motor cognition and those presumably associated with consciousness. It proposes to view this distinction in the framework of the branch of Statistical Physics currently referred to as Modern Critical Theory (Stanley, Introduction to phase transitions and critical phenomena, 1987; Marro and Dickman, Nonequilibrium phase transitions in lattice, 1999). Based on established landmarks of brain dynamics, network configurations and their role for conveying oscillatory activity of certain frequencies bands, the question is examined: what kind of state space transitions can systems with these properties undergo, and could the relation between neural processes of sensory-motor cognition and those of events in consciousness be of the same category as is characterized by state transitions in non-equilibrium physical systems? Approaches for empirical validation of this view by suitably designed brain imaging studies, and for computational simulations of the proposed principle are discussed. PMID:19003465

  2. Neural correlates of consciousness.

    PubMed

    Rees, Geraint

    2013-08-01

    Jon Driver's scientific work was characterized by an innovative combination of new methods for studying mental processes in the human brain in an integrative manner. In our collaborative work, he applied this approach to the study of attention and awareness, and their relationship to neural activity in the human brain. Here I review Jon's scientific work that relates to the neural basis of human consciousness, relating our collaborative work to a broader scientific context. I seek to show how his insights led to a deeper understanding of the causal connections between distant brain structures that are now believed to characterize the neural underpinnings of human consciousness.

  3. Neural Darwinism and consciousness.

    PubMed

    Seth, Anil K; Baars, Bernard J

    2005-03-01

    Neural Darwinism (ND) is a large scale selectionist theory of brain development and function that has been hypothesized to relate to consciousness. According to ND, consciousness is entailed by reentrant interactions among neuronal populations in the thalamocortical system (the 'dynamic core'). These interactions, which permit high-order discriminations among possible core states, confer selective advantages on organisms possessing them by linking current perceptual events to a past history of value-dependent learning. Here, we assess the consistency of ND with 16 widely recognized properties of consciousness, both physiological (for example, consciousness is associated with widespread, relatively fast, low amplitude interactions in the thalamocortical system), and phenomenal (for example, consciousness involves the existence of a private flow of events available only to the experiencing subject). While no theory accounts fully for all of these properties at present, we find that ND and its recent extensions fare well.

  4. Mechanisms of cortical neural synchronization related to healthy and impaired consciousness: evidence by quantitative electroencephalographic studies.

    PubMed

    Babiloni, Claudio; Vecchio, Fabrizio; Buffo, Paola; Iacoboni, Marco; Pistoia, Francesca; Sacco, Simona; Sara, Marco; Rossini, Paolo Maria

    2014-01-01

    In this paper, we review the contribution of our research group to the study of human consciousness by quantitative electroencephalographic (EEG) techniques. We posit that EEG techniques can be extremely useful for a direct measurement of brain electrophysiological activity related to human consciousness for their unsurpassable high temporal resolution (milliseconds). This activity can be expressed in terms of event-related potentials as well as changes of EEG rhythms of interest, for example the dominant alpha rhythms (about 8-12 Hz). The results of our studies, and those of several independent groups, lead support to the hypothesis that these techniques provide important insights about the neurophysiologic mechanisms underlying cortical neural synchronization/desynchronization and the regulation of neuromodulatory systems (e.g. dopaminergic, noradrenergic, cholinergic, etc.) at the basis of brain arousal and consciousness in healthy subjects and in patients with impairment of the consciousness. A possible interaction of these mechanisms and the drugs administered to patients with consciousness disorders is discussed.

  5. Cortical Neural Synchronization Underlies Primary Visual Consciousness of Qualia: Evidence from Event-Related Potentials

    PubMed Central

    Babiloni, Claudio; Marzano, Nicola; Soricelli, Andrea; Cordone, Susanna; Millán-Calenti, José Carlos; Del Percio, Claudio; Buján, Ana

    2016-01-01

    This article reviews three experiments on event-related potentials (ERPs) testing the hypothesis that primary visual consciousness (stimulus self-report) is related to enhanced cortical neural synchronization as a function of stimulus features. ERP peak latency and sources were compared between “seen” trials and “not seen” trials, respectively related and unrelated to the primary visual consciousness. Three salient features of visual stimuli were considered (visuospatial, emotional face expression, and written words). Results showed the typical visual ERP components in both “seen” and “not seen” trials. There was no statistical difference in the ERP peak latencies between the “seen” and “not seen” trials, suggesting a similar timing of the cortical neural synchronization regardless the primary visual consciousness. In contrast, ERP sources showed differences between “seen” and “not seen” trials. For the visuospatial stimuli, the primary consciousness was related to higher activity in dorsal occipital and parietal sources at about 400 ms post-stimulus. For the emotional face expressions, there was greater activity in parietal and frontal sources at about 180 ms post-stimulus. For the written letters, there was higher activity in occipital, parietal and temporal sources at about 230 ms post-stimulus. These results hint that primary visual consciousness is associated with an enhanced cortical neural synchronization having entirely different spatiotemporal characteristics as a function of the features of the visual stimuli and possibly, the relative qualia (i.e., visuospatial, face expression, and words). In this framework, the dorsal visual stream may be synchronized in association with the primary consciousness of visuospatial and emotional face contents. Analogously, both dorsal and ventral visual streams may be synchronized in association with the primary consciousness of linguistic contents. In this line of reasoning, the ensemble

  6. Cortical Neural Synchronization Underlies Primary Visual Consciousness of Qualia: Evidence from Event-Related Potentials.

    PubMed

    Babiloni, Claudio; Marzano, Nicola; Soricelli, Andrea; Cordone, Susanna; Millán-Calenti, José Carlos; Del Percio, Claudio; Buján, Ana

    2016-01-01

    This article reviews three experiments on event-related potentials (ERPs) testing the hypothesis that primary visual consciousness (stimulus self-report) is related to enhanced cortical neural synchronization as a function of stimulus features. ERP peak latency and sources were compared between "seen" trials and "not seen" trials, respectively related and unrelated to the primary visual consciousness. Three salient features of visual stimuli were considered (visuospatial, emotional face expression, and written words). Results showed the typical visual ERP components in both "seen" and "not seen" trials. There was no statistical difference in the ERP peak latencies between the "seen" and "not seen" trials, suggesting a similar timing of the cortical neural synchronization regardless the primary visual consciousness. In contrast, ERP sources showed differences between "seen" and "not seen" trials. For the visuospatial stimuli, the primary consciousness was related to higher activity in dorsal occipital and parietal sources at about 400 ms post-stimulus. For the emotional face expressions, there was greater activity in parietal and frontal sources at about 180 ms post-stimulus. For the written letters, there was higher activity in occipital, parietal and temporal sources at about 230 ms post-stimulus. These results hint that primary visual consciousness is associated with an enhanced cortical neural synchronization having entirely different spatiotemporal characteristics as a function of the features of the visual stimuli and possibly, the relative qualia (i.e., visuospatial, face expression, and words). In this framework, the dorsal visual stream may be synchronized in association with the primary consciousness of visuospatial and emotional face contents. Analogously, both dorsal and ventral visual streams may be synchronized in association with the primary consciousness of linguistic contents. In this line of reasoning, the ensemble of the cortical neural networks

  7. Neural correlates of consciousness: progress and problems.

    PubMed

    Koch, Christof; Massimini, Marcello; Boly, Melanie; Tononi, Giulio

    2016-05-01

    There have been a number of advances in the search for the neural correlates of consciousness--the minimum neural mechanisms sufficient for any one specific conscious percept. In this Review, we describe recent findings showing that the anatomical neural correlates of consciousness are primarily localized to a posterior cortical hot zone that includes sensory areas, rather than to a fronto-parietal network involved in task monitoring and reporting. We also discuss some candidate neurophysiological markers of consciousness that have proved illusory, and measures of differentiation and integration of neural activity that offer more promising quantitative indices of consciousness.

  8. Using brain stimulation to disentangle neural correlates of conscious vision.

    PubMed

    de Graaf, Tom A; Sack, Alexander T

    2014-01-01

    Research into the neural correlates of consciousness (NCCs) has blossomed, due to the advent of new and increasingly sophisticated brain research tools. Neuroimaging has uncovered a variety of brain processes that relate to conscious perception, obtained in a range of experimental paradigms. But methods such as functional magnetic resonance imaging or electroencephalography do not always afford inference on the functional role these brain processes play in conscious vision. Such empirical NCCs could reflect neural prerequisites, neural consequences, or neural substrates of a conscious experience. Here, we take a closer look at the use of non-invasive brain stimulation (NIBS) techniques in this context. We discuss and review how NIBS methodology can enlighten our understanding of brain mechanisms underlying conscious vision by disentangling the empirical NCCs.

  9. Using brain stimulation to disentangle neural correlates of conscious vision

    PubMed Central

    de Graaf, Tom A.; Sack, Alexander T.

    2014-01-01

    Research into the neural correlates of consciousness (NCCs) has blossomed, due to the advent of new and increasingly sophisticated brain research tools. Neuroimaging has uncovered a variety of brain processes that relate to conscious perception, obtained in a range of experimental paradigms. But methods such as functional magnetic resonance imaging or electroencephalography do not always afford inference on the functional role these brain processes play in conscious vision. Such empirical NCCs could reflect neural prerequisites, neural consequences, or neural substrates of a conscious experience. Here, we take a closer look at the use of non-invasive brain stimulation (NIBS) techniques in this context. We discuss and review how NIBS methodology can enlighten our understanding of brain mechanisms underlying conscious vision by disentangling the empirical NCCs. PMID:25295015

  10. Neural correlates of processing "self-conscious" vs. "basic" emotions.

    PubMed

    Gilead, Michael; Katzir, Maayan; Eyal, Tal; Liberman, Nira

    2016-01-29

    Self-conscious emotions are prevalent in our daily lives and play an important role in both normal and pathological behavior. Despite their immense significance, the neural substrates that are involved in the processing of such emotions are surprisingly under-studied. In light of this, we conducted an fMRI study in which participants thought of various personal events which elicited feelings of negative and positive self-conscious (i.e., guilt, pride) or basic (i.e., anger, joy) emotions. We performed a conjunction analysis to investigate the neural correlates associated with processing events that are related to self-conscious vs. basic emotions, irrespective of valence. The results show that processing self-conscious emotions resulted in activation within frontal areas associated with self-processing and self-control, namely, the mPFC extending to the dACC, and within the lateral-dorsal prefrontal cortex. Processing basic emotions resulted in activation throughout relatively phylogenetically-ancient regions of the cortex, namely in visual and tactile processing areas and in the insular cortex. Furthermore, self-conscious emotions differentially activated the mPFC such that the negative self-conscious emotion (guilt) was associated with a more dorsal activation, and the positive self-conscious emotion (pride) was associated with a more ventral activation. We discuss how these results shed light on the nature of mental representations and neural systems involved in self-reflective and affective processing.

  11. "Binaural Rivalry": Dichotic Listening as a Tool for the Investigation of the Neural Correlate of Consciousness

    ERIC Educational Resources Information Center

    Brancucci, Alfredo; Tommasi, Luca

    2011-01-01

    Since about two decades neuroscientists have systematically faced the problem of consciousness: the aim is to discover the neural activity specifically related to conscious perceptions, i.e. the biological properties of what philosophers call qualia. In this view, a neural correlate of consciousness (NCC) is a precise pattern of brain activity…

  12. Consciousness.

    PubMed

    Zeman, A

    2001-07-01

    Consciousness is topical, for reasons including its renewed respectability among psychologists, rapid progress in the neuroscience of perception, memory and action, advances in artificial intelligence and dissatisfaction with the dualistic separation of mind and body. Consciousness is an ambiguous term. It can refer to (i) the waking state; (ii) experience; and (iii) the possession of any mental state. Self-consciousness is equally ambiguous, with senses including (i) proneness to embarrassment in social settings; (ii) the ability to detect our own sensations and recall our recent actions; (iii) self-recognition; (iv) the awareness of awareness; and (v) self-knowledge in the broadest sense. The understanding of states of consciousness has been transformed by the delineation of their electrical correlates, of structures in brainstem and diencephalon which regulate the sleep-wake cycle, and of these structures' cellular physiology and regional pharmacology. Clinical studies have defined pathologies of wakefulness: coma, the persistent vegetative state, the 'locked-in' syndrome, akinetic mutism and brain death. Interest in the neural basis of perceptual awareness has focused on vision. Increasingly detailed neuronal correlates of real and illusory visual experience are being defined. Experiments exploiting circumstances in which visual experience changes while external stimulation is held constant are tightening the experimental link between consciousness and its neural correlates. Work on unconscious neural processes provides a complementary approach. 'Unperceived' stimuli have detectable effects on neural events and subsequent action in a range of circumstances: blindsight provides the classical example. Other areas of cognitive neuroscience also promise experimental insights into consciousness, in particular the distinctions between implicit and explicit memory and deliberate and automatic action. Overarching scientific theories of consciousness include

  13. Consciousness.

    PubMed

    Zeman, A

    2001-07-01

    Consciousness is topical, for reasons including its renewed respectability among psychologists, rapid progress in the neuroscience of perception, memory and action, advances in artificial intelligence and dissatisfaction with the dualistic separation of mind and body. Consciousness is an ambiguous term. It can refer to (i) the waking state; (ii) experience; and (iii) the possession of any mental state. Self-consciousness is equally ambiguous, with senses including (i) proneness to embarrassment in social settings; (ii) the ability to detect our own sensations and recall our recent actions; (iii) self-recognition; (iv) the awareness of awareness; and (v) self-knowledge in the broadest sense. The understanding of states of consciousness has been transformed by the delineation of their electrical correlates, of structures in brainstem and diencephalon which regulate the sleep-wake cycle, and of these structures' cellular physiology and regional pharmacology. Clinical studies have defined pathologies of wakefulness: coma, the persistent vegetative state, the 'locked-in' syndrome, akinetic mutism and brain death. Interest in the neural basis of perceptual awareness has focused on vision. Increasingly detailed neuronal correlates of real and illusory visual experience are being defined. Experiments exploiting circumstances in which visual experience changes while external stimulation is held constant are tightening the experimental link between consciousness and its neural correlates. Work on unconscious neural processes provides a complementary approach. 'Unperceived' stimuli have detectable effects on neural events and subsequent action in a range of circumstances: blindsight provides the classical example. Other areas of cognitive neuroscience also promise experimental insights into consciousness, in particular the distinctions between implicit and explicit memory and deliberate and automatic action. Overarching scientific theories of consciousness include

  14. Imaging neural signatures of consciousness: 'what', 'when', 'where' and 'how' does it work?

    PubMed

    Sergent, C; Naccache, L

    2012-01-01

    'What' do we call consciousness? 'When' and 'Where' in the brain do conscious states occur, and 'How' conscious processing and conscious access to a given content work? In the present paper, we present a non-exhaustive overview of each of these 4 major issues, we provide the reader with a brief description of the major difficulties related to these issues, we highlight the current theoretical points of debate, and we advocate for the explanatory power of the "global workspace" model of consciousness (Baars 1989; Dehaene and Naccache 2001; Dehaene, Changeux et al. 2006) which can accommodate for a fairly large proportion of current experimental findings, and which can be used to reinterpret apparent contradictory findings within a single theoretical framework. Most notably, we emphasize the crucial importance to distinguish genuine neural signatures of conscious access from neural events correlated with consciousness but occurring either before ('upstream') or after ('downstream'). PMID:23165871

  15. Comparing the Neural Correlates of Conscious and Unconscious Conflict Control in a Masked Stroop Priming Task.

    PubMed

    Jiang, Jun; Bailey, Kira; Xiang, Ling; Zhang, Li; Zhang, Qinglin

    2016-01-01

    Although previous studies have suggested that conflict control can occur in the absence of consciousness, the brain mechanisms underlying unconscious and conscious conflict control remain unclear. The current study used a rapid event-related functional magnetic resonance imaging design to collect data from 24 participants while they performed a masked Stroop priming task under both conscious and unconscious conditions. The results revealed that the fronto-parietal conflict network, including medial frontal cortex (MFC), left and right dorsal lateral prefrontal cortex (DLPFC), and posterior parietal cortex (PPC), was activated by both conscious and unconscious Stroop priming, even though in MFC and left DLPFC the activations elicited by unconscious Stroop priming were smaller than conscious Stroop priming. The findings provide evidence for the existence of quantitative differences between the neural substrates of conscious and unconscious conflict control. PMID:27378890

  16. Comparing the Neural Correlates of Conscious and Unconscious Conflict Control in a Masked Stroop Priming Task

    PubMed Central

    Jiang, Jun; Bailey, Kira; Xiang, Ling; Zhang, Li; Zhang, Qinglin

    2016-01-01

    Although previous studies have suggested that conflict control can occur in the absence of consciousness, the brain mechanisms underlying unconscious and conscious conflict control remain unclear. The current study used a rapid event-related functional magnetic resonance imaging design to collect data from 24 participants while they performed a masked Stroop priming task under both conscious and unconscious conditions. The results revealed that the fronto-parietal conflict network, including medial frontal cortex (MFC), left and right dorsal lateral prefrontal cortex (DLPFC), and posterior parietal cortex (PPC), was activated by both conscious and unconscious Stroop priming, even though in MFC and left DLPFC the activations elicited by unconscious Stroop priming were smaller than conscious Stroop priming. The findings provide evidence for the existence of quantitative differences between the neural substrates of conscious and unconscious conflict control. PMID:27378890

  17. Consciousness

    PubMed Central

    Sejnowski, Terrence J.

    2016-01-01

    No one did more to draw neuroscientists’ attention to the problem of consciousness in the twentieth century than Francis Crick, who may be better known as the co-discoverer (with James Watson) of the structure of DNA. Crick focused his research on visual awareness and based his analysis on the progress made over the last fifty years in uncovering the neural mechanisms underlying visual perception. Because much of what happens in our brains occurs below the level of consciousness and many of our intuitions about unconscious processing are misleading, consciousness remains an elusive problem. In the end, when all of the brain mechanisms that underlie consciousness have been identified, will we still be asking: “What is consciousness?” Or will the question shift, just as the question “What is life?” is no longer the same as it was before Francis Crick? PMID:26900168

  18. A frontal but not parietal neural correlate of auditory consciousness.

    PubMed

    Brancucci, Alfredo; Lugli, Victor; Perrucci, Mauro Gianni; Del Gratta, Cosimo; Tommasi, Luca

    2016-01-01

    Hemodynamic correlates of consciousness were investigated in humans during the presentation of a dichotic sequence inducing illusory auditory percepts with features analogous to visual multistability. The sequence consisted of a variation of the original stimulation eliciting the Deutsch's octave illusion, created to maintain a stable illusory percept long enough to allow the detection of the underlying hemodynamic activity using functional magnetic resonance imaging (fMRI). Two specular 500 ms dichotic stimuli (400 and 800 Hz) presented in alternation by means of earphones cause an illusory segregation of pitch and ear of origin which can yield up to four different auditory percepts per dichotic stimulus. Such percepts are maintained stable when one of the two dichotic stimuli is presented repeatedly for 6 s, immediately after the alternation. We observed hemodynamic activity specifically accompanying conscious experience of pitch in a bilateral network including the superior frontal gyrus (SFG, BA9 and BA10), medial frontal gyrus (BA6 and BA9), insula (BA13), and posterior lateral nucleus of the thalamus. Conscious experience of side (ear of origin) was instead specifically accompanied by bilateral activity in the MFG (BA6), STG (BA41), parahippocampal gyrus (BA28), and insula (BA13). These results suggest that the neural substrate of auditory consciousness, differently from that of visual consciousness, may rest upon a fronto-temporal rather than upon a fronto-parietal network. Moreover, they indicate that the neural correlates of consciousness depend on the specific features of the stimulus and suggest the SFG-MFG and the insula as important cortical nodes for auditory conscious experience.

  19. An adaptive workspace hypothesis about the neural correlates of consciousness: insights from neuroscience and meditation studies.

    PubMed

    Raffone, Antonino; Srinivasan, Narayanan

    2009-01-01

    While enormous progress has been made to identify neural correlates of consciousness (NCC), crucial NCC aspects are still very controversial. A major hurdle is the lack of an adequate definition and characterization of different aspects of conscious experience and also its relationship to attention and metacognitive processes like monitoring. In this paper, we therefore attempt to develop a unitary theoretical framework for NCC, with an interdependent characterization of endogenous attention, access consciousness, phenomenal awareness, metacognitive consciousness, and a non-referential form of unified consciousness. We advance an adaptive workspace hypothesis about the NCC based on the global workspace model emphasizing transient resonant neurodynamics and prefrontal cortex function, as well as meditation-related characterizations of conscious experiences. In this hypothesis, transient dynamic links within an adaptive coding net in prefrontal cortex, especially in anterior prefrontal cortex, and between it and the rest of the brain, in terms of ongoing intrinsic and long-range signal exchanges, flexibly regulate the interplay between endogenous attention, access consciousness, phenomenal awareness, and metacognitive consciousness processes. Such processes are established in terms of complementary aspects of an ongoing transition between context-sensitive global workspace assemblies, modulated moment-to-moment by body and environment states. Brain regions associated to momentary interoceptive and exteroceptive self-awareness, or first-person experiential perspective as emphasized in open monitoring meditation, play an important modulatory role in adaptive workspace transitions.

  20. A Deeper Look at the "Neural Correlate of Consciousness".

    PubMed

    Fink, Sascha Benjamin

    2016-01-01

    A main goal of the neuroscience of consciousness is: find the neural correlate to conscious experiences (NCC). When have we achieved this goal? The answer depends on our operationalization of "NCC." Chalmers (2000) shaped the widely accepted operationalization according to which an NCC is a neural system with a state which is minimally sufficient (but not necessary) for an experience. A deeper look at this operationalization reveals why it might be unsatisfactory: (i) it is not an operationalization of a correlate for occurring experiences, but of the capacity to experience; (ii) it is unhelpful for certain cases which are used to motivate a search for neural correlates of consciousness; (iii) it does not mirror the usage of "NCC" by scientists who seek for unique correlates; (iv) it hardly allows for a form of comparative testing of hypotheses, namely experimenta crucis. Because of these problems (i-iv), we ought to amend or improve on Chalmers's operationalization. Here, I present an alternative which avoids these problems. This "NCC2.0" also retains some benefits of Chalmers's operationalization, namely being compatible with contributions from extended, embedded, enacted, or embodied accounts (4E-accounts) and allowing for the possibility of non-biological or artificial experiencers. PMID:27507950

  1. Behavioral, Neural, and Computational Principles of Bodily Self-Consciousness.

    PubMed

    Blanke, Olaf; Slater, Mel; Serino, Andrea

    2015-10-01

    Recent work in human cognitive neuroscience has linked self-consciousness to the processing of multisensory bodily signals (bodily self-consciousness [BSC]) in fronto-parietal cortex and more posterior temporo-parietal regions. We highlight the behavioral, neurophysiological, neuroimaging, and computational laws that subtend BSC in humans and non-human primates. We propose that BSC includes body-centered perception (hand, face, and trunk), based on the integration of proprioceptive, vestibular, and visual bodily inputs, and involves spatio-temporal mechanisms integrating multisensory bodily stimuli within peripersonal space (PPS). We develop four major constraints of BSC (proprioception, body-related visual information, PPS, and embodiment) and argue that the fronto-parietal and temporo-parietal processing of trunk-centered multisensory signals in PPS is of particular relevance for theoretical models and simulations of BSC and eventually of self-consciousness. PMID:26447578

  2. Behavioral, Neural, and Computational Principles of Bodily Self-Consciousness.

    PubMed

    Blanke, Olaf; Slater, Mel; Serino, Andrea

    2015-10-01

    Recent work in human cognitive neuroscience has linked self-consciousness to the processing of multisensory bodily signals (bodily self-consciousness [BSC]) in fronto-parietal cortex and more posterior temporo-parietal regions. We highlight the behavioral, neurophysiological, neuroimaging, and computational laws that subtend BSC in humans and non-human primates. We propose that BSC includes body-centered perception (hand, face, and trunk), based on the integration of proprioceptive, vestibular, and visual bodily inputs, and involves spatio-temporal mechanisms integrating multisensory bodily stimuli within peripersonal space (PPS). We develop four major constraints of BSC (proprioception, body-related visual information, PPS, and embodiment) and argue that the fronto-parietal and temporo-parietal processing of trunk-centered multisensory signals in PPS is of particular relevance for theoretical models and simulations of BSC and eventually of self-consciousness.

  3. Isolating neural correlates of conscious perception from neural correlates of reporting one's perception

    PubMed Central

    Pitts, Michael A.; Metzler, Stephen; Hillyard, Steven A.

    2014-01-01

    To isolate neural correlates of conscious perception (NCCs), a standard approach has been to contrast neural activity elicited by identical stimuli of which subjects are aware vs. unaware. Because conscious experience is private, determining whether a stimulus was consciously perceived requires subjective report: e.g., button-presses indicating detection, visibility ratings, verbal reports, etc. This reporting requirement introduces a methodological confound when attempting to isolate NCCs: The neural processes responsible for accessing and reporting one's percept are difficult to distinguish from those underlying the conscious percept itself. Here, we review recent attempts to circumvent this issue via a modified inattentional blindness paradigm (Pitts et al., 2012) and present new data from a backward masking experiment in which task-relevance and visual awareness were manipulated in a 2 × 2 crossed design. In agreement with our previous inattentional blindness results, stimuli that were consciously perceived yet not immediately accessed for report (aware, task-irrelevant condition) elicited a mid-latency posterior ERP negativity (~200–240 ms), while stimuli that were accessed for report (aware, task-relevant condition) elicited additional components including a robust P3b (~380–480 ms) subsequent to the mid-latency negativity. Overall, these results suggest that some of the NCCs identified in previous studies may be more closely linked with accessing and maintaining perceptual information for reporting purposes than with encoding the conscious percept itself. An open question is whether the remaining NCC candidate (the ERP negativity at 200–240 ms) reflects visual awareness or object-based attention. PMID:25339922

  4. Neural evidence that conscious awareness of errors is reduced in depression following a traumatic brain injury.

    PubMed

    Bailey, N W; Hoy, K E; Maller, J J; Upton, D J; Segrave, R A; Fitzgibbon, B M; Fitzgerald, P B

    2015-03-01

    Impaired error awareness is related to poorer outcome following traumatic brain injury (TBI). Error awareness deficits are also found in major depressive disorder (MDD), but have not been examined in the MDD that follows a TBI (TBI-MDD). This study assessed neural activity related to error awareness in TBI-MDD. Four groups completed a response inhibition task while EEG was recorded- healthy controls (N = 15), MDD-only (N = 15), TBI-only (N = 16), and TBI-MDD (N = 12). Error related EEG activity was compared using powerful randomisation statistics that included all electrodes and time points. Participants with TBI-MDD displayed less frontally distributed neural activity, suggesting reduced contribution from frontal generating sources. Neural activity during this time window is thought to reflect conscious awareness of errors. The TBI-only and MDD-only groups did not differ from controls, and early error processing was unaffected, suggesting early error detection is intact.

  5. Consciousness of seizures and consciousness during seizures: are they related?

    PubMed

    Detyniecki, Kamil; Blumenfeld, Hal

    2014-01-01

    Recent advances have been made in the network mechanisms underlying impairment of consciousness during seizures. However, less is known about patient awareness of their own seizures. Studying patient reports or documentation of their seizures is currently the most commonly utilized mechanism to scientifically measure patient awareness of seizures. The purpose of this review is to summarize the available evidence regarding the accuracy of patient seizure counts and identify the variables that may influence unreliable seizure reporting. Several groups looking at patient documentation of seizures during continuous EEG monitoring show that patients do not report as many as 50% of their seizures. These studies also suggest that seizures accompanied by loss of consciousness, arising from the left hemisphere or the temporal lobe, or occurring during sleep are associated with significantly reduced reporting. Baseline memory performance does not appear to have a major influence on the accuracy of seizure report. Further prospective studies using validated ictal behavioral testing as well as using correlation with newer electrophysiological and neuroimaging techniques for seizure localization are needed to more fully understand the mechanisms of underreporting of seizures. Better methods to alert caregivers about unrecognized seizures and to improve seizure documentation are under investigation.

  6. No-Report Paradigms: Extracting the True Neural Correlates of Consciousness.

    PubMed

    Tsuchiya, Naotsugu; Wilke, Melanie; Frässle, Stefan; Lamme, Victor A F

    2015-12-01

    The goal of consciousness research is to reveal the neural basis of phenomenal experience. To study phenomenology, experimenters seem obliged to ask reports from the subjects to ascertain what they experience. However, we argue that the requirement of reports has biased the search for the neural correlates of consciousness over the past decades. More recent studies attempt to dissociate neural activity that gives rise to consciousness from the activity that enables the report; in particular, no-report paradigms have been utilized to study conscious experience in the full absence of any report. We discuss the advantages and disadvantages of report-based and no-report paradigms, and ask how these jointly bring us closer to understanding the true neural basis of consciousness.

  7. No-Report Paradigms: Extracting the True Neural Correlates of Consciousness.

    PubMed

    Tsuchiya, Naotsugu; Wilke, Melanie; Frässle, Stefan; Lamme, Victor A F

    2015-12-01

    The goal of consciousness research is to reveal the neural basis of phenomenal experience. To study phenomenology, experimenters seem obliged to ask reports from the subjects to ascertain what they experience. However, we argue that the requirement of reports has biased the search for the neural correlates of consciousness over the past decades. More recent studies attempt to dissociate neural activity that gives rise to consciousness from the activity that enables the report; in particular, no-report paradigms have been utilized to study conscious experience in the full absence of any report. We discuss the advantages and disadvantages of report-based and no-report paradigms, and ask how these jointly bring us closer to understanding the true neural basis of consciousness. PMID:26585549

  8. Neural mechanisms underlying conscious and unconscious attentional shifts triggered by eye gaze.

    PubMed

    Sato, Wataru; Kochiyama, Takanori; Uono, Shota; Toichi, Motomi

    2016-01-01

    Behavioral studies have shown that eye gaze triggers attentional shifts both with and without conscious awareness. However, the neural substrates of conscious and unconscious attentional shifts triggered by eye gaze remain unclear. To investigate this issue, we measured brain activity using event-related functional magnetic resonance imaging while participants observed averted or straight eye-gaze cues presented supraliminally or subliminally in the central visual field and then localized a subsequent target in the peripheral visual field. Reaction times for localizing the targets were shorter under both supraliminal and subliminal conditions when eye-gaze cues were directionally congruent with the target locations than when they were directionally neutral. Conjunction analyses revealed that a bilateral cortical network, including the middle temporal gyri, inferior parietal lobules, anterior cingulate cortices, and superior and middle frontal gyri, was activated more in response to averted eyes than to straight eyes under both supraliminal and subliminal conditions. Interaction analyses revealed that the right inferior parietal lobule was specifically active when participants viewed averted eyes relative to straight eyes under the supraliminal condition; the bilateral subcortical regions, including the superior colliculus and amygdala, and the middle temporal and inferior frontal gyri in the right hemisphere were activated in response to averted versus straight eyes under the subliminal condition. These results suggest commonalities and differences in the neural mechanisms underlying conscious and unconscious attentional shifts triggered by eye gaze. PMID:26343316

  9. Measuring consciousness in coma and related states

    PubMed Central

    Di Perri, Carol; Thibaut, Aurore; Heine, Lizette; Soddu, Andrea; Demertzi, Athena; Laureys, Steven

    2014-01-01

    Consciousness is a prismatic and ambiguous concept that still eludes any universal definition. Severe acquired brain injuries resulting in a disorder of consciousness (DOC) provide a model from which insights into consciousness can be drawn. A number of recent studies highlight the difficulty in making a diagnosis in patients with DOC based only on behavioral assessments. Here we aim to provide an overview of how neuroimaging techniques can help assess patients with DOC. Such techniques are expected to facilitate a more accurate understanding of brain function in states of unconsciousness and to improve the evaluation of the patient’s cognitive abilities by providing both diagnostic and prognostic indicators. PMID:25170396

  10. Three Centuries of Category Errors in Studies of the Neural Basis of Consciousness and Intentionality.

    PubMed

    Freeman, Walter J.

    1997-10-01

    Recent interest in consciousness and the mind-brain problem has been fueled by technological advances in brain imaging and computer modeling in artificial intelligence: can machines be conscious? The machine metaphor originated in Cartesian "reflections" and culminated in 19th century reflexology modeled on Newtonian optics. It replaced the Aquinian view of mind, which was focused on the emergence of intentionality within the body, with control of output by input through brain dynamics. The state variables for neural activity were identified successively with animal spirits, élan vital, electricity, energy, information, and, most recently, Heisenbergian potentia. The source of dynamic structure in brains was conceived to lie outside brains in genetic and environmental determinism. An alternative view has grown in the 20th century from roots in American Pragmatists, particularly John Dewey, and European philosophers, particularly Heidegger and Piaget, by which brains are intrinsically unstable and continually create themselves. This view has new support from neurobiological studies in properties of self-organizing nonlinear dynamic systems. Intentional behavior can only be understood in relation to the chaotic patterns of neural activity that produce it. The machine metaphor remains, but the machine is seen as self-determining.

  11. Direct behavioral and neural evidence for an offset-triggered conscious perception.

    PubMed

    Noguchi, Yasuki; Kimijima, Shintaro; Kakigi, Ryusuke

    2015-04-01

    Many previous theories of perceptual awareness assume that a conscious representation of a stimulus is created from sensory information carried by an onset (appearance) of the stimulus. In contrast, here we provide behavioral and neural evidence for a new phenomenon in which conscious perception is directly triggered by an offset (disappearance) of a stimulus. When a stimulus made invisible by inter-ocular suppression physically disappeared from a screen, subjects reported an appearance (not disappearance) of that stimulus, correctly reporting a color of the disappeared stimulus. Measurements of brain activity further confirmed that the physical offset of an invisible stimulus evoked neural activity reflecting conscious perception of that stimulus. Those results indicate a new role of a stimulus offset to facilitate (rather than inhibit) an emergence of consciousness. PMID:25725188

  12. Neural correlates of consciousness: what we know and what we have to learn!

    PubMed

    Calabrò, Rocco Salvatore; Cacciola, Alberto; Bramanti, Placido; Milardi, Demetrio

    2015-04-01

    Consciousness is a multifaceted concept with two major components: awareness of environment and of self (i.e., the content of consciousness) and wakefulness (i.e., the level of consciousness). Medically speaking, consciousness is the state of the patient's awareness of self and environment and his responsiveness to external stimulation and inner need. A basic understanding of consciousness and its neural correlates is of major importance for all clinicians, especially those involved with patients suffering from altered states of consciousness. To this end, in this review it is shown that consciousness is dependent on the brainstem and thalamus for arousal; that basic cognition is supported by recurrent electrical activity between the cortex and the thalamus at gamma band frequencies; and that some kind of working memory must, at least fleetingly, be present for awareness to occur. New advances in neuroimaging studies are also presented in order to better understand and demonstrate the neurophysiological basis of consciousness. In particular, recent functional magnetic resonance imaging studies have offered the possibility to measure directly and non-invasively normal and severely brain damaged subjects' brain activity, whilst diffusion tensor imaging studies have allowed evaluating white matter integrity in normal subjects and patients with disorder of consciousness.

  13. [Consciousness].

    PubMed

    Houdart, R

    1994-01-01

    "Consciousness" is the feeling that each individual has of his own existence (self-awareness) and also the state which permits him to perceive his environment (consciousness and wakefulness). These two types of consciousness, apparently quite different, are in fact the two converging stems of the perceptions that the nervous system provides to the organism. To explain this better, it is necessary to refer to the evolution of the nervous system organization among the species and to imagine what perception the nervous system provides at each stage of this evolution, or in each species harbouring a nervous system corresponding to a given stage. At the beginning, the role of the nervous system is to protect the organism and only by an automatic and reflex organization. It corresponds to an unconscious alertness which permits to perceive the environment; it is the prefiguration of the future consciousness. Self-awareness seems to appear with the centrencephalic and limbic structures which are the highest part of the nervous system in the inferior mammals and the central part in man. At this stage, acquisition memory and affectivity with its different manifestations (emotions, mood, pain...) are established. This kind of consciousness is difficult to imagine since it is only sensorial and affective. Mental consciousness appears with the mental activity in the cerebral hemispheres. It is more than likely that it exists in the superior mammals though it is impossible to imagine what it corresponds to. It reaches the highest development in the man in whose the frontal lobes have the largest extent. Speech is the most striking figure of this development. At each stage of the evolution, consciousness expresses the nervous system activity, centered on a perception, the level of which corresponds to the improvements occurring at each stage and superadded to the previous ones. Hence it is obvious that consciousness has no specific center or pathway. It relies upon structures

  14. Simulating consciousness in a bilateral neural network: "nuclear" and "fringe" awareness.

    PubMed

    Cook, N D

    1999-03-01

    A technique for the bilateral activation of neural nets that leads to a functional asymmetry of two simulated "cerebral hemispheres" is described. The simulation is designed to perform object recognition, while exhibiting characteristics typical of human consciousness-specifically, the unitary nature of conscious attention, together with a dual awareness corresponding to the "nucleus" and "fringe" described by William James (1890). Sensory neural nets self-organize on the basis of five sensory features. The system is then taught arbitrary symbolic labels for a small number of similar stimuli. Finally, the trained network is exposed to nonverbal stimuli for object recognition, leading to Gaussian activation of the "sensory" maps-with a peak at the location most closely related to the features of the external stimulus. "Verbal" maps are activated most strongly at the labeled location that lies closest to the peak on homologous sensory maps. On the verbal maps activation is characterized by both excitatory and inhibitory Gaussians (a Mexican hat), the parameters of which are determined by the relative locations of the verbal labels. Mutual homotopic inhibition across the "corpus callosum" then produces functional cerebral asymmetries, i.e., complementary activation of homologous "association" and "frontal" maps within a common focus of attention-a nucleus in the left hemisphere and a fringe in the right hemisphere. An object is recognized as corresponding to a known label when the total activation of both hemispheres (nucleus plus fringe) is strongest for that label. The functional dualities of the cerebral hemispheres are discussed in light of the nucleus/fringe asymmetry.

  15. Consciousness: a neural capacity for objectivity, especially pronounced in humans.

    PubMed

    Dijker, Anton J M

    2014-01-01

    Consciousness tends to be viewed either as subjective experience of sensations and feelings, or as perception and internal representation of objects. This paper argues that neither view sufficiently acknowledges that consciousness may refer to the brain's most adaptive property: its capacity to produce states of objectivity. It is proposed that this capacity relies on multiple sensorimotor networks for internally representing objects and their properties in terms of expectancies, as well as on motivational and motor mechanisms involved in exploration, play, and care for vulnerable living and non-living objects. States of objectivity are associated with a very special phenomenal aspect; the experience that subjective aspects are absent and one is "just looking" at the world as it really is and can be. However, these states are normally closely preceded and followed by (and tend to be combined or fused with) sensations and feelings which are caused by activation of sensory and motivational mechanisms. A capacity for objectivity may have evolved in different species and can be conceived as a common basis for other elusive psychological properties such as intelligence, conscience, and esthetic experience; all three linked to crucial behaviors in human evolution such as tool making, cooperation, and art. The brain's pervasive tendency to objectify may be responsible for wrongly equating consciousness with feelings and wrongly opposing it to well-learned or habitual ("unconscious") patterns of perception and behavior.

  16. Consciousness: a neural capacity for objectivity, especially pronounced in humans

    PubMed Central

    Dijker, Anton J. M.

    2014-01-01

    Consciousness tends to be viewed either as subjective experience of sensations and feelings, or as perception and internal representation of objects. This paper argues that neither view sufficiently acknowledges that consciousness may refer to the brain’s most adaptive property: its capacity to produce states of objectivity. It is proposed that this capacity relies on multiple sensorimotor networks for internally representing objects and their properties in terms of expectancies, as well as on motivational and motor mechanisms involved in exploration, play, and care for vulnerable living and non-living objects. States of objectivity are associated with a very special phenomenal aspect; the experience that subjective aspects are absent and one is “just looking” at the world as it really is and can be. However, these states are normally closely preceded and followed by (and tend to be combined or fused with) sensations and feelings which are caused by activation of sensory and motivational mechanisms. A capacity for objectivity may have evolved in different species and can be conceived as a common basis for other elusive psychological properties such as intelligence, conscience, and esthetic experience; all three linked to crucial behaviors in human evolution such as tool making, cooperation, and art. The brain’s pervasive tendency to objectify may be responsible for wrongly equating consciousness with feelings and wrongly opposing it to well-learned or habitual (“unconscious”) patterns of perception and behavior. PMID:24672506

  17. Neural relativity principle

    NASA Astrophysics Data System (ADS)

    Koulakov, Alexei

    Olfaction is the final frontier of our senses - the one that is still almost completely mysterious to us. Despite extensive genetic and perceptual data, and a strong push to solve the neural coding problem, fundamental questions about the sense of smell remain unresolved. Unlike vision and hearing, where relatively straightforward relationships between stimulus features and neural responses have been foundational to our understanding sensory processing, it has been difficult to quantify the properties of odorant molecules that lead to olfactory percepts. In a sense, we do not have olfactory analogs of ``red'', ``green'' and ``blue''. The seminal work of Linda Buck and Richard Axel identified a diverse family of about 1000 receptor molecules that serve as odorant sensors in the nose. However, the properties of smells that these receptors detect remain a mystery. I will review our current understanding of the molecular properties important to the olfactory system. I will also describe a theory that explains how odorant identity can be preserved despite substantial changes in the odorant concentration.

  18. Neural correlates of conscious self-regulation of emotion.

    PubMed

    Beauregard, M; Lévesque, J; Bourgouin, P

    2001-09-15

    A fundamental question about the relationship between cognition and emotion concerns the neural substrate underlying emotional self-regulation. To address this issue, brain activation was measured in normal male subjects while they either responded in a normal manner to erotic film excerpts or voluntarily attempted to inhibit the sexual arousal induced by viewing erotic stimuli. Results demonstrated that the sexual arousal experienced, in response to the erotic film excerpts, was associated with activation in "limbic" and paralimbic structures, such as the right amygdala, right anterior temporal pole, and hypothalamus. In addition, the attempted inhibition of the sexual arousal generated by viewing the erotic stimuli was associated with activation of the right superior frontal gyrus and right anterior cingulate gyrus. No activation was found in limbic areas. These findings reinforce the view that emotional self-regulation is normally implemented by a neural circuit comprising various prefrontal regions and subcortical limbic structures. They also suggest that humans have the capacity to influence the electrochemical dynamics of their brains, by voluntarily changing the nature of the mind processes unfolding in the psychological space. PMID:11549754

  19. It is time to combine the two main traditions in the research on the neural correlates of consciousness: C = L × D.

    PubMed

    Bachmann, Talis; Hudetz, Anthony G

    2014-01-01

    Research on neural correlates of consciousness has been conducted and carried out mostly from within two relatively autonomous paradigmatic traditions - studying the specific contents of conscious experience and their brain-process correlates and studying the level of consciousness. In the present paper we offer a theoretical integration suggesting that an emphasis has to be put on understanding the mechanisms of consciousness (and not a mere correlates) and in doing this, the two paradigmatic traditions must be combined. We argue that consciousness emerges as a result of interaction of brain mechanisms specialized for representing the specific contents of perception/cognition - the data - and mechanisms specialized for regulating the level of activity of whatever data the content-carrying specific mechanisms happen to represent. Each of these mechanisms are necessary because without the contents there is no conscious experience and without the required level of activity the processed contents remain unconscious. Together the two mechanisms, when activated up to a necessary degree each, provide conditions sufficient for conscious experience to emerge. This proposal is related to pertinent experimental evidence. PMID:25202297

  20. It is time to combine the two main traditions in the research on the neural correlates of consciousness: C = L × D

    PubMed Central

    Bachmann, Talis; Hudetz, Anthony G.

    2014-01-01

    Research on neural correlates of consciousness has been conducted and carried out mostly from within two relatively autonomous paradigmatic traditions – studying the specific contents of conscious experience and their brain-process correlates and studying the level of consciousness. In the present paper we offer a theoretical integration suggesting that an emphasis has to be put on understanding the mechanisms of consciousness (and not a mere correlates) and in doing this, the two paradigmatic traditions must be combined. We argue that consciousness emerges as a result of interaction of brain mechanisms specialized for representing the specific contents of perception/cognition – the data – and mechanisms specialized for regulating the level of activity of whatever data the content-carrying specific mechanisms happen to represent. Each of these mechanisms are necessary because without the contents there is no conscious experience and without the required level of activity the processed contents remain unconscious. Together the two mechanisms, when activated up to a necessary degree each, provide conditions sufficient for conscious experience to emerge. This proposal is related to pertinent experimental evidence. PMID:25202297

  1. Altered states of consciousness are related to higher sexual responsiveness.

    PubMed

    Costa, Rui M; Pestana, José; Costa, David; Wittmann, Marc

    2016-05-01

    Altered states of consciousness lead to profound changes in the sense of self, time and space. We assessed how these changes were related to sexual responsiveness during sex. 116 subjects reported (a) intensity of awareness concerning body, space and time, and (b) satisfaction, desire, arousal, and orgasm occurrence. We differentiated vaginal intercourse orgasm from noncoital orgasm. Female vaginal intercourse orgasm was further differentiated as with or without concurrent clitoral masturbation. Overall, sexual responsiveness was related to greater body awareness and lesser time and space awareness. Satisfaction, desire, and arousal were especially associated with less time awareness in women. Female orgasms during vaginal intercourse were related to greater body awareness and lesser time awareness, but noncoital orgasms were unrelated. Our findings provide empirical support for the hypotheses that altered states of consciousness with attentional absorption are strongly related to sexual responsiveness in women, and to a lesser extent in men. PMID:27003264

  2. Perceptual and contextual awareness: methodological considerations in the search for the neural correlates of consciousness.

    PubMed

    Navajas, Joaquin; Rey, Hernan G; Quian Quiroga, Rodrigo

    2014-01-01

    In the last decades, the neural correlates of consciousness (NCCs) have been explored using both invasive and non-invasive recordings by comparing the brain activity elicited by seen versus unseen visual stimuli (i.e., the contrastive analysis). Here, we review a selection of these studies and discuss a set of considerations to improve the search for the NCCs using the contrastive analysis. In particular, we first argue in favor of implementing paradigms where different perceptual outputs are obtained using identical visual inputs. Second, we propose that the large disagreement in the field -in terms of the dissimilar neural patterns proposed as NCCs- is partially explained by the fact that different studies report the neural correlates of different conscious processes in the brain. More specifically, we distinguish between the perceptual awareness of a visual stimulus, associated to a boost in object-selective neural assemblies, and a more elaborate process (contextual awareness) that we argue is reflected in the firing of concept neurons in the medial temporal lobe, triggering a rich representation of the context, associations, and memories linked to the specific stimulus. PMID:25221537

  3. Modulating conscious movement intention by noninvasive brain stimulation and the underlying neural mechanisms.

    PubMed

    Douglas, Zachary H; Maniscalco, Brian; Hallett, Mark; Wassermann, Eric M; He, Biyu J

    2015-05-01

    Conscious intention is a fundamental aspect of the human experience. Despite long-standing interest in the basis and implications of intention, its underlying neurobiological mechanisms remain poorly understood. Using high-definition transcranial DC stimulation (tDCS), we observed that enhancing spontaneous neuronal excitability in both the angular gyrus and the primary motor cortex caused the reported time of conscious movement intention to be ∼60-70 ms earlier. Slow brain waves recorded ∼2-3 s before movement onset, as well as hundreds of milliseconds after movement onset, independently correlated with the modulation of conscious intention by brain stimulation. These brain activities together accounted for 81% of interindividual variability in the modulation of movement intention by brain stimulation. A computational model using coupled leaky integrator units with biophysically plausible assumptions about the effect of tDCS captured the effects of stimulation on both neural activity and behavior. These results reveal a temporally extended brain process underlying conscious movement intention that spans seconds around movement commencement.

  4. Modulating Conscious Movement Intention by Noninvasive Brain Stimulation and the Underlying Neural Mechanisms

    PubMed Central

    Douglas, Zachary H.; Maniscalco, Brian; Hallett, Mark; Wassermann, Eric M.

    2015-01-01

    Conscious intention is a fundamental aspect of the human experience. Despite long-standing interest in the basis and implications of intention, its underlying neurobiological mechanisms remain poorly understood. Using high-definition transcranial DC stimulation (tDCS), we observed that enhancing spontaneous neuronal excitability in both the angular gyrus and the primary motor cortex caused the reported time of conscious movement intention to be ∼60–70 ms earlier. Slow brain waves recorded ∼2–3 s before movement onset, as well as hundreds of milliseconds after movement onset, independently correlated with the modulation of conscious intention by brain stimulation. These brain activities together accounted for 81% of interindividual variability in the modulation of movement intention by brain stimulation. A computational model using coupled leaky integrator units with biophysically plausible assumptions about the effect of tDCS captured the effects of stimulation on both neural activity and behavior. These results reveal a temporally extended brain process underlying conscious movement intention that spans seconds around movement commencement. PMID:25948272

  5. Identifying neural correlates of visual consciousness with ALE meta-analyses.

    PubMed

    Bisenius, Sandrine; Trapp, Sabrina; Neumann, Jane; Schroeter, Matthias L

    2015-11-15

    Neural correlates of consciousness (NCC) have been a topic of study for nearly two decades. In functional imaging studies, several regions have been proposed to constitute possible candidates for NCC, but as of yet, no quantitative summary of the literature on NCC has been done. The question whether single (striate or extrastriate) regions or a network consisting of extrastriate areas that project directly to fronto-parietal regions are necessary and sufficient neural correlates for visual consciousness is still highly debated [e.g., Rees et al., 2002, Nat Rev. Neurosci 3, 261-270; Tong, 2003, Nat Rev. Neurosci 4, 219-229]. The aim of this work was to elucidate this issue and give a synopsis of the present state of the art by conducting systematic and quantitative meta-analyses across functional magnetic resonance imaging (fMRI) studies using several standard paradigms for conscious visual perception. In these paradigms, consciousness is operationalized via perceptual changes, while the visual stimulus remains invariant. An activation likelihood estimation (ALE) meta-analysis was performed, representing the best approach for voxel-wise meta-analyses to date. In addition to computing a meta-analysis across all paradigms, separate meta-analyses on bistable perception and masking paradigms were conducted to assess whether these paradigms show common or different NCC. For the overall meta-analysis, we found significant clusters of activation in inferior and middle occipital gyrus; fusiform gyrus; inferior temporal gyrus; caudate nucleus; insula; inferior, middle, and superior frontal gyri; precuneus; as well as in inferior and superior parietal lobules. These results suggest a subcortical-extrastriate-fronto-parietal network rather than a single region that constitutes the necessary NCC. The results of our exploratory paradigm-specific meta-analyses suggest that this subcortical-extrastriate-fronto-parietal network might be differentially activated as a function of the

  6. Identifying neural correlates of visual consciousness with ALE meta-analyses.

    PubMed

    Bisenius, Sandrine; Trapp, Sabrina; Neumann, Jane; Schroeter, Matthias L

    2015-11-15

    Neural correlates of consciousness (NCC) have been a topic of study for nearly two decades. In functional imaging studies, several regions have been proposed to constitute possible candidates for NCC, but as of yet, no quantitative summary of the literature on NCC has been done. The question whether single (striate or extrastriate) regions or a network consisting of extrastriate areas that project directly to fronto-parietal regions are necessary and sufficient neural correlates for visual consciousness is still highly debated [e.g., Rees et al., 2002, Nat Rev. Neurosci 3, 261-270; Tong, 2003, Nat Rev. Neurosci 4, 219-229]. The aim of this work was to elucidate this issue and give a synopsis of the present state of the art by conducting systematic and quantitative meta-analyses across functional magnetic resonance imaging (fMRI) studies using several standard paradigms for conscious visual perception. In these paradigms, consciousness is operationalized via perceptual changes, while the visual stimulus remains invariant. An activation likelihood estimation (ALE) meta-analysis was performed, representing the best approach for voxel-wise meta-analyses to date. In addition to computing a meta-analysis across all paradigms, separate meta-analyses on bistable perception and masking paradigms were conducted to assess whether these paradigms show common or different NCC. For the overall meta-analysis, we found significant clusters of activation in inferior and middle occipital gyrus; fusiform gyrus; inferior temporal gyrus; caudate nucleus; insula; inferior, middle, and superior frontal gyri; precuneus; as well as in inferior and superior parietal lobules. These results suggest a subcortical-extrastriate-fronto-parietal network rather than a single region that constitutes the necessary NCC. The results of our exploratory paradigm-specific meta-analyses suggest that this subcortical-extrastriate-fronto-parietal network might be differentially activated as a function of the

  7. Neural detection of complex sound sequences in the absence of consciousness.

    PubMed

    Tzovara, Athina; Simonin, Alexandre; Oddo, Mauro; Rossetti, Andrea O; De Lucia, Marzia

    2015-05-01

    The neural response to a violation of sequences of identical sounds is a typical example of the brain's sensitivity to auditory regularities. Previous literature interprets this effect as a pre-attentive and unconscious processing of sensory stimuli. By contrast, a violation to auditory global regularities, i.e. based on repeating groups of sounds, is typically detectable when subjects can consciously perceive them. Here, we challenge the notion that global detection implies consciousness by testing the neural response to global violations in a group of 24 patients with post-anoxic coma (three females, age range 45-87 years), treated with mild therapeutic hypothermia and sedation. By applying a decoding analysis to electroencephalographic responses to standard versus deviant sound sequences, we found above-chance decoding performance in 10 of 24 patients (Wilcoxon signed-rank test, P < 0.001), despite five of them being mildly hypothermic, sedated and unarousable. Furthermore, consistently with previous findings based on the mismatch negativity the progression of this decoding performance was informative of patients' chances of awakening (78% predictive of awakening). Our results show for the first time that detection of global regularities at neural level exists despite a deeply unconscious state.

  8. DMN Operational Synchrony Relates to Self-Consciousness: Evidence from Patients in Vegetative and Minimally Conscious States

    PubMed Central

    Fingelkurts, Andrew A; Fingelkurts, Alexander A; Bagnato, Sergio; Boccagni, Cristina; Galardi, Giuseppe

    2012-01-01

    The default mode network (DMN) has been consistently activated across a wide variety of self-related tasks, leading to a proposal of the DMN’s role in self-related processing. Indeed, there is limited fMRI evidence that the functional connectivity within the DMN may underlie a phenomenon referred to as self-awareness. At the same time, none of the known studies have explicitly investigated neuronal functional interactions among brain areas that comprise the DMN as a function of self-consciousness loss. To fill this gap, EEG operational synchrony analysis [1, 2] was performed in patients with severe brain injuries in vegetative and minimally conscious states to study the strength of DMN operational synchrony as a function of self-consciousness expression. We demonstrated that the strength of DMN EEG operational synchrony was smallest or even absent in patients in vegetative state, intermediate in patients in minimally conscious state and highest in healthy fully self-conscious subjects. At the same time the process of ecoupling of operations performed by neuronal assemblies that comprise the DMN was highest in patients in vegetative state, intermediate in patients in minimally conscious state and minimal in healthy fully self-conscious subjects. The DMN’s frontal EEG operational module had the strongest decrease in operational synchrony strength as a function of selfconsciousness loss, when compared with the DMN’s posterior modules. Based on these results it is suggested that the strength of DMN functional connectivity could mediate the strength of self-consciousness expression. The observed alterations similarly occurred across EEG alpha, beta1 and beta2 frequency oscillations. Presented results suggest that the EEG operational synchrony within DMN may provide an objective and accurate measure for the assessment of signs of self-(un)consciousness in these challenging patient populations. This method therefore, may complement the current diagnostic procedures

  9. Raising Relational Critical Consciousness to Enhance Empathy in Clinical Hypnosis.

    PubMed

    Vargas, H Luis

    2016-01-01

    Empathic involvement theory suggests that a trance-like experience occurs when a cross-relational empathic connection is achieved. The empathically-laden relational phenomenon is thought to enhance hypnosis. Empathic involvement theory suggests hypnotizables are highly empathic. By the same token, the relational empathic connection necessitates a highly empathic practitioner of hypnosis. In the United States, where values of individualism are thought to be socially embedded and internalized, practitioners of hypnosis and clients alike may be impeded by an individually oriented worldview to empathically connect with others. Raising a relational critical consciousness is promoted as a way to increase sensitivity to the marginalization of relationships, limit empathic-effort burn-out, and promote cross-relational empathic connection. PMID:26675156

  10. A TMS Study of the Ventral Projections from V1 with Implications for the Finding of Neural Correlates of Consciousness

    ERIC Educational Resources Information Center

    Overgaard, Morten; Nielsen, Jorgen Feldbaek; Fuglsang-Frederiksen, Anders

    2004-01-01

    The study of subliminal perception in normal and brain lesioned subjects has long been of interest to scholars studying the neural mechanisms behind conscious vision. Using brief durations and a developed methodology of introspective reporting, we present an experiment with visual stimuli that gives rise to little or no subliminal perception under…

  11. From alpha to gamma: electrophysiological correlates of meditation-related states of consciousness.

    PubMed

    Fell, Juergen; Axmacher, Nikolai; Haupt, Sven

    2010-08-01

    Meditation practice is difficult to access because of its countless forms of appearances originating from the complexity of cultures it has to serve. This makes a suitable categorization for scientific use almost impossible. However, empirical data suggest that different forms of meditation show similar steps of development in terms of their neurophysiological correlates. Some electrophysiological alterations can be observed on the beginner/student level, which are closely related to non-meditative processes. Others seem to correspond to an advanced/expert level, and seem to be unique for meditation-related states of consciousness. Meditation is one possibility to specialize brain/mind functions using the brain's immanent neural plasticity. This plasticity is probably recruited by certain EEG patterns observed during or as a result of meditation, for instance, synchronized gamma oscillations. While meditation formerly has been understood to comprise mainly passive relaxation states, recent EEG findings suggest that meditation is associated with active states which involve cognitive restructuring and learning.

  12. Conscious brain, metacognition and schizophrenia.

    PubMed

    Bob, Petr; Pec, Ondrej; Mishara, Aaron L; Touskova, Tereza; Lysaker, Paul H

    2016-07-01

    Recent findings indicate that the binding and synchronization of distributed neural activities are crucial for cognitive processes and consciousness. In addition, there is increasing evidence that disrupted feature binding is related to experiences of disintegration of consciousness in schizophrenia. These data suggest that the disrupted binding and disintegration of consciousness could be typically related to schizophrenia in terms of Bleuler's concept of "splitting". In this context, deficits in metacognitive capacity in schizophrenia may be conceptualized as a spectrum from more discrete to more synthetic activities, related to specific levels of neural binding and neurocognitive deficits. This review summarizes the recent research on metacognition and its relationship to deficits of conscious awareness that may be found in schizophrenia patients. Deficits in synthetic metacognition are likely linked to the integration of information during specific processes of neural binding. Those in turn may be related to a range of mental activities including reasoning style, learning potential and insight.

  13. Beyond Relation: A Critical Exploration of "Relational Consciousness" for Spiritual Education

    ERIC Educational Resources Information Center

    Wills, Ruth

    2012-01-01

    This paper takes a philosophical view of the spiritual concept "relational consciousness" first proposed by Rebecca Nye in 1998. I will consider the "relational" aspect of spirituality through the ontology of Heidegger and the dialogical relationship "I and Thou" of Martin Buber, examining the problems that contingency and mediation within…

  14. Body-related self-conscious emotions relate to physical activity motivation and behavior in men.

    PubMed

    Castonguay, Andree L; Pila, Eva; Wrosch, Carsten; Sabiston, Catherine M

    2015-05-01

    The aim of this study was to examine the associations between the body-related self-conscious emotions of shame, guilt, and pride and physical activity motivation and behavior among adult males. Specifically, motivation regulations (external, introjected, indentified, intrinsic) were examined as possible mediators between each of the body-related self-conscious emotions and physical activity behavior. A cross-sectional study was conducted with adult men (N = 152; Mage = 23.72, SD = 10.92 years). Participants completed a questionnaire assessing body-related shame, guilt, authentic pride, hubristic pride, motivational regulations, and leisure-time physical activity. In separate multiple mediation models, body-related shame was positively associated with external and introjected regulations and negatively correlated with intrinsic regulation. Guilt was positively linked to external, introjected, and identified regulations. Authentic pride was negatively related to external regulation and positively correlated with both identified and intrinsic regulations and directly associated with physical activity behavior. Hubristic pride was positively associated with intrinsic regulation. Overall, there were both direct and indirect effects via motivation regulations between body-related self-conscious emotions and physical activity (R(2) shame = .15, guilt = .16, authentic pride = .18, hubristic pride = .16). These findings highlight the importance of targeting and understanding self-conscious emotions contextualized to the body and links to motivation and positive health behavior among men. PMID:24899517

  15. Body-related self-conscious emotions relate to physical activity motivation and behavior in men.

    PubMed

    Castonguay, Andree L; Pila, Eva; Wrosch, Carsten; Sabiston, Catherine M

    2015-05-01

    The aim of this study was to examine the associations between the body-related self-conscious emotions of shame, guilt, and pride and physical activity motivation and behavior among adult males. Specifically, motivation regulations (external, introjected, indentified, intrinsic) were examined as possible mediators between each of the body-related self-conscious emotions and physical activity behavior. A cross-sectional study was conducted with adult men (N = 152; Mage = 23.72, SD = 10.92 years). Participants completed a questionnaire assessing body-related shame, guilt, authentic pride, hubristic pride, motivational regulations, and leisure-time physical activity. In separate multiple mediation models, body-related shame was positively associated with external and introjected regulations and negatively correlated with intrinsic regulation. Guilt was positively linked to external, introjected, and identified regulations. Authentic pride was negatively related to external regulation and positively correlated with both identified and intrinsic regulations and directly associated with physical activity behavior. Hubristic pride was positively associated with intrinsic regulation. Overall, there were both direct and indirect effects via motivation regulations between body-related self-conscious emotions and physical activity (R(2) shame = .15, guilt = .16, authentic pride = .18, hubristic pride = .16). These findings highlight the importance of targeting and understanding self-conscious emotions contextualized to the body and links to motivation and positive health behavior among men.

  16. Caring for the Past: On Relationality and Historical Consciousness

    ERIC Educational Resources Information Center

    Chinnery, Ann

    2013-01-01

    Over the past 20 years, there has been a shift in history education away from a view of history as the pursuit of an objective, universal story about the past toward "historical consciousness," which seeks to cultivate an understanding of the past as something that makes moral demands on us here and now. According to Roger Simon,…

  17. Dissociative States and Neural Complexity

    ERIC Educational Resources Information Center

    Bob, Petr; Svetlak, Miroslav

    2011-01-01

    Recent findings indicate that neural mechanisms of consciousness are related to integration of distributed neural assemblies. This neural integration is particularly vulnerable to past stressful experiences that can lead to disintegration and dissociation of consciousness. These findings suggest that dissociation could be described as a level of…

  18. Neural correlates of visuospatial consciousness in 3D default space: insights from contralateral neglect syndrome.

    PubMed

    Jerath, Ravinder; Crawford, Molly W

    2014-08-01

    One of the most compelling questions still unanswered in neuroscience is how consciousness arises. In this article, we examine visual processing, the parietal lobe, and contralateral neglect syndrome as a window into consciousness and how the brain functions as the mind and we introduce a mechanism for the processing of visual information and its role in consciousness. We propose that consciousness arises from integration of information from throughout the body and brain by the thalamus and that the thalamus reimages visual and other sensory information from throughout the cortex in a default three-dimensional space in the mind. We further suggest that the thalamus generates a dynamic default three-dimensional space by integrating processed information from corticothalamic feedback loops, creating an infrastructure that may form the basis of our consciousness. Further experimental evidence is needed to examine and support this hypothesis, the role of the thalamus, and to further elucidate the mechanism of consciousness.

  19. Self-Related Processing and Deactivation of Cortical Midline Regions in Disorders of Consciousness

    PubMed Central

    Crone, Julia Sophia; Höller, Yvonne; Bergmann, Jürgen; Golaszewski, Stefan; Trinka, Eugen; Kronbichler, Martin

    2013-01-01

    Self-related stimuli activate anterior parts of cortical midline regions, which normally show task-induced deactivation. Deactivation in medial posterior and frontal regions is associated with the ability to focus attention on the demands of the task, and therefore, with consciousness. Studies investigating patients with impaired consciousness, that is, patients in minimally conscious state and patients with unresponsive wakefulness syndrome (formerly vegetative state), demonstrate that these patients show responses to self-related content in the anterior cingulate cortex. However, it remains unclear if these responses are an indication for conscious processing of stimuli or are due to automatic processing. To shed further light on this issue, we investigated responses of cortical midline regions to the own and another name in 27 patients with a disorder of consciousness and compared them to task-induced deactivation. While almost all of the control subjects responding to the own name demonstrated higher activation due to the self-related content in anterior midline regions and additional deactivation, none of the responding patients did so. Differences between groups showed a similar pattern of findings. Despite the relation between behavioral responsiveness in patients and activation in response to the own name, the findings of this study do not provide evidence for a direct association of activation in anterior midline regions and conscious processing. The deficits in processing of self-referential content in anterior midline regions may rather be due to general impairments in cognitive processing and not particularly linked to impaired consciousness. PMID:23986685

  20. Health consciousness of young people in relation to their personality.

    PubMed

    Kikuchi, Y; Inoue, T; Ito, M; Masuda, M; Yoshimura, K; Watanabe, S

    1999-04-01

    Personality of targeted individuals can be assumed to influence behavior modification by health education. In this study the influence of personality on health consciousness was analyzed by a questionnaire for lifestyle, health consciousness, and the NEO-FFI personality test. Subjects were 942 new students in the Tokyo University of Agriculture who were surveyed in April, 1998. Separately performed health examination data were used to verify reliability of answers to the questionnaire. Among students, 83.2% of males and 90.4% of females felt themselves to be healthy, and more than 80% students desired to improve their health more. The rate of having no physical complaints, however, was only 31.7% in males and 20.4% in females. Distribution of NEO-FFI scores of neuroticism (N), extraversion (E), openness (O), agreeableness (A), and conscientiousness (C) corresponded well between males and females, except for significantly higher scores of O and A in females. Odds ratios (ORs) between high and low tertial points of NEO-FFI score for health consciousness were significantly elevated in the high scoring groups of E and C (OR = 6.26, 95% CI = 1.46-26.82, and OR = 6.04, 95% CI = 1.42-25.71, respectively) in males. On the contrary, high N and O groups had low health consciousness. Smoking habit was associated with high E scores (OR = 2.24, 95% CI = 1.13-4.43). Dietary habits, regular eating time, and avoidance of salty foods were associated with high C scores in both males and females. The OR of regular eating time was 2.66 (95% CI = 1.42-1.98), and 2.20 (95% CI = 1.31-3.71) for males and females, respectively. The OR of avoidance of salty foods were 2.09 (95% CI = 1.11-3.91), 1.87 (95% CI = 1.11-3.16) for males and females, respectively. Significant associations between lifestyle and personality require further study for risk association analysis and for relationship to interventive practices for prevention of lifestyle associated diseases.

  1. How consciousness will change our view on neuroscience.

    PubMed

    Overgaard, Morten

    2010-09-01

    Abstract Victor Lamme proposed that the study of consciousness should not be based on introspection. Nevertheless, Lamme understands consciousness as a subjective phenomenon, and introspection as the way in which we acquire knowledge about consciousness. This makes the task to find introspective-free methods to study consciousness difficult. Lamme attempts to make progress by introducing "neural arguments," but fails to show how such arguments are independent of introspective methods which seem necessary in order to decide how any neural process relates to mental phenomena. This commentary paper thus aims to show that our understanding of neural correlates is shaped by introspection. PMID:24168340

  2. A Mechanistic Neural Field Theory of How Anesthesia Suppresses Consciousness: Synaptic Drive Dynamics, Bifurcations, Attractors, and Partial State Equipartitioning.

    PubMed

    Hou, Saing Paul; Haddad, Wassim M; Meskin, Nader; Bailey, James M

    2015-12-01

    With the advances in biochemistry, molecular biology, and neurochemistry there has been impressive progress in understanding the molecular properties of anesthetic agents. However, there has been little focus on how the molecular properties of anesthetic agents lead to the observed macroscopic property that defines the anesthetic state, that is, lack of responsiveness to noxious stimuli. In this paper, we use dynamical system theory to develop a mechanistic mean field model for neural activity to study the abrupt transition from consciousness to unconsciousness as the concentration of the anesthetic agent increases. The proposed synaptic drive firing-rate model predicts the conscious-unconscious transition as the applied anesthetic concentration increases, where excitatory neural activity is characterized by a Poincaré-Andronov-Hopf bifurcation with the awake state transitioning to a stable limit cycle and then subsequently to an asymptotically stable unconscious equilibrium state. Furthermore, we address the more general question of synchronization and partial state equipartitioning of neural activity without mean field assumptions. This is done by focusing on a postulated subset of inhibitory neurons that are not themselves connected to other inhibitory neurons. Finally, several numerical experiments are presented to illustrate the different aspects of the proposed theory. PMID:26438186

  3. Laminar cortical dynamics of conscious speech perception: neural model of phonemic restoration using subsequent context in noise.

    PubMed

    Grossberg, Stephen; Kazerounian, Sohrob

    2011-07-01

    How are laminar circuits of neocortex organized to generate conscious speech and language percepts? How does the brain restore information that is occluded by noise, or absent from an acoustic signal, by integrating contextual information over many milliseconds to disambiguate noise-occluded acoustical signals? How are speech and language heard in the correct temporal order, despite the influence of contexts that may occur many milliseconds before or after each perceived word? A neural model describes key mechanisms in forming conscious speech percepts, and quantitatively simulates a critical example of contextual disambiguation of speech and language; namely, phonemic restoration. Here, a phoneme deleted from a speech stream is perceptually restored when it is replaced by broadband noise, even when the disambiguating context occurs after the phoneme was presented. The model describes how the laminar circuits within a hierarchy of cortical processing stages may interact to generate a conscious speech percept that is embodied by a resonant wave of activation that occurs between acoustic features, acoustic item chunks, and list chunks. Chunk-mediated gating allows speech to be heard in the correct temporal order, even when what is heard depends upon future context.

