Learning-Dependent Potentiation in the Vibrissal Motor Cortex Is Closely Related to the Acquisition of Conditioned Whisker Responses in Behaving Mice

ERIC Educational Resources Information Center

Delgado-Garcia, Jose Maria; Troncoso, Julieta; Munera, Alejandro

2007-01-01

The role of the primary motor cortex in the acquisition of new motor skills was evaluated during classical conditioning of vibrissal protraction responses in behaving mice, using a trace paradigm. Conditioned stimulus (CS) presentation elicited a characteristic field potential in the vibrissal motor cortex, which was dependent on the synchronized…

Responses of the circadian system of rats to conditioned and unconditioned stimuli.

PubMed

de Groot, M H; Rusak, B

2000-08-01

The circadian systems of rodents respond to light pulses presented during the subjective night with phase shifts and altered cellular activity in the suprachiasmatic nuclei (SCN), including expression of immediate-early genes (IEGs) such as c-fos. A recent study showed that a nonphotic stimulus (an air disturbance generated by a fan) that does not normally induce the expression of c-fos-like immunoreactivity in the SCN of rats can be made to do so after being paired repeatedly with a light pulse in a Pavlovian conditioning paradigm. Furthermore, after conditioning (but not after noncontingent exposure to these stimuli), the fan also induced phase shifts in activity and body temperature rhythms comparable to those produced by light. The authors performed three experiments designed to replicate and extend these findings in rats. In experiment 1, rats were tested for conditioning effects of repeated pairings of a light pulse with a neutral air disturbance under a full photoperiod. In experiment 2, a modified conditioning paradigm was used in which a skeleton photoperiod served as both the entraining zeitgeber and the unconditioned stimulus. Animals in the paired and unpaired training conditions were exposed to both the light pulse and the air disturbance, but the air disturbance signaled the onset of light in the paired condition only. Phase shifts of wheel-running activity rhythms and gene expression in the SCN, intergeniculate leaflet, and paraventricular nucleus of the thalamus were assessed in animals following either of the training conditions or the control procedures. Experiment 3 assessed whether the air disturbance could entrain the circadian activity rhythms of rats with or without previous pairing with light in a classical conditioning paradigm. No evidence for classical conditioning, nor for unconditioned effects of the air disturbance on the circadian system, was found in these studies.

Molecular mechanisms underlying formation of long-term reward memories and extinction memories in the honeybee (Apis mellifera)

PubMed Central

2014-01-01

The honeybee (Apis mellifera) has long served as an invertebrate model organism for reward learning and memory research. Its capacity for learning and memory formation is rooted in the ecological need to efficiently collect nectar and pollen during summer to ensure survival of the hive during winter. Foraging bees learn to associate a flower's characteristic features with a reward in a way that resembles olfactory appetitive classical conditioning, a learning paradigm that is used to study mechanisms underlying learning and memory formation in the honeybee. Due to a plethora of studies on appetitive classical conditioning and phenomena related to it, the honeybee is one of the best characterized invertebrate model organisms from a learning psychological point of view. Moreover, classical conditioning and associated behavioral phenomena are surprisingly similar in honeybees and vertebrates, suggesting a convergence of underlying neuronal processes, including the molecular mechanisms that contribute to them. Here I review current thinking on the molecular mechanisms underlying long-term memory (LTM) formation in honeybees following classical conditioning and extinction, demonstrating that an in-depth analysis of the molecular mechanisms of classical conditioning in honeybees might add to our understanding of associative learning in honeybees and vertebrates. PMID:25225299

Cognitive and Neural Sciences Division. 1988 Programs

DTIC Science & Technology

1988-08-01

the P.I. uses a delayed reinforcement autoshaping procedure which incorporates features of both classical and operant conditioning paradigms...Progress: The PT has completed initial dose-response study of effects of TMT on autoshaping and has submitted a paper that separates "non-specific

Formal verification of mathematical software

NASA Technical Reports Server (NTRS)

Sutherland, D.

1984-01-01

Methods are investigated for formally specifying and verifying the correctness of mathematical software (software which uses floating point numbers and arithmetic). Previous work in the field was reviewed. A new model of floating point arithmetic called the asymptotic paradigm was developed and formalized. Two different conceptual approaches to program verification, the classical Verification Condition approach and the more recently developed Programming Logic approach, were adapted to use the asymptotic paradigm. These approaches were then used to verify several programs; the programs chosen were simplified versions of actual mathematical software.