  4. From Emotions to Consciousness – A Neuro-Phenomenal and Neuro-Relational Approach

    PubMed Central

    Northoff, Georg

    2012-01-01

    The James–Lange theory considers emotional feelings as perceptions of physiological body changes. This approach has recently resurfaced and modified in both neuroscientific and philosophical concepts of embodiment of emotional feelings. In addition to the body, the role of the environment in emotional feeling needs to be considered. I here claim that the environment has not merely an indirect and instrumental, i.e., modulatory role on emotional feelings via the body and its sensorimotor and vegetative functions. Instead, the environment may have a direct and non-instrumental, i.e., constitutional role in emotional feelings. This implies that the environment itself is constitutive of emotional feeling rather than the bodily representation of the environment. I call this the relational concept of emotional feeling. The present paper discusses recent data from neuroimaging that investigate emotions in relation to interoceptive processing and the brain’s intrinsic activity. These data show the intrinsic linkage of interoceptive stimulus processing to both exteroceptive stimuli and the brain’s intrinsic activity. This is possible only if the differences between intrinsic activity and intero- and exteroceptive stimuli is encoded into neural activity. Such relational coding makes possible the assignment of subjective and affective features to the otherwise objective and non-affective stimulus. I therefore consider emotions to be intrinsically affective and subjective as it is manifest in emotional feelings. The relational approach thus goes together with what may be described as neuro-phenomenal approach. Such neuro-phenomenal approach does not only inform emotions and emotional feeling but is also highly relevant to better understand the neuronal mechanisms underlying consciousness in general. PMID:22969736

  5. From sensation to perception: Using multivariate classification of visual illusions to identify neural correlates of conscious awareness in space and time.

    PubMed

    Hogendoorn, Hinze

    2015-01-01

    An important goal of cognitive neuroscience is understanding the neural underpinnings of conscious awareness. Although the low-level processing of sensory input is well understood in most modalities, it remains a challenge to understand how the brain translates such input into conscious awareness. Here, I argue that the application of multivariate pattern classification techniques to neuroimaging data acquired while observers experience perceptual illusions provides a unique way to dissociate sensory mechanisms from mechanisms underlying conscious awareness. Using this approach, it is possible to directly compare patterns of neural activity that correspond to the contents of awareness, independent from changes in sensory input, and to track these neural representations over time at high temporal resolution. I highlight five recent studies using this approach, and provide practical considerations and limitations for future implementations.

  6. The cognitive and neural correlates of "tactile consciousness": a multisensory perspective.

    PubMed

    Gallace, Alberto; Spence, Charles

    2008-03-01

    People's awareness of tactile stimuli has been investigated in far less detail than their awareness of stimuli in other sensory modalities. In an attempt to fill this gap, we provide an overview of studies that are pertinent to the topic of tactile consciousness. We discuss the results of research that has investigated phenomena such as "change blindness", phantom limb sensations, and numerosity judgments in tactile perception, together with the results obtained from the study of patients affected by deficits that can adversely affect tactile perception such as neglect, extinction, and numbsense. The similarities as well as some of the important differences that have emerged when visual and tactile conscious information processing have been compared using similar experimental procedures are highlighted. We suggest that conscious information processing in the tactile modality cannot be separated completely from the more general processing of spatial information in the brain. Finally, the importance of considering tactile consciousness within the larger framework of multisensory information processing is also discussed. PMID:17398116

  7. Body Consciousness, Illness-Related Impairment, and Patient Adherence in Hemodialysis.

    ERIC Educational Resources Information Center

    Christensen, Alan J.; And Others

    1996-01-01

    Examined the joint effects of private body consciousness (PBC) and degree of illness-related physical impairment on treatment regimen adherence in a sample of 52 hemodialysis patients. Predicted the effect of PBC on adherence would vary as a function of patients' level of illness-related physical impairment. Results are discussed in terms of…

  8. Sample Entropy Analysis of EEG Signals via Artificial Neural Networks to Model Patients' Consciousness Level Based on Anesthesiologists Experience

    PubMed Central

    Jiang, George J. A.; Fan, Shou-Zen; Abbod, Maysam F.; Huang, Hui-Hsun; Lan, Jheng-Yan; Tsai, Feng-Fang; Chang, Hung-Chi; Yang, Yea-Wen; Chuang, Fu-Lan; Chiu, Yi-Fang; Jen, Kuo-Kuang; Wu, Jeng-Fu; Shieh, Jiann-Shing

    2015-01-01

    Electroencephalogram (EEG) signals, as it can express the human brain's activities and reflect awareness, have been widely used in many research and medical equipment to build a noninvasive monitoring index to the depth of anesthesia (DOA). Bispectral (BIS) index monitor is one of the famous and important indicators for anesthesiologists primarily using EEG signals when assessing the DOA. In this study, an attempt is made to build a new indicator using EEG signals to provide a more valuable reference to the DOA for clinical researchers. The EEG signals are collected from patients under anesthetic surgery which are filtered using multivariate empirical mode decomposition (MEMD) method and analyzed using sample entropy (SampEn) analysis. The calculated signals from SampEn are utilized to train an artificial neural network (ANN) model through using expert assessment of consciousness level (EACL) which is assessed by experienced anesthesiologists as the target to train, validate, and test the ANN. The results that are achieved using the proposed system are compared to BIS index. The proposed system results show that it is not only having similar characteristic to BIS index but also more close to experienced anesthesiologists which illustrates the consciousness level and reflects the DOA successfully. PMID:25738152

  9. Neural Dynamics Underlying Event-Related Potentials

    NASA Technical Reports Server (NTRS)

    Shah, Ankoor S.; Bressler, Steven L.; Knuth, Kevin H.; Ding, Ming-Zhou; Mehta, Ashesh D.; Ulbert, Istvan; Schroeder, Charles E.

    2003-01-01

    There are two opposing hypotheses about the brain mechanisms underlying sensory event-related potentials (ERPs). One holds that sensory ERPs are generated by phase resetting of ongoing electroencephalographic (EEG) activity, and the other that they result from signal averaging of stimulus-evoked neural responses. We tested several contrasting predictions of these hypotheses by direct intracortical analysis of neural activity in monkeys. Our findings clearly demonstrate evoked response contributions to the sensory ERP in the monkey, and they suggest the likelihood that a mixed (Evoked/Phase Resetting) model may account for the generation of scalp ERPs in humans.

  10. Conscious Action/Zombie Action

    PubMed Central

    Shepherd, Joshua

    2015-01-01

    Abstract I argue that the neural realizers of experiences of trying (that is, experiences of directing effort towards the satisfaction of an intention) are not distinct from the neural realizers of actual trying (that is, actual effort directed towards the satisfaction of an intention). I then ask how experiences of trying might relate to the perceptual experiences one has while acting. First, I assess recent zombie action arguments regarding conscious visual experience, and I argue that contrary to what some have claimed, conscious visual experience plays a causal role for action control in some circumstances. Second, I propose a multimodal account of the experience of acting. According to this account, the experience of acting is (at the very least) a temporally extended, co‐conscious collection of agentive and perceptual experiences, functionally integrated and structured both by multimodal perceptual processing as well as by what an agent is, at the time, trying to do. PMID:27667859

  11. Conscious Action/Zombie Action

    PubMed Central

    Shepherd, Joshua

    2015-01-01

    Abstract I argue that the neural realizers of experiences of trying (that is, experiences of directing effort towards the satisfaction of an intention) are not distinct from the neural realizers of actual trying (that is, actual effort directed towards the satisfaction of an intention). I then ask how experiences of trying might relate to the perceptual experiences one has while acting. First, I assess recent zombie action arguments regarding conscious visual experience, and I argue that contrary to what some have claimed, conscious visual experience plays a causal role for action control in some circumstances. Second, I propose a multimodal account of the experience of acting. According to this account, the experience of acting is (at the very least) a temporally extended, co‐conscious collection of agentive and perceptual experiences, functionally integrated and structured both by multimodal perceptual processing as well as by what an agent is, at the time, trying to do.

  12. A hierarchy of event-related potential markers of auditory processing in disorders of consciousness.

    PubMed

    Beukema, Steve; Gonzalez-Lara, Laura E; Finoia, Paola; Kamau, Evelyn; Allanson, Judith; Chennu, Srivas; Gibson, Raechelle M; Pickard, John D; Owen, Adrian M; Cruse, Damian

    2016-01-01

    Functional neuroimaging of covert perceptual and cognitive processes can inform the diagnoses and prognoses of patients with disorders of consciousness, such as the vegetative and minimally conscious states (VS;MCS). Here we report an event-related potential (ERP) paradigm for detecting a hierarchy of auditory processes in a group of healthy individuals and patients with disorders of consciousness. Simple cortical responses to sounds were observed in all 16 patients; 7/16 (44%) patients exhibited markers of the differential processing of speech and noise; and 1 patient produced evidence of the semantic processing of speech (i.e. the N400 effect). In several patients, the level of auditory processing that was evident from ERPs was higher than the abilities that were evident from behavioural assessment, indicating a greater sensitivity of ERPs in some cases. However, there were no differences in auditory processing between VS and MCS patient groups, indicating a lack of diagnostic specificity for this paradigm. Reliably detecting semantic processing by means of the N400 effect in passively listening single-subjects is a challenge. Multiple assessment methods are needed in order to fully characterise the abilities of patients with disorders of consciousness. PMID:27595064

  13. [Neural representation of human body schema and corporeal self-consciousness].

    PubMed

    Naito, Eiichi; Morita, Tomoyo

    2014-04-01

    The human brain processes every sensation evoked by altered posture and builds up a constantly changing postural model of the body. This is called a body schema, and somatic signals originating from skeletal muscles and joints, i.e. proprioceptive signals, largely contribute its formation. Recent neuroimaging techniques have revealed neuronal substrates for human body schema. A dynamic limb position model seems to be computed in the central motor network (represented by the primary motor cortex). Here, proprioceptive (kinesthetic) signals from muscle spindles are transformed into motor commands, which may underlie somatic perception of limb movement and facilitate its efficient motor control. Somatic signals originating from different body parts are integrated in the course of hierarchical somatosensory processing, and activity in higher-order somatosensory parietal cortices is capable of representing a postural model of the entire body. The left fronto-parietal network associates internal motor representation with external object representation, allowing the embodiment of external objects. In contrast, the right fronto-parietal regions connected by the most inferior branch of superior longitudinal fasciculus fibers seem to have the functions of monitoring bodily states and updating body schema. We hypothesize that activity in these right-sided fronto-parietal regions is deeply involved in corporeal self-consciousness.

  14. Memory, consciousness and neuroimaging.

    PubMed Central

    Schacter, D L; Buckner, R L; Koutstaal, W

    1998-01-01

    Neuroimaging techniques that allow the assessment of memory performance in healthy human volunteers while simultaneously obtaining measurements of brain activity in vivo may offer new information on the neural correlates of particular forms of memory retrieval and their association with consciousness and intention. We consider evidence from studies with positron emission tomography and functional magnetic resonance imaging indicating that priming, a form of implicit retrieval, is associated with decreased activity in various cortical regions. We also consider evidence concerning the question of whether two components of explicit retrieval--intentional or effortful search and successful conscious recollection--are preferentially associated with increased activity in prefrontal and medial temporal regions, respectively. Last, we consider recent efforts to probe the relation between the phenomenological character of remembering and neural activity. In this instance we broaden our scope to include studies employing event-related potentials and consider evidence concerning the neural correlates of qualitatively different forms of memory, including memory that is specifically associated with a sense of self, and the recollection of particular temporal or perceptual features that might contribute to a rich and vivid experience of the past. PMID:9854258

  15. The role of body-related self-conscious emotions in motivating women's physical activity.

    PubMed

    Sabiston, Catherine M; Brunet, Jennifer; Kowalski, Kent C; Wilson, Philip M; Mack, Diane E; Crocker, Peter R E

    2010-08-01

    The purpose of this study was to test a model where body-related self-conscious emotions of shame, guilt, and pride were associated with physical activity regulations and behavior. Adult women (N = 389; M age = 29.82, SD = 15.20 years) completed a questionnaire assessing body-related pride, shame, and guilt, motivational regulations, and leisure-time physical activity. The hypothesized measurement and structural models were deemed adequate, as was a revised model examining shame-free guilt and guilt-free shame. In the revised structural model, body-related pride was positively significantly related to identified and intrinsic regulations. Body-related shame-free guilt was significantly associated with external, introjected, and identified regulations. Body-related guilt-free shame was significantly positively related to external and introjected regulation, and negatively associated with intrinsic regulation. Identified and intrinsic regulations were significantly positively related to physical activity (R2 = .62). These findings highlight the importance of targeting and understanding the realm of body-related self-conscious emotions and the associated links to regulations and physical activity behavior.

  16. Beyond consciousness of external reality: a "who" system for consciousness of action and self-consciousness.

    PubMed

    Georgieff, N; Jeannerod, M

    1998-09-01

    This paper offers a framework for consciousness of internal reality. Recent PET experiments are reviewed, showing partial overlap of cortical activation during self-produced actions and actions observed from other people. This overlap suggests that representations for actions may be shared by several individuals, a situation which creates a potential problem for correctly attributing an action to its agent. The neural conditions for correct agency judgments are thus assigned a key role in self/other distinction and self-consciousness. A series of behavioral experiments that demonstrate, in normal subjects, the poor monitoring of action-related signals and the difficulty in recognizing self-produced actions are described. In patients presenting delusions, this difficulty dramatically increases and actions become systematically misattributed. These results point to schizophrenia and related disorders as a paradigmatic alteration of a "Who?" system for self-consciousness. PMID:9787056

  17. Event-related brain potential correlates of two states of conscious awareness in memory

    PubMed Central

    Düzel, Emrah; Yonelinas, Andrew P.; Mangun, George R.; Heinze, Hans-Jochen; Tulving, Endel

    1997-01-01

    We report an event-related potential (ERP) experiment of human recognition memory that explored the relation between conscious awareness and electrophysiological activity of the brain. We recorded ERPs from healthy adults while they made “remember” and “know” recognition judgments about previously seen words. These two kinds of judgments reflect “autonoetic” and “noetic” awareness, respectively. The ERP effects differed between the two kinds of awareness while they were similar for “true” and “false” recognition. Noetic awareness was associated with a temporoparietal positivity in the N400 range (325–600 ms) and a late (600–1,000 ms) frontocentral negativity, whereas autonoetic awareness was associated with a widespread, late, bifrontal and left parietotemporal (600–1000 ms) positivity. In the very late (1,300–1,900 ms) time window, a right frontal positivity was observed for both remember and know judgments of both true and false targets. These results provide physiological evidence for two types of conscious awareness in episodic memory retrieval. PMID:9159185

  18. Sleep Neuroimaging and Models of Consciousness

    PubMed Central

    Tagliazucchi, Enzo; Behrens, Marion; Laufs, Helmut

    2013-01-01

    Human deep sleep is characterized by reduced sensory activity, responsiveness to stimuli, and conscious awareness. Given its ubiquity and reversible nature, it represents an attractive paradigm to study the neural changes which accompany the loss of consciousness in humans. In particular, the deepest stages of sleep can serve as an empirical test for the predictions of theoretical models relating the phenomenology of consciousness with underlying neural activity. A relatively recent shift of attention from the analysis of evoked responses toward spontaneous (or “resting state”) activity has taken place in the neuroimaging community, together with the development of tools suitable to study distributed functional interactions. In this review we focus on recent functional Magnetic Resonance Imaging (fMRI) studies of spontaneous activity during sleep and their relationship with theoretical models for human consciousness generation, considering the global workspace theory, the information integration theory, and the dynamical core hypothesis. We discuss the venues of research opened by these results, emphasizing the need to extend the analytic methodology in order to obtain a dynamical picture of how functional interactions change over time and how their evolution is modulated during different conscious states. Finally, we discuss the need to experimentally establish absent or reduced conscious content, even when studying the deepest sleep stages. PMID:23717291

  19. [Anesthesia and Consciousness].

    PubMed

    Ogino, Yuichi; Kawamichi, Hiroaki; Saiot, Shigeru

    2016-05-01

    The mechanism of consciousness and loss of conciousness by general anesthetics are crucial issue for the anesthesiologists. Recent non-invasive brain-imaging technology brings about light to various our emotions and sensations in human brain; however, neural correlate of consciousness is not yet still elucidated. The concept "the seat of the consciousness (is in the subcortical nuclei)" is now completely denied, but instead the consciousness is based on the idea that connectivity and communications across cortical and thalamocortical networks. Anesthetics and sleep disrupt the networks that encompass complexity and integration. The compatibility between complexity and integration is the key feature of the consciousness, which is represented by complex, extensive, communicative and integrative electroencephalograph currents evoked by transcranial magnetic stimulation, provoking a single unified conscious experience in us, humans.

  20. Trauma-related dissociation and altered states of consciousness: a call for clinical, treatment, and neuroscience research

    PubMed Central

    Lanius, Ruth A.

    2015-01-01

    The primary aim of this commentary is to describe trauma-related dissociation and altered states of consciousness in the context of a four-dimensional model that has recently been proposed (Frewen & Lanius, 2015). This model categorizes symptoms of trauma-related psychopathology into (1) those that occur within normal waking consciousness and (2) those that are dissociative and are associated with trauma-related altered states of consciousness (TRASC) along four dimensions: (1) time; (2) thought; (3) body; and (4) emotion. Clinical applications and future research directions relevant to each dimension are discussed. Conceptualizing TRASC across the dimensions of time, thought, body, and emotion has transdiagnostic implications for trauma-related disorders described in both the Diagnostic Statistical Manual and the International Classifications of Diseases. The four-dimensional model provides a framework, guided by existing models of dissociation, for future research examining the phenomenological, neurobiological, and physiological underpinnings of trauma-related dissociation. PMID:25994026

  1. Occupational Consciousness

    PubMed Central

    Ramugondo, Elelwani L.

    2015-01-01

    Occupational consciousness refers to ongoing awareness of the dynamics of hegemony and recognition that dominant practices are sustained through what people do every day, with implications for personal and collective health. The emergence of the construct in post-apartheid South Africa signifies the country’s ongoing struggle with negotiating long-standing dynamics of power that were laid down during colonialism, and maintained under black majority rule. Consciousness, a key component of the new terminology, is framed from post-colonial perspectives – notably work by Biko and Fanon – and grounded in the philosophy of liberation, in order to draw attention to continuing unequal intersubjective relations that play out through human occupation. The paper also draws important links between occupational consciousness and other related constructs, namely occupational possibilities, occupational choice, occupational apartheid, and collective occupation. The use of the term ‘consciousness’ in sociology, with related or different meanings, is also explored. Occupational consciousness is then advanced as a critical notion that frames everyday doing as a potentially liberating response to oppressive social structures. This paper advances theorizing as a scholarly practice in occupational science, and could potentially expand inter or transdisciplinary work for critical conceptualizations of human occupation. PMID:26549984

  2. The Merit of Synesthesia for Consciousness Research

    PubMed Central

    van Leeuwen, Tessa M.; Singer, Wolf; Nikolić, Danko

    2015-01-01

    Synesthesia is a phenomenon in which additional perceptual experiences are elicited by sensory stimuli or cognitive concepts. Synesthetes possess a unique type of phenomenal experiences not directly triggered by sensory stimulation. Therefore, for better understanding of consciousness it is relevant to identify the mental and physiological processes that subserve synesthetic experience. In the present work we suggest several reasons why synesthesia has merit for research on consciousness. We first review the research on the dynamic and rapidly growing field of the studies of synesthesia. We particularly draw attention to the role of semantics in synesthesia, which is important for establishing synesthetic associations in the brain. We then propose that the interplay between semantics and sensory input in synesthesia can be helpful for the study of the neural correlates of consciousness, especially when making use of ambiguous stimuli for inducing synesthesia. Finally, synesthesia-related alterations of brain networks and functional connectivity can be of merit for the study of consciousness. PMID:26696921

  3. The Merit of Synesthesia for Consciousness Research.

    PubMed

    van Leeuwen, Tessa M; Singer, Wolf; Nikolić, Danko

    2015-01-01

    Synesthesia is a phenomenon in which additional perceptual experiences are elicited by sensory stimuli or cognitive concepts. Synesthetes possess a unique type of phenomenal experiences not directly triggered by sensory stimulation. Therefore, for better understanding of consciousness it is relevant to identify the mental and physiological processes that subserve synesthetic experience. In the present work we suggest several reasons why synesthesia has merit for research on consciousness. We first review the research on the dynamic and rapidly growing field of the studies of synesthesia. We particularly draw attention to the role of semantics in synesthesia, which is important for establishing synesthetic associations in the brain. We then propose that the interplay between semantics and sensory input in synesthesia can be helpful for the study of the neural correlates of consciousness, especially when making use of ambiguous stimuli for inducing synesthesia. Finally, synesthesia-related alterations of brain networks and functional connectivity can be of merit for the study of consciousness.

  4. The Merit of Synesthesia for Consciousness Research.

    PubMed

    van Leeuwen, Tessa M; Singer, Wolf; Nikolić, Danko

    2015-01-01

    Synesthesia is a phenomenon in which additional perceptual experiences are elicited by sensory stimuli or cognitive concepts. Synesthetes possess a unique type of phenomenal experiences not directly triggered by sensory stimulation. Therefore, for better understanding of consciousness it is relevant to identify the mental and physiological processes that subserve synesthetic experience. In the present work we suggest several reasons why synesthesia has merit for research on consciousness. We first review the research on the dynamic and rapidly growing field of the studies of synesthesia. We particularly draw attention to the role of semantics in synesthesia, which is important for establishing synesthetic associations in the brain. We then propose that the interplay between semantics and sensory input in synesthesia can be helpful for the study of the neural correlates of consciousness, especially when making use of ambiguous stimuli for inducing synesthesia. Finally, synesthesia-related alterations of brain networks and functional connectivity can be of merit for the study of consciousness. PMID:26696921

  5. Aberrant Functional Connectivity of the Amygdala Complexes in PTSD during Conscious and Subconscious Processing of Trauma-Related Stimuli.

    PubMed

    Rabellino, Daniela; Densmore, Maria; Frewen, Paul A; Théberge, Jean; McKinnon, Margaret C; Lanius, Ruth A

    2016-01-01

    Post-traumatic stress disorder (PTSD) is characterized by altered functional connectivity of the amygdala complexes at rest. However, amygdala complex connectivity during conscious and subconscious threat processing remains to be elucidated. Here, we investigate specific connectivity of the centromedial amygdala (CMA) and basolateral amygdala (BLA) during conscious and subconscious processing of trauma-related words among individuals with PTSD (n = 26) as compared to non-trauma-exposed controls (n = 20). Psycho-physiological interaction analyses were performed using the right and left amygdala complexes as regions of interest during conscious and subconscious trauma word processing. These analyses revealed a differential, context-dependent responses by each amygdala seed during trauma processing in PTSD. Specifically, relative to controls, during subconscious processing, individuals with PTSD demonstrated increased connectivity of the CMA with the superior frontal gyrus, accompanied by a pattern of decreased connectivity between the BLA and the superior colliculus. During conscious processing, relative to controls, individuals with PTSD showed increased connectivity between the CMA and the pulvinar. These findings demonstrate alterations in amygdala subregion functional connectivity in PTSD and highlight the disruption of the innate alarm network during both conscious and subconscious trauma processing in this disorder. PMID:27631496

  6. Aberrant Functional Connectivity of the Amygdala Complexes in PTSD during Conscious and Subconscious Processing of Trauma-Related Stimuli

    PubMed Central

    Rabellino, Daniela; Densmore, Maria; Frewen, Paul A.; Théberge, Jean; McKinnon, Margaret C.; Lanius, Ruth A.

    2016-01-01

    Post-traumatic stress disorder (PTSD) is characterized by altered functional connectivity of the amygdala complexes at rest. However, amygdala complex connectivity during conscious and subconscious threat processing remains to be elucidated. Here, we investigate specific connectivity of the centromedial amygdala (CMA) and basolateral amygdala (BLA) during conscious and subconscious processing of trauma-related words among individuals with PTSD (n = 26) as compared to non-trauma-exposed controls (n = 20). Psycho-physiological interaction analyses were performed using the right and left amygdala complexes as regions of interest during conscious and subconscious trauma word processing. These analyses revealed a differential, context-dependent responses by each amygdala seed during trauma processing in PTSD. Specifically, relative to controls, during subconscious processing, individuals with PTSD demonstrated increased connectivity of the CMA with the superior frontal gyrus, accompanied by a pattern of decreased connectivity between the BLA and the superior colliculus. During conscious processing, relative to controls, individuals with PTSD showed increased connectivity between the CMA and the pulvinar. These findings demonstrate alterations in amygdala subregion functional connectivity in PTSD and highlight the disruption of the innate alarm network during both conscious and subconscious trauma processing in this disorder. PMID:27631496

  7. Trauma-Related Altered States of Consciousness: Exploring the 4-D Model

    PubMed Central

    Frewen, Paul A.; Lanius, Ruth A.

    2014-01-01

    Frewen and Lanius (in press) recently articulated a 4-D model as a framework for classifying symptoms of posttraumatic stress into those that potentially occur within normal waking consciousness (NWC) versus those that intrinsically represent dissociative experiences of trauma-related altered states of consciousness (TRASC). Four dimensions were specified: time-memory, thought, body, and emotion. The 4-D model further hypothesizes that in traumatized persons, symptoms of TRASC, compared with NWC forms of distress, will be (a) observed less frequently; (b) less intercorrelated, especially as measured as moment-to-moment states; (c) observed more frequently in people with high dissociative symptomatology as measured independently; and (d) observed more often in people who have experienced repeated traumatization, particularly early developmental trauma. The aim of the present research was to begin to evaluate these 4 predictions of the 4-D model. Within a sample of 74 women with posttraumatic stress disorder (PTSD) primarily due to histories of childhood trauma, as well as within a 2nd sample of 504 undergraduates (384 females), the 1st 2 hypotheses of the 4-D model were supported. In addition, within the PTSD sample, the 3rd hypothesis was supported. However, inconsistent with the 4th hypothesis, severity of childhood trauma history was not strongly associated with TRASC. We conclude that the hypotheses articulated by the 4-D model were generally supported, although further research in different trauma-related disorders is needed, and the role of childhood trauma history in the etiology of TRASC requires further research. PMID:24650122

  8. Altered heart rate-arterial pressure relation during head-out water immersion in conscious dog.

    PubMed

    Yoshino, H; Curran-Everett, D C; Hong, S K; Krasney, J A

    1988-04-01

    The influence of head-out water immersion (WI) (37 degrees C) on baroreflex control of heart rate was studied in five trained, instrumented, conscious dogs. Arterial pressure was raised and lowered using occluder cuffs implanted around the aorta and inferior vena cava. Function curves relating transmural systolic arterial pressure (TSAP = systolic arterial pressure-pleural pressure) to heart rate (HR) were constructed to compare responses in air and during WI. The resting TSAP in air [142 +/- 8 mmHg (mean +/- SE) at 78 +/- 6 beats/min] increased significantly during WI (161 +/- 9 mmHg at 109 +/- 9 beats/min). During WI, the saturation TSAP at the bradycardia plateau of the relation increased significantly, by 19 mmHg, whereas the average gain (slope) of the relation decreased significantly, from -1.426 to -0.752 beats.min-1.mmHg-1. Therefore, WI elicits both a resetting and a decrease of the average gain of the TSAP-HR relation. The heart rate range increased during WI as well. After cholinergic blockade with atropine, WI did not elicit a resetting of the relation and the change in average gain was abolished. However, after beta 1-blockade with metoprolol, the resting TSAP increased significantly during WI and resetting persisted, but the decrease of average gain was abolished. Therefore, the alteration of the TSAP-HR relation in WI is achieved via a modulation of both adrenergic and cholinergic regulation of HR.

  9. [Correlations of consciousness and the default function of the brain].

    PubMed

    Gyulaházi, Judit; Varga, Katalin

    2014-01-30

    Neural correlation with consciousness represents a main topic of neuroscience studies. New results of consciousness researches proved that based on a coherent function in between its components the default mode network activity is the condition for awake consciousness. The subject of consciousness is self. Tasks related with the self were proving a high default mode network activity. Using connections inside the network, results which were related with self, could be considered to represent a polymodal integration system are they are participating in fine processing of the highly integrated associative information. It could be a result of the convergence of cognitive binding. There is a strong connection between the level of consciousness and praecuneal activation. It was proved that the network activity is changing during sleeping (normal condition), trauma or under drug induced altered consciousness. The default network activity can be considered as the neural correlate of consciousness. Further researches are warranted to answer the question: is the activity of the network the cause or is just accompanying the development of human consciousness?

  10. Distinct neural correlates of the preference-related valuation of supraliminally and subliminally presented faces.

    PubMed

    Ito, Ayahito; Abe, Nobuhito; Kawachi, Yousuke; Kawasaki, Iori; Ueno, Aya; Yoshida, Kazuki; Sakai, Shinya; Matsue, Yoshihiko; Fujii, Toshikatsu

    2015-08-01

    Recent neuroimaging studies have investigated the neural substrates involved in the valuation of supraliminally presented targets and the subsequent preference decisions. However, the neural mechanisms of the valuation of subliminally presented targets, which can guide subsequent preference decisions, remain to be explored. In the present study, we determined whether the neural systems associated with the valuation of supraliminally presented faces are involved in the valuation of subliminally presented faces. The subjects were supraliminally and subliminally presented with faces during functional magnetic resonance imaging (fMRI). Following fMRI, the subjects were presented with pairs of faces and were asked to choose which face they preferred. We analyzed brain activation by back-sorting the fMRI data according to the subjects' choices. The present study yielded two main findings. First, the ventral striatum and the ventromedial prefrontal cortex predict preferences only for supraliminally presented faces. Second, the dorsomedial prefrontal cortex may predict preferences for subliminally presented faces. These findings indicate that neural correlates of the preference-related valuation of faces are dissociable, contingent upon whether the subjects consciously perceive the faces. PMID:25880023

  11. Relational Neural Evolution Approach to Bank Failure Prediction

    SciTech Connect

    Abudu, Bolanle; Markose, Sheri

    2007-12-26

    Relational neural networks as a concept offers a unique opportunity for improving classification accuracy by exploiting relational structure in data. The premise is that a relational classification technique, which uses information implicit in relationships, should classify more accurately than techniques that only examine objects in isolation. In this paper, we study the use of relational neural networks for predicting bank failure. Alongside classical financial ratios normally used as predictor variables, we introduced new relational variables for the network. The relational neural network structure, specified as a combination of feed forward and recurrent neural networks, is determined by bank data through neuro-evolution. We discuss empirical results comparing performance of the relational approach to standard propositional methods used for bank failure prediction.

  12. Relational Neural Evolution Approach to Bank Failure Prediction

    NASA Astrophysics Data System (ADS)

    Abudu, Bolanle; Markose, Sheri

    2007-12-01

    Relational neural networks as a concept offers a unique opportunity for improving classification accuracy by exploiting relational structure in data. The premise is that a relational classification technique, which uses information implicit in relationships, should classify more accurately than techniques that only examine objects in isolation. In this paper, we study the use of relational neural networks for predicting bank failure. Alongside classical financial ratios normally used as predictor variables, we introduced new relational variables for the network. The relational neural network structure, specified as a combination of feed forward and recurrent neural networks, is determined by bank data through neuro-evolution. We discuss empirical results comparing performance of the relational approach to standard propositional methods used for bank failure prediction.

  13. Predictable internal brain dynamics in EEG and its relation to conscious states

    PubMed Central

    Yoo, Jaewook; Kwon, Jaerock; Choe, Yoonsuck

    2014-01-01

    Consciousness is a complex and multi-faceted phenomenon defying scientific explanation. Part of the reason why this is the case is due to its subjective nature. In our previous computational experiments, to avoid such a subjective trap, we took a strategy to investigate objective necessary conditions of consciousness. Our basic hypothesis was that predictive internal dynamics serves as such a condition. This is in line with theories of consciousness that treat retention (memory), protention (anticipation), and primary impression as the tripartite temporal structure of consciousness. To test our hypothesis, we analyzed publicly available sleep and awake electroencephalogram (EEG) data. Our results show that EEG signals from awake or rapid eye movement (REM) sleep states have more predictable dynamics compared to those from slow-wave sleep (SWS). Since awakeness and REM sleep are associated with conscious states and SWS with unconscious or less consciousness states, these results support our hypothesis. The results suggest an intricate relationship among prediction, consciousness, and time, with potential applications to time perception and neurorobotics. PMID:24917813

  14. Assessing consciousness in coma and related states using transcranial magnetic stimulation combined with electroencephalography.

    PubMed

    Gosseries, O; Thibaut, A; Boly, M; Rosanova, M; Massimini, M; Laureys, S

    2014-02-01

    Thanks to advances in medical care, an increased number of patients recover from coma. However, some remain in vegetative/unresponsive wakefulness syndrome or in a minimally conscious state. Detection of awareness in severely brain-injured patients is challenging because it relies on behavioral assessments, which can be affected by motor, sensory and cognitive impairments of the patients. Other means of evaluation are needed to improve the accuracy of the diagnosis in this challenging population. We will here review the different altered states of consciousness occurring after severe brain damage, and explain the difficulties associated with behavioral assessment of consciousness. We will then describe a non-invasive technique, transcranial magnetic stimulation combined with high-density electroencephalography (TMS-EEG), which has allowed us to detect the presence or absence of consciousness in different physiological, pathological and pharmacological states. Some potential underlying mechanisms of the loss of consciousness will then be discussed. In conclusion, TMS-EEG is highly promising in identifying markers of consciousness at the individual level and might be of great value for clinicians in the assessment of consciousness. PMID:24393302

  15. The human brain processes syntax in the absence of conscious awareness.

    PubMed

    Batterink, Laura; Neville, Helen J

    2013-05-01

    Syntax is the core computational component of language. A longstanding idea about syntactic processing is that it is generally not available to conscious access, operating autonomously and automatically. However, there is little direct neurocognitive evidence on this issue. By measuring event-related potentials while human observers performed a novel cross-modal distraction task, we demonstrated that syntactic violations that were not consciously detected nonetheless produced a characteristic early neural response pattern, and also significantly delayed reaction times to a concurrent task. This early neural response was distinct from later neural activity that was observed only to syntactic violations that were consciously detected. These findings provide direct evidence that the human brain reacts to violations of syntax even when these violations are not consciously detected, indicating that even highly complex computational processes such as syntactic processing can occur outside the narrow window of conscious awareness.

  16. Water drinking-related muscle contraction induces the pressor response via mechanoreceptors in conscious rats.

    PubMed

    Abe, Chikara; Iwata, Chihiro; Morita, Hironobu

    2013-01-01

    Water drinking is known to induce the pressor response. The efferent pathway in this response involves sympathoexcitation, because the pressor response was completely abolished by ganglionic blockade or an α(1)-adrenergic antagonist. However, the afferent pathway in this response has not been identified. In the present study, we hypothesized that water itself stimulates the upper digestive tract to induce the pressor response, and/or drinking-related muscle contraction induces the pressor response via mechanoreceptors. To examine this hypothesis, we evaluated the pressor response induced by spontaneous or passive water drinking in conscious rats. Since the baroreflex modulates and obscures the pressor response, the experiments were conducted using rats with sinoaortic denervation. The pressor response was not suppressed by 1) transient oral surface anesthesia using lidocaine, 2) bilateral denervation of the glossopharyngeal nerve and sensory branch of the superior laryngeal nerve, or 3) denervation of the tunica adventitia in the esophagus. However, the pressor response was significantly suppressed (by -52%) by intravenous gadolinium chloride administration. Electrical stimulation of the hypoglossal nerve induced the pressor response, which was significantly suppressed (by -57%) by intravenous gadolinium chloride administration and completely abolished by severing the distal end of this nerve. These results indicate that afferent signals from mechanoreceptors in drinking-related muscles are involved in the water drinking-induced pressor response.

  17. Effect of Gender on Students' Emotion with Gender-Related Public Self-Consciousness as a Moderator in Mixed-Gender Physical Education Classes

    ERIC Educational Resources Information Center

    Moon, Minkwon; Jeon, Hyunsoo; Kwon, Sungho

    2016-01-01

    The present study investigates whether gender-related public self-consciousness moderates the relationship between students' gender and emotions in mixed-gender physical education classes. The Positive and Negative Affect Scales and the Gender-related Public Self-Consciousness Scale were administered to 380 middle-school students in South Korea.…

  18. Attention and Olfactory Consciousness

    PubMed Central

    Keller, Andreas

    2011-01-01

    Understanding the relation between attention and consciousness is an important part of our understanding of consciousness. Attention, unlike consciousness, can be systematically manipulated in psychophysical experiments and a law-like relation between attention and consciousness is waiting to be discovered. Most attempts to discover the nature of this relation are focused on a special type of attention: spatial visual attention. In this review I want to introduce another type of attention to the discussion: attention to the olfactory modality. I will first clarify the position of attention to smells in a general taxonomy of attention. I will then review the mechanisms and neuroanatomy of attention and consciousness in the olfactory system before using the newly introduced system to provide evidence that attention is necessary for consciousness. PMID:22203813

  19. Electrical stimulation of a small brain area reversibly disrupts consciousness.

    PubMed

    Koubeissi, Mohamad Z; Bartolomei, Fabrice; Beltagy, Abdelrahman; Picard, Fabienne

    2014-08-01

    The neural mechanisms that underlie consciousness are not fully understood. We describe a region in the human brain where electrical stimulation reproducibly disrupted consciousness. A 54-year-old woman with intractable epilepsy underwent depth electrode implantation and electrical stimulation mapping. The electrode whose stimulation disrupted consciousness was between the left claustrum and anterior-dorsal insula. Stimulation of electrodes within 5mm did not affect consciousness. We studied the interdependencies among depth recording signals as a function of time by nonlinear regression analysis (h(2) coefficient) during stimulations that altered consciousness and stimulations of the same electrode at lower current intensities that were asymptomatic. Stimulation of the claustral electrode reproducibly resulted in a complete arrest of volitional behavior, unresponsiveness, and amnesia without negative motor symptoms or mere aphasia. The disruption of consciousness did not outlast the stimulation and occurred without any epileptiform discharges. We found a significant increase in correlation for interactions affecting medial parietal and posterior frontal channels during stimulations that disrupted consciousness compared with those that did not. Our findings suggest that the left claustrum/anterior insula is an important part of a network that subserves consciousness and that disruption of consciousness is related to increased EEG signal synchrony within frontal-parietal networks.

  20. Electrical stimulation of a small brain area reversibly disrupts consciousness.

    PubMed

    Koubeissi, Mohamad Z; Bartolomei, Fabrice; Beltagy, Abdelrahman; Picard, Fabienne

    2014-08-01

    The neural mechanisms that underlie consciousness are not fully understood. We describe a region in the human brain where electrical stimulation reproducibly disrupted consciousness. A 54-year-old woman with intractable epilepsy underwent depth electrode implantation and electrical stimulation mapping. The electrode whose stimulation disrupted consciousness was between the left claustrum and anterior-dorsal insula. Stimulation of electrodes within 5mm did not affect consciousness. We studied the interdependencies among depth recording signals as a function of time by nonlinear regression analysis (h(2) coefficient) during stimulations that altered consciousness and stimulations of the same electrode at lower current intensities that were asymptomatic. Stimulation of the claustral electrode reproducibly resulted in a complete arrest of volitional behavior, unresponsiveness, and amnesia without negative motor symptoms or mere aphasia. The disruption of consciousness did not outlast the stimulation and occurred without any epileptiform discharges. We found a significant increase in correlation for interactions affecting medial parietal and posterior frontal channels during stimulations that disrupted consciousness compared with those that did not. Our findings suggest that the left claustrum/anterior insula is an important part of a network that subserves consciousness and that disruption of consciousness is related to increased EEG signal synchrony within frontal-parietal networks. PMID:24967698

  1. Robust single trial identification of conscious percepts triggered by sensory events of variable saliency.

    PubMed

    Teixeira, Marta; Pires, Gabriel; Raimundo, Miguel; Nascimento, Sérgio; Almeida, Vasco; Castelo-Branco, Miguel

    2014-01-01

    The neural correlates of visual awareness are elusive because of its fleeting nature. Here we have addressed this issue by using single trial statistical "brain reading" of neurophysiological event related (ERP) signatures of conscious perception of visual attributes with different levels of saliency. Behavioral reports were taken at every trial in 4 experiments addressing conscious access to color, luminance, and local phase offset cues. We found that single trial neurophysiological signatures of target presence can be observed around 300 ms at central parietal sites. Such signatures are significantly related with conscious perception, and their probability is related to sensory saliency levels. These findings identify a general neural correlate of conscious perception at the single trial level, since conscious perception can be decoded as such independently of stimulus salience and fluctuations of threshold levels. This approach can be generalized to successfully detect target presence in other individuals. PMID:24465957

  2. Timing and awareness of movement decisions: does consciousness really come too late?

    PubMed Central

    Guggisberg, Adrian G.; Mottaz, Anaïs

    2013-01-01

    Since Libet's seminal observation that a brain potential related to movement preparation occurs before participants report to be aware of their movement intention, it has been debated whether consciousness has causal influence on movement decisions. Here we review recent advances that provide new insights into the dynamics of human decision-making and question the validity of different markers used for determining the onset of neural and conscious events. Motor decisions involve multiple stages of goal evaluation, intention formation, and action execution. While the validity of the Bereitschaftspotential (BP) as index of neural movement preparation is controversial, improved neural markers are able to predict decision outcome even at early stages. Participants report being conscious of their decisions only at the time of final intention formation, just before the primary motor cortex starts executing the chosen action. However, accumulating evidence suggests that this is an artifact of Libet's clock method used for assessing consciousness. More refined methods suggest that intention consciousness does not appear instantaneously but builds up progressively. In this view, early neural markers of decision outcome are not unconscious but simply reflect conscious goal evaluation stages which are not final yet and therefore not reported with the clock method. Alternatives to the Libet clock are discussed that might allow for assessment of consciousness during decision making with improved sensitivity to early decision stages and with less influence from meta-conscious and perceptual inferences. PMID:23966921

  3. Consciousness, Plasticity, and Connectomics: The Role of Intersubjectivity in Human Cognition

    PubMed Central

    Allen, Micah; Williams, Gary

    2011-01-01

    Consciousness is typically construed as being explainable purely in terms of either private, raw feels or higher-order, reflective representations. In contrast to this false dichotomy, we propose a new view of consciousness as an interactive, plastic phenomenon open to sociocultural influence. We take up our account of consciousness from the observation of radical cortical neuroplasticity in human development. Accordingly, we draw upon recent research on macroscopic neural networks, including the “default mode,” to illustrate cases in which an individual's particular “connectome” is shaped by encultured social practices that depend upon and influence phenomenal and reflective consciousness. On our account, the dynamically interacting connectivity of these networks bring about important individual differences in conscious experience and determine what is “present” in consciousness. Further, we argue that the organization of the brain into discrete anti-correlated networks supports the phenomenological distinction of prereflective and reflective consciousness, but we emphasize that this finding must be interpreted in light of the dynamic, category-resistant nature of consciousness. Our account motivates philosophical and empirical hypotheses regarding the appropriate time-scale and function of neuroplastic adaptation, the relation of high and low-frequency neural activity to consciousness and cognitive plasticity, and the role of ritual social practices in neural development and cognitive function. PMID:21687435

  4. Conscious, but not unconscious, logo priming of brands and related words.

    PubMed

    Brintazzoli, Gigliola; Soetens, Eric; Deroost, Natacha; Van den Bussche, Eva

    2012-06-01

    This study assessed whether real-life stimulus material can elicit conscious and unconscious priming. A typical masked priming paradigm was used, with brand logo primes. We used a rigorous method to assess participants' awareness of the subliminal information. Our results show that shortly presented and masked brand logos (e.g., logo of McDonald's) have the power to prime their brand names (e.g., "McDonald's") and, remarkably, words associated to the brand (e.g., "hamburger"). However, this only occurred when the logos could be categorized clearly above the consciousness threshold. Once the primes were presented close to the consciousness threshold, no subliminal influences on behavior were observed. PMID:22503412

  5. Black Consciousness

    ERIC Educational Resources Information Center

    Hraba, Joseph; Siegman, Jack

    1974-01-01

    Black militancy is treated as an instance of class consciousness with criteria and scales developed to measure black consciousness and "self-placement" into black consciousness. These dimensions are then investigated with respect to the social and symbolic participation in the ideology of the black movement on the part of a sample of black…

  6. Mestiza Consciousness in Relation to Sustained Political Solidarity: A Chicana Feminist Interpretation of the Farmworker Movement

    ERIC Educational Resources Information Center

    Barvosa, Edwina

    2011-01-01

    Two of the most significant themes in Chicana feminist thought are the character of mestiza consciousness and the view that political solidarity--that is, the uniting of diverse people in common cause--should build upon diversity among peoples rather than on a single shared identity. Numerous Chicana and Latina feminists have connected these two…

  7. Neural co-activation as a yardstick of implicit motor learning and the propensity for conscious control of movement.

    PubMed

    Zhu, F F; Poolton, J M; Wilson, M R; Maxwell, J P; Masters, R S W

    2011-04-01

    Two studies examined EEG co-activation (coherence) between the verbal-analytical (T3) and motor planning (Fz) regions during a golf putting task. In Study 1, participants with a strong propensity to consciously monitor and control their movements, determined psychometrically by high scores on a movement specific Reinvestment Scale, displayed more alpha2 T3-Fz co-activation than participants with a weak propensity. In Study 2, participants who practiced a golf putting task implicitly (via an errorless learning protocol) displayed less alpha2 T3-Fz co-activation than those who practiced explicitly (by errorful learning). In addition, explicit but not implicit motor learners displayed more T3-Fz co-activation during golf putting under pressure, implying that verbal-analytical processing of putting movements increased under pressure. These findings provide neuropsychological evidence that supports claims that implicit motor learning can be used to limit movement specific reinvestment. PMID:21315795

  8. Consciousness, brain, neuroplasticity

    PubMed Central

    Askenasy, Jean; Lehmann, Joseph

    2013-01-01

    Subjectivity, intentionality, self-awareness and will are major components of consciousness in human beings. Changes in consciousness and its content following different brain processes and malfunction have long been studied. Cognitive sciences assume that brain activities have an infrastructure, but there is also evidence that consciousness itself may change this infrastructure. The two-way influence between brain and consciousness has been at the center of philosophy and less so, of science. This so-called bottom-up and top-down interrelationship is controversial and is the subject of our article. We would like to ask: how does it happen that consciousness may provoke structural changes in the brain? The living brain means continuous changes at the synaptic level with every new experience, with every new process of learning, memorizing or mastering new and existing skills. Synapses are generated and dissolved, while others are preserved, in an ever-changing process of so-called neuroplasticity. Ongoing processes of synaptic reinforcements and decay occur during wakefulness when consciousness is present, but also during sleep when it is mostly absent. We suggest that consciousness influences brain neuroplasticity both during wakefulness as well as sleep in a top-down way. This means that consciousness really activates synaptic flow and changes brain structures and functional organization. The dynamic impact of consciousness on brain never stops despite the relative stationary structure of the brain. Such a process can be a target for medical intervention, e.g., by cognitive training. PMID:23847580

  9. Physical integration: a causal account for consciousness.

    PubMed

    Manzotti, Riccardo; Chella, Antonio

    2014-06-01

    The issue of integration in neural networks is intimately connected with that of consciousness. In this paper, integration as an effective level of physical organization is contrasted with a methodological integrative approach. Understanding how consciousness arises out of neural processes requires a model of integration in just causal physical terms. Based on a set of feasible criteria (physical grounding, causal efficacy, no circularity and scaling), a causal account of physical integration for consciousness centered on joint causation is outlined.

  10. A framework for consciousness.

    PubMed

    Crick, Francis; Koch, Christof

    2003-02-01

    Here we summarize our present approach to the problem of consciousness. After an introduction outlining our general strategy, we describe what is meant by the term 'framework' and set it out under ten headings. This framework offers a coherent scheme for explaining the neural correlates of (visual) consciousness in terms of competing cellular assemblies. Most of the ideas we favor have been suggested before, but their combination is original. We also outline some general experimental approaches to the problem and, finally, acknowledge some relevant aspects of the brain that have been left out of the proposed framework.

  11. Aging Affects Neural Synchronization to Speech-Related Acoustic Modulations

    PubMed Central

    Goossens, Tine; Vercammen, Charlotte; Wouters, Jan; van Wieringen, Astrid

    2016-01-01

    As people age, speech perception problems become highly prevalent, especially in noisy situations. In addition to peripheral hearing and cognition, temporal processing plays a key role in speech perception. Temporal processing of speech features is mediated by synchronized activity of neural oscillations in the central auditory system. Previous studies indicate that both the degree and hemispheric lateralization of synchronized neural activity relate to speech perception performance. Based on these results, we hypothesize that impaired speech perception in older persons may, in part, originate from deviances in neural synchronization. In this study, auditory steady-state responses that reflect synchronized activity of theta, beta, low and high gamma oscillations (i.e., 4, 20, 40, and 80 Hz ASSR, respectively) were recorded in young, middle-aged, and older persons. As all participants had normal audiometric thresholds and were screened for (mild) cognitive impairment, differences in synchronized neural activity across the three age groups were likely to be attributed to age. Our data yield novel findings regarding theta and high gamma oscillations in the aging auditory system. At an older age, synchronized activity of theta oscillations is increased, whereas high gamma synchronization is decreased. In contrast to young persons who exhibit a right hemispheric dominance for processing of high gamma range modulations, older adults show a symmetrical processing pattern. These age-related changes in neural synchronization may very well underlie the speech perception problems in aging persons. PMID:27378906

  12. P3b, consciousness, and complex unconscious processing.

    PubMed

    Silverstein, Brian H; Snodgrass, Michael; Shevrin, Howard; Kushwaha, Ramesh

    2015-12-01

    How can perceptual consciousness be indexed in humans? Recent work with ERPs suggests that P3b, a relatively late component, may be a neural correlate of consciousness (NCC). This proposal dovetails with currently prevailing cognitive theory regarding the nature of conscious versus unconscious processes, which holds that the latter are simple and very brief, whereas consciousness is ostensibly required for more durable, complex cognitive processing. Using a P3b oddball paradigm, we instead show that P3b and even later, related slow wave activity occur under rigorously subliminal conditions. Additional principal component analysis (PCA) further differentiated the presence of both P3a and P3b components, demonstrating that the latter indeed occurred subliminally. Collectively, our results suggest that complex, sustained cognitive processing can occur unconsciously and that P3b is not an NCC after all.

  13. Fluctuation-response relation unifies dynamical behaviors in neural fields

    NASA Astrophysics Data System (ADS)

    Fung, C. C. Alan; Wong, K. Y. Michael; Mao, Hongzi; Wu, Si

    2015-08-01

    Anticipation is a strategy used by neural fields to compensate for transmission and processing delays during the tracking of dynamical information and can be achieved by slow, localized, inhibitory feedback mechanisms such as short-term synaptic depression, spike-frequency adaptation, or inhibitory feedback from other layers. Based on the translational symmetry of the mobile network states, we derive generic fluctuation-response relations, providing unified predictions that link their tracking behaviors in the presence of external stimuli to the intrinsic dynamics of the neural fields in their absence.

  14. Interactions between phasic alerting and consciousness in the fronto-striatal network.

    PubMed

    Chica, Ana B; Bayle, Dimitri J; Botta, Fabiano; Bartolomeo, Paolo; Paz-Alonso, Pedro M

    2016-01-01

    Only a small fraction of all the information reaching our senses can be the object of conscious report or voluntary action. Although some models propose that different attentional states (top-down amplification and vigilance) are necessary for conscious perception, few studies have explored how the brain activations associated with different attentional systems (such as top-down orienting and phasic alerting) lead to conscious perception of subsequent visual stimulation. The aim of the present study was to investigate the neural mechanisms associated with endogenous spatial attention and phasic alertness, and their interaction with the conscious perception of near-threshold stimuli. The only region demonstrating a neural interaction between endogenous attention and conscious perception was the thalamus, while a larger network of cortical and subcortical brain activations, typically associated with phasic alerting, was highly correlated with participants' conscious reports. Activation of the anterior cingulate cortex, supplementary motor area, frontal eye fields, thalamus, and caudate nucleus was related to perceptual consciousness. These data suggest that not all attentional systems are equally effective in enhancing conscious perception, highlighting the importance of thalamo-cortical circuits on the interactions between alerting and consciousness. PMID:27555378

  15. Interactions between phasic alerting and consciousness in the fronto-striatal network

    PubMed Central

    Chica, Ana B.; Bayle, Dimitri J.; Botta, Fabiano; Bartolomeo, Paolo; Paz-Alonso, Pedro M.

    2016-01-01

    Only a small fraction of all the information reaching our senses can be the object of conscious report or voluntary action. Although some models propose that different attentional states (top-down amplification and vigilance) are necessary for conscious perception, few studies have explored how the brain activations associated with different attentional systems (such as top-down orienting and phasic alerting) lead to conscious perception of subsequent visual stimulation. The aim of the present study was to investigate the neural mechanisms associated with endogenous spatial attention and phasic alertness, and their interaction with the conscious perception of near-threshold stimuli. The only region demonstrating a neural interaction between endogenous attention and conscious perception was the thalamus, while a larger network of cortical and subcortical brain activations, typically associated with phasic alerting, was highly correlated with participants’ conscious reports. Activation of the anterior cingulate cortex, supplementary motor area, frontal eye fields, thalamus, and caudate nucleus was related to perceptual consciousness. These data suggest that not all attentional systems are equally effective in enhancing conscious perception, highlighting the importance of thalamo-cortical circuits on the interactions between alerting and consciousness. PMID:27555378

  16. The Neurogenetic Correlates of Consciousness

    NASA Astrophysics Data System (ADS)

    Grandy, John K.

    2013-09-01

    The neurogenetic correlates of consciousness (NgCC) is a new field of consciousness studies that focuses on genes that have an effect on or are involved in the continuum of neuron-based consciousness. A framework of consciousness based on the neural correlates of consciousness (NCC) has already been established by Francis Crick and Christof Kock. In this work I propose that there are NgCC underlying the NCC which are both active during the conscious experience. So how are genes involved? There are two significant connections between DNA and neurons that are involved in the conscious experience. First, any brain system can be adversely affected by underlying genetic abnormalities which can be expressed in an individual at birth, in adulthood, or later in life. Second, the DNA molecule does not lay dormant while the neuron runs on autopilot. DNA is active in translating and transcribing RNA and protein products that are utilized during neuron functioning. Without these products being continuously produced by the DNA during a conscious experience the neurons would cease to function correctly and be rendered unable to provide a continuum of human consciousness. Consequently, in addition to NCC, NgCC must be factored in when appreciating a conscious event. In this work I will discuss and explain some NgCC citing several examples.

  17. Non-conscious visual cues related to affect and action alter perception of effort and endurance performance

    PubMed Central

    Blanchfield, Anthony; Hardy, James; Marcora, Samuele

    2014-01-01

    The psychobiological model of endurance performance proposes that endurance performance is determined by a decision-making process based on perception of effort and potential motivation. Recent research has reported that effort-based decision-making during cognitive tasks can be altered by non-conscious visual cues relating to affect and action. The effects of these non-conscious visual cues on effort and performance during physical tasks are however unknown. We report two experiments investigating the effects of subliminal priming with visual cues related to affect and action on perception of effort and endurance performance. In Experiment 1 thirteen individuals were subliminally primed with happy or sad faces as they cycled to exhaustion in a counterbalanced and randomized crossover design. A paired t-test (happy vs. sad faces) revealed that individuals cycled significantly longer (178 s, p = 0.04) when subliminally primed with happy faces. A 2 × 5 (condition × iso-time) ANOVA also revealed a significant main effect of condition on rating of perceived exertion (RPE) during the time to exhaustion (TTE) test with lower RPE when subjects were subliminally primed with happy faces (p = 0.04). In Experiment 2, a single-subject randomization tests design found that subliminal priming with action words facilitated a significantly longer TTE (399 s, p = 0.04) in comparison to inaction words. Like Experiment 1, this greater TTE was accompanied by a significantly lower RPE (p = 0.03). These experiments are the first to show that subliminal visual cues relating to affect and action can alter perception of effort and endurance performance. Non-conscious visual cues may therefore influence the effort-based decision-making process that is proposed to determine endurance performance. Accordingly, the findings raise notable implications for individuals who may encounter such visual cues during endurance competitions, training, or health related exercise. PMID:25566014

  18. Age-Related Changes in 1/f Neural Electrophysiological Noise

    PubMed Central

    Kramer, Mark A.; Case, John; Lepage, Kyle Q.; Tempesta, Zechari R.; Knight, Robert T.; Gazzaley, Adam

    2015-01-01

    Aging is associated with performance decrements across multiple cognitive domains. The neural noise hypothesis, a dominant view of the basis of this decline, posits that aging is accompanied by an increase in spontaneous, noisy baseline neural activity. Here we analyze data from two different groups of human subjects: intracranial electrocorticography from 15 participants over a 38 year age range (15–53 years) and scalp EEG data from healthy younger (20–30 years) and older (60–70 years) adults to test the neural noise hypothesis from a 1/f noise perspective. Many natural phenomena, including electrophysiology, are characterized by 1/f noise. The defining characteristic of 1/f is that the power of the signal frequency content decreases rapidly as a function of the frequency (f) itself. The slope of this decay, the noise exponent (χ), is often <−1 for electrophysiological data and has been shown to approach white noise (defined as χ = 0) with increasing task difficulty. We observed, in both electrophysiological datasets, that aging is associated with a flatter (more noisy) 1/f power spectral density, even at rest, and that visual cortical 1/f noise statistically mediates age-related impairments in visual working memory. These results provide electrophysiological support for the neural noise hypothesis of aging. SIGNIFICANCE STATEMENT Understanding the neurobiological origins of age-related cognitive decline is of critical scientific, medical, and public health importance, especially considering the rapid aging of the world's population. We find, in two separate human studies, that 1/f electrophysiological noise increases with aging. In addition, we observe that this age-related 1/f noise statistically mediates age-related working memory decline. These results significantly add to this understanding and contextualize a long-standing problem in cognition by encapsulating age-related cognitive decline within a neurocomputational model of 1/f noise

  19. Age-Related Changes in 1/f Neural Electrophysiological Noise.

    PubMed

    Voytek, Bradley; Kramer, Mark A; Case, John; Lepage, Kyle Q; Tempesta, Zechari R; Knight, Robert T; Gazzaley, Adam

    2015-09-23

    Aging is associated with performance decrements across multiple cognitive domains. The neural noise hypothesis, a dominant view of the basis of this decline, posits that aging is accompanied by an increase in spontaneous, noisy baseline neural activity. Here we analyze data from two different groups of human subjects: intracranial electrocorticography from 15 participants over a 38 year age range (15-53 years) and scalp EEG data from healthy younger (20-30 years) and older (60-70 years) adults to test the neural noise hypothesis from a 1/f noise perspective. Many natural phenomena, including electrophysiology, are characterized by 1/f noise. The defining characteristic of 1/f is that the power of the signal frequency content decreases rapidly as a function of the frequency (f) itself. The slope of this decay, the noise exponent (χ), is often <-1 for electrophysiological data and has been shown to approach white noise (defined as χ = 0) with increasing task difficulty. We observed, in both electrophysiological datasets, that aging is associated with a flatter (more noisy) 1/f power spectral density, even at rest, and that visual cortical 1/f noise statistically mediates age-related impairments in visual working memory. These results provide electrophysiological support for the neural noise hypothesis of aging. Significance statement: Understanding the neurobiological origins of age-related cognitive decline is of critical scientific, medical, and public health importance, especially considering the rapid aging of the world's population. We find, in two separate human studies, that 1/f electrophysiological noise increases with aging. In addition, we observe that this age-related 1/f noise statistically mediates age-related working memory decline. These results significantly add to this understanding and contextualize a long-standing problem in cognition by encapsulating age-related cognitive decline within a neurocomputational model of 1/f noise-induced deficits in

  20. Job satisfaction in relation to energy resource consciousness and perceptions of energy utilization in selected Illinois manufacturing firms

    SciTech Connect

    Haynes, T.S.

    1986-01-01

    This study was developed through a synthesis and review of literature and research related to the current status of job satisfaction, energy resources, and perceptions of how energy is utilized in the manufacturing work environment. This synthesis and review revolved around several proven contributing factors of job satisfaction, such as age, education, and challenge from work itself. Quality of work life programs and their components are discussed in relation to their impact on job satisfaction. The nature of energy resource utilization is traced back through history with an emphasis on the limitations of current resources and options for the future. The review highlights the current debate over what should be the future path of energy resource development. The concept of satisfaction of human needs is reviewed and related to job satisfaction and energy resources. The purpose of this research study was to contribute to the understanding of how perceptions of energy resources relate to job satisfaction. Results of the study indicated that there were no significant differences between an individual's energy resource consciousness and perceptions of energy utilization in the work place, energy resource consciousness and job satisfaction, and job satisfaction and perceptions of energy utilization in the workplace.

  1. Neural Alterations in Acquired Age-Related Hearing Loss

    PubMed Central

    Mudar, Raksha A.; Husain, Fatima T.

    2016-01-01

    Hearing loss is one of the most prevalent chronic health conditions in older adults. Growing evidence suggests that hearing loss is associated with reduced cognitive functioning and incident dementia. In this mini-review, we briefly examine literature on anatomical and functional alterations in the brains of adults with acquired age-associated hearing loss, which may underlie the cognitive consequences observed in this population, focusing on studies that have used structural and functional magnetic resonance imaging, diffusion tensor imaging, and event-related electroencephalography. We discuss structural and functional alterations observed in the temporal and frontal cortices and the limbic system. These neural alterations are discussed in the context of common cause, information-degradation, and sensory-deprivation hypotheses, and we suggest possible rehabilitation strategies. Although, we are beginning to learn more about changes in neural architecture and functionality related to age-associated hearing loss, much work remains to be done. Understanding the neural alterations will provide objective markers for early identification of neural consequences of age-associated hearing loss and for evaluating benefits of intervention approaches. PMID:27313556

  2. Single units and conscious vision.

    PubMed Central

    Logothetis, N K

    1998-01-01

    Figures that can be seen in more than one way are invaluable tools for the study of the neural basis of visual awareness, because such stimuli permit the dissociation of the neural responses that underlie what we perceive at any given time from those forming the sensory representation of a visual pattern. To study the former type of responses, monkeys were subjected to binocular rivalry, and the response of neurons in a number of different visual areas was studied while the animals reported their alternating percepts by pulling levers. Perception-related modulations of neural activity were found to occur to different extents in different cortical visual areas. The cells that were affected by suppression were almost exclusively binocular, and their proportion was found to increase in the higher processing stages of the visual system. The strongest correlations between neural activity and perception were observed in the visual areas of the temporal lobe. A strikingly large number of neurons in the early visual areas remained active during the perceptual suppression of the stimulus, a finding suggesting that conscious visual perception might be mediated by only a subset of the cells exhibiting stimulus selective responses. These physiological findings, together with a number of recent psychophysical studies, offer a new explanation of the phenomenon of binocular rivalry. Indeed, rivalry has long been considered to be closely linked with binocular fusion and stereopsis, and the sequences of dominance and suppression have been viewed as the result of competition between the two monocular channels. The physiological data presented here are incompatible with this interpretation. Rather than reflecting interocular competition, the rivalry is most probably between the two different central neural representations generated by the dichoptically presented stimuli. The mechanisms of rivalry are probably the same as, or very similar to, those underlying multistable perception in

  3. How can we construct a science of consciousness?

    PubMed

    Chalmers, David J

    2013-11-01

    This chapter gives an overview of the projects facing a science of consciousness. Such a science must integrate third-person data about behavior and brain processes with first-person data about conscious experience. Empirical projects for integrating these data include those of contrasting conscious and unconscious processes, investigating the contents of consciousness, finding neural correlates of consciousness, and eventually inferring underlying principles connecting consciousness with physical processes. These projects are discussed with reference to current experimental research on consciousness. Some obstacles that a science of consciousness faces are also discussed.

  4. Neural Sensitivity to Absolute and Relative Anticipated Reward in Adolescents

    PubMed Central

    Vaidya, Jatin G.; Knutson, Brian; O'Leary, Daniel S.; Block, Robert I.; Magnotta, Vincent

    2013-01-01

    Adolescence is associated with a dramatic increase in risky and impulsive behaviors that have been attributed to developmental differences in neural processing of rewards. In the present study, we sought to identify age differences in anticipation of absolute and relative rewards. To do so, we modified a commonly used monetary incentive delay (MID) task in order to examine brain activity to relative anticipated reward value (neural sensitivity to the value of a reward as a function of other available rewards). This design also made it possible to examine developmental differences in brain activation to absolute anticipated reward magnitude (the degree to which neural activity increases with increasing reward magnitude). While undergoing fMRI, 18 adolescents and 18 adult participants were presented with cues associated with different reward magnitudes. After the cue, participants responded to a target to win money on that trial. Presentation of cues was blocked such that two reward cues associated with $.20, $1.00, or $5.00 were in play on a given block. Thus, the relative value of the $1.00 reward varied depending on whether it was paired with a smaller or larger reward. Reflecting age differences in neural responses to relative anticipated reward (i.e., reference dependent processing), adults, but not adolescents, demonstrated greater activity to a $1 reward when it was the larger of the two available rewards. Adults also demonstrated a more linear increase in ventral striatal activity as a function of increasing absolute reward magnitude compared to adolescents. Additionally, reduced ventral striatal sensitivity to absolute anticipated reward (i.e., the difference in activity to medium versus small rewards) correlated with higher levels of trait Impulsivity. Thus, ventral striatal activity in anticipation of absolute and relative rewards develops with age. Absolute reward processing is also linked to individual differences in Impulsivity. PMID:23544046

  5. Neural sensitivity to absolute and relative anticipated reward in adolescents.

    PubMed

    Vaidya, Jatin G; Knutson, Brian; O'Leary, Daniel S; Block, Robert I; Magnotta, Vincent

    2013-01-01

    Adolescence is associated with a dramatic increase in risky and impulsive behaviors that have been attributed to developmental differences in neural processing of rewards. In the present study, we sought to identify age differences in anticipation of absolute and relative rewards. To do so, we modified a commonly used monetary incentive delay (MID) task in order to examine brain activity to relative anticipated reward value (neural sensitivity to the value of a reward as a function of other available rewards). This design also made it possible to examine developmental differences in brain activation to absolute anticipated reward magnitude (the degree to which neural activity increases with increasing reward magnitude). While undergoing fMRI, 18 adolescents and 18 adult participants were presented with cues associated with different reward magnitudes. After the cue, participants responded to a target to win money on that trial. Presentation of cues was blocked such that two reward cues associated with $.20, $1.00, or $5.00 were in play on a given block. Thus, the relative value of the $1.00 reward varied depending on whether it was paired with a smaller or larger reward. Reflecting age differences in neural responses to relative anticipated reward (i.e., reference dependent processing), adults, but not adolescents, demonstrated greater activity to a $1 reward when it was the larger of the two available rewards. Adults also demonstrated a more linear increase in ventral striatal activity as a function of increasing absolute reward magnitude compared to adolescents. Additionally, reduced ventral striatal sensitivity to absolute anticipated reward (i.e., the difference in activity to medium versus small rewards) correlated with higher levels of trait Impulsivity. Thus, ventral striatal activity in anticipation of absolute and relative rewards develops with age. Absolute reward processing is also linked to individual differences in Impulsivity. PMID:23544046

  6. Trauma-related altered states of consciousness in women with BPD with or without co-occurring PTSD

    PubMed Central

    Frewen, Paul; Kleindienst, Nikolaus; Lanius, Ruth; Schmahl, Christian

    2014-01-01

    Background A “4-D model” was recently described as a theoretical framework for categorizing trauma-related symptoms into four phenomenological dimensions (the experience of time, thought, body, and emotion) that can present either in the form of normal waking consciousness (NWC) or as dissociative experiences, that is, trauma-related altered states of consciousness (TRASC). Methods The present study examined the predictions of the 4-D model in 258 persons with borderline personality disorder (BPD) with (n=126) versus without (n=132) posttraumatic stress disorder (PTSD). Results As measured by the Borderline Symptom List, consistent with the predictions of the 4-D model, in comparison with symptom endorsements theorized to be associated with NWC, measures of TRASC were less frequent, and more strongly correlated with both Dissociative Experience Scale scores and severity of childhood emotional neglect, particularly in persons with both BPD and PTSD. Our prediction that symptoms of TRASC would be less intercorrelated in comparison with distress associated with NWC symptoms, however, was not supported. Conclusions Findings are discussed as they pertain to the symptomatology of BPD, PTSD, and dissociation. PMID:25206942

  7. A framework for investigating animal consciousness.

    PubMed

    Droege, Paula; Braithwaite, Victoria A

    2015-01-01

    An assessment of consciousness in nonverbal animals requires a framework for research that extends testing methods beyond subjective report. This chapter proposes a working definition of consciousness in terms of temporal representation that provides the critical link between internal phenomenology and external behavior and neural structure. Our claim is that consciousness represents the present moment as distinct from the past and the future in order to flexibly respond to stimuli. We discuss behavioral and neural evidence that indicates the capacity for both flexible response and temporal representation, and we illustrate these capacities in fish, a taxonomic group that challenges human intuitions about consciousness.