A System Computational Model of Implicit Emotional Learning

PubMed Central

Puviani, Luca; Rama, Sidita

2016-01-01

Nowadays, the experimental study of emotional learning is commonly based on classical conditioning paradigms and models, which have been thoroughly investigated in the last century. Unluckily, models based on classical conditioning are unable to explain or predict important psychophysiological phenomena, such as the failure of the extinction of emotional responses in certain circumstances (for instance, those observed in evaluative conditioning, in post-traumatic stress disorders and in panic attacks). In this manuscript, starting from the experimental results available from the literature, a computational model of implicit emotional learning based both on prediction errors computation and on statistical inference is developed. The model quantitatively predicts (a) the occurrence of evaluative conditioning, (b) the dynamics and the resistance-to-extinction of the traumatic emotional responses, (c) the mathematical relation between classical conditioning and unconditioned stimulus revaluation. Moreover, we discuss how the derived computational model can lead to the development of new animal models for resistant-to-extinction emotional reactions and novel methodologies of emotions modulation. PMID:27378898

A System Computational Model of Implicit Emotional Learning.

PubMed

Puviani, Luca; Rama, Sidita

2016-01-01

Nowadays, the experimental study of emotional learning is commonly based on classical conditioning paradigms and models, which have been thoroughly investigated in the last century. Unluckily, models based on classical conditioning are unable to explain or predict important psychophysiological phenomena, such as the failure of the extinction of emotional responses in certain circumstances (for instance, those observed in evaluative conditioning, in post-traumatic stress disorders and in panic attacks). In this manuscript, starting from the experimental results available from the literature, a computational model of implicit emotional learning based both on prediction errors computation and on statistical inference is developed. The model quantitatively predicts (a) the occurrence of evaluative conditioning, (b) the dynamics and the resistance-to-extinction of the traumatic emotional responses, (c) the mathematical relation between classical conditioning and unconditioned stimulus revaluation. Moreover, we discuss how the derived computational model can lead to the development of new animal models for resistant-to-extinction emotional reactions and novel methodologies of emotions modulation.

Disruption of trace conditioning of the nictitating membrane response in rabbits by central cholinergic blockade.

PubMed

Kaneko, T; Thompson, R F

1997-05-01

Central muscarinic cholinergic involvement in classical conditioning of eyeblink responses was determined in trace and delay paradigms. Rabbits were trained on a trace procedure in which a 250-ms tone conditioned stimulus (CS) and a 100-ms air-puff unconditioned stimulus (UCS) were presented with a 500-ms trace interval. Each training session day consisted of ten tone alone, ten air-puff alone and 80 paired CS-UCS trials. Scopolamine hydrochloride at doses of 0.03 and 0.1 mg/0.5 ml per kg, s.c. dose-dependently disrupted acquisition of conditioned responses. Rabbits that were treated with scopolamine and failed to learn showed a gradual increase in conditioned responses during an additional training period with saline injections and no transfer from earlier training. Scopolamine methyl bromide, which does not appreciably cross the blood-brain barrier, showed no effects in the trace conditioning paradigm at a dose of 0.1 mg/kg, s.c., indicating central cholinergic blockade is responsible for the suppressive effect of scopolamine. Scopolamine hydrochloride at a dose of 0.1 mg/kg, s.c. did not block acquisition in the delay procedure with a 250-ms inter-stimulus interval, although the rate of acquisition was somewhat reduced by the drug. These data are the first to demonstrate that classical conditioning of the eyeblink response in the trace procedure is highly sensitive to central cholinergic deficits.

Children's Preference for Stimuli Associated with Being Imitated.

ERIC Educational Resources Information Center

Parton, David A.; Priefert, Maria J.

Forty-eight preschool children were run under a classical conditioning paradigm in which some neutral stimuli were repeatedly associated with an adult matching the behavior of the subject, and other neutral stimuli were associated with the same adult mismatching the behavior of the subject. Preference for the stimuli associated with being matched…

Spatio-temporal dynamics of brain mechanisms in aversive classical conditioning: high-density event-related potential and brain electrical tomography analyses.