  8. Consciousness in dreams.

    PubMed

    Kahn, David; Gover, Tzivia

    2010-01-01

    This chapter argues that dreaming is an important state of consciousness and that it has many features that complement consciousness in the wake state. The chapter discusses consciousness in dreams and how it comes about. It discusses the changes that occur in the neuromodulatory environment and in the neuronal connectivity of the brain as we fall asleep and begin our night journeys. Dreams evolve from internal sources though the dream may look different than any one of these since something entirely new may emerge through self-organizing processes. The chapter also explores characteristics of dreaming consciousness such as acceptance of implausibility and how that might lead to creative insight. Examples of studies, which have shown creativity in dream sleep, are provided to illustrate important characteristics of dreaming consciousness. The chapter also discusses the dream body and how it relates to our consciousness while dreaming. Differences and similarities between wake, lucid, non-lucid and day dreaming are explored and the chapter concludes with a discussion on what we can learn from each of these expressions of consciousness. PMID:20870068

  9. Consciousness in dreams.

    PubMed

    Kahn, David; Gover, Tzivia

    2010-01-01

    This chapter argues that dreaming is an important state of consciousness and that it has many features that complement consciousness in the wake state. The chapter discusses consciousness in dreams and how it comes about. It discusses the changes that occur in the neuromodulatory environment and in the neuronal connectivity of the brain as we fall asleep and begin our night journeys. Dreams evolve from internal sources though the dream may look different than any one of these since something entirely new may emerge through self-organizing processes. The chapter also explores characteristics of dreaming consciousness such as acceptance of implausibility and how that might lead to creative insight. Examples of studies, which have shown creativity in dream sleep, are provided to illustrate important characteristics of dreaming consciousness. The chapter also discusses the dream body and how it relates to our consciousness while dreaming. Differences and similarities between wake, lucid, non-lucid and day dreaming are explored and the chapter concludes with a discussion on what we can learn from each of these expressions of consciousness.

  10. Dynamic Neural Processing of Linguistic Cues Related to Death

    PubMed Central

    Ma, Yina; Qin, Jungang; Han, Shihui

    2013-01-01

    Behavioral studies suggest that humans evolve the capacity to cope with anxiety induced by the awareness of death’s inevitability. However, the neurocognitive processes that underlie online death-related thoughts remain unclear. Our recent functional MRI study found that the processing of linguistic cues related to death was characterized by decreased neural activity in human insular cortex. The current study further investigated the time course of neural processing of death-related linguistic cues. We recorded event-related potentials (ERP) to death-related, life-related, negative-valence, and neutral-valence words in a modified Stroop task that required color naming of words. We found that the amplitude of an early frontal/central negativity at 84–120 ms (N1) decreased to death-related words but increased to life-related words relative to neutral-valence words. The N1 effect associated with death-related and life-related words was correlated respectively with individuals’ pessimistic and optimistic attitudes toward life. Death-related words also increased the amplitude of a frontal/central positivity at 124–300 ms (P2) and of a frontal/central positivity at 300–500 ms (P3). However, the P2 and P3 modulations were observed for both death-related and negative-valence words but not for life-related words. The ERP results suggest an early inverse coding of linguistic cues related to life and death, which is followed by negative emotional responses to death-related information. PMID:23840787

  11. Interpersonal Liking Modulates Motor-Related Neural Regions

    PubMed Central

    Sobhani, Mona; Fox, Glenn R.; Kaplan, Jonas; Aziz-Zadeh, Lisa

    2012-01-01

    Observing someone perform an action engages brain regions involved in motor planning, such as the inferior frontal, premotor, and inferior parietal cortices. Recent research suggests that during action observation, activity in these neural regions can be modulated by membership in an ethnic group defined by physical differences. In this study we expanded upon previous research by matching physical similarity of two different social groups and investigating whether likability of an outgroup member modulates activity in neural regions involved in action observation. Seventeen Jewish subjects were familiarized with biographies of eight individuals, half of the individuals belonged to Neo-Nazi groups (dislikable) and half of which did not (likable). All subjects and actors in the stimuli were Caucasian and physically similar. The subjects then viewed videos of actors portraying the characters performing simple motor actions (e.g. grasping a water bottle and raising it to the lips), while undergoing fMRI. Using multivariate pattern analysis (MVPA), we found that a classifier trained on brain activation patterns successfully discriminated between the likable and dislikable action observation conditions within the right ventral premotor cortex. These data indicate that the spatial pattern of activity in action observation related neural regions is modulated by likability even when watching a simple action such as reaching for a cup. These findings lend further support for the notion that social factors such as interpersonal liking modulate perceptual processing in motor-related cortices. PMID:23071644

  12. [What is impaired consciousness? Revisiting impaired consciousness as psychiatric concept].

    PubMed

    Kanemoto, Kousuke

    2004-01-01

    For decades, psychiatrists have considered that concepts of impaired consciousness in the study of psychiatry were inconsistent with those applied in the field of neurology, in which the usefulness of the concept of consciousness has long been seriously doubted. Gloor concluded that the concept of consciousness does not further the understanding of seizure mechanisms or brain function, which is the current representative opinion of most epileptologists. Loss of consciousness tends to be reduced to aggregates of individual impairments of higher cognitive functions, and the concept of consciousness is preferably avoided by neurologists by assigning various behavioral disturbances during disturbed consciousness to particular neuropsychological centers. In contrast, psychiatrists, especially those in Europe, are more likely to include phenomena involving problems related to phenomenological intentionality in impaired consciousness. For the present study, we first divided consciousness into vigilance and recursive consciousness, and then attempted to determine what kind of impaired consciousness would be an ideal candidate to represent pure disturbance of recursive consciousness. Then, 4 patients, 1 each with pure amnestic states followed immediately by complex partial seizures, an akinetic mutistic state caused by absence status, and mental diplopia as a manifestation of postictal psychosis, as well as a patient with Alzheimer's disease who gracefully performed Japanese tea ceremony, were studied. Based on our findings, we concluded that impaired consciousness as a generic term in general medicine does not indicate any unitary entity corresponding to some well-demarcated physiological function or constitute a base from which recursive consciousness emerges as a superstructure. From that, we stressed that a pure form of impairment of recursive consciousness could occur without the impaired consciousness named generically in general medicine. Second, following

  13. [What is impaired consciousness? Revisiting impaired consciousness as psychiatric concept].

    PubMed

    Kanemoto, Kousuke

    2004-01-01

    For decades, psychiatrists have considered that concepts of impaired consciousness in the study of psychiatry were inconsistent with those applied in the field of neurology, in which the usefulness of the concept of consciousness has long been seriously doubted. Gloor concluded that the concept of consciousness does not further the understanding of seizure mechanisms or brain function, which is the current representative opinion of most epileptologists. Loss of consciousness tends to be reduced to aggregates of individual impairments of higher cognitive functions, and the concept of consciousness is preferably avoided by neurologists by assigning various behavioral disturbances during disturbed consciousness to particular neuropsychological centers. In contrast, psychiatrists, especially those in Europe, are more likely to include phenomena involving problems related to phenomenological intentionality in impaired consciousness. For the present study, we first divided consciousness into vigilance and recursive consciousness, and then attempted to determine what kind of impaired consciousness would be an ideal candidate to represent pure disturbance of recursive consciousness. Then, 4 patients, 1 each with pure amnestic states followed immediately by complex partial seizures, an akinetic mutistic state caused by absence status, and mental diplopia as a manifestation of postictal psychosis, as well as a patient with Alzheimer's disease who gracefully performed Japanese tea ceremony, were studied. Based on our findings, we concluded that impaired consciousness as a generic term in general medicine does not indicate any unitary entity corresponding to some well-demarcated physiological function or constitute a base from which recursive consciousness emerges as a superstructure. From that, we stressed that a pure form of impairment of recursive consciousness could occur without the impaired consciousness named generically in general medicine. Second, following

  14. Harnessing anesthesia and brain imaging for the study of human consciousness.

    PubMed

    Långsjo, Jaakko W; Revonsuo, Antti; Scheinin, Harry

    2014-01-01

    Philosophers have been trying to solve the mind-body problem for hundreds of years. Consciousness is the core of this problem: How do subjective conscious sensations, perceptions, feelings, and thoughts arise out of objective physical brain activities? How is this subjective conscious world in causal interaction with the objective sensory and motor mechanisms of the brain and the body? Although we witness the seamless interaction of the mental and the physical worlds in our everyday lives, no scientific theory can yet fully describe or explain it. The hard problem of consciousness, the question why and how any brain activity should be accompanied by any subjective experiences at all, remains a mystery and a challenge for modern science. Anesthesia offers a unique and safe way to directly manipulate the state of consciousness and can, thus, be used as a tool in consciousness research. With neuroimaging, such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) performed at different states of consciousness, it is possible to visualize the state-related changes and pinpoint the brain structures or neural mechanisms related to changes in consciousness. With these tools, neurosciences now show promise in disentangling the eternal enigma of human consciousness. In this article, we will review the recent advancements in the field.

  15. ["Osteo-neural" related factors - bridge over bone homeostasis].

    PubMed

    Sato, Tsuyoshi

    2016-08-01

    Bone tissues including bone marrow are comprised of various cells. A growing body of evidence suggests that nerve cells which exist in and around bone such as periosteal and bone marrow build a close relationship with bone cells. Namely, it was revealed that central nervous system governs bone tissues via peripheral nervous system and neurotransmitters or cytokines play a role for the communication between bone and nerve in the last decade. In this paper, I would like to review "osteo-neural" related factors which has been well-documented so far. PMID:27461495

  16. The Use of Life History Collage to Explore Learning Related to the Enactment of Social Consciousness in Female Nonprofit Leaders

    ERIC Educational Resources Information Center

    Seymour, Susan R.

    2012-01-01

    The purpose of this study was to consider the development of social consciousness in female nonprofit leaders. The problem undergirding the study is that we do not know enough about social consciousness to know how it is learned, if it can be taught, if it is stable over a lifetime, and what factors and life events shape its unique expression. A…

  17. Neural Basis of Visual Distraction

    ERIC Educational Resources Information Center

    Kim, So-Yeon; Hopfinger, Joseph B.

    2010-01-01

    The ability to maintain focus and avoid distraction by goal-irrelevant stimuli is critical for performing many tasks and may be a key deficit in attention-related problems. Recent studies have demonstrated that irrelevant stimuli that are consciously perceived may be filtered out on a neural level and not cause the distraction triggered by…

  18. Fairness influences early signatures of reward-related neural processing.

    PubMed

    Massi, Bart; Luhmann, Christian C

    2015-12-01

    Many humans exhibit a strong preference for fairness during decision-making. Although there is evidence that social factors influence reward-related and affective neural processing, it is unclear if this effect is mediated by compulsory outcome evaluation processes or results from slower deliberate cognition. Here we show that the feedback-related negativity (FRN) and late positive potential (LPP), two signatures of early hedonic processing, are modulated by the fairness of rewards during a passive rating task. We find that unfair payouts elicit larger FRNs than fair payouts, whereas fair payouts elicit larger LPPs than unfair payouts. This is true both in the time-domain, where the FRN and LPP are related, and in the time-frequency domain, where the two signals are largely independent. Ultimately, this work demonstrates that fairness affects the early stages of reward and affective processing, suggesting a common biological mechanism for social and personal reward evaluation.

  19. Linking Sleep Slow Oscillations with consciousness theories: new vistas on Slow Wave Sleep unconsciousness.

    PubMed

    Gemignani, Angelo; Menicucci, Danilo; Laurino, Marco; Piarulli, Andrea; Mastorci, Francesca; Sebastiani, Laura; Allegrini, Paolo

    2015-01-01

    We review current models of consciousness in the context of wakefulness and sleep. We show that recent results on Slow Wave Sleep, including our own works, naturally fit within consciousness models. In particular, Sleep Slow Oscillations, namely low-frequency (<1Hz) oscillations, contain electrophysiological properties (up and down states) able to elicit and quench neural integration during Slow Wave Sleep. The physiological unconsciousness related to the Sleep Slow Oscillation derives from the interplay between spontaneous or evoked wake-like activities (up states) and half-a-second's electrical silences (down states). Sleep Slow Oscillation induces unconsciousness via the formation of parallel and segregated neural activities. PMID:26742667

  20. NrCAM regulating neural systems and addiction related behaviors

    PubMed Central

    Ishiguro, Hiroki; Hall, Frank S.; Horiuchi, Yasue; Sakurai, Takeshi; Hishimoto, Akitoyo; Grumet, Martin; Uhl, George R.; Onaivi, Emmanuel S.; Arinami, Tadao

    2012-01-01

    We have previously shown that a haplotype associated with decreased NrCAM expression in brain is protective against addiction vulnerability for polysubstance abuse in humans and that Nrcam knockout mice do not develop conditioned place preferences for morphine, cocaine, or amphetamine. In order to gain insight into NrCAM involvement in addiction vulnerability, which may involve specific neural circuits underlying behavioral characteristics relevant to addiction, we evaluated several behavioral phenotypes in Nrcam knockout mice. Consistent with a potential general reduction in motivational function, Nrcam knockout mice demonstrated less curiosity for novel objects and for an unfamiliar conspecific, showed also less anxiety in the zero maze. Nrcam heterozygote knockout mice reduced alcohol preference and buried fewer marbles in home cage. These observations provide further support for a role of NrCAM in substance abuse including alcoholism vulnerability, possibly through its effects on behavioral traits that may affect addiction vulnerability, including novelty seeking, obsessive compulsion and responses to aversive or anxiety-provoking stimuli. Additionally, in order to prove glutamate homeostasis hypothesis of addiction, we analyzed glutamatergic molecules regulated by NRCAM. Glutaminase appears to be involved in NrCAM-related molecular pathway in two different tissues from human and mouse. An inhibitor of the enzyme, PLG, treatment produced, at least, some of the phenotypes of mice shown in alcohol preference and in anxiety-like behavior. Thus, NrCAM could affect addiction-related behaviors via at least partial modulation of some glutamatargic pathways and neural function in brain. PMID:22780223

  1. Reward-related neural responses are dependent on the beneficiary.

    PubMed

    Braams, Barbara R; Güroğlu, Berna; de Water, Erik; Meuwese, Rosa; Koolschijn, P Cédric; Peper, Jiska S; Crone, Eveline A

    2014-07-01

    Prior studies have suggested that positive social interactions are experienced as rewarding. Yet, it is not well understood how social relationships influence neural responses to other persons' gains. In this study, we investigated neural responses during a gambling task in which healthy participants (N = 31; 18 females) could win or lose money for themselves, their best friend or a disliked other (antagonist). At the moment of receiving outcome, person-related activity was observed in the dorsal medial prefrontal cortex (dmPFC), precuneus and temporal parietal junction (TPJ), showing higher activity for friends and antagonists than for self, and this activity was independent of outcome. The only region showing an interaction between the person-participants played for and outcome was the ventral striatum. Specifically, the striatum was more active following gains than losses for self and friends, whereas for the antagonist this pattern was reversed. Together, these results show that, in a context with social and reward information, social aspects are processed in brain regions associated with social cognition (mPFC, TPJ), and reward aspects are processed in primary reward areas (striatum). Furthermore, there is an interaction of social and reward information in the striatum, such that reward-related activity was dependent on social relationship.

  2. Reward-related neural responses are dependent on the beneficiary

    PubMed Central

    Güroğlu, Berna; de Water, Erik; Meuwese, Rosa; Koolschijn, P. Cédric; Peper, Jiska S.; Crone, Eveline A.

    2014-01-01

    Prior studies have suggested that positive social interactions are experienced as rewarding. Yet, it is not well understood how social relationships influence neural responses to other persons’ gains. In this study, we investigated neural responses during a gambling task in which healthy participants (N = 31; 18 females) could win or lose money for themselves, their best friend or a disliked other (antagonist). At the moment of receiving outcome, person-related activity was observed in the dorsal medial prefrontal cortex (dmPFC), precuneus and temporal parietal junction (TPJ), showing higher activity for friends and antagonists than for self, and this activity was independent of outcome. The only region showing an interaction between the person-participants played for and outcome was the ventral striatum. Specifically, the striatum was more active following gains than losses for self and friends, whereas for the antagonist this pattern was reversed. Together, these results show that, in a context with social and reward information, social aspects are processed in brain regions associated with social cognition (mPFC, TPJ), and reward aspects are processed in primary reward areas (striatum). Furthermore, there is an interaction of social and reward information in the striatum, such that reward-related activity was dependent on social relationship. PMID:23720575

  3. Reward-related neural responses are dependent on the beneficiary.

    PubMed

    Braams, Barbara R; Güroğlu, Berna; de Water, Erik; Meuwese, Rosa; Koolschijn, P Cédric; Peper, Jiska S; Crone, Eveline A

    2014-07-01

    Prior studies have suggested that positive social interactions are experienced as rewarding. Yet, it is not well understood how social relationships influence neural responses to other persons' gains. In this study, we investigated neural responses during a gambling task in which healthy participants (N = 31; 18 females) could win or lose money for themselves, their best friend or a disliked other (antagonist). At the moment of receiving outcome, person-related activity was observed in the dorsal medial prefrontal cortex (dmPFC), precuneus and temporal parietal junction (TPJ), showing higher activity for friends and antagonists than for self, and this activity was independent of outcome. The only region showing an interaction between the person-participants played for and outcome was the ventral striatum. Specifically, the striatum was more active following gains than losses for self and friends, whereas for the antagonist this pattern was reversed. Together, these results show that, in a context with social and reward information, social aspects are processed in brain regions associated with social cognition (mPFC, TPJ), and reward aspects are processed in primary reward areas (striatum). Furthermore, there is an interaction of social and reward information in the striatum, such that reward-related activity was dependent on social relationship. PMID:23720575

  4. Demodernizing Consciousness

    ERIC Educational Resources Information Center

    Berger, Peter L.; And Others

    1973-01-01

    Youth culture and counterculture in contemporary Western societies are complex phenomena that may be viewed from a variety of social science perspectives. The authors analyze these cultures as embodiments of demodernizing consciousness with which they hold they have considerable firsthand experience. (RJ)

  5. The Neural Consequences of Age-Related Hearing Loss.

    PubMed

    Peelle, Jonathan E; Wingfield, Arthur

    2016-07-01

    During hearing, acoustic signals travel up the ascending auditory pathway from the cochlea to auditory cortex; efferent connections provide descending feedback. In human listeners, although auditory and cognitive processing have sometimes been viewed as separate domains, a growing body of work suggests they are intimately coupled. Here, we review the effects of hearing loss on neural systems supporting spoken language comprehension, beginning with age-related physiological decline. We suggest that listeners recruit domain general executive systems to maintain successful communication when the auditory signal is degraded, but that this compensatory processing has behavioral consequences: even relatively mild levels of hearing loss can lead to cascading cognitive effects that impact perception, comprehension, and memory, leading to increased listening effort during speech comprehension. PMID:27262177

  6. The Neural Consequences of Age-Related Hearing Loss.

    PubMed

    Peelle, Jonathan E; Wingfield, Arthur

    2016-07-01

    During hearing, acoustic signals travel up the ascending auditory pathway from the cochlea to auditory cortex; efferent connections provide descending feedback. In human listeners, although auditory and cognitive processing have sometimes been viewed as separate domains, a growing body of work suggests they are intimately coupled. Here, we review the effects of hearing loss on neural systems supporting spoken language comprehension, beginning with age-related physiological decline. We suggest that listeners recruit domain general executive systems to maintain successful communication when the auditory signal is degraded, but that this compensatory processing has behavioral consequences: even relatively mild levels of hearing loss can lead to cascading cognitive effects that impact perception, comprehension, and memory, leading to increased listening effort during speech comprehension.

  7. Consciousness as a state of matter

    NASA Astrophysics Data System (ADS)

    Tegmark, Max

    2015-07-01

    I examine the hypothesis that consciousness can be understood as a state of matter, "perceptronium", with distinctive information processing abilities. I explore five basic principles that may distinguish conscious matter from other physical systems such as solids, liquids and gases: the information, integration, independence, dynamics and utility principles. This approach generalizes Giulio Tononi's integrated information framework for neural-network-based consciousness to arbitrary quantum systems, and provides interesting links to error-correcting codes and condensed matter criticality, as well as an interesting connections between the emergence of consciousness and the emergence of time. (For more technical details, see arXiv:1401.1219).

  8. The compatibility between sociological and cognitive neuroscientific ideas on consciousness: is a neurosociology of consciousness possible?

    PubMed

    Shkurko, Yulia S

    2013-03-01

    This article considers the possibility of integrating sociological and cognitive neuroscience ideas on consciousness and developing a new research area: neurosociology of consciousnesses. Research was conducted taking into account the limited knowledge on consciousness produced in these disciplines and the necessity of finding ways to study the social roles concerning the neural correlates of consciousness. Applying several ideas on consciousness from these disciplines (intersubjectivity, close connection with collective forms representations, deriving awareness from the brain's processes, and so on), I show that it is difficult to reconcile the differences in the treatment of consciousness through the simple combination of the different ideas. The integration should be pursued in light of the neuroscientific findings concerning consciousness in different social contexts (role behavior, social interactions, and so on). In integrating the concepts, I predicted the role of time delay in conscious awareness in decision making, synchronization of neural oscillations under conscious perception, and the activations of certain brain zones in correspondence to different conscious cognitive processes for understanding in face-to-face situations. The study reveals that the optimal path for neurosociological research on consciousness is in its primary development without a rigid binding to either sociology or neuroscience.

  9. Neural mechanisms and management of obesity-related hypertension.

    PubMed

    Esler, Murray D; Eikelis, Nina; Lambert, Elisabeth; Straznicky, Nora

    2008-11-01

    The sympathetic nervous system is activated in human obesity and in the analogous experimental obesity produced by overfeeding. The causes remain uncertain and may be multiple. The consequences include hypertension, probably attributable to activation of the sympathetic outflow to the kidneys, and, more disputed, insulin resistance. The pattern of sympathetic activation in normal-weight and obesity-related hypertension differs in terms of the firing characteristics of individual sympathetic fibers (increased rate of nerve firing in normal-weight hypertensives, increased number of active fibers firing at a normal rate in obesity-hypertension) and the sympathetic outflows involved. The underlying mechanisms and the adverse consequences of the two modes of sympathetic activation may differ. Should antihypertensive drug therapy in obesity-hypertension specifically target the existing neural pathophysiology? Such an approach can be advocated on theoretical grounds. Perhaps more important is the requirement that chosen antihypertensives do not cause weight gain or insulin resistance.

  10. New evidence of animal consciousness.

    PubMed

    Griffin, Donald R; Speck, Gayle B

    2004-01-01

    This paper reviews evidence that increases the probability that many animals experience at least simple levels of consciousness. First, the search for neural correlates of consciousness has not found any consciousness-producing structure or process that is limited to human brains. Second, appropriate responses to novel challenges for which the animal has not been prepared by genetic programming or previous experience provide suggestive evidence of animal consciousness because such versatility is most effectively organized by conscious thinking. For example, certain types of classical conditioning require awareness of the learned contingency in human subjects, suggesting comparable awareness in similarly conditioned animals. Other significant examples of versatile behavior suggestive of conscious thinking are scrub jays that exhibit all the objective attributes of episodic memory, evidence that monkeys sometimes know what they know, creative tool-making by crows, and recent interpretation of goal-directed behavior of rats as requiring simple nonreflexive consciousness. Third, animal communication often reports subjective experiences. Apes have demonstrated increased ability to use gestures or keyboard symbols to make requests and answer questions; and parrots have refined their ability to use the imitation of human words to ask for things they want and answer moderately complex questions. New data have demonstrated increased flexibility in the gestural communication of swarming honey bees that leads to vitally important group decisions as to which cavity a swarm should select as its new home. Although no single piece of evidence provides absolute proof of consciousness, this accumulation of strongly suggestive evidence increases significantly the likelihood that some animals experience at least simple conscious thoughts and feelings. The next challenge for cognitive ethologists is to investigate for particular animals the content of their awareness and what life is

  11. Environmentally conscious patent histories

    NASA Astrophysics Data System (ADS)

    Crouch, Dennis D.; Crouch, Henry L.

    2004-02-01

    There is a need for investigators, legislators, and business leaders to understand the magnitude of innovation and discovery in the field of environmentally conscious technologies (ECTs). Knowledge of the "big picture" is important to providing a national and global account of actual environmental stewardship over the last twenty-five years. A recitation of the Environmental Protection Agency (EPA) supported Acts which have been enacted into law reveals one facet of the multifaceted dynamic of environmental consciousness. The popular discussion and debate, as well as partisan lobbying, which created the political forces leading to environmentally conscious legislation is another facet. A third facet is the corporate response to the threats and opportunities predicted by CEO"s and others through environmental scanning. This paper examines changes in environmentally conscious inventive effort by comparing data from United States Patents issued from 1976 through 2003. Patents are useful tool for measuring technological innovation because they are publicly available records of innovative activity. Although not all inventions result in patent applications, the monopoly rights granted on the invention give the inventor a strong incentive to obtain patents on any viable product or process. Among the results, we found a significant increase in patents relating to environmentally conscious products and processes during the period in question. Specifically, a dramatic increase in patent activity was seen for the decade of the 1990"s. Surprisingly, the patenting rate from 2000 to 2003 seems to have stabilized. Additionally public discussion of ECTs appears to have a positive impact on patent filings.

  12. Social power and approach-related neural activity.

    PubMed

    Boksem, Maarten A S; Smolders, Ruud; De Cremer, David

    2012-06-01

    It has been argued that power activates a general tendency to approach whereas powerlessness activates a tendency to inhibit. The assumption is that elevated power involves reward-rich environments, freedom and, as a consequence, triggers an approach-related motivational orientation and attention to rewards. In contrast, reduced power is associated with increased threat, punishment and social constraint and thereby activates inhibition-related motivation. Moreover, approach motivation has been found to be associated with increased relative left-sided frontal brain activity, while withdrawal motivation has been associated with increased right sided activations. We measured EEG activity while subjects engaged in a task priming either high or low social power. Results show that high social power is indeed associated with greater left-frontal brain activity compared to low social power, providing the first neural evidence for the theory that high power is associated with approach-related motivation. We propose a framework accounting for differences in both approach motivation and goal-directed behaviour associated with different levels of power.

  13. Consciousness Lost and Found: Subjective Experiences in an Unresponsive State

    ERIC Educational Resources Information Center

    Noreika, Valdas; Jylhankangas, Leila; Moro, Levente; Valli, Katja; Kaskinoro, Kimmo; Aantaa, Riku; Scheinin, Harry; Revonsuo, Antti

    2011-01-01

    Anesthetic-induced changes in the neural activity of the brain have been recently utilized as a research model to investigate the neural mechanisms of phenomenal consciousness. However, the anesthesiologic definition of consciousness as "responsiveness to the environment" seems to sidestep the possibility that an unresponsive individual may have…

  14. Unconscious high-level information processing: implication for neurobiological theories of consciousness.

    PubMed

    van Gaal, Simon; Lamme, Victor A F

    2012-06-01

    Theories about the neural correlates and functional relevance of consciousness have traditionally assigned a crucial role to the prefrontal cortex in generating consciousness as well as in orchestrating high-level conscious control over behavior. However, recent neuroscientific findings show that prefrontal cortex can be activated unconsciously. The depth, direction, and scope of these activations depend on several top-down factors such as the task being probed (task-set, strategy) and on (temporal/spatial) attention. Regardless, such activations-when mediated by feedforward activation only-do not lead to a conscious sensation. Although unconscious, these prefrontal activations are functional, in the sense that they are associated with behavioral effects of cognitive control, such as response inhibition, task switching, conflict monitoring, and error detection. These findings challenge the pivotal role of the prefrontal cortex in consciousness. Instead, it appears that specific brain areas (or cognitive modules) may support specific cognitive functions but that consciousness is independent of this. Conscious sensations arise only when the brain areas involved engage in recurrent interactions enabling the long-lasting exchange of information between brain regions. Moreover, recent evidence suggests that also the state of consciousness, for example, in vegetative state patients or during sleep and anesthesia, is closely related to the scope and extent of residual recurrent interactions among brain regions. PMID:21628675

  15. General and specific consciousness: a first-order representationalist approach

    PubMed Central

    Mehta, Neil; Mashour, George A.

    2013-01-01

    It is widely acknowledged that a complete theory of consciousness should explain general consciousness (what makes a state conscious at all) and specific consciousness (what gives a conscious state its particular phenomenal quality). We defend first-order representationalism, which argues that consciousness consists of sensory representations directly available to the subject for action selection, belief formation, planning, etc. We provide a neuroscientific framework for this primarily philosophical theory, according to which neural correlates of general consciousness include prefrontal cortex, posterior parietal cortex, and non-specific thalamic nuclei, while neural correlates of specific consciousness include sensory cortex and specific thalamic nuclei. We suggest that recent data support first-order representationalism over biological theory, higher-order representationalism, recurrent processing theory, information integration theory, and global workspace theory. PMID:23882231

  16. The Problem of Consciousness.

    ERIC Educational Resources Information Center

    Crick, Francis; Koch, Christof

    1992-01-01

    Discusses approaches to the problem presented in understanding consciousness as a yet undiscovered process of interacting neuron activity. Presents the historical context of research in the area of human awareness and identifies research necessary to scientifically explain how the brain relates to the mind. (MCO)

  17. Weight-related actual and ideal self-states, discrepancies, and shame, guilt, and pride: examining associations within the process model of self-conscious emotions.

    PubMed

    Castonguay, Andree L; Brunet, Jennifer; Ferguson, Leah; Sabiston, Catherine M

    2012-09-01

    The aim of this study was to examine the associations between women's actual:ideal weight-related self-discrepancies and experiences of weight-related shame, guilt, and authentic pride using self-discrepancy (Higgins, 1987) and self-conscious emotion (Tracy & Robins, 2004) theories as guiding frameworks. Participants (N=398) completed self-report questionnaires. Main analyses involved polynomial regressions, followed by the computation and evaluation of response surface values. Actual and ideal weight self-states were related to shame (R2 = .35), guilt (R2 = .25), and authentic pride (R2 = .08). When the discrepancy between actual and ideal weights increased, shame and guilt also increased, while authentic pride decreased. Findings provide partial support for self-discrepancy theory and the process model of self-conscious emotions. Experiencing weight-related self-discrepancies may be important cognitive appraisals related to shame, guilt, and authentic pride. Further research is needed exploring the relations between self-discrepancies and a range of weight-related self-conscious emotions.

  18. From affective blindsight to emotional consciousness.

    PubMed

    Celeghin, Alessia; de Gelder, Beatrice; Tamietto, Marco

    2015-11-01

    Following destruction or denervation of the primary visual cortex (V1) cortical blindness ensues. Affective blindsight refers to the uncanny ability of such patients to respond correctly, or above chance level, to visual emotional expressions presented to their blind fields. Fifteen years after its original discovery, affective blindsight still fascinates neuroscientists and philosophers alike, as it offers a unique window on the vestigial properties of our visual system that, though present in the intact brain, tend to be unnoticed or even actively inhibited by conscious processes. Here we review available studies on affective blindsight with the intent to clarify its functional properties, neural bases and theoretical implications. Evidence converges on the role of subcortical structures of old evolutionary origin such as the superior colliculus, the pulvinar and the amygdala in mediating affective blindsight and nonconscious perception of emotions. We conclude that approaching consciousness, and its absence, from the vantage point of emotion processing may uncover important relations between the two phenomena, as consciousness may have evolved as an evolutionary specialization to interact with others and become aware of their social and emotional expressions.

  19. A dual-process model of defense against conscious and unconscious death-related thoughts: an extension of terror management theory.

    PubMed

    Pyszczynski, T; Greenberg, J; Solomon, S

    1999-10-01

    Distinct defensive processes are activated by conscious and nonconscious but accessible thoughts of death. Proximal defenses, which entail suppressing death-related thoughts or pushing the problem of death into the distant future by denying one's vulnerability, are rational, threat-focused, and activated when thoughts of death are in current focal attention. Distal terror management defenses, which entail maintaining self-esteem and faith in one's cultural worldview, function to control the potential for anxiety that results from knowing that death is inevitable. These defenses are experiential, are not related to the problem of death in any semantic or logical way, and are increasingly activated as the accessibility of death-related thoughts increases, up to the point at which such thoughts enter consciousness and proximal threat-focused defenses are initiated. Experimental evidence for this analysis is presented.

  20. Neural correlates of obsessive-compulsive related dysfunctional beliefs.

    PubMed

    Alonso, Pino; Orbegozo, Arantxa; Pujol, Jesús; López-Solà, Clara; Fullana, Miquel Àngel; Segalàs, Cinto; Real, Eva; Subirà, Marta; Martínez-Zalacaín, Ignacio; Menchón, José M; Harrison, Ben J; Cardoner, Narcís; Soriano-Mas, Carles

    2013-12-01

    There have been few attempts to integrate neurobiological and cognitive models of obsessive-compulsive disorder (OCD), although this might constitute a key approach to clarify the complex etiology of the disorder. Our study aimed to explore the neural correlates underlying dysfunctional beliefs hypothesized by cognitive models to be involved in the development and maintenance of OCD. We obtained a high-resolution magnetic resonance image from fifty OCD patients and 30 healthy controls, and correlated them, voxel-wise, with the severity of OC-related dysfunctional beliefs assessed by the Obsessive Beliefs Questionnaire-44. In healthy controls, significant negative correlations were observed between anterior temporal lobe (ATL) volume and scores on perfectionism/intolerance of uncertainty and overimportance/need to control thoughts. No significant correlations between OBQ-44 domains and regional gray matter volumes were observed in OCD patients. A post-hoc region-of-interest analysis detected that the ATLs was bilaterally smaller in OCD patients. On splitting subjects into high- and low-belief subgroups, we observed that such brain structural differences between OCD patients and healthy controls were explained by significantly larger ATL volumes among healthy subjects from the low-belief subgroup. Our results suggest a significant correlation between OC-related dysfunctional beliefs and morphometric variability in the anterior temporal lobe, a brain structure related to socio-emotional processing. Future studies should address the interaction of these correlations with environmental factors to fully characterize the bases of OC-related dysfunctional beliefs and to advance in the integration of biological and cognitive models of OCD.

  1. Time to Loss of Consciousness and Its Relation to Behavior in Slaughter Pigs during Stunning with 80 or 95% Carbon Dioxide

    PubMed Central

    Verhoeven, Merel; Gerritzen, Marien; Velarde, Antonio; Hellebrekers, Ludo; Kemp, Bas

    2016-01-01

    Exposure to CO2 at high concentration is a much debated stunning method in pigs. Pigs respond aversively to high concentrations of CO2, and there is uncertainty about what behaviors occur before and after loss of consciousness. The aim was to assess timing of unconsciousness in pigs during exposure to high concentrations of CO2 based on changes in electroencephalogram (EEG) activity and the relation with the behaviors sniffing, retreat and escape attempts, lateral head movements, jumping, muscular contractions, loss of posture, and gasping. Pigs (108 ± 9 kg) were randomly assigned to 80% CO2 (80C, n = 24) or 95% CO2 (95C, n = 24). The time at which the gondola started descending into the well pre-filled with 80C or 95C was marked as T = 0. The CO2 exposure lasted 346 s after which the corneal reflex and breathing were assessed for 1 min. Visual assessment of changes in the amplitude and frequency of EEG traces after T = 0 was used to determine loss of consciousness. Time to loss of consciousness was longer in 80C pigs (47 ± 6 s) than in 95C pigs (33 ± 7 s). Time to an iso-electric EEG was similar in 80C pigs (75 ± 23 s) and 95C pigs (64 ± 32 s). When pigs descended into the well, the earlier entry of 95C pigs into high CO2 atmosphere rather than the concentration of CO2 by itself affected the latency of behavioral responses and decreasing brain activity. During exposure to the gas, 80C and 95C pigs exhibited sniffing, retreat attempts, lateral head movements, jumping, and gasping before loss of consciousness. 95C pigs exhibited all these behaviors on average earlier than 80C pigs after T = 0. But the interval between onset of these behaviors and loss of consciousness and the duration of these behaviors, except gasping, was similar for both treatments. Loss of posture was on average observed in both groups 10 s before EEG-based loss of consciousness. Furthermore, 88% of 80C pigs and 94% of 95C pigs

  2. Time to Loss of Consciousness and Its Relation to Behavior in Slaughter Pigs during Stunning with 80 or 95% Carbon Dioxide.

    PubMed

    Verhoeven, Merel; Gerritzen, Marien; Velarde, Antonio; Hellebrekers, Ludo; Kemp, Bas

    2016-01-01

    Exposure to CO2 at high concentration is a much debated stunning method in pigs. Pigs respond aversively to high concentrations of CO2, and there is uncertainty about what behaviors occur before and after loss of consciousness. The aim was to assess timing of unconsciousness in pigs during exposure to high concentrations of CO2 based on changes in electroencephalogram (EEG) activity and the relation with the behaviors sniffing, retreat and escape attempts, lateral head movements, jumping, muscular contractions, loss of posture, and gasping. Pigs (108 ± 9 kg) were randomly assigned to 80% CO2 (80C, n = 24) or 95% CO2 (95C, n = 24). The time at which the gondola started descending into the well pre-filled with 80C or 95C was marked as T = 0. The CO2 exposure lasted 346 s after which the corneal reflex and breathing were assessed for 1 min. Visual assessment of changes in the amplitude and frequency of EEG traces after T = 0 was used to determine loss of consciousness. Time to loss of consciousness was longer in 80C pigs (47 ± 6 s) than in 95C pigs (33 ± 7 s). Time to an iso-electric EEG was similar in 80C pigs (75 ± 23 s) and 95C pigs (64 ± 32 s). When pigs descended into the well, the earlier entry of 95C pigs into high CO2 atmosphere rather than the concentration of CO2 by itself affected the latency of behavioral responses and decreasing brain activity. During exposure to the gas, 80C and 95C pigs exhibited sniffing, retreat attempts, lateral head movements, jumping, and gasping before loss of consciousness. 95C pigs exhibited all these behaviors on average earlier than 80C pigs after T = 0. But the interval between onset of these behaviors and loss of consciousness and the duration of these behaviors, except gasping, was similar for both treatments. Loss of posture was on average observed in both groups 10 s before EEG-based loss of consciousness. Furthermore, 88% of 80C pigs and 94% of 95C pigs

  3. The consciousness state space (CSS)—a unifying model for consciousness and self

    PubMed Central

    Berkovich-Ohana, Aviva; Glicksohn, Joseph

    2014-01-01

    Every experience, those we are aware of and those we are not, is embedded in a subjective timeline, is tinged with emotion, and inevitably evokes a certain sense of self. Here, we present a phenomenological model for consciousness and selfhood which relates time, awareness, and emotion within one framework. The consciousness state space (CSS) model is a theoretical one. It relies on a broad range of literature, hence has high explanatory and integrative strength, and helps in visualizing the relationship between different aspects of experience. Briefly, it is suggested that all phenomenological states fall into two categories of consciousness, core and extended (CC and EC, respectively). CC supports minimal selfhood that is short of temporal extension, its scope being the here and now. EC supports narrative selfhood, which involves personal identity and continuity across time, as well as memory, imagination and conceptual thought. The CSS is a phenomenological space, created by three dimensions: time, awareness and emotion. Each of the three dimensions is shown to have a dual phenomenological composition, falling within CC and EC. The neural spaces supporting each of these dimensions, as well as CC and EC, are laid out based on the neuroscientific literature. The CSS dynamics include two simultaneous trajectories, one in CC and one in EC, typically antagonistic in normal experiences. However, this characteristic behavior is altered in states in which a person experiences an altered sense of self. Two examples are laid out, flow and meditation. The CSS model creates a broad theoretical framework with explanatory and unificatory power. It constructs a detailed map of the consciousness and selfhood phenomenology, which offers constraints for the science of consciousness. We conclude by outlining several testable predictions raised by the CSS model. PMID:24808870

  4. Dogs cannot bark: event-related brain responses to true and false negated statements as indicators of higher-order conscious processing.

    PubMed

    Herbert, Cornelia; Kübler, Andrea

    2011-01-01

    The present study investigated event-related brain potentials elicited by true and false negated statements to evaluate if discrimination of the truth value of negated information relies on conscious processing and requires higher-order cognitive processing in healthy subjects across different levels of stimulus complexity. The stimulus material consisted of true and false negated sentences (sentence level) and prime-target expressions (word level). Stimuli were presented acoustically and no overt behavioral response of the participants was required. Event-related brain potentials to target words preceded by true and false negated expressions were analyzed both within group and at the single subject level. Across the different processing conditions (word pairs and sentences), target words elicited a frontal negativity and a late positivity in the time window from 600-1000 msec post target word onset. Amplitudes of both brain potentials varied as a function of the truth value of the negated expressions. Results were confirmed at the single-subject level. In sum, our results support recent suggestions according to which evaluation of the truth value of a negated expression is a time- and cognitively demanding process that cannot be solved automatically, and thus requires conscious processing. Our paradigm provides insight into higher-order processing related to language comprehension and reasoning in healthy subjects. Future studies are needed to evaluate if our paradigm also proves sensitive for the detection of consciousness in non-responsive patients.

  5. Conscious attention, meditation, and bilateral information transfer.

    PubMed

    Bob, Petr; Zimmerman, Elizabeth M; Hamilton, Elizabeth A; Sheftel, Jenna G; Bajo, Stephanie D; Raboch, Jiri; Golla, Megan; Konopka, Lukasz M

    2013-01-01

    Recent findings indicate that conscious attention is related to large-scale information integration of various brain regions, including both hemispheres, that enables integration of parallel distributed modalities of processed information. There is also evidence that the level of information transference related to integration or splitting among brain regions, and between hemispheres, establishes a certain level of efficiency of the information processing. The level of information transference also may have modulatory influences on attentional capacity that are closely linked to the emotional arousal and autonomic response related to a stimulus. These findings suggest a hypothesis that changes in conscious attention, specifically during meditation could be reflected in the autonomic activity as the left-right information transference calculated from bilateral electrodermal activity (EDA). With the aim to compare conscious attention during meditation with other attentional states (resting state, Stroop task, and memory task), we performed bilateral EDA measurement in 7 healthy persons during resting state, Stroop task, neurofeedback memory test, and meditation. The results indicate that the information transference (ie, transinformation) is able to distinguish those attentional states, and that the highest level of the transinformation has been found during attentional processing related to meditation, indicating higher level of connectivity between left and right sides. Calculations other than pointwise transinformation (PTI) performed on EDA records, such as mean skin conductance level or laterality index, were not able to distinguish attentional states. The results suggest that PTI may present an interesting method useful for the assessment of information flow, related to neural functioning, that in the case of meditation may reflect typical integrative changes in the autonomic nervous system related to brain functions and focused attentional processing.

  6. Probing ERP correlates of verbal semantic processing in patients with impaired consciousness.

    PubMed

    Rohaut, Benjamin; Faugeras, Frédéric; Chausson, Nicolas; King, Jean-Rémi; Karoui, Imen El; Cohen, Laurent; Naccache, Lionel

    2015-01-01

    Our ability to identify covert cognitive abilities in non-communicating patients is of prime importance to improve diagnosis, to guide therapeutic decisions and to better predict their cognitive outcome. In the present study, we used a basic and rigorous paradigm contrasting pairs of words orthogonally. This paradigm enables the probing of semantic processing by comparing neural activity elicited by similar words delivered in various combinations. We describe the respective timing, topography and estimated cortical sources of two successive event-related potentials (ERP) components (N400 and late positive component (LPC)) using high-density EEG in conscious controls (N=20) and in minimally conscious (MCS; N=15) and vegetative states (VS; N=15) patients recorded at bedside. Whereas N400-like ERP components could be observed in the VS, MCS and conscious groups, only MCS and conscious groups showed a LPC response, suggesting that this late effect could be a potential specific marker of conscious semantic processing. This result is coherent with recent findings disentangling early and local non-conscious responses (e.g.: MMN in odd-ball paradigms, N400 in semantic violation paradigms) from late, distributed and conscious responses (e.g.: P3b to auditory rule violation) in controls and in patients with disorders of consciousness. However, N400 and LPC responses were not easily observed at the individual level, - even in conscious controls - , with standard ERP analyses, which is a limiting factor for its clinical use. Of potential interest, the only 3 patients presenting both significant N400 and LPC effects were MCS, and 2 of them regained consciousness and functional language abilities.

  7. Sensory-related neural activity regulates the structure of vascular networks in the cerebral cortex

    PubMed Central

    Lacoste, Baptiste; Comin, Cesar H.; Ben-Zvi, Ayal; Kaeser, Pascal S.; Xu, Xiaoyin; Costa, Luciano da F.; Gu, Chenghua

    2014-01-01

    SUMMARY Neurovascular interactions are essential for proper brain function. While the effect of neural activity on cerebral blood flow has been extensively studied, whether neural activity influences vascular patterning remains elusive. Here, we demonstrate that neural activity promotes the formation of vascular networks in the early postnatal mouse barrel cortex. Using a combination of genetics, imaging, and computational tools to allow simultaneous analysis of neuronal and vascular components, we found that vascular density and branching were decreased in the barrel cortex when sensory input was reduced by either a complete deafferentation, a genetic impairment of neurotransmitter release at thalamocortical synapses, or a selective reduction of sensory-related neural activity by whisker plucking. In contrast, enhancement of neural activity by whisker stimulation led to an increase in vascular density and branching. The finding that neural activity is necessary and sufficient to trigger alterations of vascular networks reveals a novel feature of neurovascular interactions. PMID:25155955

  8. Consciousness and Attention: On Sufficiency and Necessity

    PubMed Central

    van Boxtel, Jeroen J. A.; Tsuchiya, Naotsugu; Koch, Christof

    2010-01-01

    Recent research has slowly corroded a belief that selective attention and consciousness are so tightly entangled that they cannot be individually examined. In this review, we summarize psychophysical and neurophysiological evidence for a dissociation between top-down attention and consciousness. The evidence includes recent findings that show subjects can attend to perceptually invisible objects. More contentious is the finding that subjects can become conscious of an isolated object, or the gist of the scene in the near absence of top-down attention; we critically re-examine the possibility of “complete” absence of top-down attention. We also cover the recent flurry of studies that utilized independent manipulation of attention and consciousness. These studies have shown paradoxical effects of attention, including examples where top-down attention and consciousness have opposing effects, leading us to strengthen and revise our previous views. Neuroimaging studies with EEG, MEG, and fMRI are uncovering the distinct neuronal correlates of selective attention and consciousness in dissociative paradigms. These findings point to a functional dissociation: attention as analyzer and consciousness as synthesizer. Separating the effects of selective visual attention from those of visual consciousness is of paramount importance to untangle the neural substrates of consciousness from those for attention. PMID:21833272

  9. Science of consciousness and the hard problem

    SciTech Connect

    Stapp, H.P.

    1996-05-22

    Quantum theory is essentially a rationally coherent theory of the interaction of mind and matter, and it allows our conscious thoughts to play a causally efficacious and necessary role in brain dynamics. It therefore provides a natural basis, created by scientists, for the science of consciousness. As an illustration it is explained how the interaction of brain and consciousness can speed up brain processing, and thereby enhance the survival prospects of conscious organisms, as compared to similar organisms that lack consciousness. As a second illustration it is explained how, within the quantum framework, the consciously experienced {open_quotes}I{close_quotes} directs the actions of a human being. It is concluded that contemporary science already has an adequate framework for incorporating causally efficacious experimential events into the physical universe in a manner that: (1) puts the neural correlates of consciousness into the theory in a well defined way, (2) explains in principle how the effects of consciousness, per se, can enhance the survival prospects of organisms that possess it, (3) allows this survival effect to feed into phylogenetic development, and (4) explains how the consciously experienced {open_quotes}I{close_quotes} can direct human behaviour.

  10. The Estonian Self-Consciousness Scale and its relation to the five-factor model of personality.

    PubMed

    Realo, A; Allik, J

    1998-02-01

    The Self-Consciousness Scale (SCS), developed by Fenigstein, Scheier, and Buss (1975), was adapted to the Estonian language. In general, the results supported the 3-factor structure of the SCS. However, many items in the subscales did not load as expected. A 26-item modified scale, the Estonian SCS (ESCS), is presented. A joint factor analysis of the ESCS and the NEO Personality Inventory (NEO-PI) scales led to a 5-factor solution, where all the factors that emerged were identified as the Big Five personality dimensions, the ESCS subscales loading most significantly on 3 of these factors: Neuroticism (N), Extraversion (E), and Openness to Experience (O). Correlation analysis revealed a pattern of correlations, characterized by the strongest associations between Social Anxiety and E (r = -.77), Public Self-Consciousness (PubSC) and N (r = .40), and Private Self-Consciousness (PrivSC) and O (r = .34), which quite well corresponds to the pattern of correlations that was reported for the original versions of the SCS and the NEO-PI (Zuckerman, Kuhlman, Joireman, Teta, & Kraft, 1993). We can conclude that all the SCS subscales can be sufficiently well interpreted in terms of the Big Five model of personality dimensions--PrivSC and PubSC appear to describe some variations of the Big Five themes that are not fully elaborated by the NEO-PI rather than being completely independent domains of individual differences. PMID:9615427

  11. The Estonian Self-Consciousness Scale and its relation to the five-factor model of personality.

    PubMed

    Realo, A; Allik, J

    1998-02-01

    The Self-Consciousness Scale (SCS), developed by Fenigstein, Scheier, and Buss (1975), was adapted to the Estonian language. In general, the results supported the 3-factor structure of the SCS. However, many items in the subscales did not load as expected. A 26-item modified scale, the Estonian SCS (ESCS), is presented. A joint factor analysis of the ESCS and the NEO Personality Inventory (NEO-PI) scales led to a 5-factor solution, where all the factors that emerged were identified as the Big Five personality dimensions, the ESCS subscales loading most significantly on 3 of these factors: Neuroticism (N), Extraversion (E), and Openness to Experience (O). Correlation analysis revealed a pattern of correlations, characterized by the strongest associations between Social Anxiety and E (r = -.77), Public Self-Consciousness (PubSC) and N (r = .40), and Private Self-Consciousness (PrivSC) and O (r = .34), which quite well corresponds to the pattern of correlations that was reported for the original versions of the SCS and the NEO-PI (Zuckerman, Kuhlman, Joireman, Teta, & Kraft, 1993). We can conclude that all the SCS subscales can be sufficiently well interpreted in terms of the Big Five model of personality dimensions--PrivSC and PubSC appear to describe some variations of the Big Five themes that are not fully elaborated by the NEO-PI rather than being completely independent domains of individual differences.

  12. Volition and the Function of Consciousness

    NASA Astrophysics Data System (ADS)

    Lau, Hakwan C.

    What are the psychological functions that could only be performed consciously? People have intuitively assumed that many acts of volition are not influenced by unconscious information. These acts range from simple examples such as making a spontaneous motor movement, to higher cognitive control. How ever, the available evidence suggests that under suitable conditions, unconscious information can influence these behaviors and the underlying neural mechanisms. One possibility is that stimuli that are consciously perceived tend to yield strong signals in the brain, which makes us think that consciousness has the function of such strong signals. However, if we could create conditions where the stimuli could yield strong signals but not the conscious experience of perception, perhaps we would find that such stimuli are just as effective in influencing volitional be havior. Future studies that focus on clarifying this issue may tell us what the defining functions of consciousness are.

  13. Neural stem cells could serve as a therapeutic material for age-related neurodegenerative diseases.

    PubMed

    Suksuphew, Sarawut; Noisa, Parinya

    2015-03-26

    Progressively loss of neural and glial cells is the key event that leads to nervous system dysfunctions and diseases. Several neurodegenerative diseases, for instance Alzheimer's disease, Parkinson's disease, and Huntington's disease, are associated to aging and suggested to be a consequence of deficiency of neural stem cell pool in the affected brain regions. Endogenous neural stem cells exist throughout life and are found in specific niches of human brain. These neural stem cells are responsible for the regeneration of new neurons to restore, in the normal circumstance, the functions of the brain. Endogenous neural stem cells can be isolated, propagated, and, notably, differentiated to most cell types of the brain. On the other hand, other types of stem cells, such as mesenchymal stem cells, embryonic stem cells, and induced pluripotent stem cells can also serve as a source for neural stem cell production, that hold a great promise for regeneration of the brain. The replacement of neural stem cells, either endogenous or stem cell-derived neural stem cells, into impaired brain is highly expected as a possible therapeutic mean for neurodegenerative diseases. In this review, clinical features and current routinely treatments of age-related neurodegenerative diseases are documented. Noteworthy, we presented the promising evidence of neural stem cells and their derivatives in curing such diseases, together with the remaining challenges to achieve the best outcome for patients.

  14. Increased functional connectivity between superior colliculus and brain regions implicated in bodily self-consciousness during the rubber hand illusion.

    PubMed

    Olivé, Isadora; Tempelmann, Claus; Berthoz, Alain; Heinze, Hans-Joachim

    2015-02-01

    Bodily self-consciousness refers to bodily processes operating at personal, peripersonal, and extrapersonal spatial dimensions. Although the neural underpinnings of representations of personal and peripersonal space associated with bodily self-consciousness were thoroughly investigated, relatively few is known about the neural underpinnings of representations of extrapersonal space relevant for bodily self-consciousness. In the search to unravel brain structures generating a representation of the extrapersonal space relevant for bodily self-consciousness, we developed a functional magnetic resonance imaging (fMRI) study to investigate the implication of the superior colliculus (SC) in bodily illusions, and more specifically in the rubber hand illusion (RHi), which constitutes an established paradigm to study the neural underpinnings of bodily self-consciousness. We observed activation of the colliculus ipsilateral to the manipulated hand associated with eliciting of RHi. A generalized form of context-dependent psychophysiological interaction analysis unravelled increased illusion-dependent functional connectivity between the SC and some of the main brain areas previously involved in bodily self-consciousness: right temporoparietal junction (rTPJ), bilateral ventral premotor cortex (vPM), and bilateral postcentral gyrus. We hypothesize that the collicular map of the extrapersonal space interacts with maps of the peripersonal and personal space generated at rTPJ, vPM and the postcentral gyrus, producing a unified representation of space that is relevant for bodily self-consciousness. We suggest that processes of multisensory integration of bodily-related sensory inputs located in this unified representation of space constitute one main factor underpinning emergence of bodily self-consciousness.

  15. Rewards and punishments, goal-directed behavior and consciousness.

    PubMed

    Ressler, Newton

    2004-03-01

    A parsimonious account of consciousness is given in which it emerges as a direct consequence of basic neural processes without the necessity of any higher order system. In this model, pleasant or unpleasant conscious feelings of various stimuli in the environment stem from their higher order associations to innate rewards or punishments. When a conditioned stimulus (CS) is associated with a reward, it acquires pleasant feelings due to the temporal correlation of the activations representing its sensory features with those representing innate visceral reward acquisition processes. When the CS is associated with the punishment, it acquires unpleasant feelings due to the correlation of its sensory features with the innate visceral inhibition of punishment acquisition processes. The correlations involve coherent activity between the sensory cortex, the limbic system, the orbital and medial prefrontal cortex, and more lateral prefrontal areas where stimuli can be incorporated into working memory. A conscious act involves responses (or attempts to improve the environment) made on the basis of the feelings of such stimuli. Covert memory scans, in which comparisons are made of the reward and punishment associations of the outcomes of previous responses, are related to the motivations and attention behind the conscious selection of a current response. This model appears to fit together various empirical observations. Its relations to some higher or more abstract mental processes, and some evolutionary implications are discussed. PMID:15036931

  16. The conscious access hypothesis: Explaining the consciousness

    PubMed Central

    Prakash, Ravi

    2008-01-01

    The phenomenon of conscious awareness or consciousness is complicated but fascinating. Although this concept has intrigued the mankind since antiquity, exploration of consciousness from scientific perspectives is not very old. Among myriad of theories regarding nature, functions and mechanism of consciousness, off late, cognitive theories have received wider acceptance. One of the most exciting hypotheses in recent times has been the “conscious access hypotheses” based on the “global workspace model of consciousness”. It underscores an important property of consciousness, the global access of information in cerebral cortex. Present article reviews the “conscious access hypothesis” in terms of its theoretical underpinnings as well as experimental supports it has received. PMID:19771300

  17. Delirium: a disorder of consciousness?

    PubMed

    Eeles, E M; Pandy, S; Ray, J L

    2013-04-01

    Delirium is recognised as a disorder of consciousness, however, no evidence has been previously generated to specifically address this premise. In order to evaluate this established notion, we have attempted to review consciousness, the components of consciousness and the emerging evidence for neuroanatomical correlates and then relate this to the recognized features of delirium. We have established that the level of awareness is modulated by alertness and arousal, focused by attention and has the ability to switch between the personal resonances of the experience to the precision of cognition. We have discussed consciousness's relationship with delirium and how the degree of integration of CNS function is mandatory for realisation of higher order function and this has implications for the conceptualisation and management of delirium. We have explored the understanding of downstream, components of consciousness as not giving rise to the full condition of delirium but as a subsyndromal state. We have argued that there is a need for future diagnostic criteria, such as DSM-V, to operationalize disturbance of consciousness together with non-cognitive manifestations of delirium. Intervention studies in delirium have focussed on drugs that improve memory (cholinesterase inhibitors). If memory is only one element of consciousness then we reason instead on evaluating the determinants of consciousness that may be modifiable, such as awareness. Reinforcement of environmental awareness by managing a patient within a low stimulus or familiar surrounding may therefore offer a therapeutic intervention. Overall there seemed support for, or no evidence against, the belief that delirium is a disorder of consciousness. From Descartes 'I think therefore I am' we can say 'I am aware not therefore delirious I am'.

  18. [Functional pathophysiology of consciousness].

    PubMed

    Jellinger, Kurt A

    2009-01-01

    from important somatic and sensory pathways and acts as a control system of neuronal activities of the cerebral cortex. The principal function of the ARAS is to focus our alertness on specific stimuli or internal processes, which run via complex neuronal cell groups and numerous neurotransmitters that influence various aspects of consciousness and wakefulness. Stimulation of the ARAS produces an arousal reaction as the electric correlate of consciousness; its destruction causes coma and related states. The highest level are cortical (prefrontal and association) networks for recognition, motor activity, longterm memory and attention, the left hemisphere being considered as the dominant one. Different levels of consciousness are distinguished: 1. hyperalertness, 2. alertness (normal state of wakefulness), 3. somnolence or lethargy, 4. obtundation with tendency to fall asleep, 5. stupor, 6. coma and its subtypes, like akinetic mutism, apallic syndrome or persistent vegative state, locked-in syndrome, delirium, and catatonia. They are caused by damages in various functional levels of the brain, by psychogenic factors or experimentally, and are accompanied by characteristic neurological and psychiatric disorders. The relevant morphological lesions can be detected by electrophysiological and imaging studies. The bases of functional anatomy and pathophysiology of consciousness, its cognitive aspects and its major disorders, their causes and functional substrates with reference to sleep and both spontaneous and iatrogenic disorders of consciousness are critically summarized.

  19. [Functional pathophysiology of consciousness].

    PubMed

    Jellinger, Kurt A

    2009-01-01

    from important somatic and sensory pathways and acts as a control system of neuronal activities of the cerebral cortex. The principal function of the ARAS is to focus our alertness on specific stimuli or internal processes, which run via complex neuronal cell groups and numerous neurotransmitters that influence various aspects of consciousness and wakefulness. Stimulation of the ARAS produces an arousal reaction as the electric correlate of consciousness; its destruction causes coma and related states. The highest level are cortical (prefrontal and association) networks for recognition, motor activity, longterm memory and attention, the left hemisphere being considered as the dominant one. Different levels of consciousness are distinguished: 1. hyperalertness, 2. alertness (normal state of wakefulness), 3. somnolence or lethargy, 4. obtundation with tendency to fall asleep, 5. stupor, 6. coma and its subtypes, like akinetic mutism, apallic syndrome or persistent vegative state, locked-in syndrome, delirium, and catatonia. They are caused by damages in various functional levels of the brain, by psychogenic factors or experimentally, and are accompanied by characteristic neurological and psychiatric disorders. The relevant morphological lesions can be detected by electrophysiological and imaging studies. The bases of functional anatomy and pathophysiology of consciousness, its cognitive aspects and its major disorders, their causes and functional substrates with reference to sleep and both spontaneous and iatrogenic disorders of consciousness are critically summarized. PMID:19573504

  20. Is there conscious choice in directed mutation, phenocopies, and related phenomena? An answer based on quantum measurement theory.

    PubMed

    Goswami, A; Todd, D

    1997-01-01

    In a previous article (Goswami, 1997), it was suggested that an application of quantum measurement theory under the auspices of a monistic idealist ontology (that consciousness is the ground of being) can solve many difficult problems of neo-Darwinism, e.g., alternating rapid creativity and homeostasis observed in evolution and the directionality, origin, and nature of life. In this article, we propose an epigenetic quantum mechanism to explain the connection of developmental processes and evolution, as has been evidenced in such controversial phenomena as directed mutation and phenocopies.

  1. Visual perception from the perspective of a representational, non-reductionistic, level-dependent account of perception and conscious awareness

    PubMed Central

    Overgaard, Morten; Mogensen, Jesper

    2014-01-01

    This article proposes a new model to interpret seemingly conflicting evidence concerning the correlation of consciousness and neural processes. Based on an analysis of research of blindsight and subliminal perception, the reorganization of elementary functions and consciousness framework suggests that mental representations consist of functions at several different levels of analysis, including truly localized perceptual elementary functions and perceptual algorithmic modules, which are interconnections of the elementary functions. We suggest that conscious content relates to the ‘top level’ of analysis in a ‘situational algorithmic strategy’ that reflects the general state of an individual. We argue that conscious experience is intrinsically related to representations that are available to guide behaviour. From this perspective, we find that blindsight and subliminal perception can be explained partly by too coarse-grained methodology, and partly by top-down enhancing of representations that normally would not be relevant to action. PMID:24639581

  2. How Do Theories of Cognition and Consciousness in Ancient Indian Thought Systems Relate to Current Western Theorizing and Research?

    PubMed Central

    Sedlmeier, Peter; Srinivas, Kunchapudi

    2016-01-01

    Unknown to most Western psychologists, ancient Indian scriptures contain very rich, empirically derived psychological theories that are, however, intertwined with religious and philosophical content. This article represents our attempt to extract the psychological theory of cognition and consciousness from a prominent ancient Indian thought system: Samkhya-Yoga. We derive rather broad hypotheses from this approach that may complement and extend Western mainstream theorizing. These hypotheses address an ancient personality theory, the effects of practicing the applied part of Samkhya-Yoga on normal and extraordinary cognition, as well as different ways of perceiving reality. We summarize empirical evidence collected (mostly without reference to the Indian thought system) in diverse fields of research that allows for making judgments about the hypotheses, and suggest more specific hypotheses to be examined in future research. We conclude that the existing evidence for the (broad) hypotheses is substantial but that there are still considerable gaps in theory and research to be filled. Theories of cognition contained in the ancient Indian systems have the potential to modify and complement existing Western mainstream accounts of cognition. In particular, they might serve as a basis for arriving at more comprehensive theories for several research areas that, so far, lack strong theoretical grounding, such as meditation research or research on aspects of consciousness. PMID:27014150

  3. How Do Theories of Cognition and Consciousness in Ancient Indian Thought Systems Relate to Current Western Theorizing and Research?

    PubMed

    Sedlmeier, Peter; Srinivas, Kunchapudi

    2016-01-01

    Unknown to most Western psychologists, ancient Indian scriptures contain very rich, empirically derived psychological theories that are, however, intertwined with religious and philosophical content. This article represents our attempt to extract the psychological theory of cognition and consciousness from a prominent ancient Indian thought system: Samkhya-Yoga. We derive rather broad hypotheses from this approach that may complement and extend Western mainstream theorizing. These hypotheses address an ancient personality theory, the effects of practicing the applied part of Samkhya-Yoga on normal and extraordinary cognition, as well as different ways of perceiving reality. We summarize empirical evidence collected (mostly without reference to the Indian thought system) in diverse fields of research that allows for making judgments about the hypotheses, and suggest more specific hypotheses to be examined in future research. We conclude that the existing evidence for the (broad) hypotheses is substantial but that there are still considerable gaps in theory and research to be filled. Theories of cognition contained in the ancient Indian systems have the potential to modify and complement existing Western mainstream accounts of cognition. In particular, they might serve as a basis for arriving at more comprehensive theories for several research areas that, so far, lack strong theoretical grounding, such as meditation research or research on aspects of consciousness.

  4. The Enigma of Consciousness

    NASA Astrophysics Data System (ADS)

    Goradia, Shantilal

    2012-03-01

    The natural log of the age of the universe, 10E60 Plank times, is about 137 which, of course, does not precisely relate to the fine structure constant for a reason proposed in physics/0210040 (Pl. read it first) and elaborated here. It may take, more or less, 10 Planck times for a particle to send a message, making nature's alphabet 2E10 = 1024 or one kilobyte. Not knowing the exact language of nature, we can approximate total messages between 10E59 and 10E60. Considering each message to be a probability gives the natural log of all probabilities closer to 137. Particles moving at relativist speeds create illusions of x dimensions for x Planck times per message. Number of such dimensions (say 6 or 10) may be message dependent, explaining why we need string theories with different dimensions. If particles send messages, consciousness originates in particles per my book ``Quantum Consciousness - The Road to Reality.'' The uncertainty to us is a result of us not understanding the conscious decision of the particles. This supplements my oral presentation.

  5. Consciousness, cognition and brain networks: New perspectives.

    PubMed

    Aldana, E M; Valverde, J L; Fábregas, N

    2016-10-01

    A detailed analysis of the literature on consciousness and cognition mechanisms based on the neural networks theory is presented. The immune and inflammatory response to the anesthetic-surgical procedure induces modulation of neuronal plasticity by influencing higher cognitive functions. Anesthetic drugs can cause unconsciousness, producing a functional disruption of cortical and thalamic cortical integration complex. The external and internal perceptions are processed through an intricate network of neural connections, involving the higher nervous activity centers, especially the cerebral cortex. This requires an integrated model, formed by neural networks and their interactions with highly specialized regions, through large-scale networks, which are distributed throughout the brain collecting information flow of these perceptions. Functional and effective connectivity between large-scale networks, are essential for consciousness, unconsciousness and cognition. It is what is called the "human connectome" or map neural networks.

  6. Consciousness, cognition and brain networks: New perspectives.

    PubMed

    Aldana, E M; Valverde, J L; Fábregas, N

    2016-10-01

    A detailed analysis of the literature on consciousness and cognition mechanisms based on the neural networks theory is presented. The immune and inflammatory response to the anesthetic-surgical procedure induces modulation of neuronal plasticity by influencing higher cognitive functions. Anesthetic drugs can cause unconsciousness, producing a functional disruption of cortical and thalamic cortical integration complex. The external and internal perceptions are processed through an intricate network of neural connections, involving the higher nervous activity centers, especially the cerebral cortex. This requires an integrated model, formed by neural networks and their interactions with highly specialized regions, through large-scale networks, which are distributed throughout the brain collecting information flow of these perceptions. Functional and effective connectivity between large-scale networks, are essential for consciousness, unconsciousness and cognition. It is what is called the "human connectome" or map neural networks. PMID:26143337

  7. Neural correlates of choice behavior related to impulsivity and venturesomeness.

    PubMed

    Hinvest, Neal S; Elliott, R; McKie, S; Anderson, Ian M

    2011-07-01

    Impulsivity has been associated with several psychiatric disorders including drug addiction and gambling. Impulsive subjects typically have a preference for short-term over long-term rewards and make risky choices. This study used functional magnetic resonance imaging (fMRI) to investigate the neural correlates of self-rated impulsivity and venturesomeness during tasks involving delayed and risky choice. A broader sampling approach was taken by recruiting participants with behaviors that have been linked to impulsivity (gambling N=15, and recreational drug use N=10) and those without these behaviors (N=9). Selection between delayed or probabilistic rewards was associated with activation in fronto-parietal regions in line with previous research. When selecting between delayed rewards, activity within the pregenual anterior cingulate cortex and ventrolateral prefrontal cortex correlated positively with impulsivity scores while activity within the orbitofrontal cortex, subgenual anterior cingulate cortex and caudate correlated positively with venturesomeness scores. Selection between probabilistic rewards revealed no correlation between scores and regional activations. The results from this study provide targets for future research investigating the neural substrates of impulsivity. They also provide targets for the further investigation into the pathophysiology of addiction and impulse-control disorders.

  8. The neurophysical basis of mind and consciousness

    NASA Astrophysics Data System (ADS)

    Beichler, James

    2012-04-01

    A living body is just a complex pattern of energetic particle exchanges to physicists when compared to the biochemical processes studied by chemists and biologists. New research has centered more upon the electric, magnetic and electromagnetic characteristics of life. It is easy to model mind and consciousness as the electric and magnetic counterparts of living organisms. Mind is an extremely complex electric scalar field pattern and consciousness is the corresponding magnetic vector potential field pattern. As humans, we may have the most complex and advanced mind and consciousness known, but all living organisms display mind and consciousness at various lower levels than our human mind and consciousness. Mind and consciousness have mistakenly become associated with the brain and no other part of the body because of the dense concentration of neurons in the brain. A strict study of the magnetic vector potential field patterns associated with neural microtubules, neurons and neural nets demonstrates how thoughts and streams of thought originate in the brain and are stored magnetically. Microtubules, which act as magnetic induction coils, are the primary structural bio-unit used for building, storing and retrieving memories in the mind.

  9. [Structure and function of neural plasticity-related gene products].

    PubMed

    Yamagata, K; Sugiura, H; Suzuki, K

    1998-08-01

    We have isolated novel immediate early genes (IEGs) from the hippocampus by differential cloning techniques. These mRNAs are induced by synaptic activity and translated into proteins that may affect neural function. We have analyzed a variety of "effector" immediate early genes. These mRNAs encode: 1) cytoplasmic proteins, such as cyclooxygenase-2, a small G protein, Rheb, and a cytoskeleton-associated protein, Arc; 2) membrane-bound proteins, such as the cell adhesion protein Arcadlin, and a neurite-outgrowth protein, Neuritin; and 3) a secreted protein, Narp. We hypothesize that physiological stimulation induces "effector" proteins that might strengthen synaptic connections of activated synapses. In contrast, pathological conditions such as epilepsy or drug addiction may accelerate overproduction of these gene products, which cause abnormal synapse formation. Gene targeting and in vivo gene transfer techniques are required to prove this hypothesis. PMID:9866829

  10. Hippocampal representation of related and opposing memories develop within distinct, hierarchically organized neural schemas.

    PubMed

    McKenzie, Sam; Frank, Andrea J; Kinsky, Nathaniel R; Porter, Blake; Rivière, Pamela D; Eichenbaum, Howard

    2014-07-01

    Recent evidence suggests that the hippocampus may integrate overlapping memories into relational representations, or schemas, that link indirectly related events and support flexible memory expression. Here we explored the nature of hippocampal neural population representations for multiple features of events and the locations and contexts in which they occurred. Hippocampal networks developed hierarchical organizations of associated elements of related but separately acquired memories within a context, and distinct organizations for memories where the contexts differentiated object-reward associations. These findings reveal neural mechanisms for the development and organization of relational representations.

  11. Feminist Consciousness and Objectified Body Consciousness

    ERIC Educational Resources Information Center

    McKinley, Nita Mary

    2011-01-01

    The author has been asked to write about how her article "The Objectified Body Consciousness Scale: Development and Validation" (McKinley & Hyde, 1996) came to be published in "Psychology of Women Quarterly" ("PWQ"). In this article, she recalls the contexts in which she developed her ideas about objectified body consciousness (OBC), the process…

  12. Extending Gurwitsch's field theory of consciousness.

    PubMed

    Yoshimi, Jeff; Vinson, David W

    2015-07-01

    Aron Gurwitsch's theory of the structure and dynamics of consciousness has much to offer contemporary theorizing about consciousness and its basis in the embodied brain. On Gurwitsch's account, as we develop it, the field of consciousness has a variable sized focus or "theme" of attention surrounded by a structured periphery of inattentional contents. As the field evolves, its contents change their status, sometimes smoothly, sometimes abruptly. Inner thoughts, a sense of one's body, and the physical environment are dominant field contents. These ideas can be linked with (and help unify) contemporary theories about the neural correlates of consciousness, inattention, the small world structure of the brain, meta-stable dynamics, embodied cognition, and predictive coding in the brain.

  13. Functional MRI and the study of human consciousness.

    PubMed

    Lloyd, Dan

    2002-08-15

    Functional brain imaging offers new opportunities for the study of that most pervasive of cognitive conditions, human consciousness. Since consciousness is attendant to so much of human cognitive life, its study requires secondary analysis of multiple experimental datasets. Here, four preprocessed datasets from the National fMRI Data Center are considered: Hazeltine et al., Neural activation during response competition; Ishai et al., The representation of objects in the human occipital and temporal cortex; Mechelli et al., The effects of presentation rate during word and pseudoword reading; and Postle et al., Activity in human frontal cortex associated with spatial working memory and saccadic behavior. The study of consciousness also draws from multiple disciplines. In this article, the philosophical subdiscipline of phenomenology provides initial characterization of phenomenal structures conceptually necessary for an analysis of consciousness. These structures include phenomenal intentionality, phenomenal superposition, and experienced temporality. The empirical predictions arising from these structures require new interpretive methods for their confirmation. These methods begin with single-subject (preprocessed) scan series, and consider the patterns of all voxels as potential multivariate encodings of phenomenal information. Twenty-seven subjects from the four studies were analyzed with multivariate methods, revealing analogues of phenomenal structures, particularly the structures of temporality. In a second interpretive approach, artificial neural networks were used to detect a more explicit prediction from phenomenology, namely, that present experience contains and is inflected by past states of awareness and anticipated events. In all of 21 subjects in this analysis, nets were successfully trained to extract aspects of relative past and future brain states, in comparison with statistically similar controls. This exploratory study thus concludes that the

  14. The psychology of consciousness.

    PubMed

    Chang, S C

    1978-01-01

    All psychologic phenomena occur in consciousness. However, "consciousness" has two meanings: the faculty and the content of awareness. Traditional psychologies have largely concerned themselves with the content, neglecting the problem of the faculty, thus, limiting our understanding of human psyche. Study of meditation is a viable approach to the exploration of both meanings of consciousness. Meditation aims at a "cleansing" of the mind to reach, thereby, a content-free and conflict-free state--pure consciousness.

  15. [Altered states of consciousness].

    PubMed

    Gora, E P

    2005-01-01

    The review of modern ideas concerning the altered states of consciousness is presented in this article. Various methods of entry into the altered states of consciousness are looked over. It is shown that the altered states of consciousness are insufficiently known, but important aspects of human being existence. The role of investigation of the altered states of consciousness for the creation of integrative scientific conception base is discussed.

  16. [Altered states of consciousness].

    PubMed

    Gora, E P

    2005-01-01

    The review of modern ideas concerning the altered states of consciousness is presented in this article. Various methods of entry into the altered states of consciousness are looked over. It is shown that the altered states of consciousness are insufficiently known, but important aspects of human being existence. The role of investigation of the altered states of consciousness for the creation of integrative scientific conception base is discussed. PMID:15810684

  17. Adult Palatum as a Novel Source of Neural Crest-Related Stem Cells

    PubMed Central

    Widera, Darius; Zander, Christin; Heidbreder, Meike; Kasperek, Yvonne; Noll, Thomas; Seitz, Oliver; Saldamli, Belma; Sudhoff, Holger; Sader, Robert; Kaltschmidt, Christian; Kaltschmidt, Barbara

    2009-01-01

    Somatic neural and neural crest stem cells are promising sources for cellular therapy of several neurodegenerative diseases. However, because of practical considerations such as inadequate accessibility of the source material, the application of neural crest stem cells is strictly limited. The secondary palate is a highly regenerative and heavily innervated tissue, which develops embryonically under direct contribution of neural crest cells. Here, we describe for the first time the presence of nestin-positive neural crest-related stem cells within Meissner corpuscles and Merkel cell-neurite complexes located in the hard palate of adult Wistar rats. After isolation, palatal neural crest-related stem cells (pNC-SCs) were cultivated in the presence of epidermal growth factor and fibroblast growth factor under serum-free conditions, resulting in large amounts of neurospheres. We used immunocytochemical techniques and reverse transcriptase-polymerase chain reaction to assess the expression profile of pNC-SCs. In addition to the expression of neural crest stem cell markers such as Nestin, Sox2, and p75, we detected the expression of Klf4, Oct4, and c-Myc. pNC-SCs differentiated efficiently into neuronal and glial cells. Finally, we investigated the potential expression of stemness markers within the human palate. We identified expression of stem cell markers nestin and CD133 and the transcription factors needed for reprogramming of somatic cells into pluripotent cells: Sox2, Oct4, Klf4, and c-Myc. These data show that cells isolated from palatal rugae form neurospheres, are highly plastic, and express neural crest stem cell markers. In addition, pNC-SCs may have the ability to differentiate into functional neurons and glial cells, serving as a starting point for therapeutic studies. Stem Cells 2009;27:1899–1910 PMID:19544446

  18. Nonneurocognitive Extended Consciousness

    ERIC Educational Resources Information Center

    Wojcik, Kevin; Chemero, Anthony

    2012-01-01

    One of the attributes necessary for Watson to be considered human is that it must be conscious. From Rachlin's (2012) point of view, that of teleological behaviorism, consciousness refers to the organization of behavioral complexity in which overt behavior is distributed widely over time. Consciousness is something that humans do, or achieve, in…

  19. A systematic review of the neural bases of psychotherapy for anxiety and related disorders.

    PubMed

    Brooks, Samantha J; Stein, Dan J

    2015-09-01

    Brain imaging studies over two decades have delineated the neural circuitry of anxiety and related disorders, particularly regions involved in fear processing and in obsessive-compulsive symptoms. The neural circuitry of fear processing involves the amygdala, anterior cingulate, and insular cortex, while cortico-striatal-thalamic circuitry plays a key role in obsessive-compulsive disorder. More recently, neuroimaging studies have examined how psychotherapy for anxiety and related disorders impacts on these neural circuits. Here we conduct a systematic review of the findings of such work, which yielded 19 functional magnetic resonance imaging studies examining the neural bases of cognitive-behavioral therapy (CBT) in 509 patients with anxiety and related disorders. We conclude that, although each of these related disorders is mediated by somewhat different neural circuitry, CBT may act in a similar way to increase prefrontal control of subcortical structures. These findings are consistent with an emphasis in cognitive-affective neuroscience on the potential therapeutic value of enhancing emotional regulation in various psychiatric conditions.

  20. A systematic review of the neural bases of psychotherapy for anxiety and related disorders.

    PubMed

    Brooks, Samantha J; Stein, Dan J

    2015-09-01

    Brain imaging studies over two decades have delineated the neural circuitry of anxiety and related disorders, particularly regions involved in fear processing and in obsessive-compulsive symptoms. The neural circuitry of fear processing involves the amygdala, anterior cingulate, and insular cortex, while cortico-striatal-thalamic circuitry plays a key role in obsessive-compulsive disorder. More recently, neuroimaging studies have examined how psychotherapy for anxiety and related disorders impacts on these neural circuits. Here we conduct a systematic review of the findings of such work, which yielded 19 functional magnetic resonance imaging studies examining the neural bases of cognitive-behavioral therapy (CBT) in 509 patients with anxiety and related disorders. We conclude that, although each of these related disorders is mediated by somewhat different neural circuitry, CBT may act in a similar way to increase prefrontal control of subcortical structures. These findings are consistent with an emphasis in cognitive-affective neuroscience on the potential therapeutic value of enhancing emotional regulation in various psychiatric conditions. PMID:26487807

  1. A systematic review of the neural bases of psychotherapy for anxiety and related disorders

    PubMed Central

    Brooks, Samantha J.; Stein, Dan J.

    2015-01-01

    Brain imaging studies over two decades have delineated the neural circuitry of anxiety and related disorders, particularly regions involved in fear processing and in obsessive-compulsive symptoms. The neural circuitry of fear processing involves the amygdala, anterior cingulate, and insular cortex, while cortico-striatal-thalamic circuitry plays a key role in obsessive-compulsive disorder. More recently, neuroimaging studies have examined how psychotherapy for anxiety and related disorders impacts on these neural circuits. Here we conduct a systematic review of the findings of such work, which yielded 19 functional magnetic resonance imaging studies examining the neural bases of cognitive-behavioral therapy (CBT) in 509 patients with anxiety and related disorders. We conclude that, although each of these related disorders is mediated by somewhat different neural circuitry, CBT may act in a similar way to increase prefrontal control of subcortical structures. These findings are consistent with an emphasis in cognitive-affective neuroscience on the potential therapeutic value of enhancing emotional regulation in various psychiatric conditions. PMID:26487807

  2. Differences in Feedback- and Inhibition-Related Neural Activity in Adult ADHD

    ERIC Educational Resources Information Center

    Dibbets, Pauline; Evers, Lisbeth; Hurks, Petra; Marchetta, Natalie; Jolles, Jelle

    2009-01-01

    The objective of this study was to examine response inhibition- and feedback-related neural activity in adults with attention deficit hyperactivity disorder (ADHD) using event-related functional MRI. Sixteen male adults with ADHD and 13 healthy/normal controls participated in this study and performed a modified Go/NoGo task. Behaviourally,…

  3. Causal estimation of neural and overall baroreflex sensitivity in relation to carotid artery stiffness.

    PubMed

    Lipponen, Jukka A; Tarvainen, Mika P; Laitinen, Tomi; Karjalainen, Pasi A; Vanninen, Joonas; Koponen, Timo; Laitinen, Tiina M

    2013-12-01

    Continuous electrocardiogram, blood pressure and carotid artery ultrasound video were analyzed from 15 diabetics and 28 healthy controls. By using these measurements artery elasticity, overall baroreflex sensitivity (BRS) assessed between RR and systolic blood pressure variation, and neural BRS assessed between RR and artery diameter variation were estimated. In addition, BRS was estimated using traditional and causal methods which enable separation of feedforward and feedback variation. The aim of this study was to analyze overall and neural BRS in relation to artery stiffness and to validate the causal BRS estimation method in assessing these two types of BRS within the study population. The most significant difference between the healthy and diabetic groups (p < 0.0007) was found for the overall BRS estimated using the causal method. The difference between the groups was also significant for neural BRS (p < 0.0018). However neural BRS was normal in some old diabetics, which indicates normal functioning of autonomic nervous system (ANS), even though the elasticity in arteries of these subjects was reduced. The noncausal method overestimated neural BRS in low BRS values when compared to causal BRS. In conclusion, neural BRS estimated using the causal method is proposed as the best marker of ANS functioning. PMID:24168896

  4. Contributions of magno- and parvocellular channels to conscious and non-conscious vision.

    PubMed

    Breitmeyer, Bruno G

    2014-05-01

    The dorsal and ventral cortical pathways, driven predominantly by magnocellular (M) and parvocellular (P) inputs, respectively, assume leading roles in models of visual information processing. Although in prior proposals, the dorsal and ventral pathways support non-conscious and conscious vision, respectively, recent modelling and empirical developments indicate that each pathway plays important roles in both non-conscious and conscious vision. In these models, the ventral P-pathway consists of one subpathway processing an object's contour features, e.g. curvature, the other processing its surface attributes, e.g. colour. Masked priming studies have shown that feed-forward activity in the ventral P-pathway on its own supports non-conscious processing of contour and surface features. The dorsal M-pathway activity contributes directly to conscious vision of motion and indirectly to object vision by projecting to prefrontal cortex, which in turn injects top-down neural activity into the ventral P-pathway and there 'ignites' feed-forward-re-entrant loops deemed necessary for conscious vision. Moreover, an object's shape or contour remains invisible without the prior conscious registration of its surface properties, which for that reason are taken to comprise fundamental visual qualia. Besides suggesting avenues for future research, these developments bear on several recent and past philosophical issues.

  5. Contributions of magno- and parvocellular channels to conscious and non-conscious vision

    PubMed Central

    Breitmeyer, Bruno G.

    2014-01-01

    The dorsal and ventral cortical pathways, driven predominantly by magnocellular (M) and parvocellular (P) inputs, respectively, assume leading roles in models of visual information processing. Although in prior proposals, the dorsal and ventral pathways support non-conscious and conscious vision, respectively, recent modelling and empirical developments indicate that each pathway plays important roles in both non-conscious and conscious vision. In these models, the ventral P-pathway consists of one subpathway processing an object's contour features, e.g. curvature, the other processing its surface attributes, e.g. colour. Masked priming studies have shown that feed-forward activity in the ventral P-pathway on its own supports non-conscious processing of contour and surface features. The dorsal M-pathway activity contributes directly to conscious vision of motion and indirectly to object vision by projecting to prefrontal cortex, which in turn injects top-down neural activity into the ventral P-pathway and there ‘ignites’ feed-forward–re-entrant loops deemed necessary for conscious vision. Moreover, an object's shape or contour remains invisible without the prior conscious registration of its surface properties, which for that reason are taken to comprise fundamental visual qualia. Besides suggesting avenues for future research, these developments bear on several recent and past philosophical issues. PMID:24639584

  6. Two theories of consciousness: Semantic pointer competition vs. information integration.

    PubMed

    Thagard, Paul; Stewart, Terrence C

    2014-11-01

    Consciousness results from three mechanisms: representation by firing patterns in neural populations, binding of representations into more complex representations called semantic pointers, and competition among semantic pointers to capture the most important aspects of an organism's current state. We contrast the semantic pointer competition (SPC) theory of consciousness with the hypothesis that consciousness is the capacity of a system to integrate information (IIT). We describe computer simulations to show that SPC surpasses IIT in providing better explanations of key aspects of consciousness: qualitative features, onset and cessation, shifts in experiences, differences in kinds across different organisms, unity and diversity, and storage and retrieval.

  7. Toward physics of the mind: Concepts, emotions, consciousness, and symbols

    NASA Astrophysics Data System (ADS)

    Perlovsky, Leonid I.

    2006-03-01

    Mathematical approaches to modeling the mind since the 1950s are reviewed, including artificial intelligence, pattern recognition, and neural networks. I analyze difficulties faced by these algorithms and neural networks and relate them to the fundamental inconsistency of logic discovered by Gödel. Mathematical discussions are related to those in neurobiology, psychology, cognitive science, and philosophy. Higher cognitive functions are reviewed including concepts, emotions, instincts, understanding, imagination, intuition, consciousness. Then, I describe a mathematical formulation, unifying the mind mechanisms in a psychologically and neuro-biologically plausible system. A mechanism of the knowledge instinct drives our understanding of the world and serves as a foundation for higher cognitive functions. This mechanism relates aesthetic emotions and perception of beauty to “everyday” functioning of the mind. The article reviews mechanisms of human symbolic ability. I touch on future directions: joint evolution of the mind, language, consciousness, and cultures; mechanisms of differentiation and synthesis; a manifold of aesthetic emotions in music and differentiated instinct for knowledge. I concentrate on elucidating the first principles; review aspects of the theory that have been proven in laboratory research, relationships between the mind and brain; discuss unsolved problems, and outline a number of theoretical predictions, which will have to be tested in future mathematical simulations and neuro-biological research.

  8. Impaired consciousness in epilepsy.

    PubMed

    Blumenfeld, Hal

    2012-09-01

    Consciousness is essential to normal human life. In epileptic seizures consciousness is often transiently lost, which makes it impossible for the individual to experience or respond. These effects have huge consequences for safety, productivity, emotional health, and quality of life. To prevent impaired consciousness in epilepsy, it is necessary to understand the mechanisms that lead to brain dysfunction during seizures. Normally the consciousness system-a specialised set of cortical-subcortical structures-maintains alertness, attention, and awareness. Advances in neuroimaging, electrophysiology, and prospective behavioural testing have shed light on how epileptic seizures disrupt the consciousness system. Diverse seizure types, including absence, generalised tonic-clonic, and complex partial seizures, converge on the same set of anatomical structures through different mechanisms to disrupt consciousness. Understanding of these mechanisms could lead to improved treatment strategies to prevent impairment of consciousness and improve the quality of life of people with epilepsy.

  9. Structural qualia: a solution to the hard problem of consciousness

    PubMed Central

    Loorits, Kristjan

    2014-01-01

    The hard problem of consciousness has been often claimed to be unsolvable by the methods of traditional empirical sciences. It has been argued that all the objects of empirical sciences can be fully analyzed in structural terms but that consciousness is (or has) something over and above its structure. However, modern neuroscience has introduced a theoretical framework in which also the apparently non-structural aspects of consciousness, namely the so called qualia or qualitative properties, can be analyzed in structural terms. That framework allows us to see qualia as something compositional with internal structures that fully determine their qualitative nature. Moreover, those internal structures can be identified which certain neural patterns. Thus consciousness as a whole can be seen as a complex neural pattern that misperceives some of its own highly complex structural properties as monadic and qualitative. Such neural pattern is analyzable in fully structural terms and thereby the hard problem is solved. PMID:24672510

  10. Slow cortical potentials and "inner time consciousness" - A neuro-phenomenal hypothesis about the "width of present".

    PubMed

    Northoff, Georg

    2016-05-01

    William James postulated a "stream of consciousness" that presupposes temporal continuity. The neuronal mechanisms underlying the construction of such temporal continuity remain unclear, however, in my contribution, I propose a neuro-phenomenal hypothesis that is based on slow cortical potentials and their extension of the present moment as described in the phenomenal term of "width of present". More specifically, I focus on the way the brain's neural activity needs to be encoded in order to make possible the "stream of consciousness." This leads us again to the low-frequency fluctuations of the brain's neural activity and more specifically to slow cortical potentials (SCPs). Due to their long phase duration as low-frequency fluctuations, SCPs can integrate different stimuli and their associated neural activity from different regions in one converging region. Such integration may be central for consciousness to occur, as it was recently postulated by He and Raichle. They leave open, however, the question of the exact neuronal mechanisms, like the encoding strategy, that make possible the association of the otherwise purely neuronal SCP with consciousness and its phenomenal features. I hypothesize that SCPs allow for linking and connecting different discrete points in physical time by encoding their statistically based temporal differences rather than the single discrete time points by themselves. This presupposes difference-based coding rather than stimulus-based coding. The encoding of such statistically based temporal differences makes it possible to "go beyond" the merely physical features of the stimuli; that is, their single discrete time points and their conduction delays (as related to their neural processing in the brain). This, in turn, makes possible the constitution of "local temporal continuity" of neural activity in one particular region. The concept of "local temporal continuity" signifies the linkage and integration of different discrete time points

  11. The Value and Disvalue of Consciousness.

    PubMed

    Glannon, Walter

    2016-10-01

    Consciousness defines us as persons. It allows us to have both pleasurable and painful experiences. I present four neurological conditions in the clinical setting to explore how consciousness can be beneficial or harmful to patients: intraoperative awareness, prolonged disorders of consciousness, locked-in syndrome, and the effects of narcotics and sedation on terminally ill patients. The ethical significance of consciousness for patients in these conditions depends on two factors: the content of one's experience and whether one can report this content to others. I argue that the value or disvalue of phenomenal consciousness, what it is like to be aware, may depend on its relation to access consciousness, the ability to report or communicate the content of awareness. Phenomenal consciousness can have disvalue when one wants or expects to be unconscious. It can also have disvalue in the absence of access consciousness because it can allow the patient to experience pain and suffer. Technology that enabled neurologically compromised patients to reliably communicate their experience and wishes could benefit and prevent harm to them. More generally, the neurological conditions I discuss raise the question of when and in what respects consciousness is preferable to unconsciousness. PMID:27634712

  12. The Value and Disvalue of Consciousness.

    PubMed

    Glannon, Walter

    2016-10-01

    Consciousness defines us as persons. It allows us to have both pleasurable and painful experiences. I present four neurological conditions in the clinical setting to explore how consciousness can be beneficial or harmful to patients: intraoperative awareness, prolonged disorders of consciousness, locked-in syndrome, and the effects of narcotics and sedation on terminally ill patients. The ethical significance of consciousness for patients in these conditions depends on two factors: the content of one's experience and whether one can report this content to others. I argue that the value or disvalue of phenomenal consciousness, what it is like to be aware, may depend on its relation to access consciousness, the ability to report or communicate the content of awareness. Phenomenal consciousness can have disvalue when one wants or expects to be unconscious. It can also have disvalue in the absence of access consciousness because it can allow the patient to experience pain and suffer. Technology that enabled neurologically compromised patients to reliably communicate their experience and wishes could benefit and prevent harm to them. More generally, the neurological conditions I discuss raise the question of when and in what respects consciousness is preferable to unconsciousness.

  13. Music and Consciousness: A Continuing Project

    ERIC Educational Resources Information Center

    Clarke, David; Clarke, Eric

    2014-01-01

    If there is a topic on which the humanities might make a distinctive claim, it is that of consciousness--an essential aspect of human being. And within the humanities, music might make its own claims in relation to both consciousness and being human. To investigate this connection, David Clarke and Eric Clarke brought together a wide variety of…

  14. Brain and conscious experience.

    PubMed

    Gazzaniga, M S

    1998-01-01

    brain possesses, the greater the awareness of capacities. Think of the variations in capacity within our own species; they are not unlike the vast differences between species. Years of split-brain research have informed us that the left hemisphere has many more mental capacities than the right one. The left is capable of logical feats that the right hemisphere cannot manage. Although the right has capacities such as facial recognition systems, it is a distant second with problem-solving skills. In short, the right hemisphere's level of awareness is limited. It knows precious little about a lot of things, but the limits to human capacity are everywhere in the population. No one need be offended to realize that just as someone with normal intelligence can understand Ohm's law, others, like yours truly, are clueless about Kepler's laws. I am ignorant about them and will remain so. I am unable to be aware about what they mean for the universe. The circuits that enable me to understand these things are not present in my brain. By emphasizing specialized circuits that arise from natural selection, we see that the brain is not a unified neural net that supports a general problem-solving device. With this being understood, we can concentrate on the possibility that smaller, more manageable circuits produce awareness of a species' capacities. Holding fast to the notion of a unified neural net means we can understand human conscious experience only by figuring out the interactions of billions of neurons. That task is hopeless. My scheme is not. Hence step 3. The very same split-brain research that exposed shocking differences between the two hemispheres also showed that the human left hemisphere has the interpreter. The left brain interpreter's job is to interpret our behavior and our responses, whether cognitive or emotional, to environmental challenges. It constantly establishes a running narrative of our actions, emotions, thoughts, and dreams. It is the glue that keeps our

  15. Brain and conscious experience.

    PubMed

    Gazzaniga, M S

    1998-01-01

    brain possesses, the greater the awareness of capacities. Think of the variations in capacity within our own species; they are not unlike the vast differences between species. Years of split-brain research have informed us that the left hemisphere has many more mental capacities than the right one. The left is capable of logical feats that the right hemisphere cannot manage. Although the right has capacities such as facial recognition systems, it is a distant second with problem-solving skills. In short, the right hemisphere's level of awareness is limited. It knows precious little about a lot of things, but the limits to human capacity are everywhere in the population. No one need be offended to realize that just as someone with normal intelligence can understand Ohm's law, others, like yours truly, are clueless about Kepler's laws. I am ignorant about them and will remain so. I am unable to be aware about what they mean for the universe. The circuits that enable me to understand these things are not present in my brain. By emphasizing specialized circuits that arise from natural selection, we see that the brain is not a unified neural net that supports a general problem-solving device. With this being understood, we can concentrate on the possibility that smaller, more manageable circuits produce awareness of a species' capacities. Holding fast to the notion of a unified neural net means we can understand human conscious experience only by figuring out the interactions of billions of neurons. That task is hopeless. My scheme is not. Hence step 3. The very same split-brain research that exposed shocking differences between the two hemispheres also showed that the human left hemisphere has the interpreter. The left brain interpreter's job is to interpret our behavior and our responses, whether cognitive or emotional, to environmental challenges. It constantly establishes a running narrative of our actions, emotions, thoughts, and dreams. It is the glue that keeps our

  16. Neural mechanisms underlying ecstasy-related attentional bias.

    PubMed

    Roberts, Gloria M P; Garavan, Hugh

    2013-08-30

    Conditioned responses to cues associated with drug taking play a pivotal role in a number of theories of drug addiction. This study examined whether attentional biases towards drug-related cues exist in recreational drug users who predominantly used ecstasy (3,4-methylenedioxymethamphetamine). Experiment 1 compared 30 ecstasy users, 25 cannabis users, and 30 controls in an attentional distraction task in which neutral, evocative, and ecstasy-related pictures were presented within a coloured border, requiring participants to respond as quickly as possible to the border colour. Experiment 2 employed functional magnetic resonance imaging (fMRI) and the attentional distraction task and tested 20 ecstasy users and 20 controls. Experiment 1 revealed significant response speed interference by the ecstasy-related pictures in the ecstasy users only. Experiment 2 revealed increased prefrontal and occipital activity in ecstasy users in all conditions. Activations in response to the ecstasy stimuli in these regions showed an apparent antagonism whereby ecstasy users, relative to controls, showed increased occipital but decreased right prefrontal activation. These results are interpreted to reflect increased visual processing of, and decreased prefrontal control over, the irrelevant but salient ecstasy-related stimuli. These results suggest that right inferior frontal cortex may play an important role in controlling drug-related attentional biases and may thus play an important role in mediating control over drug usage.

  17. Neural correlates of mindfulness meditation-related anxiety relief.

    PubMed

    Zeidan, Fadel; Martucci, Katherine T; Kraft, Robert A; McHaffie, John G; Coghill, Robert C

    2014-06-01

    Anxiety is the cognitive state related to the inability to control emotional responses to perceived threats. Anxiety is inversely related to brain activity associated with the cognitive regulation of emotions. Mindfulness meditation has been found to regulate anxiety. However, the brain mechanisms involved in meditation-related anxiety relief are largely unknown. We employed pulsed arterial spin labeling MRI to compare the effects of distraction in the form of attending to the breath (ATB; before meditation training) to mindfulness meditation (after meditation training) on state anxiety across the same subjects. Fifteen healthy subjects, with no prior meditation experience, participated in 4 d of mindfulness meditation training. ATB did not reduce state anxiety, but state anxiety was significantly reduced in every session that subjects meditated. Meditation-related anxiety relief was associated with activation of the anterior cingulate cortex, ventromedial prefrontal cortex and anterior insula. Meditation-related activation in these regions exhibited a strong relationship to anxiety relief when compared to ATB. During meditation, those who exhibited greater default-related activity (i.e. posterior cingulate cortex) reported greater anxiety, possibly reflecting an inability to control self-referential thoughts. These findings provide evidence that mindfulness meditation attenuates anxiety through mechanisms involved in the regulation of self-referential thought processes.

  18. Resting state activity and the "stream of consciousness" in schizophrenia--neurophenomenal hypotheses.

    PubMed

    Northoff, Georg

    2015-01-01

    Schizophrenia is a multifaceted disorder with various symptoms including auditory hallucinations, egodisturbances, passivity phenomena, and delusions. Recent neurobiological approaches have focused on, especially, the abnormal contents of consciousness, the "substantive parts" as James said, to associate them with the neural mechanisms related to sensory, motor, and cognitive functions, and the brain's underlying stimulus-induced or task-evoked activity. This leaves open, however, the neural mechanisms that provide the temporal linkage or glue between the various contents, the transitive parts that makes possible the "stream of consciousness." Interestingly, schizophrenic patients seem to suffer from abnormalities specifically in the "transitive parts" when they experience contents as temporally disconnected or fragmented which in phenomenological psychiatry has been described as "temporal fragmentation." The aim of this article is to develop so-called neurophenomenal hypothesis about the direct relationship between phenomenal features of the "stream of consciousness," the "transitive parts," and the specific neuronal mechanisms in schizophrenia as based on healthy subjects. Rather than emphasizing stimulus-induced and task-evoked activity and sensory and lateral prefrontal cortical regions as in neurocognitive approaches with their focus on the "substantive parts," the focus shifts here to the brain's intrinsic activity, its resting state activity, which may account for the temporal linkage or glue between the contents of consciousness, the transitive parts.

  19. Resting state activity and the "stream of consciousness" in schizophrenia--neurophenomenal hypotheses.

    PubMed

    Northoff, Georg

    2015-01-01

    Schizophrenia is a multifaceted disorder with various symptoms including auditory hallucinations, egodisturbances, passivity phenomena, and delusions. Recent neurobiological approaches have focused on, especially, the abnormal contents of consciousness, the "substantive parts" as James said, to associate them with the neural mechanisms related to sensory, motor, and cognitive functions, and the brain's underlying stimulus-induced or task-evoked activity. This leaves open, however, the neural mechanisms that provide the temporal linkage or glue between the various contents, the transitive parts that makes possible the "stream of consciousness." Interestingly, schizophrenic patients seem to suffer from abnormalities specifically in the "transitive parts" when they experience contents as temporally disconnected or fragmented which in phenomenological psychiatry has been described as "temporal fragmentation." The aim of this article is to develop so-called neurophenomenal hypothesis about the direct relationship between phenomenal features of the "stream of consciousness," the "transitive parts," and the specific neuronal mechanisms in schizophrenia as based on healthy subjects. Rather than emphasizing stimulus-induced and task-evoked activity and sensory and lateral prefrontal cortical regions as in neurocognitive approaches with their focus on the "substantive parts," the focus shifts here to the brain's intrinsic activity, its resting state activity, which may account for the temporal linkage or glue between the contents of consciousness, the transitive parts. PMID:25150784

  20. Hypnotizing Libet: Readiness potentials with non-conscious volition.

    PubMed

    Schlegel, Alexander; Alexander, Prescott; Sinnott-Armstrong, Walter; Roskies, Adina; Tse, Peter Ulric; Wheatley, Thalia

    2015-05-01

    The readiness potential (RP) is one of the most controversial topics in neuroscience and philosophy due to its perceived relevance to the role of conscious willing in action. Libet and colleagues reported that RP onset precedes both volitional movement and conscious awareness of willing that movement, suggesting that the experience of conscious will may not cause volitional movement (Libet, Gleason, Wright, & Pearl, 1983). Rather, they suggested that the RP indexes unconscious processes that may actually cause both volitional movement and the accompanying conscious feeling of will (Libet et al., 1983; pg. 640). Here, we demonstrate that volitional movement can occur without an accompanying feeling of will. We additionally show that the neural processes indexed by RPs are insufficient to cause the experience of conscious willing. Specifically, RPs still occur when subjects make self-timed, endogenously-initiated movements due to a post-hypnotic suggestion, without a conscious feeling of having willed those movements.

  1. The Influence of Consciousness Research

    ERIC Educational Resources Information Center

    Exceptional Children, 1978

    1978-01-01

    Presented is a conversation with Stanley Krippner, Program Planning Coordinator at the Humanistic Psychology Institute (San Francisco, California), on the field of psychoenergetics (the interdisciplinary investigation of the relationships among consciousness, energy, and matter) and its relation to special education. (SBH)

  2. The Role of Personal Experience in the Neural Processing of Action-Related Language

    ERIC Educational Resources Information Center

    Lyons, Ian M.; Mattarella-Micke, Andrew; Cieslak, Matthew; Nusbaum, Howard C.; Small, Steven L.; Beilock, Sian L.

    2010-01-01

    We investigated how auditory language processing is modified by a listener's previous experience with the specific activities mentioned in the speech. In particular, we asked whether neural responses related to language processing depend on one's experience with the action-based content of this language. Ice-hockey players and novices passively…

  3. Exploring self-compassion as a refuge against recalling the body-related shaming of caregiver eating messages on dimensions of objectified body consciousness in college women.

    PubMed

    Daye, Chesnee A; Webb, Jennifer B; Jafari, Nadia

    2014-09-01

    Guided by an overarching body-related shame regulation framework, the present investigation examined the associations between caregiver eating messages and dimensions of objectified body consciousness and further explored whether self-compassion moderated these links in a sample of 322 U.S. college women. Correlational findings indicated that retrospective accounts of restrictive/critical caregiver eating messages were positively related to body shame and negatively related to self-compassion and appearance control beliefs. Recollections of experiencing pressure to eat from caregivers were positively correlated with body shame and inversely associated with appearance control beliefs. Higher self-compassion was associated with lower body shame and body surveillance. Self-compassion attenuated the associations between restrictive/critical caregiver eating messages and both body surveillance and body shame. Implications for advancing our understanding of the adaptive properties of a self-compassionate self-regulatory style in mitigating recall of familial body-related shaming on the internalized body-related shame regulating processes of body objectification in emerging adulthood are discussed.

  4. Transient and sustained neural responses to death-related linguistic cues.

    PubMed

    Shi, Zhenhao; Han, Shihui

    2013-06-01

    Recent research showed that perception of death-related vs death-unrelated linguistic cues produced increased frontoparietal activity but decreased insular activity. This study investigated (i) whether the increased frontoparietal and decreased insular activities are, respectively, associated with transient trial-specific processes of death-related linguistic cues and sustained death-related thought during death-relevance judgments on linguistic cues and (ii) whether the neural activity underlying death-related thought can predict individuals' dispositional death anxiety. Participants were presented with death-related/unrelated words, life-related/unrelated words, and negative-valence/neutral words in separate sessions. Participants were scanned using functional magnetic resonance imaging while performing death-relevance, life-relevance, and valence judgments on the words, respectively. The contrast of death-related vs death-unrelated words during death-relevance judgments revealed transient increased activity in the left inferior parietal lobule, the right frontal eye field, and the right superior parietal lobule. The contrast of death-relevance judgments vs life-relevance/valence judgments showed decreased activity in the bilateral insula. The sustained insular activity was correlated with dispositional death anxiety, but only in those with weak transient frontoparietal responses to death-related words. Our results dissociate the transient and sustained neural responses to death-related linguistic cues and suggest that the combination of the transient and sustained neural activities can predict dispositional death anxiety.

  5. Environmental influences on neural systems of relational complexity

    PubMed Central

    Kalbfleisch, M. Layne; deBettencourt, Megan T.; Kopperman, Rebecca; Banasiak, Meredith; Roberts, Joshua M.; Halavi, Maryam

    2013-01-01

    Constructivist learning theory contends that we construct knowledge by experience and that environmental context influences learning. To explore this principle, we examined the cognitive process relational complexity (RC), defined as the number of visual dimensions considered during problem solving on a matrix reasoning task and a well-documented measure of mature reasoning capacity. We sought to determine how the visual environment influences RC by examining the influence of color and visual contrast on RC in a neuroimaging task. To specify the contributions of sensory demand and relational integration to reasoning, our participants performed a non-verbal matrix task comprised of color, no-color line, or black-white visual contrast conditions parametrically varied by complexity (relations 0, 1, 2). The use of matrix reasoning is ecologically valid for its psychometric relevance and for its potential to link the processing of psychophysically specific visual properties with various levels of RC during reasoning. The role of these elements is important because matrix tests assess intellectual aptitude based on these seemingly context-less exercises. This experiment is a first step toward examining the psychophysical underpinnings of performance on these types of problems. The importance of this is increased in light of recent evidence that intelligence can be linked to visual discrimination. We submit three main findings. First, color and black-white visual contrast (BWVC) add demand at a basic sensory level, but contributions from color and from BWVC are dissociable in cortex such that color engages a “reasoning heuristic” and BWVC engages a “sensory heuristic.” Second, color supports contextual sense-making by boosting salience resulting in faster problem solving. Lastly, when visual complexity reaches 2-relations, color and visual contrast relinquish salience to other dimensions of problem solving. PMID:24133465

  6. Environmental influences on neural systems of relational complexity.

    PubMed

    Kalbfleisch, M Layne; Debettencourt, Megan T; Kopperman, Rebecca; Banasiak, Meredith; Roberts, Joshua M; Halavi, Maryam

    2013-01-01

    Constructivist learning theory contends that we construct knowledge by experience and that environmental context influences learning. To explore this principle, we examined the cognitive process relational complexity (RC), defined as the number of visual dimensions considered during problem solving on a matrix reasoning task and a well-documented measure of mature reasoning capacity. We sought to determine how the visual environment influences RC by examining the influence of color and visual contrast on RC in a neuroimaging task. To specify the contributions of sensory demand and relational integration to reasoning, our participants performed a non-verbal matrix task comprised of color, no-color line, or black-white visual contrast conditions parametrically varied by complexity (relations 0, 1, 2). The use of matrix reasoning is ecologically valid for its psychometric relevance and for its potential to link the processing of psychophysically specific visual properties with various levels of RC during reasoning. The role of these elements is important because matrix tests assess intellectual aptitude based on these seemingly context-less exercises. This experiment is a first step toward examining the psychophysical underpinnings of performance on these types of problems. The importance of this is increased in light of recent evidence that intelligence can be linked to visual discrimination. We submit three main findings. First, color and black-white visual contrast (BWVC) add demand at a basic sensory level, but contributions from color and from BWVC are dissociable in cortex such that color engages a "reasoning heuristic" and BWVC engages a "sensory heuristic." Second, color supports contextual sense-making by boosting salience resulting in faster problem solving. Lastly, when visual complexity reaches 2-relations, color and visual contrast relinquish salience to other dimensions of problem solving. PMID:24133465

  7. Does perceptual learning require consciousness or attention?

    PubMed

    Meuwese, Julia D I; Post, Ruben A G; Scholte, H Steven; Lamme, Victor A F

    2013-10-01

    It has been proposed that visual attention and consciousness are separate [Koch, C., & Tsuchiya, N. Attention and consciousness: Two distinct brain processes. Trends in Cognitive Sciences, 11, 16-22, 2007] and possibly even orthogonal processes [Lamme, V. A. F. Why visual attention and awareness are different. Trends in Cognitive Sciences, 7, 12-18, 2003]. Attention and consciousness converge when conscious visual percepts are attended and hence become available for conscious report. In such a view, a lack of reportability can have two causes: the absence of attention or the absence of a conscious percept. This raises an important question in the field of perceptual learning. It is known that learning can occur in the absence of reportability [Gutnisky, D. A., Hansen, B. J., Iliescu, B. F., & Dragoi, V. Attention alters visual plasticity during exposure-based learning. Current Biology, 19, 555-560, 2009; Seitz, A. R., Kim, D., & Watanabe, T. Rewards evoke learning of unconsciously processed visual stimuli in adult humans. Neuron, 61, 700-707, 2009; Seitz, A. R., & Watanabe, T. Is subliminal learning really passive? Nature, 422, 36, 2003; Watanabe, T., Náñez, J. E., & Sasaki, Y. Perceptual learning without perception. Nature, 413, 844-848, 2001], but it is unclear which of the two ingredients-consciousness or attention-is not necessary for learning. We presented textured figure-ground stimuli and manipulated reportability either by masking (which only interferes with consciousness) or with an inattention paradigm (which only interferes with attention). During the second session (24 hr later), learning was assessed neurally and behaviorally, via differences in figure-ground ERPs and via a detection task. Behavioral and neural learning effects were found for stimuli presented in the inattention paradigm and not for masked stimuli. Interestingly, the behavioral learning effect only became apparent when performance feedback was given on the task to measure learning

  8. Does perceptual learning require consciousness or attention?

    PubMed

    Meuwese, Julia D I; Post, Ruben A G; Scholte, H Steven; Lamme, Victor A F

    2013-10-01

    It has been proposed that visual attention and consciousness are separate [Koch, C., & Tsuchiya, N. Attention and consciousness: Two distinct brain processes. Trends in Cognitive Sciences, 11, 16-22, 2007] and possibly even orthogonal processes [Lamme, V. A. F. Why visual attention and awareness are different. Trends in Cognitive Sciences, 7, 12-18, 2003]. Attention and consciousness converge when conscious visual percepts are attended and hence become available for conscious report. In such a view, a lack of reportability can have two causes: the absence of attention or the absence of a conscious percept. This raises an important question in the field of perceptual learning. It is known that learning can occur in the absence of reportability [Gutnisky, D. A., Hansen, B. J., Iliescu, B. F., & Dragoi, V. Attention alters visual plasticity during exposure-based learning. Current Biology, 19, 555-560, 2009; Seitz, A. R., Kim, D., & Watanabe, T. Rewards evoke learning of unconsciously processed visual stimuli in adult humans. Neuron, 61, 700-707, 2009; Seitz, A. R., & Watanabe, T. Is subliminal learning really passive? Nature, 422, 36, 2003; Watanabe, T., Náñez, J. E., & Sasaki, Y. Perceptual learning without perception. Nature, 413, 844-848, 2001], but it is unclear which of the two ingredients-consciousness or attention-is not necessary for learning. We presented textured figure-ground stimuli and manipulated reportability either by masking (which only interferes with consciousness) or with an inattention paradigm (which only interferes with attention). During the second session (24 hr later), learning was assessed neurally and behaviorally, via differences in figure-ground ERPs and via a detection task. Behavioral and neural learning effects were found for stimuli presented in the inattention paradigm and not for masked stimuli. Interestingly, the behavioral learning effect only became apparent when performance feedback was given on the task to measure learning

  9. Natural and Artificial Intelligence, Language, Consciousness, Emotion, and Anticipation

    NASA Astrophysics Data System (ADS)

    Dubois, Daniel M.

    2010-11-01

    The classical paradigm of the neural brain as the seat of human natural intelligence is too restrictive. This paper defends the idea that the neural ectoderm is the actual brain, based on the development of the human embryo. Indeed, the neural ectoderm includes the neural crest, given by pigment cells in the skin and ganglia of the autonomic nervous system, and the neural tube, given by the brain, the spinal cord, and motor neurons. So the brain is completely integrated in the ectoderm, and cannot work alone. The paper presents fundamental properties of the brain as follows. Firstly, Paul D. MacLean proposed the triune human brain, which consists to three brains in one, following the species evolution, given by the reptilian complex, the limbic system, and the neo-cortex. Secondly, the consciousness and conscious awareness are analysed. Thirdly, the anticipatory unconscious free will and conscious free veto are described in agreement with the experiments of Benjamin Libet. Fourthly, the main section explains the development of the human embryo and shows that the neural ectoderm is the whole neural brain. Fifthly, a conjecture is proposed that the neural brain is completely programmed with scripts written in biological low-level and high-level languages, in a manner similar to the programmed cells by the genetic code. Finally, it is concluded that the proposition of the neural ectoderm as the whole neural brain is a breakthrough in the understanding of the natural intelligence, and also in the future design of robots with artificial intelligence.

  10. Non-conscious prediction and a role for consciousness in correcting prediction errors.

    PubMed

    Pally, Regina

    2005-10-01

    As a result of the evolutionary pressure for survival, the brain relies on a number of non-conscious predictive neural mechanisms which allow for rapid, efficient behavioral responses to the environment. These predictive mechanisms enable the brain to recognize objects by sampling just a few sensory inputs, to anticipate what events are likely to occur and to prepare a response before events actually occur. Consciousness appears to play a role in the detection and correction of prediction errors. The author, a psychotherapist and psychoanalyst, proposes that this monitoring or oversight function of consciousness can be used to understand how conscious awareness facilitates change in the psychotherapeutic treatment of patients who repeat maladaptive patterns of behavior.

  11. Correlates of reward-predictive value in learning-related hippocampal neural activity

    PubMed Central

    Okatan, Murat

    2009-01-01

    Temporal difference learning (TD) is a popular algorithm in machine learning. Two learning signals that are derived from this algorithm, the predictive value and the prediction error, have been shown to explain changes in neural activity and behavior during learning across species. Here, the predictive value signal is used to explain the time course of learning-related changes in the activity of hippocampal neurons in monkeys performing an associative learning task. The TD algorithm serves as the centerpiece of a joint probability model for the learning-related neural activity and the behavioral responses recorded during the task. The neural component of the model consists of spiking neurons that compete and learn the reward-predictive value of task-relevant input signals. The predictive-value signaled by these neurons influences the behavioral response generated by a stochastic decision stage, which constitutes the behavioral component of the model. It is shown that the time course of the changes in neural activity and behavioral performance generated by the model exhibits key features of the experimental data. The results suggest that information about correct associations may be expressed in the hippocampus before it is detected in the behavior of a subject. In this way, the hippocampus may be among the earliest brain areas to express learning and drive the behavioral changes associated with learning. Correlates of reward-predictive value may be expressed in the hippocampus through rate remapping within spatial memory representations, they may represent reward-related aspects of a declarative or explicit relational memory representation of task contingencies, or they may correspond to reward-related components of episodic memory representations. These potential functions are discussed in connection with hippocampal cell assembly sequences and their reverse reactivation during the awake state. The results provide further support for the proposal that neural

  12. Age-related neural changes in autobiographical remembering and imagining.

    PubMed

    Addis, Donna Rose; Roberts, Reece P; Schacter, Daniel L

    2011-11-01

    Numerous neuroimaging studies have revealed that in young adults, remembering the past and imagining the future engage a common core network. Although it has been observed that older adults engage a similar network during these tasks, it is unclear whether or not they activate this network in a similar manner to young adults. Young and older participants completed two autobiographical tasks (imagining future events and recalling past events) in addition to a semantic-visuospatial control task. Spatiotemporal Partial Least Squares analyses examined whole brain patterns of activity across both the construction and elaboration of autobiographical events. These analyses revealed that that both age groups activated a similar network during the autobiographical tasks. However, some key age-related differences in the activation of this network emerged. During the construction of autobiographical events, older adults showed less activation relative to younger adults, in regions supporting episodic detail such as the medial temporal lobes and the precuneus. Later in the trial, older adults showed differential recruitment of medial and lateral temporal regions supporting the elaboration of autobiographical events, and possibly reflecting an increased role of conceptual information when older adults describe their pasts and their futures.

  13. The temporal structure of resting-state brain activity in the medial prefrontal cortex predicts self-consciousness.

    PubMed

    Huang, Zirui; Obara, Natsuho; Davis, Henry Hap; Pokorny, Johanna; Northoff, Georg

    2016-02-01

    Recent studies have demonstrated an overlap between the neural substrate of resting-state activity and self-related processing in the cortical midline structures (CMS). However, the neural and psychological mechanisms mediating this so-called "rest-self overlap" remain unclear. To investigate the neural mechanisms, we estimated the temporal structure of spontaneous/resting-state activity, e.g. its long-range temporal correlations or self-affinity across time as indexed by the power-law exponent (PLE). The PLE was obtained in resting-state activity in the medial prefrontal cortex (MPFC) and the posterior cingulate cortex (PCC) in 47 healthy subjects by functional magnetic resonance imaging (fMRI). We performed correlation analyses of the PLE and Revised Self-Consciousness Scale (SCSR) scores, which enabled us to access different dimensions of self-consciousness and specified rest-self overlap in a psychological regard. The PLE in the MPFC's resting-state activity correlated with private self-consciousness scores from the SCSR. Conversely, we found no correlation between the PLE and the other subscales of the SCSR (public, social) or between other resting-state measures, including functional connectivity, and the SCSR subscales. This is the first evidence for the association between the scale-free dynamics of resting-state activity in the CMS and the private dimension of self-consciousness. This finding implies the relationship of especially the private dimension of self with the temporal structure of resting-state activity.

  14. Age-related modifications in neural cardiovascular control.

    PubMed

    Ferrari, A U

    1992-09-01

    Integrated cardiovascular responses to a range of different stimuli, as well as the overall, spontaneously occurring variability in blood pressure and heart rate, undergo complex changes with aging. A general trend is that homeostatic control mechanisms lose part of their ability to modulate heart rate and to buffer the concomitant blood pressure variations; the two phenomena are possibly linked by a cause-effect relationship. A detailed analysis of the age-related changes in the major reflex systems reveals a clear-cut impairment in arterial baroreceptor control of the heart rate, but much less pronounced changes in its control of blood pressure, on the other hand, both the hemodynamic and humoral components of the cardiopulmonary reflex appear to be markedly attenuated. The experimental evidence of the mechanisms underlying these changes is still largely incomplete, and it appears that the gaps will have to be filled by a systematic, detailed analysis, i.e., that no generalizations or extrapolations will be possible. Indeed, the data available so far indicate that the age-related alterations are highly non-uniform, some functions undergoing a definite impairment but others being much better preserved and some being even enhanced; thus aging is by no means associated with a generalized decline in cardiovascular functions and should instead be viewed as a complex, highly selective process. These peculiar biological features of the aging phenomena merit further investigation in both the cardiovascular and the other organ systems, in order to verify the possibility that currently unrecognized homeostatic potentials in the elderly subject may be exploited to advance his/her clinical management in health and disease.

  15. Global workspace dynamics: cortical "binding and propagation" enables conscious contents.

    PubMed

    Baars, Bernard J; Franklin, Stan; Ramsoy, Thomas Zoega

    2013-01-01

    A global workspace (GW) is a functional hub of binding and propagation in a population of loosely coupled signaling elements. In computational applications, GW architectures recruit many distributed, specialized agents to cooperate in resolving focal ambiguities. In the brain, conscious experiences may reflect a GW function. For animals, the natural world is full of unpredictable dangers and opportunities, suggesting a general adaptive pressure for brains to resolve focal ambiguities quickly and accurately. GW theory aims to understand the differences between conscious and unconscious brain events. In humans and related species the cortico-thalamic (C-T) core is believed to underlie conscious aspects of perception, thinking, learning, feelings of knowing (FOK), felt emotions, visual imagery, working memory, and executive control. Alternative theoretical perspectives are also discussed. The C-T core has many anatomical hubs, but conscious percepts are unitary and internally consistent at any given moment. Over time, conscious contents constitute a very large, open set. This suggests that a brain-based GW capacity cannot be localized in a single anatomical hub. Rather, it should be sought in a functional hub - a dynamic capacity for binding and propagation of neural signals over multiple task-related networks, a kind of neuronal cloud computing. In this view, conscious contents can arise in any region of the C-T core when multiple input streams settle on a winner-take-all equilibrium. The resulting conscious gestalt may ignite an any-to-many broadcast, lasting ∼100-200 ms, and trigger widespread adaptation in previously established networks. To account for the great range of conscious contents over time, the theory suggests an open repertoire of binding coalitions that can broadcast via theta/gamma or alpha/gamma phase coupling, like radio channels competing for a narrow frequency band. Conscious moments are thought to hold only 1-4 unrelated items; this small

  16. Global workspace dynamics: cortical "binding and propagation" enables conscious contents.

    PubMed

    Baars, Bernard J; Franklin, Stan; Ramsoy, Thomas Zoega

    2013-01-01

    A global workspace (GW) is a functional hub of binding and propagation in a population of loosely coupled signaling elements. In computational applications, GW architectures recruit many distributed, specialized agents to cooperate in resolving focal ambiguities. In the brain, conscious experiences may reflect a GW function. For animals, the natural world is full of unpredictable dangers and opportunities, suggesting a general adaptive pressure for brains to resolve focal ambiguities quickly and accurately. GW theory aims to understand the differences between conscious and unconscious brain events. In humans and related species the cortico-thalamic (C-T) core is believed to underlie conscious aspects of perception, thinking, learning, feelings of knowing (FOK), felt emotions, visual imagery, working memory, and executive control. Alternative theoretical perspectives are also discussed. The C-T core has many anatomical hubs, but conscious percepts are unitary and internally consistent at any given moment. Over time, conscious contents constitute a very large, open set. This suggests that a brain-based GW capacity cannot be localized in a single anatomical hub. Rather, it should be sought in a functional hub - a dynamic capacity for binding and propagation of neural signals over multiple task-related networks, a kind of neuronal cloud computing. In this view, conscious contents can arise in any region of the C-T core when multiple input streams settle on a winner-take-all equilibrium. The resulting conscious gestalt may ignite an any-to-many broadcast, lasting ∼100-200 ms, and trigger widespread adaptation in previously established networks. To account for the great range of conscious contents over time, the theory suggests an open repertoire of binding coalitions that can broadcast via theta/gamma or alpha/gamma phase coupling, like radio channels competing for a narrow frequency band. Conscious moments are thought to hold only 1-4 unrelated items; this small

  17. Working Memory-Related Neural Activity Predicts Future Smoking Relapse

    PubMed Central

    Loughead, James; Wileyto, E Paul; Ruparel, Kosha; Falcone, Mary; Hopson, Ryan; Gur, Ruben; Lerman, Caryn

    2015-01-01

    Brief abstinence from smoking impairs cognition, particularly executive function, and this has a role in relapse to smoking. This study examined whether working memory-related brain activity predicts subsequent smoking relapse above and beyond standard clinical and behavioral measures. Eighty treatment-seeking smokers completed two functional magnetic resonance imaging sessions (smoking satiety vs 24 h abstinence challenge) during performance of a visual N-back task. Brief counseling and a short-term quit attempt followed. Relapse during the first 7 days was biochemically confirmed by the presence of the nicotine metabolite cotinine. Mean percent blood oxygen level-dependent (BOLD) signal change was extracted from a priori regions of interest: bilateral dorsolateral prefrontal cortex (DLPFC), medial frontal/cingulate gyrus, posterior cingulate cortex (PCC), and ventromedial prefrontal cortex. Signal from these brain regions and additional clinical measures were used to model outcome status, which was then validated with resampling techniques. Relapse to smoking was predicted by increased withdrawal symptoms, decreased left DLPFC and increased PCC BOLD percent signal change (abstinence vs smoking satiety). Receiver operating characteristic analysis demonstrated 81% area under the curve using these predictors, a significant improvement over the model with clinical variables only. The combination of abstinence-induced decreases in left DLPFC activation and reduced suppression of PCC may be a prognostic marker for poor outcome, specifically early smoking relapse. PMID:25469682

  18. Recognition of distantly related protein sequences using conserved motifs and neural networks.

    PubMed

    Frishman, D; Argos, P

    1992-12-01

    A sensitive technique for protein sequence motif recognition based on neural networks has been developed. It involves three major steps. (1) At each appropriate alignment position of a set of N matched sequences, a set of N aligned oligopeptides is specified with preselected window length. N neural nets are subsequently and successively trained on N-1 amino acid spans after eliminating each ith oligopeptide. A test for recognition of each of the ith spans is performed. The average neural net recognition over N such trials is used as a measure of conservation for the particular windowed region of the multiple alignment. This process is repeated for all possible spans of given length in the multiple alignment. (2) The M most conserved regions are regarded as motifs and the oligopeptides within each are used to train intensively M individual neural networks. (3) The M networks are then applied in a search for related primary structures in a databank of known protein sequences. The oligopeptide spans in the database sequence with strongest neural net output for each of the M networks are saved and then scored according to the output signals and the proper combination that follows the expected N- to C-terminal sequence order. The motifs from the database with highest similarity scores can then be used to retrain the M neural nets, which can be subsequently utilized for further searches in the databank, thus providing even greater sensitivity to recognize distant familial proteins. This technique was successfully applied to the integrase, DNA-polymerase and immunoglobulin families.

  19. A neurofunctional theory of visual consciousness.

    PubMed

    Prinz, J

    2000-06-01

    This paper develops an empirically motivated theory of visual consciousness. It begins by outlining neuropsychological support for Jackendoff's (1987) hypothesis that visual consciousness involves mental representations at an intermediate level of processing. It then supplements that hypothesis with the further requirement that attention, which can come under the direction of high level representations, is also necessary for consciousness. The resulting theory is shown to have a number of philosophical consequences. If correct, higher-order thought accounts, the multiple drafts account, and the widely held belief that sensation precedes perception will all be found wanting. The theory will also be used to illustrate and defend a methodology that fills the gulf between functionalists who ignore the brain and neural reductionists who repudiate functionalism.

  20. Consciousness and hallucinations in schizophrenia: the role of synapse regression.

    PubMed

    Bennett A O, Maxwell R

    2008-11-01

    Consciousness takes two forms, transitive and intransitive. Transitive consciousness is a matter of being conscious of something or other whereas intransitive consciousness has no object, as being conscious or awake. Of the different forms of transitive consciousness, perceptual, somatic, kinaesthetic and so on, cognitive neuroscience has concentrated on determining the neural concomitants of perceptual consciousness. To be conscious of a percept is to be aware of it and this requires attending to it. This work sets out a hypothesis as to what brain areas are involved in a schizophrenia subject attending and becoming aware of hallucinations. First, the different areas of cortex that support different visual and auditory illusions of percepts are considered. Next it is argued that endogenous activity in these areas of cortex give rise to hallucinations of percepts that are similar to the percepts that these same areas support during illusions. The basis of such endogenous activity, it is suggested, is to be found in the paucity of afferent synapses to these cortical areas. This may occur as a consequence of loss and regression of synapses due to a degenerative disease or because of abnormal synapse formation and regression during childhood and adolescence, as is likely to be the case in schizophrenia. Finally the neural basis of attention and awareness of these hallucinations are considered for subjects suffering from schizophrenia, and a set of important questions posed that await elucidation through future experimental studies.

  1. Consciousness and Listening.

    ERIC Educational Resources Information Center

    McMaster, Michele

    To understand the demands and restrictions of human consciousness will allow teachers and students alike to actually "be" listeners. It is speculated (by K. Wilber, E. Neumann, J. Gebser and others) that human consciousness, in the course of human existence, has gone through several changes, different modes or structures, so to speak, lasting…

  2. The evolution of consciousness

    SciTech Connect

    Stapp, H.P.

    1996-08-16

    It is argued that the principles of classical physics are inimical to the development of an adequate science of consciousness. The problem is that insofar as the classical principles are valid consciousness can have no effect on the behavior, and hence on the survival prospects, of the organisms in which it inheres. Thus within the classical framework it is not possible to explain in natural terms the development of consciousness to the high-level form found in human beings. In quantum theory, on the other hand, consciousness can be dynamically efficacious: quantum theory does allow consciousness to influence behavior, and thence to evolve in accordance with the principles of natural selection. However, this evolutionary requirement places important constraints upon the details of the formulation of the quantum dynamical principles.

  3. Neural Basis of Intrinsic Motivation: Evidence from Event-Related Potentials

    PubMed Central

    Jin, Jia; Yu, Liping; Ma, Qingguo

    2015-01-01

    Human intrinsic motivation is of great importance in human behavior. However, although researchers have focused on this topic for decades, its neural basis was still unclear. The current study employed event-related potentials to investigate the neural disparity between an interesting stop-watch (SW) task and a boring watch-stop task (WS) to understand the neural mechanisms of intrinsic motivation. Our data showed that, in the cue priming stage, the cue of the SW task elicited smaller N2 amplitude than that of the WS task. Furthermore, in the outcome feedback stage, the outcome of the SW task induced smaller FRN amplitude and larger P300 amplitude than that of the WS task. These results suggested that human intrinsic motivation did exist and that it can be detected at the neural level. Furthermore, intrinsic motivation could be quantitatively indexed by the amplitude of ERP components, such as N2, FRN, and P300, in the cue priming stage or feedback stage. Quantitative measurements would also be convenient for intrinsic motivation to be added as a candidate social factor in the construction of a machine learning model. PMID:26491430

  4. Neural Basis of Intrinsic Motivation: Evidence from Event-Related Potentials.

    PubMed

    Jin, Jia; Yu, Liping; Ma, Qingguo

    2015-01-01

    Human intrinsic motivation is of great importance in human behavior. However, although researchers have focused on this topic for decades, its neural basis was still unclear. The current study employed event-related potentials to investigate the neural disparity between an interesting stop-watch (SW) task and a boring watch-stop task (WS) to understand the neural mechanisms of intrinsic motivation. Our data showed that, in the cue priming stage, the cue of the SW task elicited smaller N2 amplitude than that of the WS task. Furthermore, in the outcome feedback stage, the outcome of the SW task induced smaller FRN amplitude and larger P300 amplitude than that of the WS task. These results suggested that human intrinsic motivation did exist and that it can be detected at the neural level. Furthermore, intrinsic motivation could be quantitatively indexed by the amplitude of ERP components, such as N2, FRN, and P300, in the cue priming stage or feedback stage. Quantitative measurements would also be convenient for intrinsic motivation to be added as a candidate social factor in the construction of a machine learning model. PMID:26491430

  5. Neural dissociation of food- and money-related reward processing using an abstract incentive delay task.

    PubMed

    Simon, Joe J; Skunde, Mandy; Wu, Mudan; Schnell, Knut; Herpertz, Sabine C; Bendszus, Martin; Herzog, Wolfgang; Friederich, Hans-Christoph

    2015-08-01

    Food is an innate reward stimulus related to energy homeostasis and survival, whereas money is considered a more general reward stimulus that gains a rewarding value through learning experiences. Although the underlying neural processing for both modalities of reward has been investigated independently from one another, a more detailed investigation of neural similarities and/or differences between food and monetary reward is still missing. Here, we investigated the neural processing of food compared with monetary-related rewards in 27 healthy, normal-weight women using functional magnetic resonance imaging. We developed a task distinguishing between the anticipation and the receipt of either abstract food or monetary reward. Both tasks activated the ventral striatum during the expectation of a reward. Compared with money, greater food-related activations were observed in prefrontal, parietal and central midline structures during the anticipation and lateral orbitofrontal cortex (lOFC) during the receipt of food reward. Furthermore, during the receipt of food reward, brain activation in the secondary taste cortex was positively related to the body mass index. These results indicate that food-dependent activations encompass to a greater extent brain regions involved in self-control and self-reflection during the anticipation and phylogenetically older parts of the lOFC during the receipt of reward.

  6. Neural dissociation of food- and money-related reward processing using an abstract incentive delay task

    PubMed Central

    Skunde, Mandy; Wu, Mudan; Schnell, Knut; Herpertz, Sabine C.; Bendszus, Martin; Herzog, Wolfgang; Friederich, Hans-Christoph

    2015-01-01

    Food is an innate reward stimulus related to energy homeostasis and survival, whereas money is considered a more general reward stimulus that gains a rewarding value through learning experiences. Although the underlying neural processing for both modalities of reward has been investigated independently from one another, a more detailed investigation of neural similarities and/or differences between food and monetary reward is still missing. Here, we investigated the neural processing of food compared with monetary-related rewards in 27 healthy, normal-weight women using functional magnetic resonance imaging. We developed a task distinguishing between the anticipation and the receipt of either abstract food or monetary reward. Both tasks activated the ventral striatum during the expectation of a reward. Compared with money, greater food-related activations were observed in prefrontal, parietal and central midline structures during the anticipation and lateral orbitofrontal cortex (lOFC) during the receipt of food reward. Furthermore, during the receipt of food reward, brain activation in the secondary taste cortex was positively related to the body mass index. These results indicate that food-dependent activations encompass to a greater extent brain regions involved in self-control and self-reflection during the anticipation and phylogenetically older parts of the lOFC during the receipt of reward. PMID:25552570

  7. Does motion-related brain functional connectivity reflect both artifacts and genuine neural activity?

    PubMed

    Pujol, Jesus; Macià, Dídac; Blanco-Hinojo, Laura; Martínez-Vilavella, Gerard; Sunyer, Jordi; de la Torre, Rafael; Caixàs, Assumpta; Martín-Santos, Rocío; Deus, Joan; Harrison, Ben J

    2014-11-01

    Imaging research on functional connectivity is uniquely contributing to characterize the functional organization of the human brain. Functional connectivity measurements, however, may be significantly influenced by head motion that occurs during image acquisition. The identification of how motion influences such measurements is therefore highly relevant to the interpretation of a study's results. We have mapped the effect of head motion on functional connectivity in six different populations representing a wide range of potential influences of motion on functional connectivity. Group-level voxel-wise maps of the correlation between a summary head motion measurement and functional connectivity degree were estimated in 80 young adults, 71 children, 53 older adults, 20 patients with Down syndrome, 24 with Prader-Willi syndrome and 20 with Williams syndrome. In highly compliant young adults, motion correlated with functional connectivity measurements showing a system-specific anatomy involving the sensorimotor cortex, visual areas and default mode network. Further characterization was strongly indicative of these changes expressing genuine neural activity related to motion, as opposed to pure motion artifact. In the populations with larger head motion, results were more indicative of widespread artifacts, but showing notably distinct spatial distribution patterns. Group-level regression of motion effects was efficient in removing both generalized changes and changes putatively related to neural activity. Overall, this study endorses a relatively simple approach for mapping distinct effects of head motion on functional connectivity. Importantly, our findings support the intriguing hypothesis that a component of motion-related changes may reflect system-specific neural activity.

  8. Elevated reward-related neural activation as a unique biological marker of bipolar disorder: assessment and treatment implications.

    PubMed

    Nusslock, Robin; Young, Christina B; Damme, Katherine S F

    2014-11-01

    Growing evidence indicates that risk for bipolar disorder is characterized by elevated activation in a fronto-striatal reward neural circuit involving the ventral striatum and orbitofrontal cortex, among other regions. It is proposed that individuals with abnormally elevated reward-related neural activation are at risk for experiencing an excessive increase in approach-related motivation during life events involving rewards or goal striving and attainment. In the extreme, this increase in motivation is reflected in hypomanic/manic symptoms. By contrast, unipolar depression (without a history of hypomania/mania) is characterized by decreased reward responsivity and decreased reward-related neural activation. Collectively, this suggests that risk for bipolar disorder and unipolar depression are characterized by distinct and opposite profiles of reward processing and reward-related neural activation. The objective of the present paper is threefold. First, we review the literature on reward processing and reward-related neural activation in bipolar disorder, and in particular risk for hypomania/mania. Second, we propose that reward-related neural activation reflects a biological marker of differential risk for bipolar disorder versus unipolar depression that may help facilitate psychiatric assessment and differential diagnosis. We also discuss, however, the challenges to using neuroscience techniques and biological markers in a clinical setting for assessment and diagnostic purposes. Lastly, we address the pharmacological and psychosocial treatment implications of research on reward-related neural activation in bipolar disorder. PMID:25241675

  9. Mind and consciousness: Towards a final answer?

    PubMed

    Taylor, John G

    2005-03-01

    A review is given of recent developments in our scientific understanding of consciousness to help guide further progress, leading to a possible final answer to the question of how the brain may create consciousness. The review commences with a brief description of the nature of consciousness, and moves to an overview of various approaches presently being pursued to understand it (quantum mechanics, 40-Hz, dynamical systems theory and complexity, narrative centre of gravity, global workspace, relational mind). To help move the discussion forward we use the fact that attention acts as the gateway to consciousness, implying the need to analyze attention most closely. An engineering control approach is introduced to model the movement of attention, based on experimental data indicating separate sites for attention modulation and for the creation of that modulation: and using the analogy with motor control in the brain, to which an engineering approach has already been applied by others. Simulation and brain imaging results support the presence of several of the relevant attention control modules in the brain. The attention control framework is extended to analyze how consciousness could arise during attentive processing, in terms of the COrollary Discharge of Attention Movement (CODAM) model. The relation between the CODAM model of consciousness and modern approaches to consciousness in the philosophy of mind is then briefly described. An overall summary and a program of future explorations of the CODAM model conclude the review.

  10. Consciousness during dreams.

    PubMed

    Cicogna, P C; Bosinelli, M

    2001-03-01

    Two aspects of consciousness are first considered: consciousness as awareness (phenomenological meaning) and consciousness as strategic control (functional meaning). As to awareness, three types can be distinguished: first, awareness as the phenomenal experiences of objects and events; second, awareness as meta-awareness, i.e., the awareness of mental life itself; third, awareness as self-awareness, i.e., the awareness of being oneself. While phenomenal experience and self-awareness are usually present during dreaming (even if many modifications are possible), meta-awareness is usually absent (apart from some particular experiences of self-reflectiveness) with the major exception of lucid dreaming. Consciousness as strategic control may also be present in dreams. The functioning of consciousness is then analyzed, following a cognitive model of dream production. In such a model, the dream is supposed to be the product of the interaction of three components: (a) the bottom-up activation of mnemonic elements coming from LTM systems, (b) interpretative and elaborative top-down processes, and (c) monitoring of phenomenal experience. A feedback circulation is activated among the components, where the top-down interpretative organization and the conscious monitoring of the oneiric scene elicitates other mnemonic contents, according to the requirements of the dream plot. This dream productive activity is submitted to unconscious and conscious processes. PMID:11273624

  11. Consciousness during dreams.

    PubMed

    Cicogna, P C; Bosinelli, M

    2001-03-01

    Two aspects of consciousness are first considered: consciousness as awareness (phenomenological meaning) and consciousness as strategic control (functional meaning). As to awareness, three types can be distinguished: first, awareness as the phenomenal experiences of objects and events; second, awareness as meta-awareness, i.e., the awareness of mental life itself; third, awareness as self-awareness, i.e., the awareness of being oneself. While phenomenal experience and self-awareness are usually present during dreaming (even if many modifications are possible), meta-awareness is usually absent (apart from some particular experiences of self-reflectiveness) with the major exception of lucid dreaming. Consciousness as strategic control may also be present in dreams. The functioning of consciousness is then analyzed, following a cognitive model of dream production. In such a model, the dream is supposed to be the product of the interaction of three components: (a) the bottom-up activation of mnemonic elements coming from LTM systems, (b) interpretative and elaborative top-down processes, and (c) monitoring of phenomenal experience. A feedback circulation is activated among the components, where the top-down interpretative organization and the conscious monitoring of the oneiric scene elicitates other mnemonic contents, according to the requirements of the dream plot. This dream productive activity is submitted to unconscious and conscious processes.