PubMed

Pizzagalli, Diego A; Greischar, Lawrence L; Davidson, Richard J

2003-01-01

Social cognition, including complex social judgments and attitudes, is shaped by individual learning experiences, where affect often plays a critical role. Aversive classical conditioning-a form of associative learning involving a relationship between a neutral event (conditioned stimulus, CS) and an aversive event (unconditioned stimulus, US)-represents a well-controlled paradigm to study how the acquisition of socially relevant knowledge influences behavior and the brain. Unraveling the temporal unfolding of brain mechanisms involved appears critical for an initial understanding about how social cognition operates. Here, 128-channel ERPs were recorded in 50 subjects during the acquisition phase of a differential aversive classical conditioning paradigm. The CS+ (two fearful faces) were paired 50% of the time with an aversive noise (CS upward arrow + /Paired), whereas in the remaining 50% they were not (CS upward arrow + /Unpaired); the CS- (two different fearful faces) were never paired with the noise. Scalp ERP analyses revealed differences between CS upward arrow + /Unpaired and CS- as early as approximately 120 ms post-stimulus. Tomographic source localization analyses revealed early activation modulated by the CS+ in the ventral visual pathway (e.g. fusiform gyrus, approximately 120 ms), right middle frontal gyrus (approximately 176 ms), and precuneus (approximately 240 ms). At approximately 120 ms, the CS- elicited increased activation in the left insula and left middle frontal gyrus. These findings not only confirm a critical role of prefrontal, insular, and precuneus regions in aversive conditioning, but they also suggest that biologically and socially salient information modulates activation at early stages of the information processing flow, and thus furnish initial insight about how affect and social judgments operate.

Exploring the relationship between object realism and object-based attention effects.

PubMed

Roque, Nelson; Boot, Walter R

2015-09-01

Visual attention prioritizes processing of locations in space, and evidence also suggests that the benefits of attention can be shaped by the presence of objects (object-based attention). However, the prevalence of object-based attention effects has been called into question recently by evidence from a large-sampled study employing classic attention paradigms (Pilz et al., 2012). We conducted two experiments to explore factors that might determine when and if object-based attention effects are observed, focusing on the degree to which the concreteness and realism of objects might contribute to these effects. We adapted the classic attention paradigm first reported by Egly, Driver, and Rafal (1994) by replacing abstract bar stimuli in some conditions with objects that were more concrete and familiar to participants: items of silverware. Furthermore, we varied the realism of these items of silverware, presenting either cartoon versions or photo-realistic versions. Contrary to predictions, increased realism did not increase the size of object-based effects. In fact, no clear object-based effects were observed in either experiment, consistent with previous failures to replicate these effects in similar paradigms. While object-based attention may exist, and may have important influences on how we parse the visual world, these and other findings suggest that the two-object paradigm typically relied upon to study object-based effects may not be the best paradigm to investigate these issues. Copyright © 2015 Elsevier B.V. All rights reserved.

THE EFFECTS OF SEVERAL VERBAL PRETRAINING CONDITIONS ON PRESCHOOL CHILDREN'S TRANSFER IN PROBLEM SOLVING. FINAL REPORT.

ERIC Educational Resources Information Center

BERNHEIM, GLORIA D.

THREE- AND 4-YEAR-OLDS WERE GIVEN VERBAL LEARNING PRETRAINING TO DETERMINE ITS EFFECT UPON THE PERFORMANCE OF REVERSAL AND NONREVERSAL SHIFT DISCRIMINATION TASKS. THE EXPERIMENTAL TASK WAS THE CLASSICAL REVERSAL-NONREVERSAL SHIFT PARADIGM. THE 96 PRE-SCHOOLERS, PRIMARILY FROM THE PENNSYLVANIA STATE UNIVERSITY NURSERY SCHOOL, WERE DIVIDED INTO 4…

Planckian charged black holes in ultraviolet self-complete quantum gravity

NASA Astrophysics Data System (ADS)

Nicolini, Piero

2018-03-01

We present an analysis of the role of the charge within the self-complete quantum gravity paradigm. By studying the classicalization of generic ultraviolet improved charged black hole solutions around the Planck scale, we showed that the charge introduces important differences with respect to the neutral case. First, there exists a family of black hole parameters fulfilling the particle-black hole condition. Second, there is no extremal particle-black hole solution but quasi extremal charged particle-black holes at the best. We showed that the Hawking emission disrupts the condition of particle-black hole. By analyzing the Schwinger pair production mechanism, the charge is quickly shed and the particle-black hole condition can ultimately be restored in a cooling down phase towards a zero temperature configuration, provided non-classical effects are taken into account.

A Role of Protein Degradation in Memory Consolidation after Initial Learning and Extinction Learning in the Honeybee ("Apis mellifera")

ERIC Educational Resources Information Center

Felsenberg, Johannes; Dombrowski, Vincent; Eisenhardt, Dorothea

2012-01-01

Protein degradation is known to affect memory formation after extinction learning. We demonstrate here that an inhibitor of protein degradation, MG132, interferes with memory formation after extinction learning in a classical appetitive conditioning paradigm. In addition, we find an enhancement of memory formation when the same inhibitor is…

The Role of Orthographic Analogies in Reading for Meaning: Evidence from Readers with Dyslexia

ERIC Educational Resources Information Center

Humphrey, Neil; Richard Hanley, J.