  12. Postmodern consciousness in psychotherapy.

    PubMed

    Kawai, Toshio

    2006-06-01

    Modern consciousness is a cultural and historical achievement in the West and a developmental task for each person now. Modern consciousness consists in the emancipation from the power of community, animistic nature and the unconscious. It is connected with neurosis and psychotherapy because it has to do with inner conflicts. But today there is an increasing number of cases which are characterized by dissociation and acting out, without the feeling of conflicts. Consciousness seems to be changing toward a new conception which might be called 'postmodern consciousness'. The essence of postmodern consciousness is shown by interpreting two dreams internally. The first dream from a case of depersonalization indicates that it is not necessary to be entangled with the object. There is a different kind of coniunctio in the mode of seeing. The second dream from a case of dissociative disorder shows a world which has neither traces of pre-modern cosmology-high and low, here and the beyond-nor modern interiority. There is only surface and self-reflection without content. The discussion of dreams suggests that postmodern consciousness is not to be understood as premature and pathological. It is therapeutically important to refine and deepen postmodern consciousness.

  13. Why the Brain Knows More than We Do: Non-Conscious Representations and Their Role in the Construction of Conscious Experience

    PubMed Central

    Dresp-Langley, Birgitta

    2011-01-01

    Scientific studies have shown that non-conscious stimuli and representations influence information processing during conscious experience. In the light of such evidence, questions about potential functional links between non-conscious brain representations and conscious experience arise. This article discusses neural model capable of explaining how statistical learning mechanisms in dedicated resonant circuits could generate specific temporal activity traces of non-conscious representations in the brain. How reentrant signaling, top-down matching, and statistical coincidence of such activity traces may lead to the progressive consolidation of temporal patterns that constitute the neural signatures of conscious experience in networks extending across large distances beyond functionally specialized brain regions is then explained. PMID:24962683

  14. Perceptual Salience and Reward Both Influence Feedback-Related Neural Activity Arising from Choice.

    PubMed

    Lou, Bin; Hsu, Wha-Yin; Sajda, Paul

    2015-09-23

    For day-to-day decisions, multiple factors influence our choice between alternatives. Two dimensions of decision making that substantially affect choice are the objective perceptual properties of the stimulus (e.g., salience) and its subjective value. Here we measure EEGs in human subjects to relate their feedback-evoked EEG responses to estimates of prediction error given a neurally derived expected value for each trial. Unlike in traditional reinforcement learning paradigms, in our experiment the reward itself is not probabilistic; rather, it is a fixed value, which, when combined with the variable stimulus salience, yields uncertainty in the choice. We find that feedback-evoked event-related potentials (ERPs), specifically those classically termed feedback-related negativity, are modulated by both the reward level and stimulus salience. Using single-trial analysis of the EEG, we show stimulus-locked EEG components reflecting perceived stimulus salience can be combined with the level of reward to create an estimate of expected reward. This expected reward is used to form a prediction error that correlates with the trial-by-trial variability of the feedback ERPs for negative, but not positive, feedback. This suggests that the valence of prediction error is more important than the valence of the actual feedback, since only positive rewards were delivered in the experiment (no penalty or loss). Finally, we show that these subjectively defined prediction errors are informative of the riskiness of the subject's choice on the subsequent trial. In summary, our work shows that neural correlates of stimulus salience interact with value information to yield neural representations of subjective expected reward. Significance statement: How we make perceptual decisions depends on sensory evidence and the value of our options. These two factors often interact to yield subjective decisions; i.e., individuals integrate sensory evidence and value to form their own estimates of

  15. Attention, self-regulation and consciousness.

    PubMed Central

    Posner, M I; Rothbart, M K

    1998-01-01

    Consciousness has many aspects. These include awareness of the world, feelings of control over one's behaviour and mental state (volition), and the notion of continuing self. Focal (executive) attention is used to control details of our awareness and is thus closely related to volition. Experiments suggest an integrated network of neural areas involved in executive attention. This network is associated with our voluntary ability to select among competing items, to correct error and to regulate our emotions. Recent neuroimaging studies suggest that these various functions involve separate areas of the anterior cingulate. We have adopted a strategy of using marker tasks, shown to activate the brain area by imaging studies, as a means of tracing the development of attentional networks. Executive attention appears to develop first to regulate distress during the first year of life. During later childhood the ability to regulate conflict among competing stimuli builds upon the earlier cingulate anatomy to provide a means of cognitive control. During childhood the activation of cingulate structures relates both to the child's success on laboratory tasks involving conflict and to parental reports of self-regulation and emotional control. These studies indicate a start in understanding the anatomy, circuitry and development of executive attention networks that serve to regulate both cognition and emotion. PMID:9854264

  16. ERPS to Monitor Non-conscious Mentation

    NASA Technical Reports Server (NTRS)

    Donchin, E.

    1984-01-01

    Event Related Brain Potentials (or ERPs) are extracted from the EEG that can be recorded between a pair of electrodes placed on a person's scalp. The EEG is recorded as a continual fluctuation in voltage. It is the results of the integration of the potential fields generated by a multitude of neuronal ensembles that are active as the brain goes about its business. Within this ongoing signal it is possible to distinguish voltage fluctuations that are triggered in neural structures by the occurrence of specific events. This activity, evoked as it is by an external event, is known as the Evoked, or Event Related, Potential. The ERPs provide a unique opportunity to monitor non-conscious mentation. The inferences that can be based on ERP data are described and the limits of these inferences are emphasized. This, however, will not be an exhaustive review of the use of ERPs in Engineering Psychology. The application, its scope, and its limitations will be illustrated by means of one example. This example is preceded by a brief technical introduction to the methodology used in the study of ERPs. The manner in which ERPs are used to study cognition is described.

  17. A unified 3D default space consciousness model combining neurological and physiological processes that underlie conscious experience

    PubMed Central

    Jerath, Ravinder; Crawford, Molly W.; Barnes, Vernon A.

    2015-01-01

    The Global Workspace Theory and Information Integration Theory are two of the most currently accepted consciousness models; however, these models do not address many aspects of conscious experience. We compare these models to our previously proposed consciousness model in which the thalamus fills-in processed sensory information from corticothalamic feedback loops within a proposed 3D default space, resulting in the recreation of the internal and external worlds within the mind. This 3D default space is composed of all cells of the body, which communicate via gap junctions and electrical potentials to create this unified space. We use 3D illustrations to explain how both visual and non-visual sensory information may be filled-in within this dynamic space, creating a unified seamless conscious experience. This neural sensory memory space is likely generated by baseline neural oscillatory activity from the default mode network, other salient networks, brainstem, and reticular activating system. PMID:26379573

  18. Neural Connectivity and Immunocytochemical Studies of Anatomical Sites Related to Nauseogenic and Emetic Reflexes

    NASA Technical Reports Server (NTRS)

    Fox, Robert A. (Principal Investigator)

    1992-01-01

    The studies conducted in this research project examined several aspects of neuroanatomical structures and neurochemical processes related to motion sickness in animal models. A principle objective of these studies was to investigate neurochemical changes in the central nervous system that are related to motion sickness with the objective of defining neural mechanisms important to this malady. For purposes of exposition, the studies and research finding have been classified into five categories. These are: immunoreactivity in the brainstem, vasopressin effects, lesion studies of area postrema, role of the vagus nerve, and central nervous system structure related to adaptation to microgravity.

  19. On the Character of Consciousness.

    PubMed

    Annila, Arto

    2016-01-01

    The human brain is a particularly demanding system to infer its nature from observations. Thus, there is on one hand plenty of room for theorizing and on the other hand a pressing need for a rigorous theory. We apply statistical mechanics of open systems to describe the brain as a hierarchical system in consuming free energy in least time. This holistic tenet accounts for cellular metabolism, neuronal signaling, cognitive processes all together, or any other process by a formal equation of motion that extends down to the ultimate precision of one quantum of action. According to this general thermodynamic theory cognitive processes are no different by their operational and organizational principle from other natural processes. Cognition too will emerge and evolve along path-dependent and non-determinate trajectories by consuming free energy in least time to attain thermodynamic balance within the nervous system itself and with its surrounding systems. Specifically, consciousness can be ascribed to a natural process that integrates various neural networks for coherent consumption of free energy, i.e., for meaningful deeds. The whole hierarchy of integrated systems can be formally summed up to thermodynamic entropy. The holistic tenet provides insight to the character of consciousness also by acknowledging awareness in other systems at other levels of nature's hierarchy. PMID:27065819

  20. On the Character of Consciousness

    PubMed Central

    Annila, Arto

    2016-01-01

    The human brain is a particularly demanding system to infer its nature from observations. Thus, there is on one hand plenty of room for theorizing and on the other hand a pressing need for a rigorous theory. We apply statistical mechanics of open systems to describe the brain as a hierarchical system in consuming free energy in least time. This holistic tenet accounts for cellular metabolism, neuronal signaling, cognitive processes all together, or any other process by a formal equation of motion that extends down to the ultimate precision of one quantum of action. According to this general thermodynamic theory cognitive processes are no different by their operational and organizational principle from other natural processes. Cognition too will emerge and evolve along path-dependent and non-determinate trajectories by consuming free energy in least time to attain thermodynamic balance within the nervous system itself and with its surrounding systems. Specifically, consciousness can be ascribed to a natural process that integrates various neural networks for coherent consumption of free energy, i.e., for meaningful deeds. The whole hierarchy of integrated systems can be formally summed up to thermodynamic entropy. The holistic tenet provides insight to the character of consciousness also by acknowledging awareness in other systems at other levels of nature's hierarchy. PMID:27065819

  1. Conscious Control over Action

    PubMed Central

    Shepherd, Joshua

    2015-01-01

    The extensive involvement of nonconscious processes in human behaviour has led some to suggest that consciousness is much less important for the control of action than we might think. In this article I push against this trend, developing an understanding of conscious control that is sensitive to our best models of overt (that is, bodily) action control. Further, I assess the cogency of various zombie challenges—challenges that seek to demote the importance of conscious control for human agency. I argue that though nonconscious contributions to action control are evidently robust, these challenges are overblown. PMID:26113753

  2. Folate-related gene variants in Irish families affected by neural tube defects

    PubMed Central

    Fisk Green, Ridgely; Byrne, Julianne; Crider, Krista S.; Gallagher, Margaret; Koontz, Deborah; Berry, Robert J.

    2013-01-01

    Periconceptional folic acid use can often prevent neural tube defects (NTDs). Variants of genes involved in folate metabolism in mothers and children have been associated with occurrence of NTDs. We identified Irish families with individuals affected by neural tube defects. In these families, we observed that neural tube defects and birth defects overall occurred at a higher rate in the maternal lineage compared with the paternal lineage. The goal of this study was to look for evidence for genetic effects that could explain the discrepancy in the occurrence of these birth defects in the maternal vs. paternal lineage. We genotyped blood samples from 322 individuals from NTD-affected Irish families, identified through their membership in spina bifida associations. We looked for differences in distribution in maternal vs. paternal lineages of five genetic polymorphisms: the DHFR 19 bp deletion, MTHFD1 1958G>A, MTHFR 1298A>C, MTHFR 677C>T, and SLC19A1 80A>G. In addition to looking at genotypes individually, we determined the number of genotypes associated with decreased folate metabolism in each relative (“risk genotypes”) and compared the distribution of these genotypes in maternal vs. paternal relatives. Overall, maternal relatives had a higher number of genotypes associated with lower folate metabolism than paternal relatives (p = 0.017). We expected that relatives would share the same risk genotype as the individuals with NTDs and/or their mothers. However, we observed that maternal relatives had an over-abundance of any risk genotype, rather than one specific genotype. The observed genetic effects suggest an epigenetic mechanism in which decreased folate metabolism results in epigenetic alterations related to the increased rate of NTDs and other birth defects seen in the maternal lineage. Future studies on the etiology of NTDs and other birth defects could benefit from including multigenerational extended families, in order to explore potential epigenetic

  3. Sex-related similarities and differences in the neural correlates of beauty.

    PubMed

    Cela-Conde, Camilo J; Ayala, Francisco J; Munar, Enric; Maestú, Fernando; Nadal, Marcos; Capó, Miguel A; del Río, David; López-Ibor, Juan J; Ortiz, Tomás; Mirasso, Claudio; Marty, Gisèle

    2009-03-10

    The capacity to appreciate beauty is one of our species' most remarkable traits. Although knowledge about its neural correlates is growing, little is known about any gender-related differences. We have explored possible differences between men and women's neural correlates of aesthetic preference. We have used magnetoencephalography to record the brain activity of 10 male and 10 female participants while they decided whether or not they considered examples of artistic and natural visual stimuli to be beautiful. Our results reveal significantly different activity between the sexes in parietal regions when participants judged the stimuli as beautiful. Activity in this region was bilateral in women, whereas it was lateralized to the right hemisphere in men. It is known that the dorsal visual processing stream, which encompasses the superior parietal areas, has been significantly modified throughout human evolution. We posit that the observed gender-related differences are the result of evolutionary processes that occurred after the splitting of the human and chimpanzee lineages. In view of previous results on gender differences with respect to the neural correlates of coordinate and categorical spatial strategies, we infer that the different strategies used by men and women in assessing aesthetic preference may reflect differences in the strategies associated with the division of labor between our male and female hunter-gatherer hominin ancestors.

  4. Sex-related similarities and differences in the neural correlates of beauty

    PubMed Central

    Cela-Conde, Camilo J.; Ayala, Francisco J.; Munar, Enric; Maestú, Fernando; Nadal, Marcos; Capó, Miguel A.; del Río, David; López-Ibor, Juan J.; Ortiz, Tomás; Mirasso, Claudio; Marty, Gisèle

    2009-01-01

    The capacity to appreciate beauty is one of our species' most remarkable traits. Although knowledge about its neural correlates is growing, little is known about any gender-related differences. We have explored possible differences between men and women's neural correlates of aesthetic preference. We have used magnetoencephalography to record the brain activity of 10 male and 10 female participants while they decided whether or not they considered examples of artistic and natural visual stimuli to be beautiful. Our results reveal significantly different activity between the sexes in parietal regions when participants judged the stimuli as beautiful. Activity in this region was bilateral in women, whereas it was lateralized to the right hemisphere in men. It is known that the dorsal visual processing stream, which encompasses the superior parietal areas, has been significantly modified throughout human evolution. We posit that the observed gender-related differences are the result of evolutionary processes that occurred after the splitting of the human and chimpanzee lineages. In view of previous results on gender differences with respect to the neural correlates of coordinate and categorical spatial strategies, we infer that the different strategies used by men and women in assessing aesthetic preference may reflect differences in the strategies associated with the division of labor between our male and female hunter-gatherer hominin ancestors. PMID:19237562

  5. Sigmund Freud and the Crick-Koch hypothesis. A footnote to the history of consciousness studies.

    PubMed

    Smith, D L

    1999-06-01

    The author describes Crick and Koch's recently developed theory of the neurophysiological basis of consciousness as synchronised neural oscillations. The thesis that neural oscillations provide the neurophysiological basis for consciousness was anticipated by Sigmund Freud in his 1895 'Project for a scientific psychology'. Freud attempted to solve his neuropsychological 'problem of quality' by means of the hypothesis that information concerning conscious sensory qualities is transmitted through the mental apparatus by means of neural 'periods'. Freud believed that information carried by neural oscillations would proliferate across 'contact-barriers' (synapses) without inhibition. Freud's theory thus appears to imply that synchronised neural oscillations are an important component of the neurophysiological basis of consciousness. It is possible that Freud's thesis was developed in response to the experimental research of the American neuroscientist M. M. Garver.

  6. Modeling of relative intensity noise and terminal electrical noise of semiconductor lasers using artificial neural network

    NASA Astrophysics Data System (ADS)

    Rezaei, A.; Noori, L.

    2016-06-01

    In this paper, artificial neural network (ANN) is used to predict the source laser's relative intensity noise (RIN) and the terminal electrical noise (TEN) of semiconductor lasers. For this purpose, the multi-layer perceptron (MLP) neural network trained with the back propagation algorithm is used. To develop this model, the normalized bias current and frequency are selected as the input parameters and the RIN and TEN of semiconductor lasers are selected as the output parameters. The obtained results show that the proposed ANN model is in a good agreement with the numerical method, and a small error between the predicted values and the numerical solution is obtained. Therefore, the proposed ANN model is a useful, reliable, fast and cheap tool to predict the RIN and TEN of semiconductor lasers.

  7. Neural representation of orientation relative to gravity in the macaque cerebellum.

    PubMed

    Laurens, Jean; Meng, Hui; Angelaki, Dora E

    2013-12-18

    A fundamental challenge for maintaining spatial orientation and interacting with the world is knowledge of our orientation relative to gravity, i.e., head tilt. Sensing gravity is complicated because of Einstein's equivalence principle, in which gravitational and translational accelerations are physically indistinguishable. Theory has proposed that this ambiguity is solved by tracking head tilt through multisensory integration. Here we identify a group of Purkinje cells in the caudal cerebellar vermis with responses that reflect an estimate of head tilt. These tilt-selective cells are complementary to translation-selective Purkinje cells, such that their population activities sum to the net gravitoinertial acceleration encoded by the otolith organs, as predicted by theory. These findings reflect the remarkable ability of the cerebellum for neural computation and provide quantitative evidence for a neural representation of gravity, whose calculation relies on long-postulated theoretical concepts such as internal models and Bayesian priors.

  8. The role of consciousness in cognitive control and decision making

    PubMed Central

    van Gaal, Simon; de Lange, Floris P.; Cohen, Michael X

    2012-01-01

    Here we review studies on the complexity and strength of unconscious information processing. We focus on empirical evidence that relates awareness of information to cognitive control processes (e.g., response inhibition, conflict resolution, and task-switching), the life-time of information maintenance (e.g., working memory) and the possibility to integrate multiple pieces of information across space and time. Overall, the results that we review paint a picture of local and specific effects of unconscious information on various (high-level) brain regions, including areas in the prefrontal cortex. Although this neural activation does not elicit any conscious experience, it is functional and capable of influencing many perceptual, cognitive (control) and decision-related processes, sometimes even for relatively long periods of time. However, recent evidence also points out interesting dissociations between conscious and unconscious information processing when it comes to the duration, flexibility and the strategic use of that information for complex operations and decision-making. Based on the available evidence, we conclude that the role of task-relevance of subliminal information and meta-cognitive factors in unconscious cognition need more attention in future work. PMID:22586386

  9. Relations among pure-tone sound stimuli, neural activity, and the loudness sensation

    NASA Technical Reports Server (NTRS)

    Howes, W. L.

    1972-01-01

    Both the physiological and psychological responses to pure-tone sound stimuli are used to derive formulas which: (1) relate the loudness, loudness level, and sound-pressure level of pure tones; (2) apply continuously over most of the acoustic regime, including the loudness threshold; and (3) contain no undetermined coefficients. Some of the formulas are fundamental for calculating the loudness of any sound. Power-law formulas relating the pure-tone sound stimulus, neural activity, and loudness are derived from published data.

  10. Static torque-angle relation of human elbow joint estimated with artificial neural network technique.

    PubMed

    Uchiyama, T; Bessho, T; Akazawa, K

    1998-06-01

    Static relations between elbow joint angle and torque at constant muscle activity in normal volunteers were investigated with the aid of an artificial neural network technique. A subject sat on a chair and moved his upper- and forearm in a horizontal plane at the height of his shoulder. The subject was instructed to maintain the elbow joint at a pre-determined angle. The wrist was then pulled to extend the elbow joint by the gravitational force of a weight hanging from a pulley. Integrated electromyograms (IEMGs), elbow and shoulder joint angles and elbow joint torque were measured. Then the relation among IEMGs, joint angles and torque was modeled with the aid of the artificial neural network, where IEMGs and joint angles were the inputs and torque was the output. After back propagation learning, we presented various combinations of IEMGs, shoulder and elbow joint angles to the model and estimated the elbow joint torque to obtain the torque-angle relation for constant muscle activation. The elbow joint torque increased and then decreased with extension of the elbow joint. This suggests that if the forearm is displaced from an equilibrium point, the torque angle relation would not act like a simple spring. In a view of the musculoskeletal structure of the elbow joint, the relation between the elbow joint angle and the moment arm of the elbow flexor muscles seems to have a dominant effect on the torque-angle relation. PMID:9755039

  11. Cell cycle-related genes p57kip2, Cdk5 and Spin in the pathogenesis of neural tube defects.

    PubMed

    Li, Xinjun; Yang, Zhong; Zeng, Yi; Xu, Hong; Li, Hongli; Han, Yangyun; Long, Xiaodong; You, Chao

    2013-07-15

    In the field of developmental neurobiology, accurate and ordered regulation of the cell cycle and apoptosis are crucial factors contributing to the normal formation of the neural tube. Preliminary studies identified several genes involved in the development of neural tube defects. In this study, we established a model of developmental neural tube defects by administration of retinoic acid to pregnant rats. Gene chip hybridization analysis showed that genes related to the cell cycle and apoptosis, signal transduction, transcription and translation regulation, energy and metabolism, heat shock, and matrix and cytoskeletal proteins were all involved in the formation of developmental neural tube defects. Among these, cell cycle-related genes were predominant. Retinoic acid ment caused differential expression of three cell cycle-related genes p57kip2, Cdk5 and Spin, the expression levels of which were downregulated by retinoic acid and upregulated during normal neural tube formation. The results of this study indicate that cell cycle-related genes play an important role in the formation of neural tube defects. P57kip2, Cdk5 and Spin may be critical genes in the pathogenesis of neural tube defects.

  12. Are We Explaining Consciousness Yet?

    ERIC Educational Resources Information Center

    Dennett, Daniel

    2001-01-01

    Maintains that theorists are converging on a version of the global neuronal workspace model of consciousness, but that there are residual confusions to be dissolved. Asserts that global accessibility is not the "cause" of consciousness, it "is" consciousness. Argues that like fame, consciousness is not a momentary condition or a purely…

  13. Relation of obesity to neural activation in response to food commercials.

    PubMed

    Gearhardt, Ashley N; Yokum, Sonja; Stice, Eric; Harris, Jennifer L; Brownell, Kelly D

    2014-07-01

    Adolescents view thousands of food commercials annually, but the neural response to food advertising and its association with obesity is largely unknown. This study is the first to examine how neural response to food commercials differs from other stimuli (e.g. non-food commercials and television show) and to explore how this response may differ by weight status. The blood oxygen level-dependent functional magnetic resonance imaging activation was measured in 30 adolescents ranging from lean to obese in response to food and non-food commercials imbedded in a television show. Adolescents exhibited greater activation in regions implicated in visual processing (e.g. occipital gyrus), attention (e.g. parietal lobes), cognition (e.g. temporal gyrus and posterior cerebellar lobe), movement (e.g. anterior cerebellar cortex), somatosensory response (e.g. postcentral gyrus) and reward [e.g. orbitofrontal cortex and anterior cingulate cortex (ACC)] during food commercials. Obese participants exhibited less activation during food relative to non-food commercials in neural regions implicated in visual processing (e.g. cuneus), attention (e.g. posterior cerebellar lobe), reward (e.g. ventromedial prefrontal cortex and ACC) and salience detection (e.g. precuneus). Obese participants did exhibit greater activation in a region implicated in semantic control (e.g. medial temporal gyrus). These findings may inform current policy debates regarding the impact of food advertising to minors. PMID:23576811

  14. Automatic Neural Processing of Disorder-Related Stimuli in Social Anxiety Disorder: Faces and More

    PubMed Central

    Schulz, Claudia; Mothes-Lasch, Martin; Straube, Thomas

    2013-01-01

    It has been proposed that social anxiety disorder (SAD) is associated with automatic information processing biases resulting in hypersensitivity to signals of social threat such as negative facial expressions. However, the nature and extent of automatic processes in SAD on the behavioral and neural level is not entirely clear yet. The present review summarizes neuroscientific findings on automatic processing of facial threat but also other disorder-related stimuli such as emotional prosody or negative words in SAD. We review initial evidence for automatic activation of the amygdala, insula, and sensory cortices as well as for automatic early electrophysiological components. However, findings vary depending on tasks, stimuli, and neuroscientific methods. Only few studies set out to examine automatic neural processes directly and systematic attempts are as yet lacking. We suggest that future studies should: (1) use different stimulus modalities, (2) examine different emotional expressions, (3) compare findings in SAD with other anxiety disorders, (4) use more sophisticated experimental designs to investigate features of automaticity systematically, and (5) combine different neuroscientific methods (such as functional neuroimaging and electrophysiology). Finally, the understanding of neural automatic processes could also provide hints for therapeutic approaches. PMID:23745116

  15. Consequences of Post-Weaning Social Isolation on Anxiety Behavior and Related Neural Circuits in Rodents

    PubMed Central

    Lukkes, Jodi L.; Watt, Michael J.; Lowry, Christopher A.; Forster, Gina L.

    2009-01-01

    Exposure to adverse experiences in early-life is implicated in the later vulnerability to development of psychiatric disorders, including anxiety and affective disorders in humans. Adverse early-life experiences likely impart their long-term consequences on mental health by disrupting the normal development of neural systems involved in stress responses, emotional behavior and emotional states. Neural systems utilizing the neurotransmitters serotonin, dopamine and the neuropeptide corticotropin-releasing factor (CRF) are implicated in mediating emotive behaviors, and dysfunction of these neurochemical systems is associated with mood/anxiety disorders. These neural systems continue maturing until early or mid-adolescence in humans, thus alterations to their development are likely to contribute to the long-term consequences of adverse early-life experiences. A large body of literature suggests that post-weaning isolation rearing of rodents models the behavioral consequences of adverse early-life experiences in humans. Overall, the majority findings suggest that post-weaning social isolation that encompasses pre-adolescence produces long-lasting alterations to anxiety behavior, while measures of monoaminergic activity in various limbic regions during social isolation suggest alterations to dopamine and serotonin systems. The goal of this review is to evaluate and integrate findings from post-weaning social isolation studies specifically related to altered fear and anxiety behaviors and associated changes in neuroendocrine function and the activity of monoaminergic systems. PMID:19738931

  16. Power to Punish Norm Violations Affects the Neural Processes of Fairness-Related Decision Making.

    PubMed

    Cheng, Xuemei; Zheng, Li; Li, Lin; Guo, Xiuyan; Wang, Qianfeng; Lord, Anton; Hu, Zengxi; Yang, Guang

    2015-01-01

    Punishing norm violations is considered an important motive during rejection of unfair offers in the ultimatum game (UG). The present study investigates the impact of the power to punish norm violations on people's responses to unfairness and associated neural correlates. In the UG condition participants had the power to punish norm violations, while an alternate condition, the impunity game (IG), was presented where participants had no power to punish norm violations since rejection only reduced the responder's income to zero. Results showed that unfair offers were rejected more often in UG compared to IG. At the neural level, anterior insula and dorsal anterior cingulate cortex were more active when participants received and rejected unfair offers in both UG and IG. Moreover, greater dorsolateral prefrontal cortex activity was observed when participants rejected than accepted unfair offers in UG but not in IG. Ventromedial prefrontal cortex activation was higher in UG than IG when unfair offers were accepted as well as when rejecting unfair offers in IG as opposed to UG. Taken together, our results demonstrate that the power to punish norm violations affects not only people's behavioral responses to unfairness but also the neural correlates of the fairness-related social decision-making process.

  17. When your friends make you cringe: social closeness modulates vicarious embarrassment-related neural activity.

    PubMed

    Müller-Pinzler, Laura; Rademacher, Lena; Paulus, Frieder M; Krach, Sören

    2016-03-01

    Social closeness is a potent moderator of vicarious affect and specifically vicarious embarrassment. The neural pathways of how social closeness to another person affects our experience of vicarious embarrassment for the other's public flaws, failures and norm violations are yet unknown. To bridge this gap, we examined the neural response of participants while witnessing threats to either a friend's or a stranger's social integrity. The results show consistent responses of the anterior insula (AI) and anterior cingulate cortex (ACC), shared circuits of the aversive quality of affect, as well as the medial prefrontal cortex and temporal pole, central structures of the mentalizing network. However, the ACC/AI network activation was increased during vicarious embarrassment in response to a friend's failures. At the same time, the precuneus, a brain region associated with self-related thoughts, showed a specific activation and an increase in functional connectivity with the shared circuits in the frontal lobe while observing friends. This might indicate a neural systems mechanism for greater affective sharing and self-involvement while people interact with close others that are relevant to oneself.

  18. Transient Global Amnesia following Neural and Cardiac Angiography May Be Related to Ischemia.

    PubMed

    Duan, Hongzhou; Li, Liang; Zhang, Yang; Zhang, Jiayong; Chen, Ming; Bao, Shengde

    2016-01-01

    Introduction. Transient global amnesia (TGA) following angiography is rare, and the pathogenesis has not been illustrated clearly till now. The aim of this research is to explore the pathogenesis of TGA following angiography by analyzing our data and reviewing the literature. Methods. We retrospectively studied 20836 cases with angiography in our hospital between 2007 and 2015 and found 9 cases with TGA following angiography. The data of these 9 cases were analyzed. Results. We found all 9 cases with TGA following neural angiography (5 in 4360) or cardiac angiography (4 in 8817) and no case with TGA following peripheral angiography (0 in 7659). Statistical difference was found when comparing the neural and cardiac angiography group with peripheral group (p = 0.022). Two cases with TGA were confirmed with small acute infarctions in hippocampus after angiography. This might be related to the microemboli which were rushed into vertebral artery following blood flow during neural angiography or cardiac angiography. There was no statistical difference when comparing the different approaches for angiography (p = 0.82) and different contrast agents (p = 0.619). Conclusion. Based on the positive findings of imaging study and our analysis, we speculate that ischemia in the medial temporal lobe with the involvement of the hippocampus might be an important reason of TGA following angiography. PMID:27419129

  19. Dopamine neurons modulate neural encoding and expression of depression-related behaviour.

    PubMed

    Tye, Kay M; Mirzabekov, Julie J; Warden, Melissa R; Ferenczi, Emily A; Tsai, Hsing-Chen; Finkelstein, Joel; Kim, Sung-Yon; Adhikari, Avishek; Thompson, Kimberly R; Andalman, Aaron S; Gunaydin, Lisa A; Witten, Ilana B; Deisseroth, Karl

    2013-01-24

    Major depression is characterized by diverse debilitating symptoms that include hopelessness and anhedonia. Dopamine neurons involved in reward and motivation are among many neural populations that have been hypothesized to be relevant, and certain antidepressant treatments, including medications and brain stimulation therapies, can influence the complex dopamine system. Until now it has not been possible to test this hypothesis directly, even in animal models, as existing therapeutic interventions are unable to specifically target dopamine neurons. Here we investigated directly the causal contributions of defined dopamine neurons to multidimensional depression-like phenotypes induced by chronic mild stress, by integrating behavioural, pharmacological, optogenetic and electrophysiological methods in freely moving rodents. We found that bidirectional control (inhibition or excitation) of specified midbrain dopamine neurons immediately and bidirectionally modulates (induces or relieves) multiple independent depression symptoms caused by chronic stress. By probing the circuit implementation of these effects, we observed that optogenetic recruitment of these dopamine neurons potently alters the neural encoding of depression-related behaviours in the downstream nucleus accumbens of freely moving rodents, suggesting that processes affecting depression symptoms may involve alterations in the neural encoding of action in limbic circuitry.

  20. Relation of obesity to neural activation in response to food commercials

    PubMed Central

    Yokum, Sonja; Stice, Eric; Harris, Jennifer L.; Brownell, Kelly D.

    2014-01-01

    Adolescents view thousands of food commercials annually, but the neural response to food advertising and its association with obesity is largely unknown. This study is the first to examine how neural response to food commercials differs from other stimuli (e.g. non-food commercials and television show) and to explore how this response may differ by weight status. The blood oxygen level-dependent functional magnetic resonance imaging activation was measured in 30 adolescents ranging from lean to obese in response to food and non-food commercials imbedded in a television show. Adolescents exhibited greater activation in regions implicated in visual processing (e.g. occipital gyrus), attention (e.g. parietal lobes), cognition (e.g. temporal gyrus and posterior cerebellar lobe), movement (e.g. anterior cerebellar cortex), somatosensory response (e.g. postcentral gyrus) and reward [e.g. orbitofrontal cortex and anterior cingulate cortex (ACC)] during food commercials. Obese participants exhibited less activation during food relative to non-food commercials in neural regions implicated in visual processing (e.g. cuneus), attention (e.g. posterior cerebellar lobe), reward (e.g. ventromedial prefrontal cortex and ACC) and salience detection (e.g. precuneus). Obese participants did exhibit greater activation in a region implicated in semantic control (e.g. medial temporal gyrus). These findings may inform current policy debates regarding the impact of food advertising to minors. PMID:23576811

  1. Transient Global Amnesia following Neural and Cardiac Angiography May Be Related to Ischemia

    PubMed Central

    Zhang, Yang; Chen, Ming; Bao, Shengde

    2016-01-01

    Introduction. Transient global amnesia (TGA) following angiography is rare, and the pathogenesis has not been illustrated clearly till now. The aim of this research is to explore the pathogenesis of TGA following angiography by analyzing our data and reviewing the literature. Methods. We retrospectively studied 20836 cases with angiography in our hospital between 2007 and 2015 and found 9 cases with TGA following angiography. The data of these 9 cases were analyzed. Results. We found all 9 cases with TGA following neural angiography (5 in 4360) or cardiac angiography (4 in 8817) and no case with TGA following peripheral angiography (0 in 7659). Statistical difference was found when comparing the neural and cardiac angiography group with peripheral group (p = 0.022). Two cases with TGA were confirmed with small acute infarctions in hippocampus after angiography. This might be related to the microemboli which were rushed into vertebral artery following blood flow during neural angiography or cardiac angiography. There was no statistical difference when comparing the different approaches for angiography (p = 0.82) and different contrast agents (p = 0.619). Conclusion. Based on the positive findings of imaging study and our analysis, we speculate that ischemia in the medial temporal lobe with the involvement of the hippocampus might be an important reason of TGA following angiography. PMID:27419129

  2. Dopamine neurons modulate neural encoding and expression of depression-related behaviour

    PubMed Central

    Ferenczi, Emily A.; Tsai, Hsing-Chen; Finkelstein, Joel; Kim, Sung-Yon; Adhikari, Avishek; Thompson, Kimberly R.; Andalman, Aaron S.; Gunaydin, Lisa A.; Witten, Ilana B.; Deisseroth, Karl

    2014-01-01

    Major depression is characterized by diverse debilitating symptoms that include hopelessness and anhedonia1. Dopamine neurons involved in reward and motivation2–9 are among many neural populations that have been hypothesized to be relevant10, and certain antidepressant treatments, including medications and brain stimulation therapies, can influence the complex dopamine system. Until now it has not been possible to test this hypothesis directly, even in animal models, as existing therapeutic interventions are unable to specifically target dopamine neurons. Here we investigated directly the causal contributions of defined dopamine neurons to multidimensional depression-like phenotypes induced by chronic mild stress, by integrating behavioural, pharmacological, optogenetic and electrophysiological methods in freely moving rodents. We found that bidirectional control (inhibition or excitation) of specified midbrain dopamine neurons immediately and bidirectionally modulates (induces or relieves) multiple independent depression symptoms caused by chronic stress. By probing the circuit implementation of these effects, we observed that optogenetic recruitment of these dopamine neurons potently alters the neural encoding of depression-related behaviours in the downstream nucleus accumbens of freely moving rodents, suggesting that processes affecting depression symptoms may involve alterations in the neural encoding of action in limbic circuitry. PMID:23235822

  3. The innate alarm circuit in post-traumatic stress disorder: Conscious and subconscious processing of fear- and trauma-related cues.

    PubMed

    Rabellino, Daniela; Densmore, Maria; Frewen, Paul A; Théberge, Jean; Lanius, Ruth A

    2016-02-28

    Fast defensive responses to salient threatening stimuli are an important clinical feature of post-traumatic stress disorder (PTSD). We investigated the neural correlates of subliminal and supraliminal processing of fearful faces and individualized trauma-related words in individuals with PTSD (n=26) compared with healthy controls (n=20) using functional magnetic resonance imaging. Increased activity in the right cerebellum and the posterior cingulum was observed in individuals with PTSD during subliminal processing of trauma-related words, whereas increased activity of the basal forebrain was found within the PTSD group when processing supraliminal trauma-related words. Moreover, significant positive correlations were found between re-experiencing symptoms and response within the amygdala, and between hyper-arousal symptoms and response within the periaqueductal gray matter, during subliminal processing of trauma-related words and during supraliminal processing of fearful faces, respectively. These findings further our understanding of rapid threat processing and defensive responses, highlighting the role of the cerebellum and periaqueductal gray matter as part of an 'innate alarm system' in PTSD.

  4. EPR, Biology, and Consciousness

    NASA Astrophysics Data System (ADS)

    Goradia, Shantilal

    2006-03-01

    It seems that Darwin, in his concluding remark (1859, p490) ruled out the possibility of cosmic connection to evolution based on the fixed law of gravity, known then. More recent Dirac’s Large Number Hypothesis as described in http://www.arXiv.org/pdf/physics/0210040 v1 raises a possibility that the universal constant of gravity is decreasing and all coupling constants are increasing with time, so reported by some observations. Deeper investigation of the connection between evolution and the variation of the universal constant of gravity seems worthwhile to see if it impacts the passage of time in a stronger (gravitational according to the spirit of the above archive) field and affects the aging process, and explains locality and causality in random evolutionary mutations. If there is no physical locality and causality consistent with the special theory of relativity, there must be some spiritual locality and causality at superluminal speeds to explain the implicit hidden variables. Then there is a question of how to test spiritual locality and causality. Psychic effects and dream signals look promising, if they exist and can be tested with space age technology. This is neither about religion nor about Einstein’s orthodoxy in light of the spirit of EPR. This is about frontiers of science of the new millennium: biology, and consciousness.

  5. Promoting the use of personally relevant stimuli for investigating patients with disorders of consciousness.

    PubMed

    Perrin, Fabien; Castro, Maïté; Tillmann, Barbara; Luauté, Jacques

    2015-01-01

    Sensory stimuli are used to evaluate and to restore cognitive functions and consciousness in patients with a disorder of consciousness (DOC) following a severe brain injury. Although sophisticated protocols can help assessing higher order cognitive functions and awareness, one major drawback is their lack of sensitivity. The aim of the present review is to show that stimulus selection is crucial for an accurate evaluation of the state of patients with disorders of consciousness as it determines the levels of processing that the patient can have with stimulation from his/her environment. The probability to observe a behavioral response or a cerebral response is increased when her/his personal history and/or her/his personal preferences are taken into account. We show that personally relevant stimuli (i.e., with emotional, autobiographical, or self-related characteristics) are associated with clearer signs of perception than are irrelevant stimuli in patients with DOC. Among personally relevant stimuli, music appears to be a promising clinical tool as it boosts perception and cognition in patients with DOC and could also serve as a prognostic tool. We suggest that the effect of music on cerebral processes in patients might reflect the music's capacity to act both on the external and internal neural networks supporting consciousness. PMID:26284020

  6. Promoting the use of personally relevant stimuli for investigating patients with disorders of consciousness

    PubMed Central

    Perrin, Fabien; Castro, Maïté; Tillmann, Barbara; Luauté, Jacques

    2015-01-01

    Sensory stimuli are used to evaluate and to restore cognitive functions and consciousness in patients with a disorder of consciousness (DOC) following a severe brain injury. Although sophisticated protocols can help assessing higher order cognitive functions and awareness, one major drawback is their lack of sensitivity. The aim of the present review is to show that stimulus selection is crucial for an accurate evaluation of the state of patients with disorders of consciousness as it determines the levels of processing that the patient can have with stimulation from his/her environment. The probability to observe a behavioral response or a cerebral response is increased when her/his personal history and/or her/his personal preferences are taken into account. We show that personally relevant stimuli (i.e., with emotional, autobiographical, or self-related characteristics) are associated with clearer signs of perception than are irrelevant stimuli in patients with DOC. Among personally relevant stimuli, music appears to be a promising clinical tool as it boosts perception and cognition in patients with DOC and could also serve as a prognostic tool. We suggest that the effect of music on cerebral processes in patients might reflect the music’s capacity to act both on the external and internal neural networks supporting consciousness. PMID:26284020

  7. Different effects of executive and visuospatial working memory on visual consciousness.

    PubMed

    De Loof, Esther; Poppe, Louise; Cleeremans, Axel; Gevers, Wim; Van Opstal, Filip

    2015-11-01

    Consciousness and working memory are two widely studied cognitive phenomena. Although they have been closely tied on a theoretical and neural level, empirical work that investigates their relation is largely lacking. In this study, the relationship between visual consciousness and different working memory components is investigated by using a dual-task paradigm. More specifically, while participants were performing a visual detection task to measure their visual awareness threshold, they had to concurrently perform either an executive or visuospatial working memory task. We hypothesized that visual consciousness would be hindered depending on the type and the size of the load in working memory. Results showed that maintaining visuospatial content in working memory hinders visual awareness, irrespective of the amount of information maintained. By contrast, the detection threshold was progressively affected under increasing executive load. Interestingly, increasing executive load had a generic effect on detection speed, calling into question whether its obstructing effect is specific to the visual awareness threshold. Together, these results indicate that visual consciousness depends differently on executive and visuospatial working memory.

  8. Promoting the use of personally relevant stimuli for investigating patients with disorders of consciousness.

    PubMed

    Perrin, Fabien; Castro, Maïté; Tillmann, Barbara; Luauté, Jacques

    2015-01-01

    Sensory stimuli are used to evaluate and to restore cognitive functions and consciousness in patients with a disorder of consciousness (DOC) following a severe brain injury. Although sophisticated protocols can help assessing higher order cognitive functions and awareness, one major drawback is their lack of sensitivity. The aim of the present review is to show that stimulus selection is crucial for an accurate evaluation of the state of patients with disorders of consciousness as it determines the levels of processing that the patient can have with stimulation from his/her environment. The probability to observe a behavioral response or a cerebral response is increased when her/his personal history and/or her/his personal preferences are taken into account. We show that personally relevant stimuli (i.e., with emotional, autobiographical, or self-related characteristics) are associated with clearer signs of perception than are irrelevant stimuli in patients with DOC. Among personally relevant stimuli, music appears to be a promising clinical tool as it boosts perception and cognition in patients with DOC and could also serve as a prognostic tool. We suggest that the effect of music on cerebral processes in patients might reflect the music's capacity to act both on the external and internal neural networks supporting consciousness.

  9. Examining the neural correlates of emergent equivalence relations in Fragile X syndrome

    PubMed Central

    Klabunde, Megan; Saggar, Manish; Hustyi, Kristin M.; Kelley, Ryan G.; Reiss, Allan L.; Hall, Scott S.

    2015-01-01

    The neural mechanisms underlying the formation of stimulus equivalence relations are poorly understood, particularly in individuals with specific learning impairments. As part of a larger study, we used functional magnetic resonance imaging (fMRI) while participants with fragile X syndrome (FXS), and age- and IQ-matched controls with intellectual disability, were required to form new equivalence relations in the scanner. Following intensive training on matching fractions to pie charts (A=B relations) and pie charts to decimals (B=C relations) outside the scanner over a 2-day period, participants were tested on the trained (A=B, B=C) relations, as well as emergent symmetry (i.e., B=A and C=B) and transitivity/equivalence (i.e., A=C and C=A) relations inside the scanner. Eight participants with FXS (6 female, 2 male) and 10 controls, aged 10 to 23 years, were able to obtain at least 66.7% correct on the trained relations in the scanner and were included in the fMRI analyses. Across both groups, results showed that the emergence of symmetry relations was correlated with increased brain activation in the left inferior parietal lobule, left postcentral gyrus, and left insula, broadly supporting previous investigations of stimulus equivalence research in neurotypical populations. On the test of emergent transitivity/equivalence relations, activation was significantly greater in individuals with FXS compared with controls in the right middle temporal gyrus, left superior frontal gyrus and left precuneus. These data indicate that neural execution was significantly different in individuals with FXS than in age- and IQ-matched controls during stimulus equivalence formation. Further research concerning how gene-brain-behavior interactions may influence the emergence of stimulus equivalence in individuals with intellectual disabilities is needed. PMID:26250852

  10. The complementarity of consciousness.

    PubMed

    Jahn, R G

    2007-01-01

    The concept of complementarity, originally proposed by Bohr in a microphysical context, and subsequently extended by himself, Heisenberg and Pauli to encompass subjective as well as objective dimensions of human experience, can be further expanded to apply to many common attitudes of human consciousness. At issue is the replacement of strict polar opposition of superficially antithetical consciousness capacities, such as analysis and synthesis, logic and intuition, or doing and being, by more generous conjugation that allows the pairs to operate in constructive triangulation and harmony. In this format, the physical principle of uncertainty also acquires metaphoric relevance in limiting the attainable sharpness of specification of any consciousness complements, and may serve to define their optimum balance in establishing reality. These principles thus lend themselves to representation of wave-like vs. particle-like operations of consciousness; to trade-offs between rigor and ambience in consciousness research; to generic masculine/feminine reinforcement; and to the interplay of science and spirit in any creative enterprise.

  11. Handedness is related to neural mechanisms underlying hemispheric lateralization of face processing

    PubMed Central

    Frässle, Stefan; Krach, Sören; Paulus, Frieder Michel; Jansen, Andreas

    2016-01-01

    While the right-hemispheric lateralization of the face perception network is well established, recent evidence suggests that handedness affects the cerebral lateralization of face processing at the hierarchical level of the fusiform face area (FFA). However, the neural mechanisms underlying differential hemispheric lateralization of face perception in right- and left-handers are largely unknown. Using dynamic causal modeling (DCM) for fMRI, we aimed to unravel the putative processes that mediate handedness-related differences by investigating the effective connectivity in the bilateral core face perception network. Our results reveal an enhanced recruitment of the left FFA in left-handers compared to right-handers, as evidenced by more pronounced face-specific modulatory influences on both intra- and interhemispheric connections. As structural and physiological correlates of handedness-related differences in face processing, right- and left-handers varied with regard to their gray matter volume in the left fusiform gyrus and their pupil responses to face stimuli. Overall, these results describe how handedness is related to the lateralization of the core face perception network, and point to different neural mechanisms underlying face processing in right- and left-handers. In a wider context, this demonstrates the entanglement of structurally and functionally remote brain networks, suggesting a broader underlying process regulating brain lateralization. PMID:27250879

  12. Neural Responses During Social Reflection in Relatives of Schizophrenia Patients: Relationship to Subclinical Delusions

    PubMed Central

    Brent, Benjamin K.; Seidman, Larry J.; Coombs, Garth; Keshavan, Matcheri S.; Moran, Joseph M.; Holt, Daphne J.

    2014-01-01

    Background Deficits in the capacity to reflect about the self and others (“social reflection” [SR]) have been identified in schizophrenia, as well as in people with a genetic or clinical risk for the disorder. However, the neural underpinnings of these abnormalities are incompletely understood. Methods Responses of a network of brain regions known to be involved in self and other processing (e.g., medial prefrontal cortex (MPFC), posterior cingulate cortex (PCC), and superior temporal gyrus (STG)) were measured during SR in 16 first-degree, non-psychotic relatives (RELS) of schizophrenia patients and 16 healthy controls (CONS). Because of prior evidence linking dysfunction in this network and delusions, associations between SR-related responses of this network and subclinical delusions (measured using the Peters et al. Delusions Inventory) were also examined. Results Compared with CONS, RELS showed significantly less SR-related activity of the right and left PCC and STG. Moreover, response magnitudes were negatively correlated with levels of delusional thinking across both groups. Conclusions These findings suggest that aberrant function of the neural circuitry underpinning SR is associated with the genetic liability to schizophrenia and confers vulnerability to delusional beliefs. PMID:24951401

  13. Handedness is related to neural mechanisms underlying hemispheric lateralization of face processing

    NASA Astrophysics Data System (ADS)

    Frässle, Stefan; Krach, Sören; Paulus, Frieder Michel; Jansen, Andreas

    2016-06-01

    While the right-hemispheric lateralization of the face perception network is well established, recent evidence suggests that handedness affects the cerebral lateralization of face processing at the hierarchical level of the fusiform face area (FFA). However, the neural mechanisms underlying differential hemispheric lateralization of face perception in right- and left-handers are largely unknown. Using dynamic causal modeling (DCM) for fMRI, we aimed to unravel the putative processes that mediate handedness-related differences by investigating the effective connectivity in the bilateral core face perception network. Our results reveal an enhanced recruitment of the left FFA in left-handers compared to right-handers, as evidenced by more pronounced face-specific modulatory influences on both intra- and interhemispheric connections. As structural and physiological correlates of handedness-related differences in face processing, right- and left-handers varied with regard to their gray matter volume in the left fusiform gyrus and their pupil responses to face stimuli. Overall, these results describe how handedness is related to the lateralization of the core face perception network, and point to different neural mechanisms underlying face processing in right- and left-handers. In a wider context, this demonstrates the entanglement of structurally and functionally remote brain networks, suggesting a broader underlying process regulating brain lateralization.

  14. Neural mechanisms regulating different forms of risk-related decision-making: Insights from animal models.

    PubMed

    Orsini, Caitlin A; Moorman, David E; Young, Jared W; Setlow, Barry; Floresco, Stan B

    2015-11-01

    Over the past 20 years there has been a growing interest in the neural underpinnings of cost/benefit decision-making. Recent studies with animal models have made considerable advances in our understanding of how different prefrontal, striatal, limbic and monoaminergic circuits interact to promote efficient risk/reward decision-making, and how dysfunction in these circuits underlies aberrant decision-making observed in numerous psychiatric disorders. This review will highlight recent findings from studies exploring these questions using a variety of behavioral assays, as well as molecular, pharmacological, neurophysiological, and translational approaches. We begin with a discussion of how neural systems related to decision subcomponents may interact to generate more complex decisions involving risk and uncertainty. This is followed by an overview of interactions between prefrontal-amygdala-dopamine and habenular circuits in regulating choice between certain and uncertain rewards and how different modes of dopamine transmission may contribute to these processes. These data will be compared with results from other studies investigating the contribution of some of these systems to guiding decision-making related to rewards vs. punishment. Lastly, we provide a brief summary of impairments in risk-related decision-making associated with psychiatric disorders, highlighting recent translational studies in laboratory animals.

  15. [Experimental skeletal teratogenesis: a disturbance of relative osteo-neural growth].

    PubMed

    Roth, M

    1976-01-01

    The previously suggested concept of the closest growth relations existing between the bony and the nervous tissue at the organ level of the spinal cord and the peripheral (including the facial) nervous trunks is experimentally buttressed. It is shown that the normal gross-morphological features of the vertebrae as well as of the tubular bones (viz., their length, physiological curvatures and terminal expansions) result from the adaptation of the bone growth to the slower proceeding and vulnerable neural extensive growth, viz., from a physiological osteo-neural growth disproportion. The more or less conspicuous growth in length of the facial skeleton depends upon the phylogenetically established, more or less evolved extensive-growth potentially of the facial nervous trunks as well. The growth relation existing between the developing brain and its bony case applies essentially even for the axial organ, the extremities as well as for the facial skeleton. The experimental findings speak in favour of the theoretical expectation that the typical teratogenic deformities of the extremities (micromelia), of the spine (scoliosis, defects of the vertebrae and of the ribs) as well as of the beak (jaws) which may be produced by a great number of most diverse teratogens, result from the adaptation of the bone growth to the growth-insufficient nervous trunks, viz., from the pathologically enhanced osteo-neural growth disproportion. The cleft palate and the digital defects (syndactylia, oligodactylia) may be readily explained by the growth-inhibition of the palatal and digital nervous structures as well. The vertebrate body may be thus conceived as composed of 2 growth types, viz., the neural-extensive and the cellular-divisional (mitotic). The former is represented by an extremely dense feltwork of nerve fibers and trunks (the DONALDSON'S "nervous skeleton") which is "stuffed" with the other, mostly mitotically growing tissues. The 2 growth types are closely related partly at

  16. Cajal and consciousness. Introduction.

    PubMed

    Marijuán, P C

    2001-04-01

    One hundred years after Santiago Ramón Cajal established the bases of modern neuroscience in his masterpiece Textura del sistema nervioso del hombre y de los vertebrados, the question is stated again: What is the status of consciousness today? The responses in this book, by contemporary leading figures of neuroscience, evolution, molecular biology, computer science, and quantum physics, collectively compose a fascinating conceptual landscape. Both the evolutionary emergence of consciousness and its development towards the highest level may be analyzed by a wealth of new theories and hypotheses, including Cajal's prescient ones. Some noticeable gaps remain, however. Celebrating the centennial of Textura is a timely occasion to reassess how close--and how far--our system of the sciences is to explaining consciousness.

  17. Conscious Vision in Action.

    PubMed

    Briscoe, Robert; Schwenkler, John

    2015-09-01

    It is natural to assume that the fine-grained and highly accurate spatial information present in visual experience is often used to guide our bodily actions. Yet this assumption has been challenged by proponents of the Two Visual Systems Hypothesis (TVSH), according to which visuomotor programming is the responsibility of a "zombie" processing stream whose sources of bottom-up spatial information are entirely non-conscious (Clark, 2007, 2009; Goodale & Milner, 1992, 2004a; Milner & Goodale, 1995/2006, 2008). In many formulations of TVSH, the role of conscious vision in action is limited to "recognizing objects, selecting targets for action, and determining what kinds of action, broadly speaking, to perform" (Clark, 2007, p. 570). Our aim in this study is to show that the available evidence not only fails to support this dichotomous view but actually reveals a significant role for conscious vision in motor programming, especially for actions that require deliberate attention. PMID:25845648

  18. Measuring consciousness in dreams: the lucidity and consciousness in dreams scale.

    PubMed

    Voss, Ursula; Schermelleh-Engel, Karin; Windt, Jennifer; Frenzel, Clemens; Hobson, Allan

    2013-03-01

    In this article, we present results from an interdisciplinary research project aimed at assessing consciousness in dreams. For this purpose, we compared lucid dreams with normal non-lucid dreams from REM sleep. Both lucid and non-lucid dreams are an important contrast condition for theories of waking consciousness, giving valuable insights into the structure of conscious experience and its neural correlates during sleep. However, the precise differences between lucid and non-lucid dreams remain poorly understood. The construction of the Lucidity and Consciousness in Dreams scale (LuCiD) was based on theoretical considerations and empirical observations. Exploratory factor analysis of the data from the first survey identified eight factors that were validated in a second survey using confirmatory factor analysis: INSIGHT, CONTROL, THOUGHT, REALISM, MEMORY, DISSOCIATION, NEGATIVE EMOTION, and POSITIVE EMOTION. While all factors are involved in dream consciousness, realism and negative emotion do not differentiate between lucid and non-lucid dreams, suggesting that lucid insight is separable from both bizarreness in dreams and a change in the subjectively experienced realism of the dream. PMID:23220345

  19. Measuring consciousness in dreams: the lucidity and consciousness in dreams scale.

    PubMed

    Voss, Ursula; Schermelleh-Engel, Karin; Windt, Jennifer; Frenzel, Clemens; Hobson, Allan

    2013-03-01

    In this article, we present results from an interdisciplinary research project aimed at assessing consciousness in dreams. For this purpose, we compared lucid dreams with normal non-lucid dreams from REM sleep. Both lucid and non-lucid dreams are an important contrast condition for theories of waking consciousness, giving valuable insights into the structure of conscious experience and its neural correlates during sleep. However, the precise differences between lucid and non-lucid dreams remain poorly understood. The construction of the Lucidity and Consciousness in Dreams scale (LuCiD) was based on theoretical considerations and empirical observations. Exploratory factor analysis of the data from the first survey identified eight factors that were validated in a second survey using confirmatory factor analysis: INSIGHT, CONTROL, THOUGHT, REALISM, MEMORY, DISSOCIATION, NEGATIVE EMOTION, and POSITIVE EMOTION. While all factors are involved in dream consciousness, realism and negative emotion do not differentiate between lucid and non-lucid dreams, suggesting that lucid insight is separable from both bizarreness in dreams and a change in the subjectively experienced realism of the dream.

  20. Objects of consciousness.

    PubMed

    Hoffman, Donald D; Prakash, Chetan

    2014-01-01

    Current models of visual perception typically assume that human vision estimates true properties of physical objects, properties that exist even if unperceived. However, recent studies of perceptual evolution, using evolutionary games and genetic algorithms, reveal that natural selection often drives true perceptions to extinction when they compete with perceptions tuned to fitness rather than truth: Perception guides adaptive behavior; it does not estimate a preexisting physical truth. Moreover, shifting from evolutionary biology to quantum physics, there is reason to disbelieve in preexisting physical truths: Certain interpretations of quantum theory deny that dynamical properties of physical objects have definite values when unobserved. In some of these interpretations the observer is fundamental, and wave functions are compendia of subjective probabilities, not preexisting elements of physical reality. These two considerations, from evolutionary biology and quantum physics, suggest that current models of object perception require fundamental reformulation. Here we begin such a reformulation, starting with a formal model of consciousness that we call a "conscious agent." We develop the dynamics of interacting conscious agents, and study how the perception of objects and space-time can emerge from such dynamics. We show that one particular object, the quantum free particle, has a wave function that is identical in form to the harmonic functions that characterize the asymptotic dynamics of conscious agents; particles are vibrations not of strings but of interacting conscious agents. This allows us to reinterpret physical properties such as position, momentum, and energy as properties of interacting conscious agents, rather than as preexisting physical truths. We sketch how this approach might extend to the perception of relativistic quantum objects, and to classical objects of macroscopic scale.

  1. Objects of consciousness

    PubMed Central

    Hoffman, Donald D.; Prakash, Chetan

    2014-01-01

    Current models of visual perception typically assume that human vision estimates true properties of physical objects, properties that exist even if unperceived. However, recent studies of perceptual evolution, using evolutionary games and genetic algorithms, reveal that natural selection often drives true perceptions to extinction when they compete with perceptions tuned to fitness rather than truth: Perception guides adaptive behavior; it does not estimate a preexisting physical truth. Moreover, shifting from evolutionary biology to quantum physics, there is reason to disbelieve in preexisting physical truths: Certain interpretations of quantum theory deny that dynamical properties of physical objects have definite values when unobserved. In some of these interpretations the observer is fundamental, and wave functions are compendia of subjective probabilities, not preexisting elements of physical reality. These two considerations, from evolutionary biology and quantum physics, suggest that current models of object perception require fundamental reformulation. Here we begin such a reformulation, starting with a formal model of consciousness that we call a “conscious agent.” We develop the dynamics of interacting conscious agents, and study how the perception of objects and space-time can emerge from such dynamics. We show that one particular object, the quantum free particle, has a wave function that is identical in form to the harmonic functions that characterize the asymptotic dynamics of conscious agents; particles are vibrations not of strings but of interacting conscious agents. This allows us to reinterpret physical properties such as position, momentum, and energy as properties of interacting conscious agents, rather than as preexisting physical truths. We sketch how this approach might extend to the perception of relativistic quantum objects, and to classical objects of macroscopic scale. PMID:24987382

  2. Objects of consciousness.

    PubMed

    Hoffman, Donald D; Prakash, Chetan

    2014-01-01

    Current models of visual perception typically assume that human vision estimates true properties of physical objects, properties that exist even if unperceived. However, recent studies of perceptual evolution, using evolutionary games and genetic algorithms, reveal that natural selection often drives true perceptions to extinction when they compete with perceptions tuned to fitness rather than truth: Perception guides adaptive behavior; it does not estimate a preexisting physical truth. Moreover, shifting from evolutionary biology to quantum physics, there is reason to disbelieve in preexisting physical truths: Certain interpretations of quantum theory deny that dynamical properties of physical objects have definite values when unobserved. In some of these interpretations the observer is fundamental, and wave functions are compendia of subjective probabilities, not preexisting elements of physical reality. These two considerations, from evolutionary biology and quantum physics, suggest that current models of object perception require fundamental reformulation. Here we begin such a reformulation, starting with a formal model of consciousness that we call a "conscious agent." We develop the dynamics of interacting conscious agents, and study how the perception of objects and space-time can emerge from such dynamics. We show that one particular object, the quantum free particle, has a wave function that is identical in form to the harmonic functions that characterize the asymptotic dynamics of conscious agents; particles are vibrations not of strings but of interacting conscious agents. This allows us to reinterpret physical properties such as position, momentum, and energy as properties of interacting conscious agents, rather than as preexisting physical truths. We sketch how this approach might extend to the perception of relativistic quantum objects, and to classical objects of macroscopic scale. PMID:24987382

  3. Cephalopod consciousness: behavioural evidence.

    PubMed

    Mather, Jennifer A

    2008-03-01

    Behavioural evidence suggests that cephalopod molluscs may have a form of primary consciousness. First, the linkage of brain to behaviour seen in lateralization, sleep and through a developmental context is similar to that of mammals and birds. Second, cephalopods, especially octopuses, are heavily dependent on learning in response to both visual and tactile cues, and may have domain generality and form simple concepts. Third, these animals are aware of their position, both within themselves and in larger space, including having a working memory of foraging areas in the recent past. Thus if using a 'global workspace' which evaluates memory input and focuses attention is the criterion, cephalopods appear to have primary consciousness.

  4. DNA methyltransferase activity is required for memory-related neural plasticity in the lateral amygdala.

    PubMed

    Maddox, Stephanie A; Watts, Casey S; Schafe, Glenn E

    2014-01-01

    We have previously shown that auditory Pavlovian fear conditioning is associated with an increase in DNA methyltransferase (DNMT) expression in the lateral amygdala (LA) and that intra-LA infusion or bath application of an inhibitor of DNMT activity impairs the consolidation of an auditory fear memory and long-term potentiation (LTP) at thalamic and cortical inputs to the LA, in vitro. In the present study, we use awake behaving neurophysiological techniques to examine the role of DNMT activity in memory-related neurophysiological changes accompanying fear memory consolidation and reconsolidation in the LA, in vivo. We show that auditory fear conditioning results in a training-related enhancement in the amplitude of short-latency auditory-evoked field potentials (AEFPs) in the LA. Intra-LA infusion of a DNMT inhibitor impairs both fear memory consolidation and, in parallel, the consolidation of training-related neural plasticity in the LA; that is, short-term memory (STM) and short-term training-related increases in AEFP amplitude in the LA are intact, while long-term memory (LTM) and long-term retention of training-related increases in AEFP amplitudes are impaired. In separate experiments, we show that intra-LA infusion of a DNMT inhibitor following retrieval of an auditory fear memory has no effect on post-retrieval STM or short-term retention of training-related changes in AEFP amplitude in the LA, but significantly impairs both post-retrieval LTM and long-term retention of AEFP amplitude changes in the LA. These findings are the first to demonstrate the necessity of DNMT activity in the consolidation and reconsolidation of memory-associated neural plasticity, in vivo.

  5. Genetic dyslexia risk variant is related to neural connectivity patterns underlying phonological awareness in children.

    PubMed

    Skeide, Michael A; Kirsten, Holger; Kraft, Indra; Schaadt, Gesa; Müller, Bent; Neef, Nicole; Brauer, Jens; Wilcke, Arndt; Emmrich, Frank; Boltze, Johannes; Friederici, Angela D

    2015-09-01

    Phonological awareness is the best-validated predictor of reading and spelling skill and therefore highly relevant for developmental dyslexia. Prior imaging genetics studies link several dyslexia risk genes to either brain-functional or brain-structural factors of phonological deficits. However, coherent evidence for genetic associations with both functional and structural neural phenotypes underlying variation in phonological awareness has not yet been provided. Here we demonstrate that rs11100040, a reported modifier of SLC2A3, is related to the functional connectivity of left fronto-temporal phonological processing areas at resting state in a sample of 9- to 12-year-old children. Furthermore, we provide evidence that rs11100040 is related to the fractional anisotropy of the arcuate fasciculus, which forms the structural connection between these areas. This structural connectivity phenotype is associated with phonological awareness, which is in turn associated with the individual retrospective risk scores in an early dyslexia screening as well as to spelling. These results suggest a link between a dyslexia risk genotype and a functional as well as a structural neural phenotype, which is associated with a phonological awareness phenotype. The present study goes beyond previous work by integrating genetic, brain-functional and brain-structural aspects of phonological awareness within a single approach. These combined findings might be another step towards a multimodal biomarker for developmental dyslexia.

  6. Reward-related neural dysfunction across depression and impulsivity: A dimensional approach.

    PubMed

    Ait Oumeziane, Belel; Foti, Dan

    2016-08-01

    Recent theoretical models underline reward sensitivity as a potential endophenotype for major depressive disorder. Neural and behavioral evidence reveals depression is associated with reduced reward sensitivity. However, reward dysfunction is not unique to depression, as it is also common across disorders of poor impulse control. We examined the interrelationships of depression (Depression, Anxiety, and Stress Scale [DASS-21]) and impulsivity (UPPS-P Impulsive Behavior Scale) with reward sensitivity among a large, representative sample (N = 260). ERPs were recorded to isolate two neural indicators of consummatory reward processing: initial evaluation of rewards in the 250-350 ms time window postonset of feedback (reward positivity [RewP]), and salience to monetary outcomes (P3). Significant interactions were observed between depression and impulsivity facets across these two stages of reward processing: depression and positive urgency predicted RewP amplitude to reward outcomes (win vs. loss); depression and one other impulsivity trait, (lack of) premeditation, predicted P3 amplitude to monetary outcomes. Conversely, high symptoms of depression were related to three biobehavioral profiles: (1) blunted RewP in conjunction with high positive urgency, (2) combination of blunted RewP and low (lack of) premeditation, and (3) blunted P3 to monetary wins/losses, in conjunction with low (lack of) premeditation. Findings illustrate that reward-related dysfunctions may be optimally conceptualized when examining the interactions between dimensions of internalizing and externalizing psychopathology. PMID:27193188

  7. Neural correlates of conceptual object priming in young and older adults: An event-related fMRI study

    PubMed Central

    Ballesteros, Soledad; Bischof, Gérard N.; Goh, Joshua O.; Park, Denise C.

    2012-01-01

    In this event-related fMRI study, we investigated age-related differences in brain activity associated with conceptual repetition priming in young and older adults. Participants performed a speeded “living/non-living” classification task with three repetitions of familiar objects. Both young and older adults showed a similar magnitude of behavioral priming to repeated objects and evidencing repetition-related activation reductions in fusiform gyrus, superior occipital, middle and inferior temporal cortex, as well as inferior frontal and insula regions. The neural priming effect in young adults was extensive and continued through both the second and third stimulus repetitions, whereas neural priming in older adults was markedly attenuated and reached floor at the second repetition. In young adults, greater neural priming in multiple brain regions correlated with greater behavioral facilitation whereas in older adults, only activation reduction in the left inferior frontal correlated with faster behavioral responses. These findings provide evidence for altered neural priming in older adults despite preserved behavioral priming, and suggest the possibility that age-invariant behavioral priming is observed as a result of more sustained neural processing of stimuli in older adults which may be a form of compensatory neural activity. PMID:23102512

  8. Neural correlates of conceptual object priming in young and older adults: an event-related functional magnetic resonance imaging study.

    PubMed

    Ballesteros, Soledad; Bischof, Gérard N; Goh, Joshua O; Park, Denise C

    2013-04-01

    In this event-related functional magnetic resonance imaging study, we investigated age-related differences in brain activity associated with conceptual repetition priming in young and older adults. Participants performed a speeded "living/nonliving" classification task with 3 repetitions of familiar objects. Both young and older adults showed a similar magnitude of behavioral priming to repeated objects and evidenced repetition-related activation reductions in fusiform gyrus, superior occipital, middle, and inferior temporal cortex, and inferior frontal and insula regions. The neural priming effect in young adults was extensive and continued through both the second and third stimulus repetitions, and neural priming in older adults was markedly attenuated and reached floor at the second repetition. In young adults, greater neural priming in multiple brain regions correlated with greater behavioral facilitation and in older adults, only activation reduction in the left inferior frontal correlated with faster behavioral responses. These findings provide evidence for altered neural priming in older adults despite preserved behavioral priming, and suggest the possibility that age-invariant behavioral priming is observed as a result of more sustained neural processing of stimuli in older adults which might be a form of compensatory neural activity.

  9. Neural correlates of conceptual object priming in young and older adults: an event-related functional magnetic resonance imaging study.

    PubMed

    Ballesteros, Soledad; Bischof, Gérard N; Goh, Joshua O; Park, Denise C

    2013-04-01

    In this event-related functional magnetic resonance imaging study, we investigated age-related differences in brain activity associated with conceptual repetition priming in young and older adults. Participants performed a speeded "living/nonliving" classification task with 3 repetitions of familiar objects. Both young and older adults showed a similar magnitude of behavioral priming to repeated objects and evidenced repetition-related activation reductions in fusiform gyrus, superior occipital, middle, and inferior temporal cortex, and inferior frontal and insula regions. The neural priming effect in young adults was extensive and continued through both the second and third stimulus repetitions, and neural priming in older adults was markedly attenuated and reached floor at the second repetition. In young adults, greater neural priming in multiple brain regions correlated with greater behavioral facilitation and in older adults, only activation reduction in the left inferior frontal correlated with faster behavioral responses. These findings provide evidence for altered neural priming in older adults despite preserved behavioral priming, and suggest the possibility that age-invariant behavioral priming is observed as a result of more sustained neural processing of stimuli in older adults which might be a form of compensatory neural activity. PMID:23102512

  10. [Francisco Varela's neurophenomenology of time: temporality of consciousness explained?].

    PubMed

    Vargas, Esteban; Canales-Johnson, Andrés; Claudio Fuentes, B

    2013-01-01

    This article attempts to clarify Francisco Varela's proposal of a neurophenomenology of time consciousness in the light of distinctions based on the philosophical literature of phenomenology and recent advances of neurobiology. The analysis is carried out considering three aspects. In the first of them, we discuss the phenomenological aspect of consciousness, accessible in first-person, which describes time as a structure with three inseparable moments (past-present-future) and three levels of temporality, and not merely as the chronometric time or clock time. In the second one, we analyze the neurobiological aspect of consciousness that tends to "explain" the phenomenological time in terms of three possible levels of neuronal integration. Thus, we propose a correspondence between the levels of phenomenological time and neural integration processes. Finally, we try to analyze this "correspondence" and the issues that follow from this by considering that the notion of time in this correspondence is, in essence, the clock time and not the phenomenological time consciousness.