2004-01-01

The aim of this experiment was to investigate the use of orthographic analogies in conditions that involved making sense of print (picture-word matching) and pronouncing print (reading aloud) for readers with dyslexia. An adapted version of the classic clue-word paradigm developed by Goswami was used. Participants were 40 readers with dyslexia and…

Transfer of classical eyeblink conditioning with electrical stimulation of mPFC or tone as conditioned stimulus in guinea pigs.

PubMed

Yao, Juan; Wu, Guang-Yan; Liu, Guo-Long; Liu, Shu-Lei; Yang, Yi; Wu, Bing; Li, Xuan; Feng, Hua; Sui, Jian-Feng

2014-11-01

Learning with a stimulus from one sensory modality can facilitate subsequent learning with a new stimulus from a different sensory modality. To date, the characteristics and mechanism of this phenomenon named transfer effect still remain ambiguous. Our previous work showed that electrical stimulation of medial prefrontal cortex (mPFC) as a conditioned stimulus (CS) could successfully establish classical eyeblink conditioning (EBC). The present study aimed to (1) observe whether transfer of EBC learning would occur when CSs shift between central (mPFC electrical stimulation as a CS, mPFC-CS) and peripheral (tone as a CS, tone CS); (2) compare the difference in transfer effect between the two paradigms, delay EBC (DEBC) and trace EBC (TEBC). A total of 8 groups of guinea pigs were tested in the study, including 4 experimental groups and 4 control groups. Firstly, the experimental groups accepted central (or peripheral) CS paired with corneal airpuff unconditioned stimulus (US); then, CS shifted to the peripheral (or central) and paired with US. The control groups accepted corresponding central (or peripheral) CS and pseudo-paired with US, and then shifted CS from central (or peripheral) to peripheral (or central) and paired with US. The results showed that the acquisition rates of EBC were higher in experimental groups than in control groups after CS switching from central to peripheral or vice versa, and the CR acquisition rate was remarkably higher in DEBC than in TEBC in both transfer ways. The results indicate that EBC transfer can occur between learning established with mPFC-CS and tone CS. Memory of CS-US association for delay paradigm was less disturbed by the sudden switch of CS than for trace paradigm. This study provides new insight into neural mechanisms underlying conditioned reflex as well as the role of mPFC. Copyright © 2014 Elsevier B.V. All rights reserved.

Weaker cognitive control abilities of Pi (Spleen) qi-deficient individuals supported Chinese medicine diagnosis.

PubMed

Lin, Hui-Yan; Zhao, Yan-Ping; Xu, Gui-Ping; Li, Yun-Si; Xie, Wei-Yun; Bai, Li-Hua; Jin, Hua

2017-07-28

To investigate whether Pi (Spleen) qi-deficiency affected psychological and neural responses in relevance to cognitive control. Pi qi-deficient and balanced participants were asked to perform the Stroop task, a classical cognitive control paradigm. In this paradigm, participants had to judge the color of the prompted word. The word's meaning indicated the color (the consistent condition) or not (the inconsistent condition), or were unrelated to the color (the neutral condition). Electroencephalograph (EEG) was recorded during the task. Event-related potential (ERP) results showed that Pi qi-deficient individuals failed to exhibit a normal Stroop effect as Balanced individuals did, such as the accuracy differences between the consistent and the inconsistent conditions as well as the N450 effect (P>0.05). Meanwhile, Pi qi-deficient individuals displayed larger P2 and P3 amplitudes than balanced individuals did during performing the cognitive control task (P<0.05). Pi qi-deficiency had psychological and neural basis at least in cognitive control aspect.

An embodied biologically constrained model of foraging: from classical and operant conditioning to adaptive real-world behavior in DAC-X.

PubMed

Maffei, Giovanni; Santos-Pata, Diogo; Marcos, Encarni; Sánchez-Fibla, Marti; Verschure, Paul F M J