  11. Electrophysiological correlates of block-wise strategic adaptations to consciously and unconsciously triggered conflict.

    PubMed

    Jiang, Jun; van Gaal, Simon; Bailey, Kira; Chen, Antao; Zhang, Qinglin

    2013-11-01

    The role of consciousness in conflict adaptation has been a topic of much debate. The purpose of the current study was to investigate the neural correlates of block-wise conflict adaptations elicited by conscious and unconscious conflicting stimuli in a meta-contrast masked priming task. Event-related potentials (ERPs) were recorded while individuals responded to prime-target pairs in mostly congruent (80% congruent trials, 20% incongruent trials) and mostly incongruent blocks of trials (20% congruent trials, 80% incongruent trials). Mean response times and error rates revealed that the conflict effect (incongruent trials-congruent trials) was reduced in mostly incongruent blocks relative to mostly congruent blocks. Furthermore, conflict related ERP signals (the amplitude difference between congruent and incongruent trials) for three ERP components (early occipito-parietal negativity, the fronto-central N2 and the centro-parietal P3) were attenuated in mostly incongruent blocks compared to mostly congruent blocks, reflecting block-wise adaptation to the frequency of conflict. The conflict-related frontal N2 component differentiated most strongly between visibility conditions. These results further specify the electrophysiological correlates of block-wise strategic adaptations to consciously and unconsciously elicited conflict.

  12. Cybernetics and consciousness.

    PubMed

    Trabka, J

    1999-01-01

    This paper is a review of hypotheses of consciousness which arose from application of the theory of information and regulation and the cybernetic theory of mathematical machines in medicine. The author presents these hypotheses on the examples of his own works.

  13. States of Consciousness

    PubMed Central

    Bell, Carl C.

    1980-01-01

    The art of psychiatry offers many different viewpoints from which to catalog behavior and thinking styles and, therefore, many physicians tend to have difficulty in conceptualizing features of behavioral medicine. A classification of states of consciousness with clinical examples of such states is presented to aid in a more clear understanding of human behavior. PMID:7365821

  14. Adolescents’ risky decision-making activates neural networks related to social cognition and cognitive control processes

    PubMed Central

    Rodrigo, María José; Padrón, Iván; de Vega, Manuel; Ferstl, Evelyn C.

    2014-01-01

    This study examines by means of functional magnetic resonance imaging the neural mechanisms underlying adolescents’ risk decision-making in social contexts. We hypothesize that the social context could engage brain regions associated with social cognition processes and developmental changes are also expected. Sixty participants (adolescents: 17–18, and young adults: 21–22 years old) read narratives describing typical situations of decision-making in the presence of peers. They were asked to make choices in risky situations (e.g., taking or refusing a drug) or ambiguous situations (e.g., eating a hamburger or a hotdog). Risky as compared to ambiguous scenarios activated bilateral temporoparietal junction (TPJ), bilateral middle temporal gyrus (MTG), right medial prefrontal cortex, and the precuneus bilaterally; i.e., brain regions related to social cognition processes, such as self-reflection and theory of mind (ToM). In addition, brain structures related to cognitive control were active [right anterior cingulate cortex (ACC), bilateral dorsolateral prefrontal cortex (DLPFC), bilateral orbitofrontal cortex], whereas no significant clusters were obtained in the reward system (ventral striatum). Choosing the dangerous option involved a further activation of control areas (ACC) and emotional and social cognition areas (temporal pole). Adolescents employed more neural resources than young adults in the right DLPFC and the right TPJ in risk situations. When choosing the dangerous option, young adults showed a further engagement in ToM related regions (bilateral MTG) and in motor control regions related to the planning of actions (pre-supplementary motor area). Finally, the right insula and the right superior temporal gyrus were more activated in women than in men, suggesting more emotional involvement and more intensive modeling of the others’ perspective in the risky conditions. These findings call for more comprehensive developmental accounts of decision

  15. Adolescents' risky decision-making activates neural networks related to social cognition and cognitive control processes.

    PubMed

    Rodrigo, María José; Padrón, Iván; de Vega, Manuel; Ferstl, Evelyn C

    2014-01-01

    This study examines by means of functional magnetic resonance imaging the neural mechanisms underlying adolescents' risk decision-making in social contexts. We hypothesize that the social context could engage brain regions associated with social cognition processes and developmental changes are also expected. Sixty participants (adolescents: 17-18, and young adults: 21-22 years old) read narratives describing typical situations of decision-making in the presence of peers. They were asked to make choices in risky situations (e.g., taking or refusing a drug) or ambiguous situations (e.g., eating a hamburger or a hotdog). Risky as compared to ambiguous scenarios activated bilateral temporoparietal junction (TPJ), bilateral middle temporal gyrus (MTG), right medial prefrontal cortex, and the precuneus bilaterally; i.e., brain regions related to social cognition processes, such as self-reflection and theory of mind (ToM). In addition, brain structures related to cognitive control were active [right anterior cingulate cortex (ACC), bilateral dorsolateral prefrontal cortex (DLPFC), bilateral orbitofrontal cortex], whereas no significant clusters were obtained in the reward system (ventral striatum). Choosing the dangerous option involved a further activation of control areas (ACC) and emotional and social cognition areas (temporal pole). Adolescents employed more neural resources than young adults in the right DLPFC and the right TPJ in risk situations. When choosing the dangerous option, young adults showed a further engagement in ToM related regions (bilateral MTG) and in motor control regions related to the planning of actions (pre-supplementary motor area). Finally, the right insula and the right superior temporal gyrus were more activated in women than in men, suggesting more emotional involvement and more intensive modeling of the others' perspective in the risky conditions. These findings call for more comprehensive developmental accounts of decision-making in

  16. Disentangling the attention network test: behavioral, event related potentials, and neural source analyses

    PubMed Central

    Galvao-Carmona, Alejandro; González-Rosa, Javier J.; Hidalgo-Muñoz, Antonio R.; Páramo, Dolores; Benítez, María L.; Izquierdo, Guillermo; Vázquez-Marrufo, Manuel

    2014-01-01

    Background: The study of the attentional system remains a challenge for current neuroscience. The “Attention Network Test” (ANT) was designed to study simultaneously three different attentional networks (alerting, orienting, and executive) based in subtraction of different experimental conditions. However, some studies recommend caution with these calculations due to the interactions between the attentional networks. In particular, it is highly relevant that several interpretations about attentional impairment have arisen from these calculations in diverse pathologies. Event related potentials (ERPs) and neural source analysis can be applied to disentangle the relationships between these attentional networks not specifically shown by behavioral measures. Results: This study shows that there is a basic level of alerting (tonic alerting) in the no cue (NC) condition, represented by a slow negative trend in the ERP trace prior to the onset of the target stimuli. A progressive increase in the CNV amplitude related to the amount of information provided by the cue conditions is also shown. Neural source analysis reveals specific modulations of the CNV related to a task-related expectancy presented in the NC condition; a late modulation triggered by the central cue (CC) condition and probably representing a generic motor preparation; and an early and late modulation for spatial cue (SC) condition suggesting specific motor and sensory preactivation. Finally, the first component in the information processing of the target stimuli modulated by the interaction between orienting network and the executive system can be represented by N1. Conclusions: The ANT is useful as a paradigm to study specific attentional mechanisms and their interactions. However, calculation of network effects is based in subtractions with non-comparable experimental conditions, as evidenced by the present data, which can induce misinterpretations in the study of the attentional capacity in human

  17. Neural activity related to cognitive and emotional empathy in post-traumatic stress disorder.

    PubMed

    Mazza, Monica; Tempesta, Daniela; Pino, Maria Chiara; Nigri, Anna; Catalucci, Alessia; Guadagni, Veronica; Gallucci, Massimo; Iaria, Giuseppe; Ferrara, Michele

    2015-04-01

    The aim of this study is to evaluate the empathic ability and its functional brain correlates in post-traumatic stress disorder subjects (PTSD). Seven PTSD subjects and ten healthy controls, all present in the L'Aquila area during the earthquake of the April 2009, underwent fMRI during which they performed a modified version of the Multifaceted Empathy Test. PTSD patients showed impairments in implicit and explicit emotional empathy, but not in cognitive empathy. Brain responses during cognitive empathy showed an increased activation in patients compared to controls in the right medial frontal gyrus and the left inferior frontal gyrus. During implicit emotional empathy responses patients with PTSD, compared to controls, exhibited greater neural activity in the left pallidum and right insula; instead the control group showed an increased activation in right inferior frontal gyrus. Finally, in the explicit emotional empathy responses the PTSD group showed a reduced neural activity in the left insula and the left inferior frontal gyrus. The behavioral deficit limited to the emotional empathy dimension, accompanied by different patterns of activation in empathy related brain structures, represent a first piece of evidence of a dissociation between emotional and cognitive empathy in PTSD patients. The present findings support the idea that empathy is a multidimensional process, with different facets depending on distinct anatomical substrates. PMID:25555525

  18. Global familiarity of visual stimuli affects repetition-related neural plasticity but not repetition priming

    PubMed Central

    Soldan, Anja; Zarahn, Eric; Hilton, H. John; Stern, Yaakov

    2007-01-01

    In this study we tested the prediction of the component process model of priming (Henson, 2003) that repetition priming of familiar and unfamiliar objects produces qualitatively different neural repetition effects. In an fMRI study, subjects viewed four repetitions of familiar objects and globally unfamiliar objects with familiar components. Reliable behavioral priming occurred for both item types across the four presentations and was of a similar magnitude for both stimulus types. The imaging data was analyzed using multivariate linear modeling, which permits explicit testing of the hypothesis that the repetition effects for familiar and unfamiliar objects are qualitatively different (i.e., non-scaled versions of one another). The results showed the presence of two qualitatively different latent spatial patterns of repetition effects from presenation one to presentation four for familiar and unfamilar objects, indicating that familiarity with an object’s global structural, semantic, or lexical features is an important factor in priming-related neural plasticity. The first latent spatial pattern strongly weighted regions with a similar repetition effect for both item types. The second pattern strongly weighted regions contributing a repetition suppression effect for the familiar objects and repetition enhancement for the unfamiliar objects, particularly the posterior insula, superior temporal gyrus, precentral gyrus, and cingulate cortex. This differential repetition effect might reflect the formation of novel memory representations for the unfamiliar items, which already exist for the familiar objects, consistent with the component-process model of priming. PMID:17913513

  19. Neural correlates of abstract rule learning: an event-related potential study.

    PubMed

    Sun, Fang; Hoshi-Shiba, Reiko; Abla, Dilshat; Okanoya, Kazuo

    2012-09-01

    Abstract rule learning is a fundamental aspect of human cognition, and is essential for language acquisition. However, despite its importance, the neural mechanisms underlying abstract rule learning are still largely unclear. In this study, we investigated the neural correlates of abstract rule learning by recording auditory event-related potentials (ERPs). Participants were first presented with artificial three-syllable sequences containing ABA or ABB abstract rules for learning. They were then tested on sequences of novel syllables following the ABA or ABB abstract rules, half of which were inconsistent with the rule previously learned. Grand-averaged ERPs revealed significant decreases in positivity at 200-260ms in response to consistent sequences during the earlier session of the test phase, and increased negativity at around 400ms in response to inconsistent sequences in the later session. The potentials exhibited a left anterior-dominant distribution. The appearance of the N400-like negativity in the later session suggests that temporal ERP changes occurred with the abstract rule learning process, and that the N400-like negativity is associated with the acquisition of abstract rules.

  20. Trait self-esteem and neural activities related to self-evaluation and social feedback.

    PubMed

    Yang, Juan; Xu, Xiaofan; Chen, Yu; Shi, Zhenhao; Han, Shihui

    2016-01-01

    Self-esteem has been associated with neural responses to self-reflection and attitude toward social feedback but in different brain regions. The distinct associations might arise from different tasks or task-related attitudes in the previous studies. The current study aimed to clarify these by investigating the association between self-esteem and neural responses to evaluation of one's own personality traits and of others' opinion about one's own personality traits. We scanned 25 college students using functional MRI during evaluation of oneself or evaluation of social feedback. Trait self-esteem was measured using the Rosenberg self-esteem scale after scanning. Whole-brain regression analyses revealed that trait self-esteem was associated with the bilateral orbitofrontal activity during evaluation of one's own positive traits but with activities in the medial prefrontal cortex, posterior cingulate, and occipital cortices during evaluation of positive social feedback. Our findings suggest that trait self-esteem modulates the degree of both affective processes in the orbitofrontal cortex during self-reflection and cognitive processes in the medial prefrontal cortex during evaluation of social feedback. PMID:26842975

  1. Neural activity related to cognitive and emotional empathy in post-traumatic stress disorder.

    PubMed

    Mazza, Monica; Tempesta, Daniela; Pino, Maria Chiara; Nigri, Anna; Catalucci, Alessia; Guadagni, Veronica; Gallucci, Massimo; Iaria, Giuseppe; Ferrara, Michele

    2015-04-01

    The aim of this study is to evaluate the empathic ability and its functional brain correlates in post-traumatic stress disorder subjects (PTSD). Seven PTSD subjects and ten healthy controls, all present in the L'Aquila area during the earthquake of the April 2009, underwent fMRI during which they performed a modified version of the Multifaceted Empathy Test. PTSD patients showed impairments in implicit and explicit emotional empathy, but not in cognitive empathy. Brain responses during cognitive empathy showed an increased activation in patients compared to controls in the right medial frontal gyrus and the left inferior frontal gyrus. During implicit emotional empathy responses patients with PTSD, compared to controls, exhibited greater neural activity in the left pallidum and right insula; instead the control group showed an increased activation in right inferior frontal gyrus. Finally, in the explicit emotional empathy responses the PTSD group showed a reduced neural activity in the left insula and the left inferior frontal gyrus. The behavioral deficit limited to the emotional empathy dimension, accompanied by different patterns of activation in empathy related brain structures, represent a first piece of evidence of a dissociation between emotional and cognitive empathy in PTSD patients. The present findings support the idea that empathy is a multidimensional process, with different facets depending on distinct anatomical substrates.

  2. Trait self-esteem and neural activities related to self-evaluation and social feedback

    PubMed Central

    Yang, Juan; Xu, Xiaofan; Chen, Yu; Shi, Zhenhao; Han, Shihui

    2016-01-01

    Self-esteem has been associated with neural responses to self-reflection and attitude toward social feedback but in different brain regions. The distinct associations might arise from different tasks or task-related attitudes in the previous studies. The current study aimed to clarify these by investigating the association between self-esteem and neural responses to evaluation of one’s own personality traits and of others’ opinion about one’s own personality traits. We scanned 25 college students using functional MRI during evaluation of oneself or evaluation of social feedback. Trait self-esteem was measured using the Rosenberg self-esteem scale after scanning. Whole-brain regression analyses revealed that trait self-esteem was associated with the bilateral orbitofrontal activity during evaluation of one’s own positive traits but with activities in the medial prefrontal cortex, posterior cingulate, and occipital cortices during evaluation of positive social feedback. Our findings suggest that trait self-esteem modulates the degree of both affective processes in the orbitofrontal cortex during self-reflection and cognitive processes in the medial prefrontal cortex during evaluation of social feedback. PMID:26842975

  3. Trait self-esteem and neural activities related to self-evaluation and social feedback.

    PubMed

    Yang, Juan; Xu, Xiaofan; Chen, Yu; Shi, Zhenhao; Han, Shihui

    2016-01-01

    Self-esteem has been associated with neural responses to self-reflection and attitude toward social feedback but in different brain regions. The distinct associations might arise from different tasks or task-related attitudes in the previous studies. The current study aimed to clarify these by investigating the association between self-esteem and neural responses to evaluation of one's own personality traits and of others' opinion about one's own personality traits. We scanned 25 college students using functional MRI during evaluation of oneself or evaluation of social feedback. Trait self-esteem was measured using the Rosenberg self-esteem scale after scanning. Whole-brain regression analyses revealed that trait self-esteem was associated with the bilateral orbitofrontal activity during evaluation of one's own positive traits but with activities in the medial prefrontal cortex, posterior cingulate, and occipital cortices during evaluation of positive social feedback. Our findings suggest that trait self-esteem modulates the degree of both affective processes in the orbitofrontal cortex during self-reflection and cognitive processes in the medial prefrontal cortex during evaluation of social feedback.

  4. Afference copy as a quantitative neurophysiological model for consciousness.

    PubMed

    Cornelis, Hugo; Coop, Allan D

    2014-06-01

    Consciousness is a topic of considerable human curiosity with a long history of philosophical analysis and debate. We consider there is nothing particularly complicated about consciousness when viewed as a necessary process of the vertebrate nervous system. Here, we propose a physiological "explanatory gap" is created during each present moment by the temporal requirements of neuronal activity. The gap extends from the time exteroceptive and proprioceptive stimuli activate the nervous system until they emerge into consciousness. During this "moment", it is impossible for an organism to have any conscious knowledge of the ongoing evolution of its environment. In our schematic model, a mechanism of "afference copy" is employed to bridge the explanatory gap with consciously experienced percepts. These percepts are fabricated from the conjunction of the cumulative memory of previous relevant experience and the given stimuli. They are structured to provide the best possible prediction of the expected content of subjective conscious experience likely to occur during the period of the gap. The model is based on the proposition that the neural circuitry necessary to support consciousness is a product of sub/preconscious reflexive learning and recall processes. Based on a review of various psychological and neurophysiological findings, we develop a framework which contextualizes the model and briefly discuss further implications. PMID:25012715

  5. General Markers of Conscious Visual Perception and Their Timing.

    PubMed

    Rutiku, Renate; Aru, Jaan; Bachmann, Talis

    2016-01-01

    Previous studies have observed different onset times for the neural markers of conscious perception. This variability could be attributed to procedural differences between studies. Here we show that the onset times for the markers of conscious visual perception can strongly vary even within a single study. A heterogeneous stimulus set was presented at threshold contrast. Trials with and without conscious perception were contrasted on 100 balanced subsets of the data. Importantly, the 100 subsets with heterogeneous stimuli did not differ in stimulus content, but only with regard to specific trials used. This approach enabled us to study general markers of conscious visual perception independent of stimulus content, characterize their onset and its variability within one study. N200 and P300 were the two reliable markers of conscious visual perception common to all perceived stimuli and absent for all non-perceived stimuli. The estimated mean onset latency for both markers was shortly after 200 ms. However, the onset latency of these markers was associated with considerable variability depending on which subsets of the data were considered. We show that it is first and foremost the amplitude fluctuation in the condition without conscious perception that explains the observed variability in onset latencies of the markers of conscious visual perception.

  6. Afference copy as a quantitative neurophysiological model for consciousness.

    PubMed

    Cornelis, Hugo; Coop, Allan D

    2014-06-01

    Consciousness is a topic of considerable human curiosity with a long history of philosophical analysis and debate. We consider there is nothing particularly complicated about consciousness when viewed as a necessary process of the vertebrate nervous system. Here, we propose a physiological "explanatory gap" is created during each present moment by the temporal requirements of neuronal activity. The gap extends from the time exteroceptive and proprioceptive stimuli activate the nervous system until they emerge into consciousness. During this "moment", it is impossible for an organism to have any conscious knowledge of the ongoing evolution of its environment. In our schematic model, a mechanism of "afference copy" is employed to bridge the explanatory gap with consciously experienced percepts. These percepts are fabricated from the conjunction of the cumulative memory of previous relevant experience and the given stimuli. They are structured to provide the best possible prediction of the expected content of subjective conscious experience likely to occur during the period of the gap. The model is based on the proposition that the neural circuitry necessary to support consciousness is a product of sub/preconscious reflexive learning and recall processes. Based on a review of various psychological and neurophysiological findings, we develop a framework which contextualizes the model and briefly discuss further implications.

  7. General Markers of Conscious Visual Perception and Their Timing

    PubMed Central

    Rutiku, Renate; Aru, Jaan; Bachmann, Talis

    2016-01-01

    Previous studies have observed different onset times for the neural markers of conscious perception. This variability could be attributed to procedural differences between studies. Here we show that the onset times for the markers of conscious visual perception can strongly vary even within a single study. A heterogeneous stimulus set was presented at threshold contrast. Trials with and without conscious perception were contrasted on 100 balanced subsets of the data. Importantly, the 100 subsets with heterogeneous stimuli did not differ in stimulus content, but only with regard to specific trials used. This approach enabled us to study general markers of conscious visual perception independent of stimulus content, characterize their onset and its variability within one study. N200 and P300 were the two reliable markers of conscious visual perception common to all perceived stimuli and absent for all non-perceived stimuli. The estimated mean onset latency for both markers was shortly after 200 ms. However, the onset latency of these markers was associated with considerable variability depending on which subsets of the data were considered. We show that it is first and foremost the amplitude fluctuation in the condition without conscious perception that explains the observed variability in onset latencies of the markers of conscious visual perception. PMID:26869905

  8. Inferential Bridging Relations Reveal Distinct Neural Mechanisms: Evidence from Event-Related Brain Potentials

    ERIC Educational Resources Information Center

    Burkhardt, Petra

    2006-01-01

    This study investigates the online comprehension of Determiner Phrases (DPs) as a function of the given-new distinction in two-sentence texts in German and further focuses on DPs whose interpretation depends on inferential information (so-called "bridging relations"). Previous reaction time studies report an advantage of given over new…

  9. Do cortical midline variability and low frequency fluctuations mediate William James' "Stream of Consciousness"? "Neurophenomenal Balance Hypothesis" of "Inner Time Consciousness".

    PubMed

    Northoff, Georg

    2014-11-01

    William James famously characterized consciousness by 'stream of consciousness' which describes the temporal continuity and flow of the contents of consciousness in our 'inner time consciousness'. More specifically he distinguished between "substantive parts", the contents of consciousness, and "transitive parts", the linkages between different contents. While much research has recently focused on the substantive parts, the neural mechanisms underlying the transitive parts and their characterization by the balance between 'sensible continuity' and 'continuous change' remain unclear. The aim of this paper is to develop so-called neuro-phenomenal hypothesis about specifically the transitive parts and their two phenomenal hallmark features, sensible continuity and continuous change in 'inner time consciousness'. Based on recent findings, I hypothesize that the cortical midline structures and their high degree of variability and strong low frequency fluctuations play an essential role in mediating the phenomenal balance between sensible continuity and continuous change.

  10. Behavioral and neural correlates of visual preference decision

    NASA Astrophysics Data System (ADS)

    Shimojo, Shinsuke

    2009-02-01

    Three sets of findings are reported here, all related to behavioral and neural correlates of preference decision. First, when one is engaged in a preference decision task with free observation, one's gaze is biased towards the to-be-chosen stimulus (eg. face) long before (s)he is consciously aware of the decision ("gaze cascade effect"). Second, an fMRI study suggested that implicit activity in a subcortical structure (the Nucleus Accumbens) precedes cognitive and conscious decision of preference. Finally, both novelty and familiarity causally contribute to attractiveness, but differently across object categories (such as faces and natural scenes). Taken together, these results point to dynamical and implicit processes both in short- and long-term, towards conscious preference decision. Finally, some discussion will be given on aesthetic decision (i.e. "beauty").

  11. Answering questions about consciousness by modeling perception as covert behavior.

    PubMed

    Markkula, Gustav

    2015-01-01

    Two main open questions in current consciousness research concern (i) the neural correlates of consciousness (NCC) and (ii) the relationship between neural activity and first-person, subjective experience. Here, possible answers are sketched for both of these, by means of a model-based analysis of what is required for one to admit having a conscious experience. To this end, a model is proposed that allows reasoning, albeit necessarily in a simplistic manner, about all of the so called "easy problems" of consciousness, from discrimination of stimuli to control of behavior and language. First, it is argued that current neuroscientific knowledge supports the view of perception and action selection as two examples of the same basic phenomenon, such that one can meaningfully refer to neuronal activations involved in perception as covert behavior. Building on existing neuroscientific and psychological models, a narrative behavior model is proposed, outlining how the brain selects covert (and sometimes overt) behaviors to construct a complex, multi-level narrative about what it is like to be the individual in question. It is hypothesized that we tend to admit a conscious experience of X if, at the time of judging consciousness, we find ourselves acceptably capable of performing narrative behavior describing X. It is argued that the proposed account reconciles seemingly conflicting empirical results, previously presented as evidence for competing theories of consciousness, and suggests that well-defined, experiment-independent NCCs are unlikely to exist. Finally, an analysis is made of what the modeled narrative behavior machinery is and is not capable of. It is discussed how an organism endowed with such a machinery could, from its first-person perspective, come to adopt notions such as "subjective experience," and of there being "hard problems," and "explanatory gaps" to be addressed in order to understand consciousness.

  12. Answering questions about consciousness by modeling perception as covert behavior.

    PubMed

    Markkula, Gustav

    2015-01-01

    Two main open questions in current consciousness research concern (i) the neural correlates of consciousness (NCC) and (ii) the relationship between neural activity and first-person, subjective experience. Here, possible answers are sketched for both of these, by means of a model-based analysis of what is required for one to admit having a conscious experience. To this end, a model is proposed that allows reasoning, albeit necessarily in a simplistic manner, about all of the so called "easy problems" of consciousness, from discrimination of stimuli to control of behavior and language. First, it is argued that current neuroscientific knowledge supports the view of perception and action selection as two examples of the same basic phenomenon, such that one can meaningfully refer to neuronal activations involved in perception as covert behavior. Building on existing neuroscientific and psychological models, a narrative behavior model is proposed, outlining how the brain selects covert (and sometimes overt) behaviors to construct a complex, multi-level narrative about what it is like to be the individual in question. It is hypothesized that we tend to admit a conscious experience of X if, at the time of judging consciousness, we find ourselves acceptably capable of performing narrative behavior describing X. It is argued that the proposed account reconciles seemingly conflicting empirical results, previously presented as evidence for competing theories of consciousness, and suggests that well-defined, experiment-independent NCCs are unlikely to exist. Finally, an analysis is made of what the modeled narrative behavior machinery is and is not capable of. It is discussed how an organism endowed with such a machinery could, from its first-person perspective, come to adopt notions such as "subjective experience," and of there being "hard problems," and "explanatory gaps" to be addressed in order to understand consciousness. PMID:26136704

  13. Answering questions about consciousness by modeling perception as covert behavior

    PubMed Central

    Markkula, Gustav

    2015-01-01

    Two main open questions in current consciousness research concern (i) the neural correlates of consciousness (NCC) and (ii) the relationship between neural activity and first-person, subjective experience. Here, possible answers are sketched for both of these, by means of a model-based analysis of what is required for one to admit having a conscious experience. To this end, a model is proposed that allows reasoning, albeit necessarily in a simplistic manner, about all of the so called “easy problems” of consciousness, from discrimination of stimuli to control of behavior and language. First, it is argued that current neuroscientific knowledge supports the view of perception and action selection as two examples of the same basic phenomenon, such that one can meaningfully refer to neuronal activations involved in perception as covert behavior. Building on existing neuroscientific and psychological models, a narrative behavior model is proposed, outlining how the brain selects covert (and sometimes overt) behaviors to construct a complex, multi-level narrative about what it is like to be the individual in question. It is hypothesized that we tend to admit a conscious experience of X if, at the time of judging consciousness, we find ourselves acceptably capable of performing narrative behavior describing X. It is argued that the proposed account reconciles seemingly conflicting empirical results, previously presented as evidence for competing theories of consciousness, and suggests that well-defined, experiment-independent NCCs are unlikely to exist. Finally, an analysis is made of what the modeled narrative behavior machinery is and is not capable of. It is discussed how an organism endowed with such a machinery could, from its first-person perspective, come to adopt notions such as “subjective experience,” and of there being “hard problems,” and “explanatory gaps” to be addressed in order to understand consciousness. PMID:26136704

  14. The evolutionary and genetic origins of consciousness in the Cambrian Period over 500 million years ago

    PubMed Central

    Feinberg, Todd E.; Mallatt, Jon

    2013-01-01

    Vertebrates evolved in the Cambrian Period before 520 million years ago, but we do not know when or how consciousness arose in the history of the vertebrate brain. Here we propose multiple levels of isomorphic or somatotopic neural representations as an objective marker for sensory consciousness. All extant vertebrates have these, so we deduce that consciousness extends back to the group's origin. The first conscious sense may have been vision. Then vision, coupled with additional sensory systems derived from ectodermal placodes and neural crest, transformed primitive reflexive systems into image forming brains that map and perceive the external world and the body's interior. We posit that the minimum requirement for sensory consciousness and qualia is a brain including a forebrain (but not necessarily a developed cerebral cortex/pallium), midbrain, and hindbrain. This brain must also have (1) hierarchical systems of intercommunicating, isomorphically organized, processing nuclei that extensively integrate the different senses into representations that emerge in upper levels of the neural hierarchy; and (2) a widespread reticular formation that integrates the sensory inputs and contributes to attention, awareness, and neural synchronization. We propose a two-step evolutionary history, in which the optic tectum was the original center of multi-sensory conscious perception (as in fish and amphibians: step 1), followed by a gradual shift of this center to the dorsal pallium or its cerebral cortex (in mammals, reptiles, birds: step 2). We address objections to the hypothesis and call for more studies of fish and amphibians. In our view, the lamprey has all the neural requisites and is likely the simplest extant vertebrate with sensory consciousness and qualia. Genes that pattern the proposed elements of consciousness (isomorphism, neural crest, placodes) have been identified in all vertebrates. Thus, consciousness is in the genes, some of which are already known. PMID

  15. Age-related changes to the neural correlates of working memory which emerge after midlife

    PubMed Central

    Macpherson, Helen N.; White, David J.; Ellis, Kathryn A.; Stough, Con; Camfield, David; Silberstein, Richard; Pipingas, Andrew

    2014-01-01

    Previous research has indicated that the neural processes which underlie working memory change with age. Both age-related increases and decreases to cortical activity have been reported. This study investigated which stages of working memory are most vulnerable to age-related changes after midlife. To do this we examined age-differences in the 13 Hz steady state visually evoked potential (SSVEP) associated with a spatial working memory delayed response task. Participants were 130 healthy adults separated into a midlife (40–60 years) and an older group (61–82 years). Relative to the midlife group, older adults demonstrated greater bilateral frontal activity during encoding and this pattern of activity was related to better working memory performance. In contrast, evidence of age-related under activation was identified over left frontal regions during retrieval. Findings from this study suggest that after midlife, under-activation of frontal regions during retrieval contributes to age-related decline in working memory performance. PMID:24795625

  16. The Neural Bases of Taxonomic and Thematic Conceptual Relations: An MEG Study

    PubMed Central

    Lewis, Gwyneth A.; Poeppel, David; Murphy, Gregory L.

    2015-01-01

    Converging evidence from behavioral and neuroimaging studies of human concepts indicate distinct neural systems for taxonomic and thematic knowledge. A recent study of naming in aphasia found involvement of the anterior temporal lobe (ATL) during taxonomic (feature-based) processing, and involvement of the temporoparietal junction (TPJ) during thematic (function-based) processing. We conducted an online magnetoencephalography (MEG) study to examine the spatio-temporal nature of taxonomic and thematic relations. We measured participants’ brain responses to words preceded by either a taxonomically or thematically related item (e.g., cottage→castle, king→castle). In a separate experiment we collected relatedness ratings of the word pairs from participants. We examined effects of relatedness and relation type on activation in ATL and TPJ regions of interest (ROIs) using permutation t-tests to identify differences in ROI activation between conditions as well as single-trial correlational analyses to examine the millisecond-by-millisecond influence of the stimulus variables on the ROIs. Taxonomic relations strongly predicted ATL activation, and both kinds of relations influenced the TPJ. Our results further strengthen the view of the ATL's importance to taxonomic knowledge. Moreover, they provide a nuanced view of thematic relations as involving taxonomic knowledge. PMID:25582406

  17. Model predictions of features in microsaccade-related neural responses in a feedforward network with short-term synaptic depression

    NASA Astrophysics Data System (ADS)

    Zhou, Jian-Fang; Yuan, Wu-Jie; Zhou, Zhao; Zhou, Changsong

    2016-02-01

    Recently, the significant microsaccade-induced neural responses have been extensively observed in experiments. To explore the underlying mechanisms of the observed neural responses, a feedforward network model with short-term synaptic depression has been proposed [Yuan, W.-J., Dimigen, O., Sommer, W. and Zhou, C. Front. Comput. Neurosci. 7, 47 (2013)]. The depression model not only gave an explanation for microsaccades in counteracting visual fading, but also successfully reproduced several microsaccade-related features in experimental findings. These results strongly suggest that, the depression model is very useful to investigate microsaccade-related neural responses. In this paper, by using the model, we extensively study and predict the dependance of microsaccade-related neural responses on several key parameters, which could be tuned in experiments. Particularly, we provide a significant prediction that microsaccade-related neural response also complies with the property “sharper is better” observed in many contexts in neuroscience. Importantly, the property exhibits a power-law relationship between the width of input signal and the responsive effectiveness, which is robust against many parameters in the model. By using mean field theory, we analytically investigate the robust power-law property. Our predictions would give theoretical guidance for further experimental investigations of the functional role of microsaccades in visual information processing.

  18. Activational and effort-related aspects of motivation: neural mechanisms and implications for psychopathology.

    PubMed

    Salamone, John D; Yohn, Samantha E; López-Cruz, Laura; San Miguel, Noemí; Correa, Mercè

    2016-05-01

    Motivation has been defined as the process that allows organisms to regulate their internal and external environment, and control the probability, proximity and availability of stimuli. As such, motivation is a complex process that is critical for survival, which involves multiple behavioural functions mediated by a number of interacting neural circuits. Classical theories of motivation suggest that there are both directional and activational aspects of motivation, and activational aspects (i.e. speed and vigour of both the instigation and persistence of behaviour) are critical for enabling organisms to overcome work-related obstacles or constraints that separate them from significant stimuli. The present review discusses the role of brain dopamine and related circuits in behavioural activation, exertion of effort in instrumental behaviour, and effort-related decision-making, based upon both animal and human studies. Impairments in behavioural activation and effort-related aspects of motivation are associated with psychiatric symptoms such as anergia, fatigue, lassitude and psychomotor retardation, which cross multiple pathologies, including depression, schizophrenia, and Parkinson's disease. Therefore, this review also attempts to provide an interdisciplinary approach that integrates findings from basic behavioural neuroscience, behavioural economics, clinical neuropsychology, psychiatry, and neurology, to provide a coherent framework for future research and theory in this critical field. Although dopamine systems are a critical part of the brain circuitry regulating behavioural activation, exertion of effort, and effort-related decision-making, mesolimbic dopamine is only one part of a distributed circuitry that includes multiple neurotransmitters and brain areas. Overall, there is a striking similarity between the brain areas involved in behavioural activation and effort-related processes in rodents and in humans. Animal models of effort-related decision

  19. Activational and effort-related aspects of motivation: neural mechanisms and implications for psychopathology.

    PubMed

    Salamone, John D; Yohn, Samantha E; López-Cruz, Laura; San Miguel, Noemí; Correa, Mercè

    2016-05-01

    Motivation has been defined as the process that allows organisms to regulate their internal and external environment, and control the probability, proximity and availability of stimuli. As such, motivation is a complex process that is critical for survival, which involves multiple behavioural functions mediated by a number of interacting neural circuits. Classical theories of motivation suggest that there are both directional and activational aspects of motivation, and activational aspects (i.e. speed and vigour of both the instigation and persistence of behaviour) are critical for enabling organisms to overcome work-related obstacles or constraints that separate them from significant stimuli. The present review discusses the role of brain dopamine and related circuits in behavioural activation, exertion of effort in instrumental behaviour, and effort-related decision-making, based upon both animal and human studies. Impairments in behavioural activation and effort-related aspects of motivation are associated with psychiatric symptoms such as anergia, fatigue, lassitude and psychomotor retardation, which cross multiple pathologies, including depression, schizophrenia, and Parkinson's disease. Therefore, this review also attempts to provide an interdisciplinary approach that integrates findings from basic behavioural neuroscience, behavioural economics, clinical neuropsychology, psychiatry, and neurology, to provide a coherent framework for future research and theory in this critical field. Although dopamine systems are a critical part of the brain circuitry regulating behavioural activation, exertion of effort, and effort-related decision-making, mesolimbic dopamine is only one part of a distributed circuitry that includes multiple neurotransmitters and brain areas. Overall, there is a striking similarity between the brain areas involved in behavioural activation and effort-related processes in rodents and in humans. Animal models of effort-related decision

  20. Brain Damage and the Moral Significance of Consciousness

    PubMed Central

    kahane, Guy

    2009-01-01

    Neuroimaging studies of brain-damaged patients diagnosed as in the vegetative state suggest that the patients might be conscious. This might seem to raise no new ethical questions given that in related disputes both sides agree that evidence for consciousness gives strong reason to preserve life. We question this assumption. We clarify the widely held but obscure principle that consciousness is morally significant. It is hard to apply this principle to difficult cases given that philosophers of mind distinguish between a range of notions of consciousness and that is unclear which of these is assumed by the principle. We suggest that the morally relevant notion is that of phenomenal consciousness and then use our analysis to interpret cases of brain damage. We argue that enjoyment of consciousness might actually give stronger moral reasons not to preserve a patient's life and, indeed, that these might be stronger when patients retain significant cognitive function. PMID:19193694

  1. Neuronal integration in visual cortex elevates face category tuning to conscious face perception.

    PubMed

    Fahrenfort, Johannes J; Snijders, Tineke M; Heinen, Klaartje; van Gaal, Simon; Scholte, H Steven; Lamme, Victor A F

    2012-12-26

    The human brain has the extraordinary capability to transform cluttered sensory input into distinct object representations. For example, it is able to rapidly and seemingly without effort detect object categories in complex natural scenes. Surprisingly, category tuning is not sufficient to achieve conscious recognition of objects. What neural process beyond category extraction might elevate neural representations to the level where objects are consciously perceived? Here we show that visible and invisible faces produce similar category-selective responses in the ventral visual cortex. The pattern of neural activity evoked by visible faces could be used to decode the presence of invisible faces and vice versa. However, only visible faces caused extensive response enhancements and changes in neural oscillatory synchronization, as well as increased functional connectivity between higher and lower visual areas. We conclude that conscious face perception is more tightly linked to neural processes of sustained information integration and binding than to processes accommodating face category tuning. PMID:23236162

  2. The minimally conscious state: defining the borders of consciousness.

    PubMed

    Giacino, J T

    2005-01-01

    There is no agreement as to where the limits of consciousness lie, or even if these putative borders exist. Problems inherent to the study of consciousness continue to confound efforts to establish a universally accepted theory of consciousness. Consequently, clinical definitions of consciousness and unconsciousness are unavoidably arbitrary. Recently, a condition of severely altered consciousness has been described, which characterizes the borderzone between the vegetative state and so-called "normal" consciousness. This condition, referred to as the minimally conscious state (MCS), is distinguished from the vegetative state by the presence of minimal but clearly discernible behavioral evidence of self or environmental awareness. This chapter reviews the diagnostic criteria, pathophysiology, prognostic relevance, neurobehavioral assessment procedures and treatment implications associated with MCS.

  3. Parental Socioeconomic Status and the Neural Basis of Arithmetic: Differential Relations to Verbal and Visuo-Spatial Representations

    ERIC Educational Resources Information Center

    Demir, Özlem Ece; Prado, Jérôme; Booth, James R.

    2015-01-01

    We examined the relation of parental socioeconomic status (SES) to the neural bases of subtraction in school-age children (9- to 12-year-olds). We independently localized brain regions subserving verbal versus visuo-spatial representations to determine whether the parental SES-related differences in children's reliance on these neural…

  4. Motivated to win: Relationship between anticipatory and outcome reward-related neural activity.

    PubMed

    Pornpattananangkul, Narun; Nusslock, Robin

    2015-11-01

    Reward-processing involves two temporal stages characterized by two distinct neural processes: reward-anticipation and reward-outcome. Intriguingly, very little research has examined the relationship between neural processes involved in reward-anticipation and reward-outcome. To investigate this, one needs to consider the heterogeneity of reward-processing within each stage. To identify different stages of reward processing, we adapted a reward time-estimation task. While EEG data were recorded, participants were instructed to button-press 3.5s after the onset of an Anticipation-Cue and received monetary reward for good time-estimation on the Reward trials, but not on No-Reward trials. We first separated reward-anticipation into event related potentials (ERPs) occurring at three sub-stages: reward/no-reward cue-evaluation, motor-preparation and feedback-anticipation. During reward/no-reward cue-evaluation, the Reward-Anticipation Cue led to a smaller N2 and larger P3. During motor-preparation, we report, for the first time, that the Reward-Anticipation Cue enhanced the Readiness Potential (RP), starting approximately 1s before movement. At the subsequent feedback-anticipation stage, the Reward-Anticipation Cue elevated the Stimulus-Preceding Negativity (SPN). We also separated reward-outcome ERPs into different components occurring at different time-windows: the Feedback-Related Negativity (FRN), Feedback-P3 (FB-P3) and Late-Positive Potentials (LPP). Lastly, we examined the relationship between reward-anticipation and reward-outcome ERPs. We report that individual-differences in specific reward-anticipation ERPs uniquely predicted specific reward-outcome ERPs. In particular, the reward-anticipation Early-RP (1-.8s before movement) predicted early reward-outcome ERPs (FRN and FB-P3), whereas, the reward-anticipation SPN most strongly predicted a later reward-outcome ERP (LPP). Results have important implications for understanding the nature of the relationship

  5. Motivated to win: Relationship between anticipatory and outcome reward-related neural activity.

    PubMed

    Pornpattananangkul, Narun; Nusslock, Robin

    2015-11-01

    Reward-processing involves two temporal stages characterized by two distinct neural processes: reward-anticipation and reward-outcome. Intriguingly, very little research has examined the relationship between neural processes involved in reward-anticipation and reward-outcome. To investigate this, one needs to consider the heterogeneity of reward-processing within each stage. To identify different stages of reward processing, we adapted a reward time-estimation task. While EEG data were recorded, participants were instructed to button-press 3.5s after the onset of an Anticipation-Cue and received monetary reward for good time-estimation on the Reward trials, but not on No-Reward trials. We first separated reward-anticipation into event related potentials (ERPs) occurring at three sub-stages: reward/no-reward cue-evaluation, motor-preparation and feedback-anticipation. During reward/no-reward cue-evaluation, the Reward-Anticipation Cue led to a smaller N2 and larger P3. During motor-preparation, we report, for the first time, that the Reward-Anticipation Cue enhanced the Readiness Potential (RP), starting approximately 1s before movement. At the subsequent feedback-anticipation stage, the Reward-Anticipation Cue elevated the Stimulus-Preceding Negativity (SPN). We also separated reward-outcome ERPs into different components occurring at different time-windows: the Feedback-Related Negativity (FRN), Feedback-P3 (FB-P3) and Late-Positive Potentials (LPP). Lastly, we examined the relationship between reward-anticipation and reward-outcome ERPs. We report that individual-differences in specific reward-anticipation ERPs uniquely predicted specific reward-outcome ERPs. In particular, the reward-anticipation Early-RP (1-.8s before movement) predicted early reward-outcome ERPs (FRN and FB-P3), whereas, the reward-anticipation SPN most strongly predicted a later reward-outcome ERP (LPP). Results have important implications for understanding the nature of the relationship

  6. Neural correlates of fixation duration in natural reading: Evidence from fixation-related fMRI.

    PubMed

    Henderson, John M; Choi, Wonil; Luke, Steven G; Desai, Rutvik H

    2015-10-01

    A key assumption of current theories of natural reading is that fixation duration reflects underlying attentional, language, and cognitive processes associated with text comprehension. The neurocognitive correlates of this relationship are currently unknown. To investigate this relationship, we compared neural activation associated with fixation duration in passage reading and a pseudo-reading control condition. The results showed that fixation duration was associated with activation in oculomotor and language areas during text reading. Fixation duration during pseudo-reading, on the other hand, showed greater involvement of frontal control regions, suggesting flexibility and task dependency of the eye movement network. Consistent with current models, these results provide support for the hypothesis that fixation duration in reading reflects attentional engagement and language processing. The results also demonstrate that fixation-related fMRI provides a method for investigating the neurocognitive bases of natural reading.

  7. Cough-related neural processing in the brain: a roadmap for cough dysfunction?

    PubMed

    Ando, Ayaka; Farrell, Michael J; Mazzone, Stuart B

    2014-11-01

    Cough is a complex respiratory behavior essential for airway protection, consisting of sensory, motor, affective and cognitive attributes. Accordingly, the cough neural circuitry extends beyond a simple pontomedullary reflex arc to incorporate a network of neurons that are also widely distributed throughout the subcortical and cortical brain. Studies have described discrete regional responses in the brain that likely give rise to sensory discriminative processes, voluntary and urge-related cough control mechanisms and aspects of the emotive responses following airways irritation and coughing. Data from these studies highlight the central nervous system as a plausible target for therapeutic intervention and, consistent with this, a careful appraisal of the many and varied clinical disorders of coughing control would argue that more diversified therapies are needed to treat patients with cough dysfunction. In this paper we explore these concepts in detail to highlight unanswered questions and stimulate discussion for potential research of cough in the future.

  8. Prediction of the relative texture coefficient of nanocrystalline nickel coatings using artificial neural networks

    NASA Astrophysics Data System (ADS)

    Rashidi, A. M.; Hayati, M.; Rezaei, A.

    2011-08-01

    In this paper, the relative texture coefficient (RTC) of nanocrystalline (NC) nickel as a function of electroplating parameters has been modeled using artificial neural network (ANN). In the model, the inputs are the electroplating parameters namely current density, concentration of sodium saccharin in bath and plating temperature. In order to train and test the ANN model with a consistent set of experimental data, NC nickel coatings has been provided using a Watts-type bath, in which the significant parameters such as current density, concentration of sodium saccharin in bath and plating temperature have been systematically varied. The RTC has been determined using the peak intensities of diffracted x-ray radiation from (hkl) crystallographic planes of deposits with respect to coarse grained nickel (reference sample). An excellent agreement between the model predictions and the experimental data was obtained indicating that the ANN approach can be used as a reliable and accurate tool for prediction of the RTC of NC nickel coatings.

  9. Neural correlates of fixation duration in natural reading: Evidence from fixation-related fMRI.

    PubMed

    Henderson, John M; Choi, Wonil; Luke, Steven G; Desai, Rutvik H

    2015-10-01

    A key assumption of current theories of natural reading is that fixation duration reflects underlying attentional, language, and cognitive processes associated with text comprehension. The neurocognitive correlates of this relationship are currently unknown. To investigate this relationship, we compared neural activation associated with fixation duration in passage reading and a pseudo-reading control condition. The results showed that fixation duration was associated with activation in oculomotor and language areas during text reading. Fixation duration during pseudo-reading, on the other hand, showed greater involvement of frontal control regions, suggesting flexibility and task dependency of the eye movement network. Consistent with current models, these results provide support for the hypothesis that fixation duration in reading reflects attentional engagement and language processing. The results also demonstrate that fixation-related fMRI provides a method for investigating the neurocognitive bases of natural reading. PMID:26151101

  10. Synthetic consciousness: the distributed adaptive control perspective.

    PubMed

    Verschure, Paul F M J

    2016-08-19

    Understanding the nature of consciousness is one of the grand outstanding scientific challenges. The fundamental methodological problem is how phenomenal first person experience can be accounted for in a third person verifiable form, while the conceptual challenge is to both define its function and physical realization. The distributed adaptive control theory of consciousness (DACtoc) proposes answers to these three challenges. The methodological challenge is answered relative to the hard problem and DACtoc proposes that it can be addressed using a convergent synthetic methodology using the analysis of synthetic biologically grounded agents, or quale parsing. DACtoc hypothesizes that consciousness in both its primary and secondary forms serves the ability to deal with the hidden states of the world and emerged during the Cambrian period, affording stable multi-agent environments to emerge. The process of consciousness is an autonomous virtualization memory, which serializes and unifies the parallel and subconscious simulations of the hidden states of the world that are largely due to other agents and the self with the objective to extract norms. These norms are in turn projected as value onto the parallel simulation and control systems that are driving action. This functional hypothesis is mapped onto the brainstem, midbrain and the thalamo-cortical and cortico-cortical systems and analysed with respect to our understanding of deficits of consciousness. Subsequently, some of the implications and predictions of DACtoc are outlined, in particular, the prediction that normative bootstrapping of conscious agents is predicated on an intentionality prior. In the view advanced here, human consciousness constitutes the ultimate evolutionary transition by allowing agents to become autonomous with respect to their evolutionary priors leading to a post-biological Anthropocene.This article is part of the themed issue 'The major synthetic evolutionary transitions'. PMID

  11. Interactivity and reward-related neural activation during a serious videogame.

    PubMed

    Cole, Steven W; Yoo, Daniel J; Knutson, Brian

    2012-01-01

    This study sought to determine whether playing a "serious" interactive digital game (IDG)--the Re-Mission videogame for cancer patients--activates mesolimbic neural circuits associated with incentive motivation, and if so, whether such effects stem from the participatory aspects of interactive gameplay, or from the complex sensory/perceptual engagement generated by its dynamic event-stream. Healthy undergraduates were randomized to groups in which they were scanned with functional magnetic resonance imaging (FMRI) as they either actively played Re-Mission or as they passively observed a gameplay audio-visual stream generated by a yoked active group subject. Onset of interactive game play robustly activated mesolimbic projection regions including the caudate nucleus and nucleus accumbens, as well as a subregion of the parahippocampal gyrus. During interactive gameplay, subjects showed extended activation of the thalamus, anterior insula, putamen, and motor-related regions, accompanied by decreased activation in parietal and medial prefrontal cortex. Offset of interactive gameplay activated the anterior insula and anterior cingulate. Between-group comparisons of within-subject contrasts confirmed that mesolimbic activation was significantly more pronounced in the active playgroup than in the passive exposure control group. Individual difference analyses also found the magnitude of parahippocampal activation following gameplay onset to correlate with positive attitudes toward chemotherapy assessed both at the end of the scanning session and at an unannounced one-month follow-up. These findings suggest that IDG-induced activation of reward-related mesolimbic neural circuits stems primarily from participatory engagement in gameplay (interactivity), rather than from the effects of vivid and dynamic sensory stimulation.

  12. Interactivity and Reward-Related Neural Activation during a Serious Videogame

    PubMed Central

    Cole, Steven W.; Yoo, Daniel J.; Knutson, Brian

    2012-01-01

    This study sought to determine whether playing a “serious” interactive digital game (IDG) – the Re-Mission videogame for cancer patients – activates mesolimbic neural circuits associated with incentive motivation, and if so, whether such effects stem from the participatory aspects of interactive gameplay, or from the complex sensory/perceptual engagement generated by its dynamic event-stream. Healthy undergraduates were randomized to groups in which they were scanned with functional magnetic resonance imaging (FMRI) as they either actively played Re-Mission or as they passively observed a gameplay audio-visual stream generated by a yoked active group subject. Onset of interactive game play robustly activated mesolimbic projection regions including the caudate nucleus and nucleus accumbens, as well as a subregion of the parahippocampal gyrus. During interactive gameplay, subjects showed extended activation of the thalamus, anterior insula, putamen, and motor-related regions, accompanied by decreased activation in parietal and medial prefrontal cortex. Offset of interactive gameplay activated the anterior insula and anterior cingulate. Between-group comparisons of within-subject contrasts confirmed that mesolimbic activation was significantly more pronounced in the active playgroup than in the passive exposure control group. Individual difference analyses also found the magnitude of parahippocampal activation following gameplay onset to correlate with positive attitudes toward chemotherapy assessed both at the end of the scanning session and at an unannounced one-month follow-up. These findings suggest that IDG-induced activation of reward-related mesolimbic neural circuits stems primarily from participatory engagement in gameplay (interactivity), rather than from the effects of vivid and dynamic sensory stimulation. PMID:22442733

  13. Age-Related Neural Oscillation Patterns During the Processing of Temporally Manipulated Speech.

    PubMed

    Rufener, Katharina S; Oechslin, Mathias S; Wöstmann, Malte; Dellwo, Volker; Meyer, Martin

    2016-05-01

    This EEG-study aims to investigate age-related differences in the neural oscillation patterns during the processing of temporally modulated speech. Viewing from a lifespan perspective, we recorded the electroencephalogram (EEG) data of three age samples: young adults, middle-aged adults and older adults. Stimuli consisted of temporally degraded sentences in Swedish-a language unfamiliar to all participants. We found age-related differences in phonetic pattern matching when participants were presented with envelope-degraded sentences, whereas no such age-effect was observed in the processing of fine-structure-degraded sentences. Irrespective of age, during speech processing the EEG data revealed a relationship between envelope information and the theta band (4-8 Hz) activity. Additionally, an association between fine-structure information and the gamma band (30-48 Hz) activity was found. No interaction, however, was found between acoustic manipulation of stimuli and age. Importantly, our main finding was paralleled by an overall enhanced power in older adults in high frequencies (gamma: 30-48 Hz). This occurred irrespective of condition. For the most part, this result is in line with the Asymmetric Sampling in Time framework (Poeppel in Speech Commun 41:245-255, 2003), which assumes an isomorphic correspondence between frequency modulations in neurophysiological patterns and acoustic oscillations in spoken language. We conclude that speech-specific neural networks show strong stability over adulthood, despite initial processes of cortical degeneration indicated by enhanced gamma power. The results of our study therefore confirm the concept that sensory and cognitive processes undergo multidirectional trajectories within the context of healthy aging.

  14. Age-Related Neural Oscillation Patterns During the Processing of Temporally Manipulated Speech.

    PubMed

    Rufener, Katharina S; Oechslin, Mathias S; Wöstmann, Malte; Dellwo, Volker; Meyer, Martin

    2016-05-01

    This EEG-study aims to investigate age-related differences in the neural oscillation patterns during the processing of temporally modulated speech. Viewing from a lifespan perspective, we recorded the electroencephalogram (EEG) data of three age samples: young adults, middle-aged adults and older adults. Stimuli consisted of temporally degraded sentences in Swedish-a language unfamiliar to all participants. We found age-related differences in phonetic pattern matching when participants were presented with envelope-degraded sentences, whereas no such age-effect was observed in the processing of fine-structure-degraded sentences. Irrespective of age, during speech processing the EEG data revealed a relationship between envelope information and the theta band (4-8 Hz) activity. Additionally, an association between fine-structure information and the gamma band (30-48 Hz) activity was found. No interaction, however, was found between acoustic manipulation of stimuli and age. Importantly, our main finding was paralleled by an overall enhanced power in older adults in high frequencies (gamma: 30-48 Hz). This occurred irrespective of condition. For the most part, this result is in line with the Asymmetric Sampling in Time framework (Poeppel in Speech Commun 41:245-255, 2003), which assumes an isomorphic correspondence between frequency modulations in neurophysiological patterns and acoustic oscillations in spoken language. We conclude that speech-specific neural networks show strong stability over adulthood, despite initial processes of cortical degeneration indicated by enhanced gamma power. The results of our study therefore confirm the concept that sensory and cognitive processes undergo multidirectional trajectories within the context of healthy aging. PMID:26613726

  15. Neural basis of psychosis-related behaviour in the infection model of schizophrenia.

    PubMed

    Meyer, Urs; Feldon, Joram

    2009-12-01

    Maternal infection during pregnancy is a notable risk factor for the offspring to develop severe neuropsychiatric disorders, including schizophrenia. One prevalent hypothesis suggests that infection-induced disruption of early prenatal brain development predisposes the organism for long-lasting structural and functional brain abnormalities, leading to the emergence of psychopathological behaviour in adulthood. The feasibility of this causal link has received considerable support from several experimental models established in both rats and mice. In this review, we provide an integrative summary of the long-term neuropathological consequences of prenatal exposure to infection and/or inflammation as identified in various experimental models of prenatal immune challenge. In addition, we highlight how abnormalities in distinct brain areas and neurotransmitter systems following prenatal immune activation may provide a neural basis for the emergence of specific forms of psychosis-related behaviour. Specifically, we suggest that prenatal infection-induced imbalances in the mesolimibic and mesocortical dopamine pathways may constitute critical neural mechanisms for disturbances in sensorimotor gating, abnormalities in selective associative learning and hypersensitivity to psychostimulant drugs. On the other hand, the emergence of working memory deficiency following prenatal immune challenge may be crucially linked to the concomitant disruption of GABAergic and glutamatergic functions in prefrontal cortical and hippocampal structures. Notably, many of the identified neuronal abnormalities are directly implicated in the neuropathology of schizophrenia. The findings from prenatal infection models of schizophrenia thus provide considerable experimental evidence for the assumption that prenatal exposure to infection and/or inflammation is a relevant environmental link to specific neuronal abnormalities underlying psychosis-related behaviour in humans. PMID:19154759

  16. Giving Voice to Consciousness.

    PubMed

    Fins, Joseph J

    2016-10-01

    In the 2015 David Kopf Lecture on Neuroethics of the Society for Neuroscience, Dr. Joseph Fins presents his work on neuroethics and disorders of consciousness through the experience of Maggie and Nancy Worthen, a young woman who sustained a severe brain injury and her mother who cared for her. The central protagonists in his book, Rights Come to Mind: Brain Injury, Ethics and the Struggle for Consciousness (Cambridge University Press, 2015), their experience is emblematic of the challenges faced by families touched by severe brain injury and the possibility for improved diagnosis and treatment offered by progress in neuroscience. By telling their story, and those of other families interviewed as part of the research for Rights Come to Mind, Fins calls for improved care for this population arguing that this is both an access to care issue and a civil and disability rights issue worthy of greater societal attention. PMID:27634711

  17. Giving Voice to Consciousness.

    PubMed

    Fins, Joseph J

    2016-10-01

    In the 2015 David Kopf Lecture on Neuroethics of the Society for Neuroscience, Dr. Joseph Fins presents his work on neuroethics and disorders of consciousness through the experience of Maggie and Nancy Worthen, a young woman who sustained a severe brain injury and her mother who cared for her. The central protagonists in his book, Rights Come to Mind: Brain Injury, Ethics and the Struggle for Consciousness (Cambridge University Press, 2015), their experience is emblematic of the challenges faced by families touched by severe brain injury and the possibility for improved diagnosis and treatment offered by progress in neuroscience. By telling their story, and those of other families interviewed as part of the research for Rights Come to Mind, Fins calls for improved care for this population arguing that this is both an access to care issue and a civil and disability rights issue worthy of greater societal attention.

  18. Defining the states of consciousness.

    PubMed

    Tassi, P; Muzet, A

    2001-03-01

    Consciousness remains an elusive concept due to the difficulty to define what has been regarded for many years as a subjective experience, therefore irrelevant for scientific study. Recent development in this field of research has allowed to provide some new insight to a possible way to define consciousness. Going through the extensive literature in this domain, several perspectives are proposed to define this concept. (1) Consciousness and Attention may not reflect the same process. (2) Consciousness during wake and sleep may not involve the same mechanisms. (3) Besides physiological states of consciousness, human beings can experience modified states of consciousness either by self-training (transcendental meditation, hypnosis, etc.) or by drug intake (hallucinogens, anaesthetics, etc.). Altogether, we address the question of a more precise terminology, given the theoretical weight words can convey. To this respect, we propose different definitions for concepts like consciousness, vigilance, arousal and alertness as candidates to separate functional entities.

  19. Natural Evolution and Human Consciousness

    PubMed Central

    Holmgren, Jan

    2014-01-01

    A visual conscious experience is my empirical basis. All that we know comes to us through conscious experiences. Thanks to natural evolution, we have nearly direct perception, and can largely trust the information we attain. There is full integration, with no gaps, of organisms in the continuous world. Human conscious experiences, on the other hand, are discrete. Consciousness has certain limits for its resolution. This is illustrated by the so-called light-cone, with consequences for foundations in physics. Traditional universals are replaced by feels and distributions. Conscious experiences can be ordered within a framework of conceptual spaces. Triple Aspect Monism (TAM) can represent the dynamics of conscious systems. However, to fully represent the creative power of human consciousness, an all-inclusive view is suggested: Multi Aspect Monism (MAM). PMID:24891802

  20. Temperature and Relative Humidity Estimation and Prediction in the Tobacco Drying Process Using Artificial Neural Networks

    PubMed Central

    Martínez-Martínez, Víctor; Baladrón, Carlos; Gomez-Gil, Jaime; Ruiz-Ruiz, Gonzalo; Navas-Gracia, Luis M.; Aguiar, Javier M.; Carro, Belén

    2012-01-01

    This paper presents a system based on an Artificial Neural Network (ANN) for estimating and predicting environmental variables related to tobacco drying processes. This system has been validated with temperature and relative humidity data obtained from a real tobacco dryer with a Wireless Sensor Network (WSN). A fitting ANN was used to estimate temperature and relative humidity in different locations inside the tobacco dryer and to predict them with different time horizons. An error under 2% can be achieved when estimating temperature as a function of temperature and relative humidity in other locations. Moreover, an error around 1.5 times lower than that obtained with an interpolation method can be achieved when predicting the temperature inside the tobacco mass as a function of its present and past values with time horizons over 150 minutes. These results show that the tobacco drying process can be improved taking into account the predicted future value of the monitored variables and the estimated actual value of other variables using a fitting ANN as proposed. PMID:23202032

  1. Neural synchronization as a hypothetical explanation of the psychoanalytic unconscious.

    PubMed

    Ceylan, Mehmet Emin; Dönmez, Aslıhan; Ünsalver, Barış Önen; Evrensel, Alper

    2016-02-01

    Cognitive scientists have tried to explain the neural mechanisms of unconscious mental states such as coma, epileptic seizures, and anesthesia-induced unconsciousness. However these types of unconscious states are different from the psychoanalytic unconscious. In this review, we aim to present our hypothesis about the neural correlates underlying psychoanalytic unconscious. To fulfill this aim, we firstly review the previous explanations about the neural correlates of conscious and unconscious mental states, such as brain oscillations, synchronicity of neural networks, and cognitive binding. By doing so, we hope to lay a neuroscientific ground for our hypothesis about neural correlates of psychoanalytic unconscious; parallel but unsynchronized neural networks between different layers of consciousness and unconsciousness. Next, we propose a neuroscientific mechanism about how the repressed mental events reach the conscious awareness; the lock of neural synchronization between two mental layers of conscious and unconscious. At the last section, we will discuss the data about schizophrenia as a clinical example of our proposed hypothesis. PMID:26744848

  2. A BOLD Perspective on Age-Related Neurometabolic-Flow Coupling and Neural Efficiency Changes in Human Visual Cortex

    PubMed Central

    Hutchison, Joanna Lynn; Shokri-Kojori, Ehsan; Lu, Hanzhang; Rypma, Bart

    2013-01-01

    Age-related performance declines in visual tasks have been attributed to reductions in processing efficiency. The neural basis of these declines has been explored by comparing the blood-oxygen-level-dependent (BOLD) index of neural activity in older and younger adults during visual task performance. However, neural activity is one of many factors that change with age and lead to BOLD signal differences. We investigated the origin of age-related BOLD changes by comparing blood flow and oxygen metabolic constituents of BOLD signal. Subjects periodically viewed flickering annuli and pressed a button when detecting luminance changes in a central fixation cross. Using magnetic resonance dual-echo arterial spin labeling and CO2 ingestion, we observed age-equivalent (i.e., similar in older and younger groups) fractional cerebral blood flow (ΔCBF) in the presence of age-related increases in fractional cerebral metabolic rate of oxygen (ΔCMRO2). Reductions in ΔCBF responsiveness to increased ΔCMRO2 in elderly led to paradoxical age-related BOLD decreases. Age-related ΔCBF/ΔCMRO2 ratio decreases were associated with reaction times, suggesting that age-related slowing resulted from less efficient neural activity. We hypothesized that reduced vascular responsiveness to neural metabolic demand would lead to a reduction in ΔCBF/ΔCMRO2. A simulation of BOLD relative to ΔCMRO2 for lower and higher neurometabolic-flow coupling ratios (approximating those for old and young, respectively) indicated less BOLD signal change in old than young in relatively lower CMRO2 ranges, as well as greater BOLD signal change in young compared to old in relatively higher CMRO2 ranges. These results suggest that age-comparative studies relying on BOLD signal might be misinterpreted, as age-related BOLD changes do not merely reflect neural activity changes. Age-related declines in neurometabolic-flow coupling might lead to neural efficiency reductions that can adversely affect visual task

  3. The rise of machine consciousness: studying consciousness with computational models.

    PubMed

    Reggia, James A

    2013-08-01

    Efforts to create computational models of consciousness have accelerated over the last two decades, creating a field that has become known as artificial consciousness. There have been two main motivations for this controversial work: to develop a better scientific understanding of the nature of human/animal consciousness and to produce machines that genuinely exhibit conscious awareness. This review begins by briefly explaining some of the concepts and terminology used by investigators working on machine consciousness, and summarizes key neurobiological correlates of human consciousness that are particularly relevant to past computational studies. Models of consciousness developed over the last twenty years are then surveyed. These models are largely found to fall into five categories based on the fundamental issue that their developers have selected as being most central to consciousness: a global workspace, information integration, an internal self-model, higher-level representations, or attention mechanisms. For each of these five categories, an overview of past work is given, a representative example is presented in some detail to illustrate the approach, and comments are provided on the contributions and limitations of the methodology. Three conclusions are offered about the state of the field based on this review: (1) computational modeling has become an effective and accepted methodology for the scientific study of consciousness, (2) existing computational models have successfully captured a number of neurobiological, cognitive, and behavioral correlates of conscious information processing as machine simulations, and (3) no existing approach to artificial consciousness has presented a compelling demonstration of phenomenal machine consciousness, or even clear evidence that artificial phenomenal consciousness will eventually be possible. The paper concludes by discussing the importance of continuing work in this area, considering the ethical issues it raises

  4. Quantum effects in the understanding of consciousness.

    PubMed

    Hameroff, Stuart R; Craddock, Travis J A; Tuszynski, Jack A

    2014-06-01

    This paper presents a historical perspective on the development and application of quantum physics methodology beyond physics, especially in biology and in the area of consciousness studies. Quantum physics provides a conceptual framework for the structural aspects of biological systems and processes via quantum chemistry. In recent years individual biological phenomena such as photosynthesis and bird navigation have been experimentally and theoretically analyzed using quantum methods building conceptual foundations for quantum biology. Since consciousness is attributed to human (and possibly animal) mind, quantum underpinnings of cognitive processes are a logical extension. Several proposals, especially the Orch OR hypothesis, have been put forth in an effort to introduce a scientific basis to the theory of consciousness. At the center of these approaches are microtubules as the substrate on which conscious processes in terms of quantum coherence and entanglement can be built. Additionally, Quantum Metabolism, quantum processes in ion channels and quantum effects in sensory stimulation are discussed in this connection. We discuss the challenges and merits related to quantum consciousness approaches as well as their potential extensions.

  5. The emergence of consciousness: Science and ethics.

    PubMed

    Lagercrantz, Hugo

    2014-10-01

    The newborn human infant is conscious at a minimal level. It is aware of its body, itself and to some extent of the outside world. It recognizes faces and vowels to which it has been exposed. It expresses emotions like joy. Functional magnetic resonance imaging of the newborn brain shows highest activity in the somatosensory, auditory, and visual cortex but less activity in association area and the prefrontal cortex as compared with adults. There is an incomplete default mode network which is assumed to be related to consciousness. Although the fetus reacts to pain, maternal speaking, etc., it is probably not aware of this due to the low oxygen level and sedation. Assuming that consciousness is mainly localized in the cortex, consciousness cannot emerge before 24 gestational weeks when the thalamocortical connections from the sense organs are established. Thus the limit of legal abortion at 22-24 weeks in many countries makes sense. It should also be possible to withdraw or withhold life-saving therapy of extremely preterm infants, especially if they are severely brain-damaged. This may also apply to full-term infants with grade III hypoxic-ischemic encephalopathy, who show no signs of consciousness.

  6. On self-feedback connectivity in neural mass models applied to event-related potentials.

    PubMed

    Youssofzadeh, Vahab; Prasad, Girijesh; Wong-Lin, KongFatt

    2015-03-01

    Neural mass models (NMMs) applied to neuroimaging data often do not emphasise intrinsic self-feedback within a neural population. However, based on mean-field theory, any population of coupled neurons is intrinsically endowed with effective self-coupling. In this work, we examine the effectiveness of three cortical NMMs with different self-feedbacks using a dynamic causal modelling approach. Specifically, we compare the classic Jansen and Rit (1995) model (no self-feedback), a modified model by Moran et al. (2007) (only inhibitory self-feedback), and our proposed model with inhibitory and excitatory self-feedbacks. Using bifurcation analysis, we show that single-unit Jansen-Rit model is less robust in generating oscillatory behaviour than the other two models. Next, under Bayesian inversion, we simulate single-channel event-related potentials (ERPs) within a mismatch negativity auditory oddball paradigm. We found fully self-feedback model (FSM) to provide the best fit to single-channel data. By analysing the posterior covariances of model parameters, we show that self-feedback connections are less sensitive to the generated evoked responses than the other model parameters, and hence can be treated analogously to "higher-order" parameter corrections of the original Jansen-Rit model. This is further supported in the more realistic multi-area case where FSM can replicate data better than JRM and MoM in the majority of subjects by capturing the finer features of the ERP data more accurately. Our work informs how NMMs with full self-feedback connectivity are not only more consistent with the underlying neurophysiology, but can also account for more complex features in ERP data.

  7. Long-Range Temporal Correlations, Multifractality, and the Causal Relation between Neural Inputs and Movements

    PubMed Central

    Hu, Jing; Zheng, Yi; Gao, Jianbo

    2013-01-01

    Understanding the causal relation between neural inputs and movements is very important for the success of brain-machine interfaces (BMIs). In this study, we analyze 104 neurons’ firings using statistical, information theoretic, and fractal analysis. The latter include Fano factor analysis, multifractal adaptive fractal analysis (MF-AFA), and wavelet multifractal analysis. We find neuronal firings are highly non-stationary, and Fano factor analysis always indicates long-range correlations in neuronal firings, irrespective of whether those firings are correlated with movement trajectory or not, and thus does not reveal any actual correlations between neural inputs and movements. On the other hand, MF-AFA and wavelet multifractal analysis clearly indicate that when neuronal firings are not well correlated with movement trajectory, they do not have or only have weak temporal correlations. When neuronal firings are well correlated with movements, they are characterized by very strong temporal correlations, up to a time scale comparable to the average time between two successive reaching tasks. This suggests that neurons well correlated with hand trajectory experienced a “re-setting” effect at the start of each reaching task, in the sense that within the movement correlated neurons the spike trains’ long-range dependences persisted about the length of time the monkey used to switch between task executions. A new task execution re-sets their activity, making them only weakly correlated with their prior activities on longer time scales. We further discuss the significance of the coalition of those important neurons in executing cortical control of prostheses. PMID:24130549

  8. Fluid Intelligence and Automatic Neural Processes in Facial Expression Perception: An Event-Related Potential Study.

    PubMed

    Liu, Tongran; Xiao, Tong; Li, Xiaoyan; Shi, Jiannong

    2015-01-01

    The relationship between human fluid intelligence and social-emotional abilities has been a topic of considerable interest. The current study investigated whether adolescents with different intellectual levels had different automatic neural processing of facial expressions. Two groups of adolescent males were enrolled: a high IQ group and an average IQ group. Age and parental socioeconomic status were matched between the two groups. Participants counted the numbers of the central cross changes while paired facial expressions were presented bilaterally in an oddball paradigm. There were two experimental conditions: a happy condition, in which neutral expressions were standard stimuli (p = 0.8) and happy expressions were deviant stimuli (p = 0.2), and a fearful condition, in which neutral expressions were standard stimuli (p = 0.8) and fearful expressions were deviant stimuli (p = 0.2). Participants were required to concentrate on the primary task of counting the central cross changes and to ignore the expressions to ensure that facial expression processing was automatic. Event-related potentials (ERPs) were obtained during the tasks. The visual mismatch negativity (vMMN) components were analyzed to index the automatic neural processing of facial expressions. For the early vMMN (50-130 ms), the high IQ group showed more negative vMMN amplitudes than the average IQ group in the happy condition. For the late vMMN (320-450 ms), the high IQ group had greater vMMN responses than the average IQ group over frontal and occipito-temporal areas in the fearful condition, and the average IQ group evoked larger vMMN amplitudes than the high IQ group over occipito-temporal areas in the happy condition. The present study elucidated the close relationships between fluid intelligence and pre-attentive change detection on social-emotional information. PMID:26375031

  9. Self-Consciousness, Friendship Quality, and Adolescent Internalizing Problems

    ERIC Educational Resources Information Center

    Bowker, Julie C.; Rubin, Kenneth H.

    2009-01-01

    The correlates between public and private self-consciousness and internalizing difficulties were examined during early adolescence. Friendship quality was assessed as a possible moderator of the relation between self-consciousness and maladjustment. One hundred and thirty-seven young adolescents (N = 87 girls; M age = 13.98 years) reported on…

  10. How Consciousness-Raising Affects Intonation and Facilitates Reading Comprehension

    ERIC Educational Resources Information Center

    Shariati, Mohammad

    2007-01-01

    This paper reports on an investigation about the relation between a student's conscious awareness of the structure of a sentence and the degree of his/her intonation accuracy as well as his/her reading comprehension. The research was done based on the hypothesis that: "if the students are made conscious of the infrastructure of lengthy sentences…

  11. Age-related alterations in the neural coding of envelope periodicities.

    PubMed

    Walton, Joseph P; Simon, Henry; Frisina, Robert D

    2002-08-01

    This research was guided by the working hypothesis that the aging auditory system progressively loses its ability to process rapid acoustic transients efficiently, and in elderly listeners, this results in difficulties in speech perception. Neural correlates of age-related deficits in temporal processing were investigated by recording from inferior colliculus (IC) neurons from young adult and old CBA mice. Single-unit responses were recorded to sinusoidally amplitude-modulated (SAM) noise carriers, presented at 65-80 dB SPL, having modulation frequencies (MFs) that ranged from 10 to 800 Hz. Because phasic-type temporal response patterns dominate responses to tone and noise in mammalian IC, we limited our analyses to only phasic units. Modulation transfer functions (MTF) for both rate (rMTF) and synchronization (sMTF) measures were used to derive respective best modulation frequencies (rBMF and sBMF). The main age-related finding was that there was an overall increase in response rate to SAM noise carriers and a decrease in the median upper cutoff frequency in units from old mice. At rBMF, the median spike count from units from old animals was 1.63 times greater, and at the sBMF, the median spike count was 2.29 times greater than the young adult sample. We explored whether the increase in driven activity was due to a change in the transient (first cycle response) or periodic (remaining response) component of the response to SAM noise. Median spike counts of the transient component decreased with increasing MF for both young adult and old units, with median counts consistently greater in the old sample as compared with young. Median spike counts for the periodic response remained relatively constant as a function of MF; however, there was a significantly greater (3 times) response for older units in a restricted range of MFs. The greater median spike counts found for the transient and periodic response was also evident when we analyzed the cycle-by-cycle response

  12. A Plastic Temporal Brain Code for Conscious State Generation

    PubMed Central

    Dresp-Langley, Birgitta; Durup, Jean

    2009-01-01

    Consciousness is known to be limited in processing capacity and often described in terms of a unique processing stream across a single dimension: time. In this paper, we discuss a purely temporal pattern code, functionally decoupled from spatial signals, for conscious state generation in the brain. Arguments in favour of such a code include Dehaene et al.'s long-distance reverberation postulate, Ramachandran's remapping hypothesis, evidence for a temporal coherence index and coincidence detectors, and Grossberg's Adaptive Resonance Theory. A time-bin resonance model is developed, where temporal signatures of conscious states are generated on the basis of signal reverberation across large distances in highly plastic neural circuits. The temporal signatures are delivered by neural activity patterns which, beyond a certain statistical threshold, activate, maintain, and terminate a conscious brain state like a bar code would activate, maintain, or inactivate the electronic locks of a safe. Such temporal resonance would reflect a higher level of neural processing, independent from sensorial or perceptual brain mechanisms. PMID:19644552

  13. Age and experience shape developmental changes in the neural basis of language-related learning

    PubMed Central

    McNealy, Kristin; Mazziotta, John C.; Dapretto, Mirella

    2013-01-01

    Very little is known about the neural underpinnings of language learning across the lifespan and how these might be modified by maturational and experiential factors. Building on behavioral research highlighting the importance of early word segmentation (i.e. the detection of word boundaries in continuous speech) for subsequent language learning, here we characterize developmental changes in brain activity as this process occurs online, using data collected in a mixed cross-sectional and longitudinal design. One hundred and fifty-six participants, ranging from age 5 to adulthood, underwent functional magnetic resonance imaging (fMRI) while listening to three novel streams of continuous speech, which contained either strong statistical regularities, strong statistical regularities and speech cues, or weak statistical regularities providing minimal cues to word boundaries. All age groups displayed significant signal increases over time in temporal cortices for the streams with high statistical regularities; however, we observed a significant right-to-left shift in the laterality of these learning-related increases with age. Interestingly, only the 5- to 10-year-old children displayed significant signal increases for the stream with low statistical regularities, suggesting an age-related decrease in sensitivity to more subtle statistical cues. Further, in a sample of 78 10-year-olds, we examined the impact of proficiency in a second language and level of pubertal development on learning-related signal increases, showing that the brain regions involved in language learning are influenced by both experiential and maturational factors. PMID:22010887

  14. Age and experience shape developmental changes in the neural basis of language-related learning.

    PubMed

    McNealy, Kristin; Mazziotta, John C; Dapretto, Mirella

    2011-11-01

    Very little is known about the neural underpinnings of language learning across the lifespan and how these might be modified by maturational and experiential factors. Building on behavioral research highlighting the importance of early word segmentation (i.e. the detection of word boundaries in continuous speech) for subsequent language learning, here we characterize developmental changes in brain activity as this process occurs online, using data collected in a mixed cross-sectional and longitudinal design. One hundred and fifty-six participants, ranging from age 5 to adulthood, underwent functional magnetic resonance imaging (fMRI) while listening to three novel streams of continuous speech, which contained either strong statistical regularities, strong statistical regularities and speech cues, or weak statistical regularities providing minimal cues to word boundaries. All age groups displayed significant signal increases over time in temporal cortices for the streams with high statistical regularities; however, we observed a significant right-to-left shift in the laterality of these learning-related increases with age. Interestingly, only the 5- to 10-year-old children displayed significant signal increases for the stream with low statistical regularities, suggesting an age-related decrease in sensitivity to more subtle statistical cues. Further, in a sample of 78 10-year-olds, we examined the impact of proficiency in a second language and level of pubertal development on learning-related signal increases, showing that the brain regions involved in language learning are influenced by both experiential and maturational factors.

  15. Neural Computation of Surface Border Ownership and Relative Surface Depth from Ambiguous Contrast Inputs.

    PubMed

    Dresp-Langley, Birgitta; Grossberg, Stephen

    2016-01-01

    The segregation of image parts into foreground and background is an important aspect of the neural computation of 3D scene perception. To achieve such segregation, the brain needs information about border ownership; that is, the belongingness of a contour to a specific surface represented in the image. This article presents psychophysical data derived from 3D percepts of figure and ground that were generated by presenting 2D images composed of spatially disjoint shapes that pointed inward or outward relative to the continuous boundaries that they induced along their collinear edges. The shapes in some images had the same contrast (black or white) with respect to the background gray. Other images included opposite contrasts along each induced continuous boundary. Psychophysical results demonstrate conditions under which figure-ground judgment probabilities in response to these ambiguous displays are determined by the orientation of contrasts only, not by their relative contrasts, despite the fact that many border ownership cells in cortical area V2 respond to a preferred relative contrast. Studies are also reviewed in which both polarity-specific and polarity-invariant properties obtain. The FACADE and 3D LAMINART models are used to explain these data. PMID:27516746

  16. Neural Computation of Surface Border Ownership and Relative Surface Depth from Ambiguous Contrast Inputs

    PubMed Central

    Dresp-Langley, Birgitta; Grossberg, Stephen

    2016-01-01

    The segregation of image parts into foreground and background is an important aspect of the neural computation of 3D scene perception. To achieve such segregation, the brain needs information about border ownership; that is, the belongingness of a contour to a specific surface represented in the image. This article presents psychophysical data derived from 3D percepts of figure and ground that were generated by presenting 2D images composed of spatially disjoint shapes that pointed inward or outward relative to the continuous boundaries that they induced along their collinear edges. The shapes in some images had the same contrast (black or white) with respect to the background gray. Other images included opposite contrasts along each induced continuous boundary. Psychophysical results demonstrate conditions under which figure-ground judgment probabilities in response to these ambiguous displays are determined by the orientation of contrasts only, not by their relative contrasts, despite the fact that many border ownership cells in cortical area V2 respond to a preferred relative contrast. Studies are also reviewed in which both polarity-specific and polarity-invariant properties obtain. The FACADE and 3D LAMINART models are used to explain these data. PMID:27516746

  17. Age and experience shape developmental changes in the neural basis of language-related learning.

    PubMed

    McNealy, Kristin; Mazziotta, John C; Dapretto, Mirella

    2011-11-01

    Very little is known about the neural underpinnings of language learning across the lifespan and how these might be modified by maturational and experiential factors. Building on behavioral research highlighting the importance of early word segmentation (i.e. the detection of word boundaries in continuous speech) for subsequent language learning, here we characterize developmental changes in brain activity as this process occurs online, using data collected in a mixed cross-sectional and longitudinal design. One hundred and fifty-six participants, ranging from age 5 to adulthood, underwent functional magnetic resonance imaging (fMRI) while listening to three novel streams of continuous speech, which contained either strong statistical regularities, strong statistical regularities and speech cues, or weak statistical regularities providing minimal cues to word boundaries. All age groups displayed significant signal increases over time in temporal cortices for the streams with high statistical regularities; however, we observed a significant right-to-left shift in the laterality of these learning-related increases with age. Interestingly, only the 5- to 10-year-old children displayed significant signal increases for the stream with low statistical regularities, suggesting an age-related decrease in sensitivity to more subtle statistical cues. Further, in a sample of 78 10-year-olds, we examined the impact of proficiency in a second language and level of pubertal development on learning-related signal increases, showing that the brain regions involved in language learning are influenced by both experiential and maturational factors. PMID:22010887

  18. Neural Computation of Surface Border Ownership and Relative Surface Depth from Ambiguous Contrast Inputs.

    PubMed

    Dresp-Langley, Birgitta; Grossberg, Stephen

    2016-01-01

    The segregation of image parts into foreground and background is an important aspect of the neural computation of 3D scene perception. To achieve such segregation, the brain needs information about border ownership; that is, the belongingness of a contour to a specific surface represented in the image. This article presents psychophysical data derived from 3D percepts of figure and ground that were generated by presenting 2D images composed of spatially disjoint shapes that pointed inward or outward relative to the continuous boundaries that they induced along their collinear edges. The shapes in some images had the same contrast (black or white) with respect to the background gray. Other images included opposite contrasts along each induced continuous boundary. Psychophysical results demonstrate conditions under which figure-ground judgment probabilities in response to these ambiguous displays are determined by the orientation of contrasts only, not by their relative contrasts, despite the fact that many border ownership cells in cortical area V2 respond to a preferred relative contrast. Studies are also reviewed in which both polarity-specific and polarity-invariant properties obtain. The FACADE and 3D LAMINART models are used to explain these data.

  19. Neural correlates of age-related decline and compensation in visual attention capacity.

    PubMed

    Wiegand, Iris; Töllner, Thomas; Dyrholm, Mads; Müller, Hermann J; Bundesen, Claus; Finke, Kathrin

    2014-09-01

    We identified neural correlates of declined and preserved basic visual attention functions in aging individuals based on Bundesen "Theory of Visual Attention". In an interindividual difference approach, we contrasted electrophysiology of higher- and lower-performing younger and older participants. In both age groups, the same distinct components indexed performance levels of parameters visual processing speed C and visual short-term memory storage capacity K. The posterior N1 marked interindividual differences in C and the contralateral delay activity marked interindividual differences in K. Moreover, both parameters were selectively related to 2 further event-related potential waves in older age. The anterior N1 was reduced for older participants with lower processing speed, indicating that age-related loss of attentional resources slows encoding. An enhanced right-central positivity was found only for older participants with high storage capacity, suggesting compensatory recruitment for retaining visual short-term memory performance. Together, our results demonstrate that attentional capacity in older age depends on both preservation and successful reorganization of the underlying brain circuits.

  20. Object of desire self-consciousness theory.

    PubMed

    Bogaert, Anthony F; Brotto, Lori A

    2014-01-01

    In this article, the authors discuss the construct of object of desire self-consciousness, the perception that one is romantically and sexually desirable in another's eyes. The authors discuss the nature of the construct, variations in its expression, and how it may function as part of a self-schemata or script related to romance and sexuality. The authors suggest that object of desire self-consciousness may be an adaptive, evolved psychological mechanism allowing sexual and romantic tactics suitable to one's mate value. The authors also suggest that it can act as a signal that one has high mate value in the sexual marketplace. The authors then review literature (e.g., on fantasies, on sexual activity preferences, on sexual dysfunctions, on language) suggesting that object of desire self-consciousness plays a particularly important role in heterosexual women's sexual/romantic functioning and desires. PMID:23905711

  1. The neural mechanisms underlying the aging-related enhancement of positive affects: electrophysiological evidences

    PubMed Central

    Meng, Xianxin; Yang, Jiemin; Cai, AYan; Ding, XinSheng; Liu, Wenwen; Li, Hong; Yuan, JiaJin

    2015-01-01

    Background: Previous studies reported that old adults, relative to young adults, showed improvement of emotional stability and increased experiences of positive affects. Methods: In order to better understand the neural underpinnings behind the aging-related enhancement of positive affects, it is necessary to investigate whether old and young adults differ in the threshold of eliciting positive or negative emotional reactions. However, no studies have examined emotional reaction differences between old and young adults by manipulating the intensity of emotional stimuli to date. To clarify this issue, the present study examined the impact of aging on the brain’s susceptibility to affective pictures of varying emotional intensities. We recorded event-related potentials (ERP) for highly negative (HN), mildly negative (MN) and neutral pictures in the negative experimental block; and for highly positive (HP), mildly positive (MP) and neutral pictures in the positive experimental block, when young and old adults were required to count the number of pictures, irrespective of the emotionality of the pictures. Results: Event-related potentials results showed that LPP (late positive potentials) amplitudes were larger for HN and MN stimuli compared to neutral stimuli in young adults, but not in old adults. By contrast, old adults displayed larger LPP amplitudes for HP and MP relative to neutral stimuli, while these effects were absent for young adults. In addition, old adults reported more frequent perception of positive stimuli and less frequent perception of negative stimuli than young adults. The post-experiment stimulus assessment showed more positive ratings of Neutral and MP stimuli, and reduced arousal ratings of HN stimuli in old compared to young adults. Conclusion: These results suggest that old adults are more resistant to the impact of negative stimuli, while they are equipped with enhanced attentional bias for positive stimuli. The implications of these results

  2. Are we explaining consciousness yet?

    PubMed

    Dennett, D

    2001-04-01

    Theorists are converging from quite different quarters on a version of the global neuronal workspace model of consciousness, but there are residual confusions to be dissolved. In particular, theorists must resist the temptation to see global accessibility as the cause of consciousness (as if consciousness were some other, further condition); rather, it is consciousness. A useful metaphor for keeping this elusive idea in focus is that consciousness is rather like fame in the brain. It is not a privileged medium of representation, or an added property some states have; it is the very mutual accessibility that gives some informational states the powers that come with a subject's consciousness of that information. Like fame, consciousness is not a momentary condition, or a purely dispositional state, but rather a matter of actual influence over time. Theorists who take on the task of accounting for the aftermath that is critical for consciousness often appear to be leaving out the Subject of consciousness, when in fact they are providing an analysis of the Subject, a necessary component in any serious theory of consciousness.

  3. The biological function of consciousness

    PubMed Central

    Earl, Brian

    2014-01-01

    This research is an investigation of whether consciousness—one's ongoing experience—influences one's behavior and, if so, how. Analysis of the components, structure, properties, and temporal sequences of consciousness has established that, (1) contrary to one's intuitive understanding, consciousness does not have an active, executive role in determining behavior; (2) consciousness does have a biological function; and (3) consciousness is solely information in various forms. Consciousness is associated with a flexible response mechanism (FRM) for decision-making, planning, and generally responding in nonautomatic ways. The FRM generates responses by manipulating information and, to function effectively, its data input must be restricted to task-relevant information. The properties of consciousness correspond to the various input requirements of the FRM; and when important information is missing from consciousness, functions of the FRM are adversely affected; both of which indicate that consciousness is the input data to the FRM. Qualitative and quantitative information (shape, size, location, etc.) are incorporated into the input data by a qualia array of colors, sounds, and so on, which makes the input conscious. This view of the biological function of consciousness provides an explanation why we have experiences; why we have emotional and other feelings, and why their loss is associated with poor decision-making; why blindsight patients do not spontaneously initiate responses to events in their blind field; why counter-habitual actions are only possible when the intended action is in mind; and the reason for inattentional blindness. PMID:25140159

  4. Generalization characteristics of complex-valued feedforward neural networks in relation to signal coherence.

    PubMed

    Hirose, Akira; Yoshida, Shotaro

    2012-04-01

    Applications of complex-valued neural networks (CVNNs) have expanded widely in recent years-in particular in radar and coherent imaging systems. In general, the most important merit of neural networks lies in their generalization ability. This paper compares the generalization characteristics of complex-valued and real-valued feedforward neural networks in terms of the coherence of the signals to be dealt with. We assume a task of function approximation such as interpolation of temporal signals. Simulation and real-world experiments demonstrate that CVNNs with amplitude-phase-type activation function show smaller generalization error than real-valued networks, such as bivariate and dual-univariate real-valued neural networks. Based on the results, we discuss how the generalization characteristics are influenced by the coherence of the signals depending on the degree of freedom in the learning and on the circularity in neural dynamics.

  5. A Neural Region of Abstract Working Memory

    ERIC Educational Resources Information Center

    Cowan, Nelson; Li, Dawei; Moffitt, Amanda; Becker, Theresa M.; Martin, Elizabeth A.; Saults, J. Scott; Christ, Shawn E.

    2011-01-01

    Over 350 years ago, Descartes proposed that the neural basis of consciousness must be a brain region in which sensory inputs are combined. Using fMRI, we identified at least one such area for working memory, the limited information held in mind, described by William James as the trailing edge of consciousness. Specifically, a region in the left…

  6. Food-Related Neural Circuitry in Prader-Willi Syndrome: Response to High- versus Low-Calorie Foods

    ERIC Educational Resources Information Center

    Dimitropoulos, Anastasia; Schultz, Robert T.

    2008-01-01

    Prader-Willi syndrome (PWS) is a neurodevelopmental disorder characterized by hyperphagia and food preoccupations. Although dysfunction of the hypothalamus likely has a critical role in hyperphagia, it is only one of several regions involved in the regulation of eating. The purpose of this research was to examine food-related neural circuitry…

  7. What the brain's intrinsic activity can tell us about consciousness? A tri-dimensional view.

    PubMed

    Northoff, Georg

    2013-05-01

    Current neuroscience applies a bi-dimensional model to consciousness. Content and level of consciousness have been distinguished from each other in their underlying neuronal mechanisms. This though leaves open the role of the brain's intrinsic activity and its particular temporal and spatial structure in consciousness. I here review and investigate the spatial and temporal features of the brain's intrinsic activity in detail and postulate what I describe as spatiotemporal structure that implies a virtual (e.g., statistically based) spatiotemporal continuity. Such spatiotemporal continuity is supposed to structure and organize the neural processing of the incoming extrinsic stimuli and their potential association with consciousness. I therefore conclude that the current bi-dimensional view of consciousness focusing only on content and level may need to be complemented by a third dimension, the form, e.g., spatiotemporal structure, as provided by the intrinsic activity. In short, I here opt for tri-rather than bi-dimensional view of consciousness.

  8. Understanding visual consciousness in autism spectrum disorders

    PubMed Central

    Yatziv, Tal; Jacobson, Hilla

    2015-01-01

    The paper focuses on the question of what the (visual) perceptual differences are between individuals with autism spectrum disorders (ASD) and typically developing (TD) individuals. We argue against the view that autistic subjects have a deficiency in the most basic form of perceptual consciousness—namely, phenomenal consciousness. Instead, we maintain, the perceptual atypicality of individuals with autism is of a more conceptual and cognitive sort—their perceptual experiences share crucial aspects with TD individuals. Our starting point is Ben Shalom’s (2005, 2009) three-level processing framework for explaining atypicality in several domains of processing among autistics, which we compare with two other tripartite models of perception—Jackendoff’s (1987) and Prinz’s (2000, 2005a, 2007) Intermediate Level Hypothesis and Lamme’s (2004, 2006, 2010) neural account of consciousness. According to these models, whereas the second level of processing is concerned with viewer-centered visual representations of basic visual properties and incorporates some early forms of integration, the third level is more cognitive and conceptual. We argue that the data suggest that the atypicality in autism is restricted mainly to the third level. More specifically, second-level integration, which is the mark of phenomenal consciousness, is typical, yet third-level integration of perceptual objects and concepts is atypical. Thus, the basic experiences of individuals with autism are likely to be similar to typical subjects’ experiences; the main difference lies in the sort of cognitive access the subjects have to their experiences. We conclude by discussing implications of the suggested analysis of experience in autism for conceptions of phenomenal consciousness. PMID:25954180

  9. Implications of movement-related cortical potential for understanding neural adaptations in muscle strength tasks

    PubMed Central

    2014-01-01

    This systematic review aims to provide information about the implications of the movement-related cortical potential (MRCP) in acute and chronic responses to the counter resistance training. The structuring of the methods of this study followed the proposals of the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses). It was performed an electronically search in Pubmed/Medline and ISI Web of Knowledge data bases, from 1987 to 2013, besides the manual search in the selected references. The following terms were used: Bereitschaftspotential, MRCP, strength and force. The logical operator “AND” was used to combine descriptors and terms used to search publications. At the end, 11 studies attended all the eligibility criteria and the results demonstrated that the behavior of MRCP is altered because of different factors such as: force level, rate of force development, fatigue induced by exercise, and the specific phase of muscular action, leading to an increase in the amplitude in eccentric actions compared to concentric actions, in acute effects. The long-term adaptations demonstrated that the counter resistance training provokes an attenuation in the amplitude in areas related to the movement, which may be caused by neural adaptation occurred in the motor cortex. PMID:24602228

  10. Disentangling the neural mechanisms involved in Hinduism- and Buddhism-related meditations.

    PubMed

    Tomasino, Barbara; Chiesa, Alberto; Fabbro, Franco

    2014-10-01

    The most diffuse forms of meditation derive from Hinduism and Buddhism spiritual traditions. Different cognitive processes are set in place to reach these meditation states. According to an historical-philological hypothesis (Wynne, 2009) the two forms of meditation could be disentangled. While mindfulness is the focus of Buddhist meditation reached by focusing sustained attention on the body, on breathing and on the content of the thoughts, reaching an ineffable state of nothigness accompanied by a loss of sense of self and duality (Samadhi) is the main focus of Hinduism-inspired meditation. It is possible that these different practices activate separate brain networks. We tested this hypothesis by conducting an activation likelihood estimation (ALE) meta-analysis of functional magnetic resonance imaging (fMRI) studies. The network related to Buddhism-inspired meditation (16 experiments, 263 subjects, and 96 activation foci) included activations in some frontal lobe structures associated with executive attention, possibly confirming the fundamental role of mindfulness shared by many Buddhist meditations. By contrast, the network related to Hinduism-inspired meditation (8 experiments, 54 activation foci and 66 subjects) triggered a left lateralized network of areas including the postcentral gyrus, the superior parietal lobe, the hippocampus and the right middle cingulate cortex. The dissociation between anterior and posterior networks support the notion that different meditation styles and traditions are characterized by different patterns of neural activation.

  11. Learning from experience: event-related potential correlates of reward processing, neural adaptation, and behavioral choice.

    PubMed

    Walsh, Matthew M; Anderson, John R

    2012-09-01

    To behave adaptively, we must learn from the consequences of our actions. Studies using event-related potentials (ERPs) have been informative with respect to the question of how such learning occurs. These studies have revealed a frontocentral negativity termed the feedback-related negativity (FRN) that appears after negative feedback. According to one prominent theory, the FRN tracks the difference between the values of actual and expected outcomes, or reward prediction errors. As such, the FRN provides a tool for studying reward valuation and decision making. We begin this review by examining the neural significance of the FRN. We then examine its functional significance. To understand the cognitive processes that occur when the FRN is generated, we explore variables that influence its appearance and amplitude. Specifically, we evaluate four hypotheses: (1) the FRN encodes a quantitative reward prediction error; (2) the FRN is evoked by outcomes and by stimuli that predict outcomes; (3) the FRN and behavior change with experience; and (4) the system that produces the FRN is maximally engaged by volitional actions.

  12. Disentangling the neural mechanisms involved in Hinduism- and Buddhism-related meditations.

    PubMed

    Tomasino, Barbara; Chiesa, Alberto; Fabbro, Franco

    2014-10-01

    The most diffuse forms of meditation derive from Hinduism and Buddhism spiritual traditions. Different cognitive processes are set in place to reach these meditation states. According to an historical-philological hypothesis (Wynne, 2009) the two forms of meditation could be disentangled. While mindfulness is the focus of Buddhist meditation reached by focusing sustained attention on the body, on breathing and on the content of the thoughts, reaching an ineffable state of nothigness accompanied by a loss of sense of self and duality (Samadhi) is the main focus of Hinduism-inspired meditation. It is possible that these different practices activate separate brain networks. We tested this hypothesis by conducting an activation likelihood estimation (ALE) meta-analysis of functional magnetic resonance imaging (fMRI) studies. The network related to Buddhism-inspired meditation (16 experiments, 263 subjects, and 96 activation foci) included activations in some frontal lobe structures associated with executive attention, possibly confirming the fundamental role of mindfulness shared by many Buddhist meditations. By contrast, the network related to Hinduism-inspired meditation (8 experiments, 54 activation foci and 66 subjects) triggered a left lateralized network of areas including the postcentral gyrus, the superior parietal lobe, the hippocampus and the right middle cingulate cortex. The dissociation between anterior and posterior networks support the notion that different meditation styles and traditions are characterized by different patterns of neural activation. PMID:24975229

  13. Implications of movement-related cortical potential for understanding neural adaptations in muscle strength tasks.

    PubMed

    Lattari, Eduardo; Arias-Carrión, Oscar; Monteiro-Junior, Renato Sobral; Mello Portugal, Eduardo Matta; Paes, Flávia; Menéndez-González, Manuel; Silva, Adriana Cardoso; Nardi, Antonio Egidio; Machado, Sergio

    2014-01-01

    This systematic review aims to provide information about the implications of the movement-related cortical potential (MRCP) in acute and chronic responses to the counter resistance training. The structuring of the methods of this study followed the proposals of the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses). It was performed an electronically search in Pubmed/Medline and ISI Web of Knowledge data bases, from 1987 to 2013, besides the manual search in the selected references. The following terms were used: Bereitschaftspotential, MRCP, strength and force. The logical operator "AND" was used to combine descriptors and terms used to search publications. At the end, 11 studies attended all the eligibility criteria and the results demonstrated that the behavior of MRCP is altered because of different factors such as: force level, rate of force development, fatigue induced by exercise, and the specific phase of muscular action, leading to an increase in the amplitude in eccentric actions compared to concentric actions, in acute effects. The long-term adaptations demonstrated that the counter resistance training provokes an attenuation in the amplitude in areas related to the movement, which may be caused by neural adaptation occurred in the motor cortex. PMID:24602228

  14. Neural Correlates to Food-Related Behavior in Normal-Weight and Overweight/Obese Participants

    PubMed Central

    Ho, Alan; Kennedy, James; Dimitropoulos, Anastasia

    2012-01-01

    Two thirds of US adults are either obese or overweight and this rate is rising. Although the etiology of obesity is not yet fully understood, neuroimaging studies have demonstrated that the central nervous system has a principal role in regulating eating behavior. In this study, functional magnetic resonance imaging and survey data were evaluated for correlations between food-related problem behaviors and the neural regions underlying responses to visual food cues before and after eating in normal-weight individuals and overweight/obese individuals. In normal-weight individuals, activity in the left amygdala in response to high-calorie food vs. nonfood object cues was positively correlated with impaired satiety scores during fasting, suggesting that those with impaired satiety scores may have an abnormal anticipatory reward response. In overweight/obese individuals, activity in the dorsolateral prefrontal cortex (DLPFC) in response to low-calorie food cues was negatively correlated with impaired satiety during fasting, suggesting that individuals scoring lower in satiety impairment were more likely to activate the DLPFC inhibitory system. After eating, activity in both the putamen and the amygdala was positively correlated with impaired satiety scores among obese/overweight participants. While these individuals may volitionally suggest they are full, their functional response to food cues suggests food continues to be salient. These findings suggest brain regions involved in the evaluation of visual food cues may be mediated by satiety-related problems, dependent on calorie content, state of satiation, and body mass index. PMID:23028988

  15. Brain Networks Maintain a Scale-Free Organization across Consciousness, Anesthesia, and Recovery: Evidence for Adaptive Reconfiguration

    PubMed Central

    Lee, UnCheol; Oh, GabJin; Kim, Seunghwan; Noh, GyuJung; Choi, ByungMoon

    2010-01-01

    Background Loss of consciousness is an essential feature of general anesthesia. Although alterations of neural networks during anesthesia have been identified in the spatial domain, there has been relatively little study of temporal organization. Methods Ten normal male volunteers were anesthetized with an induction dose of propofol on two separate occasions. The duration of network connections in the brain was analyzed by multichannel electroencephalography and the minimum spanning tree method. Entropy of the connections was calculated based on Shannon entropy. The global temporal configuration of networks was investigated by constructing the cumulative distribution function of connection times in different frequency bands and different states of consciousness. Results General anesthesia was associated with a significant reduction in the number of network connections, as well as significant alterations of their duration. These changes were most prominent in the delta bandwidth and were also associated with a significant reduction in entropy of the connection matrix. Despite these and other changes, a global “scale-free” organization was consistently preserved across multiple subjects, multiple anesthetic exposures, multiple states of consciousness and multiple frequencies of the electroencephalogram. Conclusions Our data suggest a fundamental principle of temporal organization of network connectivity that is maintained during both consciousness and anesthesia, despite local changes. These findings are consistent with a process of adaptive reconfiguration during general anesthesia. PMID:20881595

  16. Shadowing the wandering mind: how understanding the mind-wandering state can inform our appreciation of conscious experience.

    PubMed

    Konishi, Mahiko; Smallwood, Jonathan

    2016-07-01

    The mind-wandering state illustrates two fundamental aspects of consciousness: its generative nature, which is reflected by the stimulus-independent content of thought that occurs when our minds wander; and metacognition, the unique capacity of the mind to reflect and understand itself. Self-generated thought, which allows us to consider people and events that are not present in the immediate environment, and metacognition, allowing us to introspect and report our inner experiences, are both essential to the scientific study of mind-wandering. Nevertheless, they also inevitably lead to specific issues that mirror more general problems in the field of consciousness research. The generative nature of consciousness makes it difficult to have direct control on the phenomenon, and the act of introspecting on inner experience has the potential to influence the state itself. We illustrate how the field of mind-wandering research can overcome these problems. Its generative nature can be understood by triangulating the objective measures (such as neural function) with subjective measures of experience and it can be manipulated indirectly by varying the demands of the external environment. Furthermore, we describe candidate covert markers for the mind-wandering state, which allow the phenomenon to be observed without direct interference, minimizing the concern that instructions to introspect necessarily change conscious experience. WIREs Cogn Sci 2016, 7:233-246. doi: 10.1002/wcs.1392 For further resources related to this article, please visit the WIREs website.

  17. Environment Conscious Ceramics (Ecoceramics)

    NASA Technical Reports Server (NTRS)

    Singh, Mrityunjay; Levine, Stanley R. (Technical Monitor)

    2000-01-01

    Environment conscious ceramics (Ecoceramics) are a new class of materials, which can be produced with renewable natural resources (wood) or wood wastes (wood sawdust). Silicon carbide-based ecoceramics have been fabricated by reactive infiltration of carbonaceous preforms by molten silicon or silicon-refractory metal alloys. These carbonaceous preforms have been fabricated by pyrolysis of solid wood bodies at 1000 C. The fabrication approach, microstructure, and mechanical properties of SiC-based ecoceramics are presented. Ecoceramics have tailorable properties and behave like ceramic materials manufactured by conventional approaches.

  18. Consciousness -- A Verifiable Prediction

    NASA Astrophysics Data System (ADS)

    Panchapakesan, N.

    2014-07-01

    Consciousness may or may not be completely within the realm of science. We have argued elsewhere that there is a high probability that it is not within the purview of science, just like humanities and arts are outside science. Even social sciences do not come under science when human interactions are involved. Here, we suggest a possible experiment to decide whether it is part of science. We suggest that a scientific signal may be available to investigate the prediction in the form of an electromagnetic brainwave background radiation.

  19. Investigating age-related changes in anterior and posterior neural activity throughout the information processing stream.

    PubMed

    Alperin, Brittany R; Tusch, Erich S; Mott, Katherine K; Holcomb, Phillip J; Daffner, Kirk R

    2015-10-01

    Event-related potential (ERP) and other functional imaging studies often demonstrate age-related increases in anterior neural activity and decreases in posterior activity while subjects carry out task demands. It remains unclear whether this "anterior shift" is limited to late cognitive operations like those indexed by the P3 component, or is evident during other stages of information processing. The temporal resolution of ERPs provided an opportunity to address this issue. Temporospatial principal component analysis (PCA) was used to identify underlying components that may be obscured by overlapping ERP waveforms. ERPs were measured during a visual oddball task in 26 young, 26 middle-aged, and 29 old subjects who were well-matched for IQ, executive function, education, and task performance. PCA identified six anterior factors peaking between ∼140 ms and 810 ms, and four posterior factors peaking between ∼300 ms and 810 ms. There was an age-related increase in the amplitude of anterior factors between ∼200 and 500 ms, and an age-associated decrease in amplitude of posterior factors after ∼500 ms. The increase in anterior processing began as early as middle-age, was sustained throughout old age, and appeared to be linear in nature. These results suggest that age-associated increases in anterior activity occur after early sensory processing has taken place, and are most prominent during a period in which attention is being marshaled to evaluate a stimulus. In contrast, age-related decreases in posterior activity manifest during operations involved in stimulus categorization, post-decision monitoring, and preparation for an upcoming event. PMID:26295684

  20. Neural correlates and causal mechanisms.

    PubMed

    Hohwy, Jakob

    2012-06-01

    What Joseph Neisser calls for is exactly right: more philosophy of science will help us better understand and refine the idea of neural correlates of consciousness (NCC). But (i) the key bit of philosophy of science Neisser appeals to is itself in need of clarification; (ii) the orthodox NCC definition is more resourceful than Neisser allows, and (iii) it is possible to resist the phenomenological conception of conscious experience that fuels some of Neisser's argument.

  1. The “Id” Knows More than the “Ego” Admits: Neuropsychoanalytic and Primal Consciousness Perspectives on the Interface Between Affective and Cognitive Neuroscience

    PubMed Central

    Solms, Mark; Panksepp, Jaak

    2012-01-01

    It is commonly believed that consciousness is a higher brain function. Here we consider the likelihood, based on abundant neuroevolutionary data that lower brain affective phenomenal experiences provide the “energy” for the developmental construction of higher forms of cognitive consciousness. This view is concordant with many of the theoretical formulations of Sigmund Freud. In this reconceptualization, all of consciousness may be dependent on the original evolution of affective phenomenal experiences that coded survival values. These subcortical energies provided a foundation that could be used for the epigenetic construction of perceptual and other higher forms of consciousness. From this perspective, perceptual experiences were initially affective at the primary-process brainstem level, but capable of being elaborated by secondary learning and memory processes into tertiary-cognitive forms of consciousness. Within this view, although all individual neural activities are unconscious, perhaps along with secondary-process learning and memory mechanisms, the primal sub-neocortical networks of emotions and other primal affects may have served as the sentient scaffolding for the construction of resolved perceptual and higher mental activities within the neocortex. The data supporting this neuro-psycho-evolutionary vision of the emergence of mind is discussed in relation to classical psychoanalytical models. PMID:24962770

  2. Genes and experience shape brain networks of conscious control.

    PubMed

    Posner, Michael I

    2005-01-01

    One aspect of consciousness involves voluntary control over thoughts and feelings, often called will. Progress in neuroimaging and in sequencing the human genome makes it possible to think about voluntary control in terms of a specific neural network that includes midline and lateral frontal areas. A number of cognitive tasks involving conflict as well as the control of emotions have been shown to activate these brain areas. Studies have traced the development of this network in the ability to regulate cognition and emotion from about 2.5 to 7 years of age. Individual differences in this network have been related to parental reports of the ability of children to regulate their behavior, to delay reward and to develop a conscience. In adolescents these individual differences predict the propensity for antisocial behavior. Differences in specific genes are related to individual efficiency in performance of the network, and by neuroimaging, to the strength of its activation of this network. Future animal studies may make it possible to learn in detail how genes influence the common pattern of development of self-regulation made possible by this network. Moreover, a number of neurological and psychiatric pathologies involving difficulties in awareness and volition show deficits in parts of this network. We are now studying whether specific training experiences can influence the development of this network in 4-year-old children and if so, for whom it is most effective. Voluntary control is also important for the regulation of conscious input from the sensory environment. It seems likely that the same network involved in self-regulation is also crucial for focal attention to the sensory world.

  3. Meditation reduces pain-related neural activity in the anterior cingulate cortex, insula, secondary somatosensory cortex, and thalamus

    PubMed Central

    Nakata, Hiroki; Sakamoto, Kiwako; Kakigi, Ryusuke

    2014-01-01

    Recent studies have shown that meditation inhibits or relieves pain perception. To clarify the underlying mechanisms for this phenomenon, neuroimaging methods, such as functional magnetic resonance imaging, and neurophysiological methods, such as magnetoencephalography and electroencephalography, have been used. However, it has been difficult to interpret the results, because there is some paradoxical evidence. For example, some studies reported increased neural responses to pain stimulation during meditation in the anterior cingulate cortex (ACC) and insula, whereas others showed a decrease in these regions. There have been inconsistent findings to date. Moreover, in general, since the activities of the ACC and insula are correlated with pain perception, the increase in neural activities during meditation would be related to the enhancement of pain perception rather than its reduction. These contradictions might directly contribute to the ‘mystery of meditation.’ In this review, we presented previous findings for brain regions during meditation and the anatomical changes that occurred in the brain with long-term meditation training. We then discussed the findings of previous studies that examined pain-related neural activity during meditation. We also described the brain mechanisms responsible for pain relief during meditation, and possible reasons for paradoxical evidence among previous studies. By thoroughly overviewing previous findings, we hypothesized that meditation reduces pain-related neural activity in the ACC, insula, secondary somatosensory cortex, and thalamus. We suggest that the characteristics of the modulation of this activity may depend on the kind of meditation and/or number of years of experience of meditation, which were associated with paradoxical findings among previous studies that investigated pain-related neural activities during meditation. PMID:25566158

  4. Conscious Experience and Episodic Memory: Hippocampus at the Crossroads

    PubMed Central

    Behrendt, Ralf-Peter

    2013-01-01

    If an instance of conscious experience of the seemingly objective world around us could be regarded as a newly formed event memory, much as an instance of mental imagery has the content of a retrieved event memory, and if, therefore, the stream of conscious experience could be seen as evidence for ongoing formation of event memories that are linked into episodic memory sequences, then unitary conscious experience could be defined as a symbolic representation of the pattern of hippocampal neuronal firing that encodes an event memory – a theoretical stance that may shed light into the mind-body and binding problems in consciousness research. Exceedingly detailed symbols that describe patterns of activity rapidly self-organizing, at each cycle of the θ rhythm, in the hippocampus are instances of unitary conscious experience that jointly constitute the stream of consciousness. Integrating object information (derived from the ventral visual stream and orbitofrontal cortex) with contextual emotional information (from the anterior insula) and spatial environmental information (from the dorsal visual stream), the hippocampus rapidly forms event codes that have the informational content of objects embedded in an emotional and spatiotemporally extending context. Event codes, formed in the CA3-dentate network for the purpose of their memorization, are not only contextualized but also allocentric representations, similarly to conscious experiences of events and objects situated in a seemingly objective and observer-independent framework of phenomenal space and time. Conscious perception, creating the spatially and temporally extending world that we perceive around us, is likely to be evolutionarily related to more fleeting and seemingly internal forms of conscious experience, such as autobiographical memory recall, mental imagery, including goal anticipation, and to other forms of externalized conscious experience, namely dreaming and hallucinations; and evidence pointing

  5. What is consciousness?

    PubMed

    Solms, M

    1997-01-01

    In the past few years scientists and scholars in a variety of disciplines have been making concerted efforts to answer an ancient question, namely, How exactly do the physical processes in the brain cause consciousness? What is distinctive about the way in which modern scientists and scholars are approaching this question is that they are treating it as a scientific problem rather than a metaphysical one. This transition reflects the air of expectation in contemporary cognitive science to the effect that an empirical solution is imminent to a philosophical problem that previously was considered insoluble. Nevertheless, a recent authoritative review of the publications of such leading contemporary workers in the field as Francis Crick, Daniel Dennett, Gerald Edelman, Roger Penrose, and Israel Rosenfield has concluded that they have all failed to provide a satisfactory answer to the question (Searle 1995a). The present paper makes a psychoanalytic contribution to this interdisciplinary effort and provides an alternative answer to the question, based on Freud's conceptualization of the problem of consciousness. The paper takes a concrete example from Searle's review, reanalyses it within Freud's metapsychological frame of reference, and shows how this frame provides a radical solution to the problem. This implication of Freud's work has not hitherto been recognized and so has not received the attention it deserves.

  6. The conscious cell.

    PubMed

    Margulis, L

    2001-04-01

    The evolutionary antecedent of the nervous system is "microbial consciousness." In my description of the origin of the eukaryotic cell via bacterial cell merger, the components fused via symbiogenesis are already "conscious" entities. I have reconstructed an aspect of the origin of the neurotubule system by a hypothesis that can be directly tested. The idea is that the system of microtubules that became neurotubules has as its origin once-independent eubacteria of a very specific kind. Nothing, I claim, has ever been lost without a trace in evolution. The remains of the evolutionary process, the sequence that occurred that produced Cajal's neuron and other cells, live today. By study of obscure protists that we take to be extant decendants of steps in the evolution of cells, we reconstruct the past directly from living organisms. Even remnants of "microbial mind" can be inferred from behaviors of thriving microorganisms. All of the eukaryotes, not just lichens or an animal's neurons, are products of symbiogenesis among formerly free-living bacteria, some highly motile. Eukaryotes have evolved by the inheritance of acquired genomes; they have gained all their new features by ingesting and not digesting whole bacterial cells with complete genomes.

  7. Distribution of language-related Cntnap2 protein in neural circuits critical for vocal learning

    PubMed Central

    Condro, Michael C.; White, Stephanie A.

    2013-01-01

    Variants of the contactin associated protein-like 2 (Cntnap2) gene are risk factors for language-related disorders including autism spectrum disorder, specific language impairment, and stuttering. Songbirds are useful models for study of human speech disorders due to their shared capacity for vocal learning, which relies on similar cortico-basal ganglia circuitry and genetic factors. Here, we investigate Cntnap2 protein expression in the brain of the zebra finch, a songbird species in which males, but not females, learn their courtship songs. We hypothesize that Cntnap2 has overlapping functions in vocal learning species, and expect to find protein expression in song-related areas of the zebra finch brain. We further expect that the distribution of this membrane-bound protein may not completely mirror its mRNA distribution due to the distinct subcellular localization of the two molecular species. We find that Cntnap2 protein is enriched in several song control regions relative to surrounding tissues, particularly within the adult male, but not female, robust nucleus of the arcopallium (RA), a cortical song control region analogous to human layer 5 primary motor cortex. The onset of this sexually dimorphic expression coincides with the onset of sensorimotor learning in developing males. Enrichment in male RA appears due to expression in projection neurons within the nucleus, as well as to additional expression in nerve terminals of cortical projections to RA from the lateral magnocellular nucleus of the nidopallium. Cntnap2 protein expression in zebra finch brain supports the hypothesis that this molecule affects neural connectivity critical for vocal learning across taxonomic classes. PMID:23818387

  8. Global Workspace Dynamics: Cortical “Binding and Propagation” Enables Conscious Contents

    PubMed Central

    Baars, Bernard J.; Franklin, Stan; Ramsoy, Thomas Zoega

    2013-01-01

    A global workspace (GW) is a functional hub of binding and propagation in a population of loosely coupled signaling elements. In computational applications, GW architectures recruit many distributed, specialized agents to cooperate in resolving focal ambiguities. In the brain, conscious experiences may reflect a GW function. For animals, the natural world is full of unpredictable dangers and opportunities, suggesting a general adaptive pressure for brains to resolve focal ambiguities quickly and accurately. GW theory aims to understand the differences between conscious and unconscious brain events. In humans and related species the cortico-thalamic (C-T) core is believed to underlie conscious aspects of perception, thinking, learning, feelings of knowing (FOK), felt emotions, visual imagery, working memory, and executive control. Alternative theoretical perspectives are also discussed. The C-T core has many anatomical hubs, but conscious percepts are unitary and internally consistent at any given moment. Over time, conscious contents constitute a very large, open set. This suggests that a brain-based GW capacity cannot be localized in a single anatomical hub. Rather, it should be sought in a functional hub – a dynamic capacity for binding and propagation of neural signals over multiple task-related networks, a kind of neuronal cloud computing. In this view, conscious contents can arise in any region of the C-T core when multiple input streams settle on a winner-take-all equilibrium. The resulting conscious gestalt may ignite an any-to-many broadcast, lasting ∼100–200 ms, and trigger widespread adaptation in previously established networks. To account for the great range of conscious contents over time, the theory suggests an open repertoire of binding1 coalitions that can broadcast via theta/gamma or alpha/gamma phase coupling, like radio channels competing for a narrow frequency band. Conscious moments are thought to hold only 1–4 unrelated items; this

  9. Habitual Alcohol Seeking: Neural Bases and Possible Relations to Alcohol Use Disorders.

    PubMed

    Corbit, Laura H; Janak, Patricia H

    2016-07-01

    Loss of flexible control over alcohol use may contribute to the development of alcohol use disorders. An increased contribution of response habits to alcohol-related behaviors may help explain this loss of control. Focusing on data from outcome devaluation and Pavlovian-instrumental transfer procedures, we review evidence for loss of goal-directed control over alcohol seeking and consumption drawing from both preclinical findings and clinical data where they exist. Over the course of extended alcohol self-administration and exposure, the performance of alcohol-seeking responses becomes less sensitive to reduction in the value of alcohol and more vulnerable to the influences of alcohol-predictive stimuli. These behavioral changes are accompanied by a shift in the corticostriatal circuits that control responding from circuits centered on the dorsomedial to those centered on the dorsolateral striatum. These changes in behavioral and neural control could help explain failures to abstain from alcohol despite intention to do so. Understanding and ultimately ameliorating these changes will aid development of more effective treatment interventions. PMID:27223341

  10. Habitual Alcohol Seeking: Neural Bases and Possible Relations to Alcohol Use Disorders.

    PubMed

    Corbit, Laura H; Janak, Patricia H

    2016-07-01

    Loss of flexible control over alcohol use may contribute to the development of alcohol use disorders. An increased contribution of response habits to alcohol-related behaviors may help explain this loss of control. Focusing on data from outcome devaluation and Pavlovian-instrumental transfer procedures, we review evidence for loss of goal-directed control over alcohol seeking and consumption drawing from both preclinical findings and clinical data where they exist. Over the course of extended alcohol self-administration and exposure, the performance of alcohol-seeking responses becomes less sensitive to reduction in the value of alcohol and more vulnerable to the influences of alcohol-predictive stimuli. These behavioral changes are accompanied by a shift in the corticostriatal circuits that control responding from circuits centered on the dorsomedial to those centered on the dorsolateral striatum. These changes in behavioral and neural control could help explain failures to abstain from alcohol despite intention to do so. Understanding and ultimately ameliorating these changes will aid development of more effective treatment interventions.

  11. Protective Effect of Puerarin Against Oxidative Stress Injury of Neural Cells and Related Mechanisms

    PubMed Central

    Cheng, Yuan; Leng, Wei; Zhang, Jingshu

    2016-01-01

    Background Parkinson’s disease (PD) is manifested as degeneration of dopaminergic neurons in substantia nigra compacta. The mitochondrial dysfunction induced by oxidative stress is believed to a major cause of PD. Puerarin has been widely applied due to its estrogen nature and anti-oxidative function. This study thus investigated the protective role of puerarin against oxidative stress injury on PC12 neural cells, in addition to related mechanisms. Material/Methods PC12 cells were pre-treated with gradient concentrations of puerarin, followed by the induction of 0.5 mM H2O2. MTT assay was used to detect cell viability. Enzyme-linked immunosorbent assay (ELISA) was employed to detect intracellular level of superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH). Cell apoptosis was determined by Annexin-V/7-AAD double labelling. Reactive oxidative species (ROS) and lactate dehydrogenase (LDH) activities were then measured. Cellular levels of caspase-3 and caspase-9 were also determined. Results The pre-treatment using puerarin significantly reversed H2O2-induced oxidative stress injury, as it can increase proliferation, SOD and GSH activities, decrease MDA activity, suppress apoptosis of PC12 cells, and decrease ROS and LDH production (p<0.05 in all cases). Further assays showed depressed up-regulation of caspase-3 and caspase-9 after puerarin pretreatment. Conclusions Puerarin pretreatment can decrease activity of caspase-3 and caspase-9 activity in PC12 cells, thus protecting cells from oxidative injury. PMID:27074962

  12. Brooding Is Related to Neural Alterations during Autobiographical Memory Retrieval in Aging

    PubMed Central

    Schneider, Sophia; Brassen, Stefanie

    2016-01-01

    Brooding rumination is considered a central aspect of depression in midlife. As older people tend to review their past, rumination tendency might be particularly crucial in late life since it might hinder older adults to adequately evaluate previous events. We scanned 22 non-depressed older adults with varying degrees of brooding tendency with functional magnetic resonance imaging (MRI) while they performed the construction and elaboration of autobiographical memories. Behavioral findings demonstrate that brooders reported lower mood states, needed more time for memory construction and rated their memories as less detailed and less positive. On the neural level, brooding tendency was related to increased amygdala activation during the search for specific memories and reduced engagement of cortical networks during elaboration. Moreover, coupling patterns of the subgenual cingulate cortex with the hippocampus (HC) and the amygdala predicted details and less positive valence of memories in brooders. Our findings support the hypothesis that ruminative thinking interferes with the search for specific memories while facilitating the uncontrolled retrieval of negatively biased self-schemes. The observed neurobehavioral dysfunctions might put older people with brooding tendency at high risk for becoming depressed when reviewing their past. Training of autobiographical memory ability might therefore be a promising approach to increase resilience against depression in late-life. PMID:27695414

  13. Music training relates to the development of neural mechanisms of selective auditory attention.

    PubMed

    Strait, Dana L; Slater, Jessica; O'Connell, Samantha; Kraus, Nina

    2015-04-01

    Selective attention decreases trial-to-trial variability in cortical auditory-evoked activity. This effect increases over the course of maturation, potentially reflecting the gradual development of selective attention and inhibitory control. Work in adults indicates that music training may alter the development of this neural response characteristic, especially over brain regions associated with executive control: in adult musicians, attention decreases variability in auditory-evoked responses recorded over prefrontal cortex to a greater extent than in nonmusicians. We aimed to determine whether this musician-associated effect emerges during childhood, when selective attention and inhibitory control are under development. We compared cortical auditory-evoked variability to attended and ignored speech streams in musicians and nonmusicians across three age groups: preschoolers, school-aged children and young adults. Results reveal that childhood music training is associated with reduced auditory-evoked response variability recorded over prefrontal cortex during selective auditory attention in school-aged child and adult musicians. Preschoolers, on the other hand, demonstrate no impact of selective attention on cortical response variability and no musician distinctions. This finding is consistent with the gradual emergence of attention during this period and may suggest no pre-existing differences in this attention-related cortical metric between children who undergo music training and those who do not.

  14. Brooding Is Related to Neural Alterations during Autobiographical Memory Retrieval in Aging

    PubMed Central

    Schneider, Sophia; Brassen, Stefanie

    2016-01-01

    Brooding rumination is considered a central aspect of depression in midlife. As older people tend to review their past, rumination tendency might be particularly crucial in late life since it might hinder older adults to adequately evaluate previous events. We scanned 22 non-depressed older adults with varying degrees of brooding tendency with functional magnetic resonance imaging (MRI) while they performed the construction and elaboration of autobiographical memories. Behavioral findings demonstrate that brooders reported lower mood states, needed more time for memory construction and rated their memories as less detailed and less positive. On the neural level, brooding tendency was related to increased amygdala activation during the search for specific memories and reduced engagement of cortical networks during elaboration. Moreover, coupling patterns of the subgenual cingulate cortex with the hippocampus (HC) and the amygdala predicted details and less positive valence of memories in brooders. Our findings support the hypothesis that ruminative thinking interferes with the search for specific memories while facilitating the uncontrolled retrieval of negatively biased self-schemes. The observed neurobehavioral dysfunctions might put older people with brooding tendency at high risk for becoming depressed when reviewing their past. Training of autobiographical memory ability might therefore be a promising approach to increase resilience against depression in late-life.

  15. Discrepancy of neural response between exogenous and endogenous task switching: an event-related potentials study.

    PubMed

    Miyajima, Maki; Toyomaki, Atsuhito; Hashimoto, Naoki; Kusumi, Ichiro; Murohashi, Harumitsu; Koyama, Tsukasa

    2012-08-01

    Task switching is a well-known cognitive paradigm to explore task-set reconfiguration processes such as rule shifting. In particular, endogenous task switching is thought to differ qualitatively from stimulus-triggered exogenous task switching. However, no previous study has examined the neural substrate of endogenous task switching. The purpose of the present study is to explore the differences between event-related potential responses to exogenous and endogenous rule switching at cue stimulus. We modified two patterns of cued switching tasks: exogenous (bottom-up) rule switching and endogenous (top-down) rule switching. In each task cue stimulus was configured to induce switching or maintaining rule. In exogenous switching tasks, late positive deflection was larger in the switch rule condition than in the maintain rule condition. However, in endogenous switching tasks late positive deflection was unexpectedly larger in the maintain-rule condition than in the switch-rule condition. These results indicate that exogenous rule switching is explicit stimulus-driven processes, whereas endogenous rule switching is implicitly parallel processes independent of external stimulus.

  16. Age-related differences in enhancement and suppression of neural activity underlying selective attention in matched young and old adults.

    PubMed

    Haring, A E; Zhuravleva, T Y; Alperin, B R; Rentz, D M; Holcomb, P J; Daffner, K R

    2013-03-01

    Selective attention reflects the top-down control of sensory processing that is mediated by enhancement or inhibition of neural activity. ERPs were used to investigate age-related differences in neural activity in an experiment examining selective attention to color under Attend and Ignore conditions, as well as under a Neutral condition in which color was task-irrelevant. We sought to determine whether differences in neural activity between old and young adult subjects were due to differences in age rather than executive capacity. Old subjects were matched to two groups of young subjects on the basis of neuropsychological test performance: one using age-appropriate norms and the other using test scores not adjusted for age. We found that old and young subject groups did not differ in the overall modulation of selective attention between Attend and Ignore conditions, as indexed by the size of the anterior Selection Positivity. However, in contrast to either young adult group, old subjects did not exhibit reduced neural activity under the Ignore relative to Neutral condition, but showed enhanced activity under the Attend condition. The onset and peak of the Selection Positivity occurred later for old than young subjects. In summary, older adults execute selective attention less efficiently than matched younger subjects, with slowed processing and failed suppression under Ignore. Increased enhancement under Attend may serve as a compensatory mechanism.

  17. Ego and Self: A Synthesis of Theories of Consciousness and Personality.

    ERIC Educational Resources Information Center

    Tatzel, Miriam

    Ego and self refer to two ways of being. They are related on the one hand to neurosis and health and on the other hand to rational and intuitive modes of consciousness. The author in this article considers consciousness as it pertains to knowing oneself. She examines how ego, the rational consciousness as applied to oneself, can obstruct…

  18. Consciousness: individuated information in action

    PubMed Central

    Jonkisz, Jakub

    2015-01-01

    Within theoretical and empirical enquiries, many different meanings associated with consciousness have appeared, leaving the term itself quite vague. This makes formulating an abstract and unifying version of the concept of consciousness – the main aim of this article –into an urgent theoretical imperative. It is argued that consciousness, characterized as dually accessible (cognized from the inside and the outside), hierarchically referential (semantically ordered), bodily determined (embedded in the working structures of an organism or conscious system), and useful in action (pragmatically functional), is a graded rather than an all-or-none phenomenon. A gradational approach, however, despite its explanatory advantages, can lead to some counterintuitive consequences and theoretical problems. In most such conceptions consciousness is extended globally (attached to primitive organisms or artificial systems), but also locally (connected to certain lower-level neuronal and bodily processes). For example, according to information integration theory (as introduced recently by Tononi and Koch, 2014), even such simple artificial systems as photodiodes possess miniscule amounts of consciousness. The major challenge for this article, then, is to establish reasonable, empirically justified constraints on how extended the range of a graded consciousness could be. It is argued that conscious systems are limited globally by the ability to individuate information (where individuated information is understood as evolutionarily embedded, socially altered, and private), whereas local limitations should be determined on the basis of a hypothesis about the action-oriented nature of the processes that select states of consciousness. Using these constraints, an abstract concept of consciousness is arrived at, hopefully contributing to a more unified state of play within consciousness studies itself. PMID:26283987

  19. Conscious Wireless Electroretinogram and Visual Evoked Potentials in Rats

    PubMed Central

    He, Zheng; Dang, Trung M.; Vingrys, Algis J.; Fish, Rebecca L.; Gurrell, Rachel; Brain, Phil; Bui, Bang V.

    2013-01-01

    The electroretinogram (ERG, retina) and visual evoked potential (VEP, brain) are widely used in vivo tools assaying the integrity of the visual pathway. Current recordings in preclinical models are conducted under anesthesia, which alters neural physiology and contaminates responses. We describe a conscious wireless ERG and VEP recording platform in rats. Using a novel surgical technique to chronically implant electrodes subconjunctivally on the eye and epidurally over the visual cortex, we are able to record stable and repeatable conscious ERG and VEP signals over at least 1 month. We show that the use of anaesthetics, necessary for conventional ERG and VEP measurements, alters electrophysiology recordings. Conscious visual electrophysiology improves the viability of longitudinal studies by eliminating complications associated with repeated anaesthesia. It will also enable uncontaminated assessment of drug effects, allowing the eye to be used as an effective biomarker of the central nervous system. PMID:24069276

  20. Neural networks related to dysfunctional face processing in autism spectrum disorder

    PubMed Central

    Nickl-Jockschat, Thomas; Rottschy, Claudia; Thommes, Johanna; Schneider, Frank; Laird, Angela R.; Fox, Peter T.; Eickhoff, Simon B.

    2016-01-01

    One of the most consistent neuropsychological findings in autism spectrum disorders (ASD) is a reduced interest in and impaired processing of human faces. We conducted an activation likelihood estimation meta-analysis on 14 functional imaging studies on neural correlates of face processing enrolling a total of 164 ASD patients. Subsequently, normative whole-brain functional connectivity maps for the identified regions of significant convergence were computed for the task-independent (resting-state) and task-dependent (co-activations) state in healthy subjects. Quantitative functional decoding was performed by reference to the BrainMap database. Finally, we examined the overlap of the delineated network with the results of a previous meta-analysis on structural abnormalities in ASD as well as with brain regions involved in human action observation/imitation. We found a single cluster in the left fusiform gyrus showing significantly reduced activation during face processing in ASD across all studies. Both task-dependent and task-independent analyses indicated significant functional connectivity of this region with the temporo-occipital and lateral occipital cortex, the inferior frontal and parietal cortices, the thalamus and the amygdala. Quantitative reverse inference then indicated an association of these regions mainly with face processing, affective processing, and language-related tasks. Moreover, we found that the cortex in the region of right area V5 displaying structural changes in ASD patients showed consistent connectivity with the region showing aberrant responses in the context of face processing. Finally, this network was also implicated in the human action observation/imitation network. In summary, our findings thus suggest a functionally and structurally disturbed network of occipital regions related primarily to face (but potentially also language) processing, which interact with inferior frontal as well as limbic regions and may be the core of

  1. Protein kinase C substrate phosphorylation in relation to neural growth and synaptic plasticity: a common molecular mechanism underlying multiple neural functions

    SciTech Connect

    Nelson, R.B.

    1987-01-01

    In these studies, we addressed the issues of: (1) whether neural protein kinase C (PKC) substrates might be altered in phosphorylation following induction of long-term potentiation (LTP); (2) whether PKC substrate phosphorylation might be specifically related to a model of neural plasticity other than LTP; and (3) whether the PKC substrates implicated in adult synaptic plasticity might be present in axonal growth cones given reports that high concentrations of PKC are found in these structures. Using quantitative analysis of multiple two-dimensional gels, we found that the two major substrates of exogenous purified PKC in adult hippocampal homogenate are both directly correlated to persistence of LTP. In rhesus monkey cerebral cortex, the proteins corresponding to protein F1 and 80k displayed topographical gradients in /sup 32/P-incorporation along the occipitotemporal visual processing pathway. The phosphorylation of both proteins was 11- and 14-fold higher, respectively, in temporal regions of this pathway implicated in the storage of visual representations, than in occipital regions, which do not appear to directly participate in visual memory functions.

  2. Connecting Conscious and Unconscious Processing

    ERIC Educational Resources Information Center

    Cleeremans, Axel

    2014-01-01

    Consciousness remains a mystery--"a phenomenon that people do not know how to think about--yet" (Dennett, D. C., 1991, p. 21). Here, I consider how the connectionist perspective on information processing may help us progress toward the goal of understanding the computational principles through which conscious and unconscious processing…

  3. Naturalizing consciousness: A theoretical framework

    PubMed Central

    Edelman, Gerald M.

    2003-01-01

    Consciousness has a number of apparently disparate properties, some of which seem to be highly complex and even inaccessible to outside observation. To place these properties within a biological framework requires a theory based on a set of evolutionary and developmental principles. This paper describes such a theory, which aims to provide a unifying account of conscious phenomena. PMID:12702758

  4. Education for Critical Moral Consciousness

    ERIC Educational Resources Information Center

    Mustakova-Possardt, Elena

    2004-01-01

    This paper proposes a lifespan developmental model of critical moral consciousness and examines its implications for education in childhood, adolescence and adulthood. Mature moral consciousness, central to negotiating the challenges of the 21st century, is characterized by a deepening lifelong integration of moral motivation, agency and critical…

  5. Psychology Tomorrow: Explorations of Consciousness.

    ERIC Educational Resources Information Center

    Bancroft, Norris R.

    Psychology is again revitalizing efforts to explore the nature and extent of human consciousness. Although consciousness has always been the central subject matter of psychology, various metholodological and ideological "schools" have often quarreled as to exactly what constitutes the appropriate measure of the subject. What is most significant…

  6. A Neural Network Approach to fMRI Binocular Visual Rivalry Task Analysis

    PubMed Central

    Bertolino, Nicola; Ferraro, Stefania; Nigri, Anna; Bruzzone, Maria Grazia; Ghielmetti, Francesco; Leonardi, Matilde; Agostino Parati, Eugenio; Grazia Bruzzone, Maria; Franceschetti, Silvana; Caldiroli, Dario; Sattin, Davide; Giovannetti, Ambra; Pagani, Marco; Covelli, Venusia; Ciaraffa, Francesca; Vela Gomez, Jesus; Reggiori, Barbara; Ferraro, Stefania; Nigri, Anna; D'Incerti, Ludovico; Minati, Ludovico; Andronache, Adrian; Rosazza, Cristina; Fazio, Patrik; Rossi, Davide; Varotto, Giulia; Panzica, Ferruccio; Benti, Riccardo; Marotta, Giorgio; Molteni, Franco

    2014-01-01

    The purpose of this study was to investigate whether artificial neural networks (ANN) are able to decode participants’ conscious experience perception from brain activity alone, using complex and ecological stimuli. To reach the aim we conducted pattern recognition data analysis on fMRI data acquired during the execution of a binocular visual rivalry paradigm (BR). Twelve healthy participants were submitted to fMRI during the execution of a binocular non-rivalry (BNR) and a BR paradigm in which two classes of stimuli (faces and houses) were presented. During the binocular rivalry paradigm, behavioral responses related to the switching between consciously perceived stimuli were also collected. First, we used the BNR paradigm as a functional localizer to identify the brain areas involved the processing of the stimuli. Second, we trained the ANN on the BNR fMRI data restricted to these regions of interest. Third, we applied the trained ANN to the BR data as a ‘brain reading’ tool to discriminate the pattern of neural activity between the two stimuli. Fourth, we verified the consistency of the ANN outputs with the collected behavioral indicators of which stimulus was consciously perceived by the participants. Our main results showed that the trained ANN was able to generalize across the two different tasks (i.e. BNR and BR) and to identify with high accuracy the cognitive state of the participants (i.e. which stimulus was consciously perceived) during the BR condition. The behavioral response, employed as control parameter, was compared with the network output and a statistically significant percentage of correspondences (p-value <0.05) were obtained for all subjects. In conclusion the present study provides a method based on multivariate pattern analysis to investigate the neural basis of visual consciousness during the BR phenomenon when behavioral indicators lack or are inconsistent, like in disorders of consciousness or sedated patients. PMID:25121595

  7. Declarative Consciousness for Reconstruction

    NASA Astrophysics Data System (ADS)

    Seymour, Leslie G.

    2013-12-01

    Existing information technology tools are harnessed and integrated to provide digital specification of human consciousness of individual persons. An incremental compilation technology is proposed as a transformation of LifeLog derived persona specifications into a Canonical representation of the neocortex architecture of the human brain. The primary purpose is to gain an understanding of the semantical allocation of the neocortex capacity. Novel neocortex content allocation simulators with browsers are proposed to experiment with various approaches of relieving the brain from overload conditions. An IT model of the neocortex is maintained, which is then updated each time new stimuli are received from the LifeLog data stream; new information is gained from brain signal measurements; and new functional dependencies are discovered between live persona consumed/produced signals

  8. [Brain and consciousness].

    PubMed

    Fernández de Molina, Antonio

    2002-01-01

    The philosophical and biological concepts of consciousness are briefly reviewed, from Aristoteles to Descartes to the modern neurobiologist of the last 15 years. The CRICK's corticothalamic integration view, the Edelman's primary and higher order consciousness concept as well as the Edelman and Tononi's dynamic core concept were discussed. Then the corticothalamic resonance theory by Llinás was reported. Central to Llinás's theory is the existence of electrical intrinsic properties of neurones in the central nervous system that allows them to oscillate at different frequencies and if the membrane properties are suitable also to resonate at specific frequencies. From this oscillation and the neuronal connectivity result the corticothalamic dynamic loops specific and non specific. The dynamic corticothalamic loop of the specific thalamic nuclei connect directly as well as through the inhibitory interneurones in layer 4, with the pyramids in layer 5 and 6. The pyramids's rhythmic discharge excite the thalamic specific neurones and indirectly through the reticular neurones a rebound burst is also generated in the specific relay neurones. The oscillatory properties of cortical inhibitory interneurones initiates the action of the recurrent circuit whose function is to inform the cerebral cortex of the content of the sensory pathways. On the other side, the thalamocortical resonant loops of the non especific nuclei, particularly the intralaminar, connect with theapical dendrites of layer 1 pyramids whose discharge go to the thalamic relay neurones directly and through the reticular nucleus. The clinical and MEG data are consistent with the suggestion that the intralaminar nucleus works as providing the binding signal to the sensory specif le information conveyed by the specific pathways. In this way the non specific corticothalamic loop would act as the conjunction mechanism along the dendritic apical shaft with the specific sensory information. The specific loop will

  9. Conscience and consciousness: a definition.

    PubMed

    Vithoulkas, G; Muresanu, D F

    2014-03-15

    While consciousness has been examined extensively in its different aspects, like in philosophy, psychiatry, neurophysiology, neuroplasticity, etc., conscience though it is an equal important aspect of the human existence, which remains an unknown to a great degree as an almost transcendental aspect of the human mind. It has not been examined as thoroughly as consciousness and largely remains a "terra incognita" for its neurophysiology, brain topography, etc. Conscience and consciousness are part of a system of information that governs our experience and decision making process. The intent of this paper is to define these terms, to discuss about consciousness from both neurological and quantum physics point of view, the relationship between the dynamics of consciousness and neuroplasticity and to highlight the relationship between conscience, stress and health.

  10. [The "bright spot of consciousness"].

    PubMed

    Simonov, P V

    1990-01-01

    I.P. Pavlov considered consciousness as an area of optimum excitability moving over the human cerebral cortex depending on the character of performed mental activity. Contemporary methods of computer analysis of electrical activity and brain thermal production have allowed to turn this metaphor into experimentally observed reality. It is shown that preservation of connections of cortical gnostic zones with verbal structures of the left hemisphere is the obligatory condition for consciousness functioning. These data reinforce the determination of consciousness as operation with knowledge, which by means of words, mathematic symbols and art images can be transmitted to other people. Communicative origin of consciousness creates possibility of mental dialogue with oneself, i.e. leads to the appearance of self-consciousness of the personality.

  11. Neural substrates related to auditory working memory comparisons in dyslexia: an fMRI study.

    PubMed

    Conway, Tim; Heilman, Kenneth M; Gopinath, Kaundinya; Peck, Kyung; Bauer, Russell; Briggs, Richard W; Torgesen, Joseph K; Crosson, Bruce

    2008-07-01

    Adult readers with developmental phonological dyslexia exhibit significant difficulty comparing pseudowords and pure tones in auditory working memory (AWM). This suggests deficient AWM skills for adults diagnosed with dyslexia. Despite behavioral differences, it is unknown whether neural substrates of AWM differ between adults diagnosed with dyslexia and normal readers. Prior neuroimaging of adults diagnosed with dyslexia and normal readers, and post-mortem findings of neural structural anomalies in adults diagnosed with dyslexia support the hypothesis of atypical neural activity in temporoparietal and inferior frontal regions during AWM tasks in adults diagnosed with dyslexia. We used fMRI during two binaural AWM tasks (pseudowords or pure tones comparisons) in adults diagnosed with dyslexia (n = 11) and normal readers (n = 11). For both AWM tasks, adults diagnosed with dyslexia exhibited greater activity in left posterior superior temporal (BA 22) and inferior parietal regions (BA 40) than normal readers. Comparing neural activity between groups and between stimuli contrasts (pseudowords vs. tones), adults diagnosed with dyslexia showed greater primary auditory cortex activity (BA 42; tones > pseudowords) than normal readers. Thus, greater activity in primary auditory, posterior superior temporal, and inferior parietal cortices during linguistic and non-linguistic AWM tasks for adults diagnosed with dyslexia compared to normal readers indicate differences in neural substrates of AWM comparison tasks. PMID:18577292

  12. Contemplative Neuroscience as an Approach to Volitional Consciousness

    NASA Astrophysics Data System (ADS)

    Thompson, Evan

    This chapter presents a methodological approach to volitional consciousness for cognitive neuroscience based on studying the voluntary self-generation and self-regulation of mental states in meditation. Called contemplative neuroscience, this approach views attention, awareness, and emotion regulation as flexible and trainable skills, and works with experimental participants who have undergone training in contemplative practices designed to hone these skills. Drawing from research on the dynamical neural correlates of contemplative mental states and theories of large-scale neural coordination dynamics, I argue for the importance of global system causation in brain activity and present an "interventionist" approach to intentional causation.

  13. Low Density Lipoprotein Receptor Related Proteins as Regulators of Neural Stem and Progenitor Cell Function

    PubMed Central

    Landowski, Lila M.; Young, Kaylene M.

    2016-01-01

    The central nervous system (CNS) is a highly organised structure. Many signalling systems work in concert to ensure that neural stem cells are appropriately directed to generate progenitor cells, which in turn mature into functional cell types including projection neurons, interneurons, astrocytes, and oligodendrocytes. Herein we explore the role of the low density lipoprotein (LDL) receptor family, in particular family members LRP1 and LRP2, in regulating the behaviour of neural stem and progenitor cells during development and adulthood. The ability of LRP1 and LRP2 to bind a diverse and extensive range of ligands, regulate ligand endocytosis, recruit nonreceptor tyrosine kinases for direct signal transduction and signal in conjunction with other receptors, enables them to modulate many crucial neural cell functions. PMID:26949399

  14. Common and Segregated Neural Substrates for Automatic Conceptual and Affective Priming as Revealed by Event-Related Functional Magnetic Resonance Imaging

    ERIC Educational Resources Information Center

    Liu, Hongyan; Hu, Zhiguo; Peng, Danling; Yang, Yanhui; Li, Kuncheng

    2010-01-01

    The brain activity associated with automatic semantic priming has been extensively studied. Thus far there has been no prior study that directly contrasts the neural mechanisms of semantic and affective priming. The present study employed event-related fMRI to examine the common and distinct neural bases underlying conceptual and affective priming…

  15. Adaptive skeletal muscle action requires anticipation and "conscious broadcasting".

    PubMed

    Poehlman, T Andrew; Jantz, Tiffany K; Morsella, Ezequiel

    2012-01-01

    Historically, the conscious and anticipatory processes involved in voluntary action have been associated with the loftiest heights of nervous function. Concepts like mental time travel, "theory of mind," and the formation of "the self" have been at the center of many attempts to determine the purpose of consciousness. Eventually, more reductionistic accounts of consciousness emerged, proposing rather that conscious states play a much more basic role in nervous function. Though the widely held integration consensus proposes that conscious states integrate information-processing structures and events that would otherwise be independent, Supramodular Interaction Theory (SIT) argues that conscious states are necessary for the integration of only certain kinds of information. As revealed in this selective review, this integration is related to what is casually referred to as "voluntary" action, which is intimately related to the skeletal muscle output system. Through a peculiar form of broadcasting, conscious integration often controls and guides action via "ideomotor" mechanisms, where anticipatory processes play a central role. Our selective review covers evidence (including findings from anesthesia research) for the integration consensus, SIT, and ideomotor theory.

  16. Age and Experience Shape Developmental Changes in the Neural Basis of Language-Related Learning

    ERIC Educational Resources Information Center

    McNealy, Kristin; Mazziotta, John C.; Dapretto, Mirella

    2011-01-01

    Very little is known about the neural underpinnings of language learning across the lifespan and how these might be modified by maturational and experiential factors. Building on behavioral research highlighting the importance of early word segmentation (i.e. the detection of word boundaries in continuous speech) for subsequent language learning,…

  17. Neural dynamics of prediction and surprise in infants.

    PubMed

    Kouider, Sid; Long, Bria; Le Stanc, Lorna; Charron, Sylvain; Fievet, Anne-Caroline; Barbosa, Leonardo S; Gelskov, Sofie V

    2015-01-01

    Prior expectations shape neural responses in sensory regions of the brain, consistent with a Bayesian predictive coding account of perception. Yet, it remains unclear whether such a mechanism is already functional during early stages of development. To address this issue, we study how the infant brain responds to prediction violations using a cross-modal cueing paradigm. We record electroencephalographic responses to expected and unexpected visual events preceded by auditory cues in 12-month-old infants. We find an increased response for unexpected events. However, this effect of prediction error is only observed during late processing stages associated with conscious access mechanisms. In contrast, early perceptual components reveal an amplification of neural responses for predicted relative to surprising events, suggesting that selective attention enhances perceptual processing for expected events. Taken together, these results demonstrate that cross-modal statistical regularities are used to generate predictions that differentially influence early and late neural responses in infants. PMID:26460901

  18. Neural dynamics of prediction and surprise in infants

    PubMed Central

    Kouider, Sid; Long, Bria; Le Stanc, Lorna; Charron, Sylvain; Fievet, Anne-Caroline; Barbosa, Leonardo S.; Gelskov, Sofie V.

    2015-01-01

    Prior expectations shape neural responses in sensory regions of the brain, consistent with a Bayesian predictive coding account of perception. Yet, it remains unclear whether such a mechanism is already functional during early stages of development. To address this issue, we study how the infant brain responds to prediction violations using a cross-modal cueing paradigm. We record electroencephalographic responses to expected and unexpected visual events preceded by auditory cues in 12-month-old infants. We find an increased response for unexpected events. However, this effect of prediction error is only observed during late processing stages associated with conscious access mechanisms. In contrast, early perceptual components reveal an amplification of neural responses for predicted relative to surprising events, suggesting that selective attention enhances perceptual processing for expected events. Taken together, these results demonstrate that cross-modal statistical regularities are used to generate predictions that differentially influence early and late neural responses in infants. PMID:26460901

  19. Quantum-holographic and classical Hopfield-like associative nnets: implications for modeling two cognitive modes of consciousness

    NASA Astrophysics Data System (ADS)

    Rakovic, D.; Dugic, M.

    2005-05-01

    Quantum bases of consciousness are considered with psychosomatic implications of three front lines of psychosomatic medicine (hesychastic spirituality, holistic Eastern medicine, and symptomatic Western medicine), as well as cognitive implications of two modes of individual consciousness (quantum-coherent transitional and altered states, and classically reduced normal states) alongside with conditions of transformations of one mode into another (considering consciousness quantum-coherence/classical-decoherence acupuncture system/nervous system interaction, direct and reverse, with and without threshold limits, respectively) - by using theoretical methods of associative neural networks and quantum neural holography combined with quantum decoherence theory.

  20. Conscious and Non-conscious Representations of Emotional Faces in Asperger's Syndrome.

    PubMed

    Chien, Vincent S C; Tsai, Arthur C; Yang, Han Hsuan; Tseng, Yi-Li; Savostyanov, Alexander N; Liou, Michelle

    2016-07-31

    Several neuroimaging studies have suggested that the low spatial frequency content in an emotional face mainly activates the amygdala, pulvinar, and superior colliculus especially with fearful faces(1-3). These regions constitute the limbic structure in non-conscious perception of emotions and modulate cortical activity either directly or indirectly(2). In contrast, the conscious representation of emotions is more pronounced in the anterior cingulate, prefrontal cortex, and somatosensory cortex for directing voluntary attention to details in faces(3,4). Asperger's syndrome (AS)(5,6) represents an atypical mental disturbance that affects sensory, affective and communicative abilities, without interfering with normal linguistic skills and intellectual ability. Several studies have found that functional deficits in the neural circuitry important for facial emotion recognition can partly explain social communication failure in patients with AS(7-9). In order to clarify the interplay between conscious and non-conscious representations of emotional faces in AS, an EEG experimental protocol is designed with two tasks involving emotionality evaluation of either photograph or line-drawing faces. A pilot study is introduced for selecting face stimuli that minimize the differences in reaction times and scores assigned to facial emotions between the pretested patients with AS and IQ/gender-matched healthy controls. Information from the pretested patients was used to develop the scoring system used for the emotionality evaluation. Research into facial emotions and visual stimuli with different spatial frequency contents has reached discrepant findings depending on the demographic characteristics of participants and task demands(2). The experimental protocol is intended to clarify deficits in patients with AS in processing emotional faces when compared with healthy controls by controlling for factors unrelated to recognition of facial emotions, such as task difficulty, IQ and

  1. Conscious and Non-conscious Representations of Emotional Faces in Asperger's Syndrome.

    PubMed

    Chien, Vincent S C; Tsai, Arthur C; Yang, Han Hsuan; Tseng, Yi-Li; Savostyanov, Alexander N; Liou, Michelle

    2016-01-01

    Several neuroimaging studies have suggested that the low spatial frequency content in an emotional face mainly activates the amygdala, pulvinar, and superior colliculus especially with fearful faces(1-3). These regions constitute the limbic structure in non-conscious perception of emotions and modulate cortical activity either directly or indirectly(2). In contrast, the conscious representation of emotions is more pronounced in the anterior cingulate, prefrontal cortex, and somatosensory cortex for directing voluntary attention to details in faces(3,4). Asperger's syndrome (AS)(5,6) represents an atypical mental disturbance that affects sensory, affective and communicative abilities, without interfering with normal linguistic skills and intellectual ability. Several studies have found that functional deficits in the neural circuitry important for facial emotion recognition can partly explain social communication failure in patients with AS(7-9). In order to clarify the interplay between conscious and non-conscious representations of emotional faces in AS, an EEG experimental protocol is designed with two tasks involving emotionality evaluation of either photograph or line-drawing faces. A pilot study is introduced for selecting face stimuli that minimize the differences in reaction times and scores assigned to facial emotions between the pretested patients with AS and IQ/gender-matched healthy controls. Information from the pretested patients was used to develop the scoring system used for the emotionality evaluation. Research into facial emotions and visual stimuli with different spatial frequency contents has reached discrepant findings depending on the demographic characteristics of participants and task demands(2). The experimental protocol is intended to clarify deficits in patients with AS in processing emotional faces when compared with healthy controls by controlling for factors unrelated to recognition of facial emotions, such as task difficulty, IQ and

  2. “What” Precedes “Which”: Developmental Neural Tuning in Face- and Place-Related Cortex

    PubMed Central

    Luna, Beatriz; Avidan, Galia; Behrmann, Marlene

    2011-01-01

    Although category-specific activation for faces in the ventral visual pathway appears adult-like in adolescence, recognition abilities for individual faces are still immature. We investigated how the ability to represent “individual” faces and houses develops at the neural level. Category-selective regions of interest (ROIs) for faces in the fusiform gyrus (FG) and for places in the parahippocampal place area (PPA) were identified individually in children, adolescents, and adults. Then, using an functional magnetic resonance imaging adaptation paradigm, we measured category selectivity and individual-level adaptation for faces and houses in each ROI. Only adults exhibited both category selectivity and individual-level adaptation bilaterally for faces in the FG and for houses in the PPA. Adolescents showed category selectivity bilaterally for faces in the FG and houses in the PPA. Despite this profile of category selectivity, adolescents only exhibited individual-level adaptation for houses bilaterally in the PPA and for faces in the “left” FG. Children only showed category-selective responses for houses in the PPA, and they failed to exhibit category-selective responses for faces in the FG and individual-level adaptation effects anywhere in the brain. These results indicate that category-level neural tuning develops prior to individual-level neural tuning and that face-related cortex is disproportionately slower in this developmental transition than is place-related cortex. PMID:21257673

  3. Tracing ‘driver’ versus ‘modulator’ information flow throughout large-scale, task-related neural circuitry

    PubMed Central

    2009-01-01

    Primary objective To determine the relative uses of neural action potential (‘spike’) data versus local field potentials (LFPs) for modeling information flow through complex brain networks. Hypothesis The common use of LFP data, which are continuous and therefore more mathematically suited for spectral information-flow modeling techniques such as Granger causality analysis, can lead to spurious inferences about whether a given brain area ‘drives’ the spiking in a downstream area. Experiment We recorded spikes and LFPs from the forelimb motor cortex (M1) and the magnocellular red nucleus (mRN), which receives axon collaterals from M1 projection cells onto its distal dendrites, but not onto its perisomatic regions, as rats performed a skilled reaching task. Results and implications As predicted, Granger causality analysis on the LFPs—which are mainly composed of vector-summed dendritic currents—produced results that if conventionally interpreted would suggest that the M1 cells drove spike firing in the mRN, whereas analyses of spiking in the two recorded regions revealed no significant correlations. These results suggest that mathematical models of information flow should treat the sampled dendritic activity as more likely to reflect intrinsic dendritic and input-related processing in neural networks, whereas spikes are more likely to provide information about the output of neural network processing. PMID:19768125

  4. Tracking real-time neural activation of conceptual knowledge using single-trial event-related potentials.

    PubMed

    Amsel, Ben D

    2011-04-01

    Empirically derived semantic feature norms categorized into different types of knowledge (e.g., visual, functional, auditory) can be summed to create number-of-feature counts per knowledge type. Initial evidence suggests several such knowledge types may be recruited during language comprehension. The present study provides a more detailed understanding of the timecourse and intensity of influence of several such knowledge types on real-time neural activity. A linear mixed-effects model was applied to single trial event-related potentials for 207 visually presented concrete words measured on total number of features (semantic richness), imageability, and number of visual motion, color, visual form, smell, taste, sound, and function features. Significant influences of multiple feature types occurred before 200ms, suggesting parallel neural computation of word form and conceptual knowledge during language comprehension. Function and visual motion features most prominently influenced neural activity, underscoring the importance of action-related knowledge in computing word meaning. The dynamic time courses and topographies of these effects are most consistent with a flexible conceptual system wherein temporally dynamic recruitment of representations in modal and supramodal cortex are a crucial element of the constellation of processes constituting word meaning computation in the brain.

  5. Photons, clocks, and consciousness

    NASA Technical Reports Server (NTRS)

    Brainard, George C.; Hanifin, John P.

    2005-01-01

    Light profoundly impacts human consciousness through the stimulation of the visual system and powerfully regulates the human circadian system, which, in turn, has a broad regulatory impact on virtually all tissues in the body. For more than 25 years, the techniques of action spectroscopy have yielded insights into the wavelength sensitivity of circadian input in humans and other mammalian species. The seminal discovery of melanopsin, the photopigment in intrinsically photosensitive retinal ganglion cells, has provided a significant turning point for understanding human circadian phototransduction. Action spectra in humans show that the peak wavelength sensitivity for this newly discovered sensory system is within the blue portion of the spectrum. This is fundamentally different from the three-cone photopic visual system, as well as the individual rod and cone photoreceptor peaks. Studies on rodents, nonhuman primates, and humans indicate that despite having a different wavelength fingerprint, these classic visual photoreceptors still provide an element of input to the circadian system. These findings open the door to innovations in light therapy for circadian and affective disorders, as well as possible architectural light applications.

  6. Modulation of the default-mode network and the attentional network by self-referential processes in patients with disorder of consciousness.

    PubMed

    Mäki-Marttunen, Verónica; Castro, Mariana; Olmos, Lisandro; Leiguarda, Ramón; Villarreal, Mirta

    2016-02-01

    Disorders of consciousness (DOC) are related to an altered capacity of the brain to successfully integrate and segregate information. Alterations in brain functional networks structure have been found in fMRI studies, which could account for the incapability of the brain to efficiently manage internally and externally generated information. Here we assess the modulation of neural activity in areas of the networks related to active introspective or extrospective processing in 9 patients with DOC and 17 controls using fMRI. In addition, we assess the functional connectivity between those areas in resting state. Patients were experimentally studied in an early phase after the event of brain injury (3±1 months after the event) and subsequently in a second session 4±1 months after the first session. The results showed that the concerted modulation of the default mode network (DMN) and attentional network (AN) in response to the active involvement in the task improved with the level of consciousness, reflecting an integral recovery of the brain in its ability to be engaged in cognitive processes. In addition, functional connectivity decreased between the DMN and AN with recovery. Our results help to further understand the neural underpins of the disorders of consciousness. PMID:26796715

  7. A Heuristic Model of Consciousness with Applications to the Development of Science and Society

    NASA Technical Reports Server (NTRS)

    Curreri, Peter A.

    2010-01-01

    A working model of consciousness is fundamental to understanding of the interactions of the observer in science. This paper examines contemporary understanding of consciousness. A heuristic model of consciousness is suggested that is consistent with psycophysics measurements of bandwidth of consciousness relative to unconscious perception. While the self reference nature of consciousness confers a survival benefit by assuring the all points of view regarding a problem are experienced in sufficiently large population, conscious bandwidth is constrained by design to avoid chaotic behavior. The multiple hypotheses provided by conscious reflection enable the rapid progression of science and technology. The questions of free will and the problem of attention are discussed in relation to the model. Finally the combination of rapid technology growth with the assurance of many unpredictable points of view is considered in respect to contemporary constraints to the development of society.

  8. Difficulty-related changes in inter-regional neural synchrony are dissociated between target and non-target processing.

    PubMed

    Choi, Jeong Woo; Cha, Kwang Su; Choi, Jong Doo; Jung, Ki-Young; Kim, Kyung Hwan

    2015-04-01

    The major purpose of this study was to explore the changes in the local/global gamma-band neural synchronies during target/non-target processing due to task difficulty under an auditory three-stimulus oddball paradigm. Multichannel event-related potentials (ERPs) were recorded from fifteen healthy participants during the oddball task. In addition to the conventional ERP analysis, we investigated the modulations in gamma-band activity (GBA) and inter-regional gamma-band phase synchrony (GBPS) for infrequent target and non-target processing due to task difficulty. The most notable finding was that the difficulty-related changes in inter-regional GBPS (33-35 Hz) at P300 epoch (350-600 ms) completely differed for target and non-target processing. As task difficulty increased, the GBPS significantly reduced for target processing but increased for non-target processing. This result contrasts with the local neural synchrony in gamma-bands, which was not affected by task difficulty. Another major finding was that the spatial patterns of functional connectivity were dissociated for target and non-target processing with regard to the difficult task. The spatial pattern for target processing was compatible with the top-down attention network, whereas that for the non-target corresponded to the bottom-up attention network. Overall, we found that the inter-regional gamma-band neural synchronies during target/non-target processing change significantly with task difficulty and that this change is dissociated between target and non-target processing. Our results indicate that large-scale neural synchrony is more relevant for the difference in information processing between target and non-target stimuli.

  9. Thalamic stimulation to improve level of consciousness after seizures: Evaluation of electrophysiology and behavior

    PubMed Central

    Gummadavelli, Abhijeet; Motelow, Joshua E.; Smith, Nicholas; Zhan, Qiong; Schiff, Nicholas D.; Blumenfeld, Hal

    2015-01-01

    Summary Objective Understanding the neural mechanisms that support human consciousness is an important frontier in neuroscience and medicine. We previously developed a rodent model of temporal lobe seizures that recapitulates the human electroencephalography (EEG) signature of ictal and postictal neocortical slow waves associated with behavioral impairments in level of consciousness. The mechanism of slow-wave production in epilepsy may involve suppression of the subcortical arousal systems including the brainstem and intralaminar thalamic nuclei. We hypothesized that intralaminar thalamic stimulation may lead to electrophysiologic and functional rescue from postictal slow waves and behavioral arrest. Methods We electrically stimulated the central lateral thalamic nucleus (a member of the intralaminar nuclei) under anesthesia and after electrically induced hippocampal seizures in anesthetized and in awake-behaving animal model preparations. Results We demonstrated a proof-of-principle restoration of electrophysiologic and behavioral measures of consciousness by stimulating the intralaminar thalamic nuclei after seizures. We measured decreased cortical slow waves and increased desynchronization and multiunit activity in the cortex with thalamic stimulation following seizures. Functionally, thalamic stimulation produced resumption of exploratory behaviors in the postictal state. Significance Targeting of nodes in the neural circuitry of consciousness has important medical implications. Impaired consciousness with epilepsy has dangerous consequences including decreased school/work performance, social stigmatization, and impaired airway protection. These data suggest a novel therapeutic approach for restoring consciousness after seizures. If paired with responsive neurostimulation, this may allow rapid implementation to improve level of consciousness in patients with epilepsy. PMID:25442843

  10. The brain basis of a "consciousness monitor": scientific and medical significance.

    PubMed

    Baars, B J

    2001-06-01

    Surgical patients under anesthesia can wake up unpredictably and be exposed to intense, traumatic pain. Current medical techniques cannot maintain depth of anesthesia at a perfectly stable and safe level; the depth of unconsciousness may change from moment to moment. Without an effective consciousness monitor anesthesiologists may not be able to adjust dosages in time to protect patients from pain. An estimated 40,000 to 200,000 midoperative awakenings may occur in the United States annually. E. R. John and coauthors present the scientific basis of a practical "consciousness monitor" in two articles. One article is empirical and shows widespread and consistent electrical field changes across subjects and anesthetic agents as soon as consciousness is lost; these changes reverse when consciousness is regained afterward. These findings form the basis of a surgical consciousness monitor that recently received approval from the U.S. Food and Drug Administration. This may be the first practical application of research on the brain basis of consciousness. The other John article suggests theoretical explanations at three levels, a neurophysiological account of anesthesia, a neural dynamic account of conscious and unconscious states, and an integrative field theory. Of these, the neurophysiology is the best understood. Neural dynamics is evolving rapidly, with several alternative points of view. The field theory sketched here is the most novel and controversial.

  11. There Are Conscious and Unconscious Agendas in the Brain and Both Are Important—Our Will Can Be Conscious as Well as Unconscious

    PubMed Central

    Deecke, Lüder

    2012-01-01

    I have been asked to write a few words on consciousness in this editorial issue. My thoughts on consciousness will focus on the relation between consciousness and will. Consciousness is not an epiphenomenon as some people believe—it is not a psychological construct either. Consciousness is a brain function. With deeper thought it is even more than that—a brain state. Writing this, I am in a conscious state, I hope at least. In every day philosophy, a close connection of consciousness with will is ventured, and is expressed in the term “conscious free will”. However, this does not mean that our will is totally determined and not free, be it conscious or unconscious. Total determinists postulate total freedom from nature in order to speak of free will. Absolute freedom from nature is an a priori impossibility; there is no way to escape from nature. However, we have relative freedom, graded freedom, freedom in degrees, enabling us to make responsible decisions and be captains of our own destiny. We are not totally determined. We can upregulate our degrees of freedom by self-management or we can downregulate them by self-mismanagement. In the present communication consciousness and the unconscious are discussed in their various aspects and interactions. PMID:24961200

  12. Conscious sedation for surgical procedures

    MedlinePlus

    Sherwood ER, Williams CG, Prough DS. Anesthesiology principles, pain management, and conscious sedation. In: Townsend CM, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery . 19th ed. ...

  13. The relation between finger gnosis and mathematical ability: why redeployment of neural circuits best explains the finding

    PubMed Central

    Penner-Wilger, Marcie; Anderson, Michael L.

    2013-01-01

    This paper elaborates a novel hypothesis regarding the observed predictive relation between finger gnosis and mathematical ability. In brief, we suggest that these two cognitive phenomena have overlapping neural substrates, as the result of the re-use (“redeployment”) of part of the finger gnosis circuit for the purpose of representing numbers. We offer some background on the relation and current explanations for it; an outline of our alternate hypothesis; some evidence supporting redeployment over current views; and a plan for further research. PMID:24367341

  14. The relation between finger gnosis and mathematical ability: why redeployment of neural circuits best explains the finding.

    PubMed

    Penner-Wilger, Marcie; Anderson, Michael L

    2013-01-01

    This paper elaborates a novel hypothesis regarding the observed predictive relation between finger gnosis and mathematical ability. In brief, we suggest that these two cognitive phenomena have overlapping neural substrates, as the result of the re-use ("redeployment") of part of the finger gnosis circuit for the purpose of representing numbers. We offer some background on the relation and current explanations for it; an outline of our alternate hypothesis; some evidence supporting redeployment over current views; and a plan for further research. PMID:24367341

  15. Infectious diseases and impaired consciousness.

    PubMed

    Wilson, Michael R; Roos, Karen L

    2011-11-01

    Any of a number of neuroinfectious diseases can cause a disorder of consciousness. The priority in the care of the patient is to identify an infectious disease that is treatable. This article examines disorders of consciousness that may be caused by a septic encephalopathy, bacterial meningoencephalitis, viral encephalitis, tick-borne bacterial disease, fungal meningitis, tuberculous meningitis, a focal infectious mass lesion, such as a brain abscess, or an autoimmune-mediated disorder as a complication of infection. PMID:22032667

  16. Intentional attunement: mirror neurons and the neural underpinnings of interpersonal relations.

    PubMed

    Gallese, Vittorio; Eagle, Morris N; Migone, Paolo

    2007-01-01

    The neural circuits activated in a person carrying out actions, expressing emotions, and experiencing sensations are activated also, automatically via a mirror neuron system, in the observer of those actions, emotions, and sensations. It is proposed that this finding of shared activation suggests a functional mechanism of "embodied simulation" that consists of the automatic, unconscious, and noninferential simulation in the observer of actions, emotions, and sensations carried out and experienced by the observed. It is proposed also that the shared neural activation pattern and the accompanying embodied simulation constitute a fundamental biological basis for understanding another's mind. The implications of this perspective for psychoanalysis are discussed, particularly regarding unconscious communication, projective identification, attunement, empathy, autism, therapeutic action, and transference-countertransference interactions.

  17. Functionally integrated neural processing of linguistic and talker information: An event-related fMRI and ERP study.

    PubMed

    Zhang, Caicai; Pugh, Kenneth R; Mencl, W Einar; Molfese, Peter J; Frost, Stephen J; Magnuson, James S; Peng, Gang; Wang, William S-Y

    2016-01-01

    Speech signals contain information of both linguistic content and a talker's voice. Conventionally, linguistic and talker processing are thought to be mediated by distinct neural systems in the left and right hemispheres respectively, but there is growing evidence that linguistic and talker processing interact in many ways. Previous studies suggest that talker-related vocal tract changes are processed integrally with phonetic changes in the bilateral posterior superior temporal gyrus/superior temporal sulcus (STG/STS), because the vocal tract parameter influences the perception of phonetic information. It is yet unclear whether the bilateral STG is also activated by the integral processing of another parameter - pitch, which influences the perception of lexical tone information and is related to talker differences in tone languages. In this study, we conducted separate functional magnetic resonance imaging (fMRI) and event-related potential (ERP) experiments to examine the spatial and temporal loci of interactions of lexical tone and talker-related pitch processing in Cantonese. We found that the STG was activated bilaterally during the processing of talker changes when listeners attended to lexical tone changes in the stimuli and during the processing of lexical tone changes when listeners attended to talker changes, suggesting that lexical tone and talker processing are functionally integrated in the bilateral STG. It extends the previous study, providing evidence for a general neural mechanism of integral phonetic and talker processing in the bilateral STG. The ERP results show interactions of lexical tone and talker processing 500-800ms after auditory word onset (a simultaneous posterior P3b and a frontal negativity). Moreover, there is some asymmetry in the interaction, such that unattended talker changes affect linguistic processing more than vice versa, which may be related to the ambiguity that talker changes cause in speech perception and/or attention bias

  18. Functionally integrated neural processing of linguistic and talker information: An event-related fMRI and ERP study.

    PubMed

    Zhang, Caicai; Pugh, Kenneth R; Mencl, W Einar; Molfese, Peter J; Frost, Stephen J; Magnuson, James S; Peng, Gang; Wang, William S-Y

    2016-01-01

    Speech signals contain information of both linguistic content and a talker's voice. Conventionally, linguistic and talker processing are thought to be mediated by distinct neural systems in the left and right hemispheres respectively, but there is growing evidence that linguistic and talker processing interact in many ways. Previous studies suggest that talker-related vocal tract changes are processed integrally with phonetic changes in the bilateral posterior superior temporal gyrus/superior temporal sulcus (STG/STS), because the vocal tract parameter influences the perception of phonetic information. It is yet unclear whether the bilateral STG is also activated by the integral processing of another parameter - pitch, which influences the perception of lexical tone information and is related to talker differences in tone languages. In this study, we conducted separate functional magnetic resonance imaging (fMRI) and event-related potential (ERP) experiments to examine the spatial and temporal loci of interactions of lexical tone and talker-related pitch processing in Cantonese. We found that the STG was activated bilaterally during the processing of talker changes when listeners attended to lexical tone changes in the stimuli and during the processing of lexical tone changes when listeners attended to talker changes, suggesting that lexical tone and talker processing are functionally integrated in the bilateral STG. It extends the previous study, providing evidence for a general neural mechanism of integral phonetic and talker processing in the bilateral STG. The ERP results show interactions of lexical tone and talker processing 500-800ms after auditory word onset (a simultaneous posterior P3b and a frontal negativity). Moreover, there is some asymmetry in the interaction, such that unattended talker changes affect linguistic processing more than vice versa, which may be related to the ambiguity that talker changes cause in speech perception and/or attention bias

  19. Neuroimaging in aphasia treatment research: Issues of experimental design for relating cognitive to neural changes

    PubMed Central

    Rapp, Brenda; Caplan, David; Edwards, Susan; Visch-Brink, Evy; Thompson, Cynthia K.

    2012-01-01

    The design of functional neuroimaging studies investigating the neural changes that support treatment-based recovery of targeted language functions in acquired aphasia faces a number of challenges. In this paper, we discuss these challenges and focus on experimental tasks and experimental designs that can be used to address the challenges, facilitate the interpretation of results and promote integration of findings across studies. PMID:22974976

  20. Neural network approaches to tracer identification as related to PIV research

    SciTech Connect

    Seeley, C.H. Jr.

    1992-12-01

    Neural networks have become very powerful tools in many fields of interest. This thesis examines the application of neural networks to another rapidly growing field flow visualization. Flow visualization research is used to experimentally determine how fluids behave and to verify computational results obtained analytically. A form of flow visualization, particle image velocimetry (PIV). determines the flow movement by tracking neutrally buoyant particles suspended in the fluid. PIV research has begun to improve rapidly with the advent of digital imagers, which can quickly digitize an image into arrays of grey levels. These grey level arrays are analyzed to determine the location of the tracer particles. Once the particles positions have been determined across multiple image frames, it is possible to track their movements, and hence, the flow of the fluid. This thesis explores the potential of several different neural networks to identify the positions of the tracer particles. Among these networks are Backpropagation, Kohonen (counter-propagation), and Cellular. Each of these algorithms were employed in their basic form, and training and testing were performed on a synthetic grey level array. Modifications were then made to them in attempts to improve the results.

  1. Social Consciousness, Education and Transformative Activity

    ERIC Educational Resources Information Center

    Pavlidis, Periklis

    2015-01-01

    This paper examines two aspects of social consciousness: consciousness in the sense of knowledge of the objective reality and consciousness in the sense of awareness of oneself as a subject in his/her social ties with other persons-subjects. In the light of such an approach to consciousness in this essay we discuss the importance of education and…

  2. Consciousness, Psychology, and Education: A Speculative Essay.

    ERIC Educational Resources Information Center

    1980

    This monograph explores implications of the psychology of consciousness for education. The psychology of consciousness encompasses the relationships among behavior, experience, and states of consciousness. It is interpreted to include different states of consciousness, paranormal phenomena, mystical experiences, dreams, psychic healing, and other…

  3. Consciousness and body image: lessons from phantom limbs, Capgras syndrome and pain asymbolia.

    PubMed Central

    Ramachandran, V S

    1998-01-01

    Words such as 'consciousness' and 'self' actually encompass a number of distinct phenomena that are loosely lumped together. The study of neurological syndromes allows us to explore the neural mechanisms that might underlie different aspects of self, such as body image and emotional responses to sensory stimuli, and perhaps even laughter and humour. Mapping the 'functional logic' of the many different attributes of human nature on to specific neural circuits in the brain offers the best hope of understanding how the activity of neurons gives rise to conscious experience. We consider three neurological syndromes (phantom limbs, Capgras delusion and pain asymbolia) to illustrate this idea. PMID:9854257

  4. Pure state consciousness and its local reduction to neuronal space

    NASA Astrophysics Data System (ADS)

    Duggins, A. J.

    2013-01-01

    The single neuronal state can be represented as a vector in a complex space, spanned by an orthonormal basis of integer spike counts. In this model a scalar element of experience is associated with the instantaneous firing rate of a single sensory neuron over repeated stimulus presentations. Here the model is extended to composite neural systems that are tensor products of single neuronal vector spaces. Depiction of the mental state as a vector on this tensor product space is intended to capture the unity of consciousness. The density operator is introduced as its local reduction to the single neuron level, from which the firing rate can again be derived as the objective correlate of a subjective element. However, the relational structure of perceptual experience only emerges when the non-local mental state is considered. A metric of phenomenal proximity between neuronal elements of experience is proposed, based on the cross-correlation function of neurophysiology, but constrained by the association of theoretical extremes of correlation/anticorrelation in inseparable 2-neuron states with identical and opponent elements respectively.

  5. Managing prolonged disorders of consciousness.

    PubMed

    Wade, Derick T

    2014-03-01

    After acute severe brain damage, many people are rendered unconscious or comatose for more than 24 hours. Although a significant number can still recover fully, some will not and a substantial minority remain unconscious for days, weeks or longer. These patients have a prolonged disorder of consciousness. A specialist multidisciplinary team should be closely involved in the management of every patient from the outset. Assessment of a patient's level of awareness is not straightforward, and requires a team with suitable experience and expertise. The underlying neurological damage, whether or not there is an intact primary sensory input and motor output, and if there are reversible causes such as a high level of a sedating drug, or a subdural haematoma have to be established. If recovery of awareness has not occurred by six months after hypoxic or hypoglycaemic brain damage and 12 months after most other causes of brain damage, then the patient is very unlikely to recover any awareness and is described as being in a permanent vegetative state. The family must be closely and fully involved from the outset. Families legally cannot, and should not be asked to, make decisions concerning healthcare, unless a family member is a legally appointed deputy or has been given power of attorney in relation to healthcare matters. Family members can, and should be asked to, give information about the patient's wishes, life choices etc as part of the best interests decision-making process, and they should be involved in best interests meetings.

  6. Disentangling neural processing of masked and masking stimulus by means of event-related contralateral - ipsilateral differences of EEG potentials.

    PubMed

    Verleger, Rolf; Jaśkowski, Piotr

    2007-01-01

    In spite of the excellent temporal resolution of event-related EEG potentials (ERPs), the overlapping potentials evoked by masked and masking stimuli are hard to disentangle. However, when both masked and masking stimuli consist of pairs of relevant and irrelevant stimuli, one left and one right from fixation, with the side of the relevant element varying between pairs, effects of masked and masking stimuli can be distinguished by means of the contralateral preponderance of the potentials evoked by the relevant elements, because the relevant elements may independently change sides in masked and masking stimuli. Based on a reanalysis of data from which only selected contralateral-ipsilateral effects had been previously published, the present contribution will provide a more complete picture of the ERP effects in a masked-priming task. Indeed, effects evoked by masked primes and masking targets heavily overlapped in conventional ERPs and could be disentangled to a certain degree by contralateral-ipsilateral differences. Their major component, the N2pc, is interpreted as indicating preferential processing of stimuli matching the target template, which process can neither be identified with conscious perception nor with shifts of spatial attention. The measurements showed that the triggering of response preparation by the masked stimuli did not depend on their discriminability, and their priming effects on the processing of the following target stimuli were qualitatively different for stimulus identification and for response preparation. These results provide another piece of evidence for the independence of motor-related and perception-related effects of masked stimuli.

  7. Neuroontology, neurobiological naturalism, and consciousness: A challenge to scientific reduction and a solution

    NASA Astrophysics Data System (ADS)

    Feinberg, Todd E.

    2012-03-01

    One of the great challenges to a science of consciousness is the inability to reduce critical features of consciousness to neural processes. In this paper I identify four neuroontologically irreducible features (NOIF) - referral of neural states, mental unity, qualia, and mental causation - defined as aspects of consciousness in which subjective experience is not wholly reducible to objectively observed or objectively understood neurons (ontological subjectivity). I next analyze the emergent and unique system properties of the neural hierarchy and argue that while the NOIF are indeed ontologically subjective, each of the NOIF individually can be explained by the unique architecture and functional properties of the neural hierarchy that lead to both emergent properties and their irreducibility in a manner that does not violate any known physical laws nor require any new physics or the application of physics to emergence or reduction beyond that normally applied to biology in general. I conclude that consciousness is a neurobiologically unique and local phenomenon that is specific to particular neural systems, a view that is consistent with both ontological subjectivity and biological naturalism. I call this position weakly emergent nonreductive physicalism or neurobiological naturalism.

  8. Organization of the sleep-related neural systems in the brain of the minke whale (Balaenoptera acutorostrata).

    PubMed

    Dell, Leigh-Anne; Karlsson, Karl Ae; Patzke, Nina; Spocter, Muhammad A; Siegel, Jerome M; Manger, Paul R

    2016-07-01

    The current study analyzed the nuclear organization of the neural systems related to the control and regulation of sleep and wake in the basal forebrain, diencephalon, midbrain, and pons of the minke whale, a mysticete cetacean. While odontocete cetaceans sleep in an unusual manner, with unihemispheric slow wave sleep (USWS) and suppressed REM sleep, it is unclear whether the mysticete whales show a similar sleep pattern. Previously, we detailed a range of features in the odontocete brain that appear to be related to odontocete-type sleep, and here present our analysis of these features in the minke whale brain. All neural elements involved in sleep regulation and control found in bihemispheric sleeping mammals and the harbor porpoise were present in the minke whale, with no specific nuclei being absent, and no novel nuclei being present. This qualitative similarity relates to the cholinergic, noradrenergic, serotonergic and orexinergic systems, and the GABAergic elements of these nuclei. Quantitative analysis revealed that the numbers of pontine cholinergic (274,242) and noradrenergic (203,686) neurons, and hypothalamic orexinergic neurons (277,604), are markedly higher than other large-brained bihemispheric sleeping mammals. Small telencephalic commissures (anterior, corpus callosum, and hippocampal), an enlarged posterior commissure, supernumerary pontine cholinergic and noradrenergic cells, and an enlarged peripheral division of the dorsal raphe nuclear complex of the minke whale, all indicate that the suite of neural characteristics thought to be involved in the control of USWS and the suppression of REM in the odontocete cetaceans are present in the minke whale. J. Comp. Neurol. 524:2018-2035, 2016. © 2015 Wiley Periodicals, Inc.

  9. Consciousness of Unification: The Mind-Matter Phallacy Bites the Dust

    NASA Astrophysics Data System (ADS)

    Beichler, James E.

    A complete theoretical model of how consciousness arises in neural nets can be developed based on a mixed quantum/classical basis. Both mind and consciousness are multi-leveled scalar and vector electromagnetic complexity patterns, respectively, which emerge within all living organisms through the process of evolution. Like life, the mind and consciousness patterns extend throughout living organisms (bodies), but the neural nets and higher level groupings that distinguish higher levels of consciousness only exist in the brain so mind and consciousness have been traditionally associated with the brain alone. A close study of neurons and neural nets in the brain shows that the microtubules within axons are classical bio-magnetic inductors that emit and absorb electromagnetic pulses from each other. These pulses establish interference patterns that influence the quantized vector potential patterns of interstitial water molecules within the neurons as well as create the coherence within neurons and neural nets that scientists normally associate with more complex memories, thought processes and streams of thought. Memory storage and recall are guided by the microtubules and the actual memory patterns are stored as magnetic vector potential complexity patterns in the points of space at the quantum level occupied by the water molecules. This model also accounts for the plasticity of the brain and implies that mind and consciousness, like life itself, are the result of evolutionary processes. However, consciousness can evolve independent of an organism's birth genetics once it has evolved by normal bottom-up genetic processes and thus force a new type of top-down evolution on living organisms and species as a whole that can be explained by expanding the laws of thermodynamics to include orderly systems.

  10. Neural tube defects – disorders of neurulation and related embryonic processes

    PubMed Central

    Copp, Andrew J.; Greene, Nicholas D. E.

    2014-01-01

    Neural tube defects (NTDs) are severe congenital malformations affecting 1 in every 1000 pregnancies. ‘Open’ NTDs result from failure of primary neurulation as seen in anencephaly, myelomeningocele (open spina bifida) and craniorachischisis. Degeneration of the persistently open neural tube in utero leads to loss of neurological function below the lesion level. ‘Closed’ NTDs are skin-covered disorders of spinal cord structure, ranging from asymptomatic spina bifida occulta to severe spinal cord tethering, and usually traceable to disruption of secondary neurulation. ‘Herniation’ NTDs are those in which meninges, with or without brain or spinal cord tissue, become exteriorised through a pathological opening in the skull or vertebral column (e.g. encephalocele and meningocele). NTDs have multifactorial etiology, with genes and environmental factors interacting to determine individual risk of malformation. While over 200 mutant genes cause open NTDs in mice, much less is known about the genetic causation of human NTDs. Recent evidence has implicated genes of the planar cell polarity signalling pathway in a proportion of cases. The embryonic development of NTDs is complex, with diverse cellular and molecular mechanisms operating at different levels of the body axis. Molecular regulatory events include the BMP and Sonic hedgehog pathways which have been implicated in control of neural plate bending. Primary prevention of NTDs has been implemented clinically following the demonstration that folic acid, when taken as a peri-conceptional supplement, can prevent many cases. Not all NTDs respond to folic acid, however, and adjunct therapies are required for prevention of this folic acid-resistant category. PMID:24009034

  11. Individual differences in attentional bias associated with cocaine dependence are related to varying engagement of neural processing networks.

    PubMed

    Kilts, Clint D; Kennedy, Ashley; Elton, Amanda L; Tripathi, Shanti Prakash; Young, Jonathan; Cisler, Josh M; James, G Andrew

    2014-04-01

    Cocaine and other drug dependencies are associated with significant attentional bias for drug use stimuli that represents a candidate cognitive marker of drug dependence and treatment outcomes. We explored, using fMRI, the role of discrete neural processing networks in the representation of individual differences in the drug attentional bias effect associated with cocaine dependence (AB-coc) using a word counting Stroop task with personalized cocaine use stimuli (cocStroop). The cocStroop behavioral and neural responses were further compared with those associated with a negative emotional word Stroop task (eStroop) and a neutral word counting Stroop task (cStroop). Brain-behavior correlations were explored using both network-level correlation analysis following independent component analysis (ICA) and voxel-level, brain-wide univariate correlation analysis. Variation in the attentional bias effect for cocaine use stimuli among cocaine-dependent men and women was related to the recruitment of two separate neural processing networks related to stimulus attention and salience attribution (inferior frontal-parietal-ventral insula), and the processing of the negative affective properties of cocaine stimuli (frontal-temporal-cingulate). Recruitment of a sensory-motor-dorsal insula network was negatively correlated with AB-coc and suggested a regulatory role related to the sensorimotor processing of cocaine stimuli. The attentional bias effect for cocaine stimuli and for negative affective word stimuli were significantly correlated across individuals, and both were correlated with the activity of the frontal-temporal-cingulate network. Functional connectivity for a single prefrontal-striatal-occipital network correlated with variation in general cognitive control (cStroop) that was unrelated to behavioral or neural network correlates of cocStroop- or eStroop-related attentional bias. A brain-wide mass univariate analysis demonstrated the significant correlation of

  12. Neural mechanisms of the testosterone-aggression relation: the role of orbitofrontal cortex.

    PubMed

    Mehta, Pranjal H; Beer, Jennifer

    2010-10-01

    Testosterone plays a role in aggressive behavior, but the mechanisms remain unclear. The present study tested the hypothesis that testosterone influences aggression through the OFC, a region implicated in self-regulation and impulse control. In a decision-making paradigm in which people chose between aggression and monetary reward (the ultimatum game), testosterone was associated with increased aggression following social provocation (rejecting unfair offers). The effect of testosterone on aggression was explained by reduced activity in the medial OFC. The findings suggest that testosterone increases the propensity toward aggression because of reduced activation of the neural circuitry of impulse control and self-regulation. PMID:19925198

  13. Pure consciousness: distinct phenomenological and physiological correlates of "consciousness itself".

    PubMed

    Travis, F; Pearson, C

    2000-01-01

    This paper explores subjective reports and physiological correlates of the experience of "consciousness itself"--self awareness isolated from the processes and objects of experience during Transcendental Meditation practice. Subjectively, this state is characterized by the absence of the very framework (time, space, and body sense) and content (qualities of inner and outer perception) that define waking experiences. Physiologically, this state is distinguished by the presence of apneustic breathing, autonomic orienting at the onset of breath changes, and increases in the frequency of peak EEG power. A model, called the junction point model, is presented that integrates pure consciousness with waking, dreaming, or sleeping. It could provide a structure to generate a coherent program of research to test the full range of consciousness and so enable us to understand what it means to be fully human.

  14. Pure Consciousness: Distinct Phenomenological and Physiological Correlates of "Consciousness Itself"

    PubMed

    Travis; Pearson

    1999-01-01

    This paper explores subjective reports and physiological correlates of the experience of "consciousness itself" - self awareness isolated from the processes and objects of experience during Transcendental Meditation practice. Subjectively, this state is characterized by the absence of the very framework (time, space, and body sense) and content (qualities of inner and outer perception) that define waking experiences. Physiologically, this state is distinguished by the presence of apneustic breathing, autonomic orienting at the onset of breath changes, and increases in the frequency of peak EEG power. A model, called the junction point model, is presented that integrates pure consciousness with waking, dreaming, or sleeping. It could provide a structure to generate a coherent program of research to test the full range of consciousness and so enable us to understand what it means to be fully human.

  15. What Explains Consciousness? Or…What Consciousness Explains?

    PubMed Central

    Dulany, Donelson E.

    2014-01-01

    In this invited commentary I focus on the topic addressed in three papers: De Sousa's (2013[1617]) Toward an Integrative Theory of Consciousness, a monograph with Parts 1 & 2, as well as commentaries by Pereira (2013a[59]) and Hirstein (2013[42]). All three are impressively scholarly and can stand—and shout—on their own. But theory of consciousness? My aim is to slice that topic into the two fundamentally different kinds of theories of consciousness, say what appears to be an ideology, out of behaviourism into cognitivism, now also influencing the quest for an “explanation of consciousness” in cognitive neuroscience. I will then say what can be expected given what we know of the complexity of brain structure, the richness of a conscious “vocabulary”, and current technological limits of brain imaging. This will then turn to the strategy for examining “what consciousness explains”—metatheory, theories, mappings, and a methodology of competitive support, a methodology especially important where there are competing commitments. There are also increasingly common identifications of methodological bias in, along with failures to replicate, studies reporting unconscious controls in decision, social priming—as there have been in perception, learning, problem solving, etc. The literature critique has provided evidence taken as reducing, and in some cases eliminating, a role for conscious controls—a position consistent with that ideology out of behaviourism into cognitivism. It is an ideological position that fails to recognize the fundamental distinction between theoretical and metaphysical assertions. PMID:24891796

  16. Towards the routine use of brain imaging to aid the clinical diagnosis of disorders of consciousness.

    PubMed

    Coleman, M R; Davis, M H; Rodd, J M; Robson, T; Ali, A; Owen, A M; Pickard, J D

    2009-09-01

    Clinical audits have highlighted the many challenges and dilemmas faced by clinicians assessing persons with disorders of consciousness (vegetative state and minimally conscious state). The diagnostic decision-making process is highly subjective, dependent upon the skills of the examiner and invariably dictated by the patients' ability to move or speak. Whilst a considerable amount has been learnt since Jennett and Plum coined the term 'vegetative state', the assessment process remains largely unchanged; conducted at the bedside, using behavioural assessment tools, which are susceptible to environmental and physiological factors. This has created a situation where the rate of misdiagnosis is unacceptably high (up to 43%). In order to address these problems, various functional brain imaging paradigms, which do not rely upon the patient's ability to move or speak, have been proposed as a source of additional information to inform the diagnostic decision making process. Although accumulated evidence from brain imaging, particularly functional magnetic resonance imaging (fMRI), has been encouraging, the empirical evidence is still based on relatively small numbers of patients. It remains unclear whether brain imaging is capable of informing the diagnosis beyond the behavioural assessment and whether brain imaging has any prognostic utility. In this study, we describe the functional brain imaging findings from a group of 41 patients with disorders of consciousness, who undertook a hierarchical speech processing task. We found, contrary to the clinical impression of a specialist team using behavioural assessment tools, that two patients referred to the study with a diagnosis of vegetative state did in fact demonstrate neural correlates of speech comprehension when assessed using functional brain imaging. These fMRI findings were found to have no association with the patient's behavioural presentation at the time of investigation and thus provided additional diagnostic

  17. Consciousness: here, there and everywhere?

    PubMed

    Tononi, Giulio; Koch, Christof

    2015-05-19

    The science of consciousness has made great strides by focusing on the behavioural and neuronal correlates of experience. However, while such correlates are important for progress to occur, they are not enough if we are to understand even basic facts, for example, why the cerebral cortex gives rise to consciousness but the cerebellum does not, though it has even more neurons and appears to be just as complicated. Moreover, correlates are of little help in many instances where we would like to know if consciousness is present: patients with a few remaining islands of functioning cortex, preterm infants, non-mammalian species and machines that are rapidly outperforming people at driving, recognizing faces and objects, and answering difficult questions. To address these issues, we need not only more data but also a theory of consciousness-one that says what experience is and what type of physical systems can have it. Integrated information theory (IIT) does so by starting from experience itself via five phenomenological axioms: intrinsic existence, composition, information, integration and exclusion. From these it derives five postulates about the properties required of physical mechanisms to support consciousness. The theory provides a principled account of both the quantity and the quality of an individual experience (a quale), and a calculus to evaluate whether or not a particular physical system is conscious and of what. Moreover, IIT can explain a range of clinical and laboratory findings, makes a number of testable predictions and extrapolates to a number of problematic conditions. The theory holds that consciousness is a fundamental property possessed by physical systems having specific causal properties. It predicts that consciousness is graded, is common among biological organisms and can occur in some very simple systems. Conversely, it predicts that feed-forward networks, even complex ones, are not conscious, nor are aggregates such as groups of individuals

  18. Consciousness: here, there and everywhere?

    PubMed

    Tononi, Giulio; Koch, Christof

    2015-05-19

    The science of consciousness has made great strides by focusing on the behavioural and neuronal correlates of experience. However, while such correlates are important for progress to occur, they are not enough if we are to understand even basic facts, for example, why the cerebral cortex gives rise to consciousness but the cerebellum does not, though it has even more neurons and appears to be just as complicated. Moreover, correlates are of little help in many instances where we would like to know if consciousness is present: patients with a few remaining islands of functioning cortex, preterm infants, non-mammalian species and machines that are rapidly outperforming people at driving, recognizing faces and objects, and answering difficult questions. To address these issues, we need not only more data but also a theory of consciousness-one that says what experience is and what type of physical systems can have it. Integrated information theory (IIT) does so by starting from experience itself via five phenomenological axioms: intrinsic existence, composition, information, integration and exclusion. From these it derives five postulates about the properties required of physical mechanisms to support consciousness. The theory provides a principled account of both the quantity and the quality of an individual experience (a quale), and a calculus to evaluate whether or not a particular physical system is conscious and of what. Moreover, IIT can explain a range of clinical and laboratory findings, makes a number of testable predictions and extrapolates to a number of problematic conditions. The theory holds that consciousness is a fundamental property possessed by physical systems having specific causal properties. It predicts that consciousness is graded, is common among biological organisms and can occur in some very simple systems. Conversely, it predicts that feed-forward networks, even complex ones, are not conscious, nor are aggregates such as groups of individuals

  19. The neural network for tool-related cognition: An activation likelihood estimation meta-analysis of 70 neuroimaging contrasts.

    PubMed

    Ishibashi, Ryo; Pobric, Gorana; Saito, Satoru; Lambon Ralph, Matthew A

    2016-01-01

    The ability to recognize and use a variety of tools is an intriguing human cognitive function. Multiple neuroimaging studies have investigated neural activations with various types of tool-related tasks. In the present paper, we reviewed tool-related neural activations reported in 70 contrasts from 56 neuroimaging studies and performed a series of activation likelihood estimation (ALE) meta-analyses to identify tool-related cortical circuits dedicated either to general tool knowledge or to task-specific processes. The results indicate the following: (a) Common, task-general processing regions for tools are located in the left inferior parietal lobule (IPL) and ventral premotor cortex; and (b) task-specific regions are located in superior parietal lobule (SPL) and dorsal premotor area for imagining/executing actions with tools and in bilateral occipito-temporal cortex for recognizing/naming tools. The roles of these regions in task-general and task-specific activities are discussed with reference to evidence from neuropsychology, experimental psychology and other neuroimaging studies. PMID:27362967

  20. The neural network for tool-related cognition: An activation likelihood estimation meta-analysis of 70 neuroimaging contrasts

    PubMed Central

    Ishibashi, Ryo; Pobric, Gorana; Saito, Satoru; Lambon Ralph, Matthew A.

    2016-01-01

    ABSTRACT The ability to recognize and use a variety of tools is an intriguing human cognitive function. Multiple neuroimaging studies have investigated neural activations with various types of tool-related tasks. In the present paper, we reviewed tool-related neural activations reported in 70 contrasts from 56 neuroimaging studies and performed a series of activation likelihood estimation (ALE) meta-analyses to identify tool-related cortical circuits dedicated either to general tool knowledge or to task-specific processes. The results indicate the following: (a) Common, task-general processing regions for tools are located in the left inferior parietal lobule (IPL) and ventral premotor cortex; and (b) task-specific regions are located in superior parietal lobule (SPL) and dorsal premotor area for imagining/executing actions with tools and in bilateral occipito-temporal cortex for recognizing/naming tools. The roles of these regions in task-general and task-specific activities are discussed with reference to evidence from neuropsychology, experimental psychology and other neuroimaging studies. PMID:27362967

  1. Paradox in AI - AI 2.0: The Way to Machine Consciousness

    NASA Astrophysics Data System (ADS)

    Palensky, Peter; Bruckner, Dietmar; Tmej, Anna; Deutsch, Tobias

    Artificial Intelligence, the big promise of the last millennium, has apparently made its way into our daily lives. Cell phones with speech control, evolutionary computing in data mining or power grids, optimized via neural network, show its applicability in industrial environments. The original expectation of true intelligence and thinking machines lies still ahead of us. Researchers are, however, optimistic as never before. This paper tries to compare the views, challenges and approaches of several disciplines: engineering, psychology, neuroscience, philosophy. It gives a short introduction to Psychoanalysis, discusses the term consciousness, social implications of intelligent machines, related theories, and expectations and shall serve as a starting point for first attempts of combining these diverse thoughts.

  2. Consciousness, biology and quantum hypotheses

    NASA Astrophysics Data System (ADS)

    Baars, Bernard J.; Edelman, David B.

    2012-09-01

    Natural phenomena are reducible to quantum events in principle, but quantum mechanics does not always provide the best level of analysis. The many-body problem, chaotic avalanches, materials properties, biological organisms, and weather systems are better addressed at higher levels. Animals are highly organized, goal-directed, adaptive, selectionist, information-preserving, functionally redundant, multicellular, quasi-autonomous, highly mobile, reproducing, dissipative systems that conserve many fundamental features over remarkably long periods of time at the species level. Animal brains consist of massive, layered networks of specialized signaling cells with 10,000 communication points per cell, and interacting up to 1000 Hz. Neurons begin to divide and differentiate very early in gestation, and continue to develop until middle age. Waking brains operate far from thermodynamic equilibrium under delicate homeostatic control, making them extremely sensitive to a range of physical and chemical stimuli, highly adaptive, and able to produce a remarkable range of goal-relevant actions. Consciousness is “a difference that makes a difference” at the level of massive neuronal interactions in the most parallel-interactive anatomical structure of the mammalian brain, the cortico-thalamic (C-T) system. Other brain structures are not established to result in direct conscious experiences, at least in humans. However, indirect extra-cortical influences on the C-T system are pervasive. Learning, brain plasticity and major life adaptations may require conscious cognition. While brains evolved over hundreds of millions of years, and individual brains grow over months, years and decades, conscious events appear to have a duty cycle of ∼100 ms, fading after a few seconds. They can of course be refreshed by inner rehearsal, re-visualization, or attending to recurrent stimulus sources. These very distinctive brain events are needed when animals seek out and cope with new

  3. Consciousness, biology and quantum hypotheses.

    PubMed

    Baars, Bernard J; Edelman, David B

    2012-09-01

    Natural phenomena are reducible to quantum events in principle, but quantum mechanics does not always provide the best level of analysis. The many-body problem, chaotic avalanches, materials properties, biological organisms, and weather systems are better addressed at higher levels. Animals are highly organized, goal-directed, adaptive, selectionist, information-preserving, functionally redundant, multicellular, quasi-autonomous, highly mobile, reproducing, dissipative systems that conserve many fundamental features over remarkably long periods of time at the species level. Animal brains consist of massive, layered networks of specialized signaling cells with 10,000 communication points per cell, and interacting up to 1000 Hz. Neurons begin to divide and differentiate very early in gestation, and continue to develop until middle age. Waking brains operate far from thermodynamic equilibrium under delicate homeostatic control, making them extremely sensitive to a range of physical and chemical stimuli, highly adaptive, and able to produce a remarkable range of goal-relevant actions. Consciousness is "a difference that makes a difference" at the level of massive neuronal interactions in the most parallel-interactive anatomical structure of the mammalian brain, the cortico-thalamic (C-T) system. Other brain structures are not established to result in direct conscious experiences, at least in humans. However, indirect extra-cortical influences on the C-T system are pervasive. Learning, brain plasticity and major life adaptations may require conscious cognition. While brains evolved over hundreds of millions of years, and individual brains grow over months, years and decades, conscious events appear to have a duty cycle of ∼100 ms, fading after a few seconds. They can of course be refreshed by inner rehearsal, re-visualization, or attending to recurrent stimulus sources. These very distinctive brain events are needed when animals seek out and cope with new

  4. Consciousness, biology and quantum hypotheses.

    PubMed

    Baars, Bernard J; Edelman, David B

    2012-09-01

    Natural phenomena are reducible to quantum events in principle, but quantum mechanics does not always provide the best level of analysis. The many-body problem, chaotic avalanches, materials properties, biological organisms, and weather systems are better addressed at higher levels. Animals are highly organized, goal-directed, adaptive, selectionist, information-preserving, functionally redundant, multicellular, quasi-autonomous, highly mobile, reproducing, dissipative systems that conserve many fundamental features over remarkably long periods of time at the species level. Animal brains consist of massive, layered networks of specialized signaling cells with 10,000 communication points per cell, and interacting up to 1000 Hz. Neurons begin to divide and differentiate very early in gestation, and continue to develop until middle age. Waking brains operate far from thermodynamic equilibrium under delicate homeostatic control, making them extremely sensitive to a range of physical and chemical stimuli, highly adaptive, and able to produce a remarkable range of goal-relevant actions. Consciousness is "a difference that makes a difference" at the level of massive neuronal interactions in the most parallel-interactive anatomical structure of the mammalian brain, the cortico-thalamic (C-T) system. Other brain structures are not established to result in direct conscious experiences, at least in humans. However, indirect extra-cortical influences on the C-T system are pervasive. Learning, brain plasticity and major life adaptations may require conscious cognition. While brains evolved over hundreds of millions of years, and individual brains grow over months, years and decades, conscious events appear to have a duty cycle of ∼100 ms, fading after a few seconds. They can of course be refreshed by inner rehearsal, re-visualization, or attending to recurrent stimulus sources. These very distinctive brain events are needed when animals seek out and cope with new

  5. Neural correlates of inhibition and contextual cue processing related to treatment response in PTSD.

    PubMed

    van Rooij, Sanne J H; Geuze, Elbert; Kennis, Mitzy; Rademaker, Arthur R; Vink, Matthijs

    2015-02-01

    Thirty to fifty percent of posttraumatic stress disorder (PTSD) patients do not respond to treatment. Understanding the neural mechanisms underlying treatment response could contribute to improve response rates. PTSD is often associated with decreased inhibition of fear responses in a safe environment. Importantly, the mechanism of effective treatment (psychotherapy) relies on inhibition and so-called contextual cue processing. Therefore, we investigate inhibition and contextual cue processing in the context of treatment. Forty-one male war veterans with PTSD and 22 healthy male war veterans (combat controls) were scanned twice with a 6- to 8-month interval, in which PTSD patients received treatment (psychotherapy). We distinguished treatment responders from nonresponders on the base of percentage symptom decrease. Inhibition and contextual cue processing were assessed with the stop-signal anticipation task. Behavioral and functional MRI measures were compared between PTSD patients and combat controls, and between responders and nonresponders using repeated measures analyses. PTSD patients showed behavioral and neural deficits in inhibition and contextual cue processing at both time points compared with combat controls. These deficits were unaffected by treatment; therefore, they likely represent vulnerability factors or scar aspects of PTSD. Second, responders showed increased pretreatment activation of the left inferior parietal lobe (IPL) during contextual cue processing compared with nonresponders. Moreover, left IPL activation predicted percentage symptom improvement. The IPL has an important role in contextual cue processing, and may therefore facilitate the effect of psychotherapy. Hence, increased left IPL activation may represent a potential predictive biomarker for PTSD treatment response.

  6. Graph-based variability estimation in single-trial event-related neural responses.

    PubMed

    Gramfort, Alexandre; Keriven, Renaud; Clerc, Maureen

    2010-05-01

    Extracting information from multitrial magnetoencephalography or electroencephalography (EEG) recordings is challenging because of the very low SNR, and because of the inherent variability of brain responses. The problem of low SNR is commonly tackled by averaging multiple repetitions of the recordings, also called trials, but the variability of response across trials leads to biased results and limits interpretability. This paper proposes to decode the variability of neural responses by making use of graph representations. Our approach has several advantages compared to other existing methods that process single-trial data: first, it avoids the a priori definition of a model for the waveform of the neural response; second, it does not make use of the average data for parameter estimation; third, it does not suffer from initialization problems by providing solutions that are global optimum of cost functions; and last, it is fast. We proceed in two steps. First, a manifold learning algorithm, based on a graph Laplacian, offers an efficient way of ordering trials with respect to the response variability, under the condition that this variability itself depends on a single parameter. Second, the estimation of the variability is formulated as a combinatorial optimization that can be solved very efficiently using graph cuts. Details and validation of this second step are provided for latency estimation. Performance and robustness experiments are conducted on synthetic data, and results are presented on EEG data from a P300 oddball experiment. PMID:20142163

  7. Dissociation of Neural Networks for Predisposition and for Training-Related Plasticity in Auditory-Motor Learning.

    PubMed

    Herholz, Sibylle C; Coffey, Emily B J; Pantev, Christo; Zatorre, Robert J

    2016-07-01

    Skill learning results in changes to brain function, but at the same time individuals strongly differ in their abilities to learn specific skills. Using a 6-week piano-training protocol and pre- and post-fMRI of melody perception and imagery in adults, we dissociate learning-related patterns of neural activity from pre-training activity that predicts learning rates. Fronto-parietal and cerebellar areas related to storage of newly learned auditory-motor associations increased their response following training; in contrast, pre-training activity in areas related to stimulus encoding and motor control, including right auditory cortex, hippocampus, and caudate nuclei, was predictive of subsequent learning rate. We discuss the implications of these results for models of perceptual and of motor learning. These findings highlight the importance of considering individual predisposition in plasticity research and applications. PMID:26139842

  8. Consciousness, biology and quantum hypotheses

    NASA Astrophysics Data System (ADS)

    Baars, Bernard J.; Edelman, David B.

    2012-09-01

    Natural phenomena are reducible to quantum events in principle, but quantum mechanics does not always provide the best level of analysis. The many-body problem, chaotic avalanches, materials properties, biological organisms, and weather systems are better addressed at higher levels. Animals are highly organized, goal-directed, adaptive, selectionist, information-preserving, functionally redundant, multicellular, quasi-autonomous, highly mobile, reproducing, dissipative systems that conserve many fundamental features over remarkably long periods of time at the species level. Animal brains consist of massive, layered networks of specialized signaling cells with 10,000 communication points per cell, and interacting up to 1000 Hz. Neurons begin to divide and differentiate very early in gestation, and continue to develop until middle age. Waking brains operate far from thermodynamic equilibrium under delicate homeostatic control, making them extremely sensitive to a range of physical and chemical stimuli, highly adaptive, and able to produce a remarkable range of goal-relevant actions. Consciousness is “a difference that makes a difference” at the level of massive neuronal interactions in the most parallel-interactive anatomical structure of the mammalian brain, the cortico-thalamic (C-T) system. Other brain structures are not established to result in direct conscious experiences, at least in humans. However, indirect extra-cortical influences on the C-T system are pervasive. Learning, brain plasticity and major life adaptations may require conscious cognition. While brains evolved over hundreds of millions of years, and individual brains grow over months, years and decades, conscious events appear to have a duty cycle of ∼100 ms, fading after a few seconds. They can of course be refreshed by inner rehearsal, re-visualization, or attending to recurrent stimulus sources. These very distinctive brain events are needed when animals seek out and cope with new

  9. Avian reflex and electroencephalogram responses in different states of consciousness.

    PubMed

    Sandercock, Dale A; Auckburally, Adam; Flaherty, Derek; Sandilands, Victoria; McKeegan, Dorothy E F

    2014-06-22

    Defining states of clinical consciousness in animals is important in veterinary anaesthesia and in studies of euthanasia and welfare assessment at slaughter. The aim of this study was to validate readily observable reflex responses in relation to different conscious states, as confirmed by EEG analysis, in two species of birds under laboratory conditions (35-week-old layer hens (n=12) and 11-week-old turkeys (n=10)). We evaluated clinical reflexes and characterised electroencephalograph (EEG) activity (as a measure of brain function) using spectral analyses in four different clinical states of consciousness: conscious (fully awake), semi-conscious (sedated), unconscious-optimal (general anaesthesia), unconscious-sub optimal (deep hypnotic state), as well as assessment immediately following euthanasia. Jaw or neck muscle tone was the most reliable reflex measure distinguishing between conscious and unconscious states. Pupillary reflex was consistently observed until respiratory arrest. Nictitating membrane reflex persisted for a short time (<1 min) after respiratory arrest and brain death (isoelectric EEG). The results confirm that the nictitating membrane reflex is a conservative measure of death in poultry. Using spectral analyses of the EEG waveforms it was possible to readily distinguish between the different states of clinical consciousness. In all cases, when birds progressed from a conscious to unconscious state; total spectral power (PTOT) significantly increased, whereas median (F50) and spectral edge (F95) frequencies significantly decreased. This study demonstrates that EEG analysis can differentiate between clinical states (and loss of brain function at death) in birds and provides a unique integration of reflex responses and EEG activity.

  10. Integrated information theory of consciousness: an updated account.

    PubMed

    Tononi, G

    2012-12-01

    information integration and related quantities, the article presents some theoretical considerations about the relationship between information and causation and about the relational structure of concepts within a qua/e. It also explores the relationship between the temporal grain size of information integration and the dynamic of metastable states in the corticothalamic complex. Finally, it summarizes how liT accounts for empirical findings about the neural substrate of