2015-12-01

Animals successfully forage within new environments by learning, simulating and adapting to their surroundings. The functions behind such goal-oriented behavior can be decomposed into 5 top-level objectives: 'how', 'why', 'what', 'where', 'when' (H4W). The paradigms of classical and operant conditioning describe some of the behavioral aspects found in foraging. However, it remains unclear how the organization of their underlying neural principles account for these complex behaviors. We address this problem from the perspective of the Distributed Adaptive Control theory of mind and brain (DAC) that interprets these two paradigms as expressing properties of core functional subsystems of a layered architecture. In particular, we propose DAC-X, a novel cognitive architecture that unifies the theoretical principles of DAC with biologically constrained computational models of several areas of the mammalian brain. DAC-X supports complex foraging strategies through the progressive acquisition, retention and expression of task-dependent information and associated shaping of action, from exploration to goal-oriented deliberation. We benchmark DAC-X using a robot-based hoarding task including the main perceptual and cognitive aspects of animal foraging. We show that efficient goal-oriented behavior results from the interaction of parallel learning mechanisms accounting for motor adaptation, spatial encoding and decision-making. Together, our results suggest that the H4W problem can be solved by DAC-X building on the insights from the study of classical and operant conditioning. Finally, we discuss the advantages and limitations of the proposed biologically constrained and embodied approach towards the study of cognition and the relation of DAC-X to other cognitive architectures. Copyright © 2015 Elsevier Ltd. All rights reserved.

Facing Challenges in Differential Classical Conditioning Research: Benefits of a Hybrid Design for Simultaneous Electrodermal and Electroencephalographic Recording.

PubMed

Pastor, M Carmen; Rehbein, Maimu Alissa; Junghöfer, Markus; Poy, Rosario; López, Raul; Moltó, Javier

2015-01-01

Several challenges make it difficult to simultaneously investigate central and autonomous nervous system correlates of conditioned stimulus (CS) processing in classical conditioning paradigms. Such challenges include, for example, the discrepant requirements of electroencephalography (EEG) and electrodermal activity (EDA) recordings with regard to multiple repetitions of conditions and sufficient trial duration. Here, we propose a MultiCS conditioning set-up, in which we increased the number of CSs, decreased the number of learning trials, and used trials of short and long durations for meeting requirements of simultaneous EEG-EDA recording in a differential aversive conditioning task. Forty-eight participants underwent MultiCS conditioning, in which four neutral faces (CS+) were paired four times each with aversive electric stimulation (unconditioned stimulus) during acquisition, while four different neutral faces (CS-) remained unpaired. When comparing after relative to before learning measurements, EEG revealed an enhanced centro-posterior positivity to CS+ vs. CS- during 368-600 ms, and subjective ratings indicated CS+ to be less pleasant and more arousing than CS-. Furthermore, changes in CS valence and arousal were strong enough to bias subjective ratings when faces of CS+/CS- identity were displayed with different emotional expression (happy, angry) in a post-experimental behavioral task. In contrast to a persistent neural and evaluative CS+/CS- differentiation that sustained multiple unreinforced CS presentations, electrodermal differentiation was rapidly extinguished. Current results suggest that MultiCS conditioning provides a promising paradigm for investigating pre-post-learning changes under minimal influences of extinction and overlearning of simple stimulus features. Our data also revealed methodological pitfalls, such as the possibility of occurring artifacts when combining different acquisition systems for central and peripheral psychophysiological measures.

Facing Challenges in Differential Classical Conditioning Research: Benefits of a Hybrid Design for Simultaneous Electrodermal and Electroencephalographic Recording

PubMed Central

Pastor, M. Carmen; Rehbein, Maimu Alissa; Junghöfer, Markus; Poy, Rosario; López, Raul; Moltó, Javier

2015-01-01

Several challenges make it difficult to simultaneously investigate central and autonomous nervous system correlates of conditioned stimulus (CS) processing in classical conditioning paradigms. Such challenges include, for example, the discrepant requirements of electroencephalography (EEG) and electrodermal activity (EDA) recordings with regard to multiple repetitions of conditions and sufficient trial duration. Here, we propose a MultiCS conditioning set-up, in which we increased the number of CSs, decreased the number of learning trials, and used trials of short and long durations for meeting requirements of simultaneous EEG–EDA recording in a differential aversive conditioning task. Forty-eight participants underwent MultiCS conditioning, in which four neutral faces (CS+) were paired four times each with aversive electric stimulation (unconditioned stimulus) during acquisition, while four different neutral faces (CS−) remained unpaired. When comparing after relative to before learning measurements, EEG revealed an enhanced centro-posterior positivity to CS+ vs. CS− during 368–600 ms, and subjective ratings indicated CS+ to be less pleasant and more arousing than CS−. Furthermore, changes in CS valence and arousal were strong enough to bias subjective ratings when faces of CS+/CS− identity were displayed with different emotional expression (happy, angry) in a post-experimental behavioral task. In contrast to a persistent neural and evaluative CS+/CS− differentiation that sustained multiple unreinforced CS presentations, electrodermal differentiation was rapidly extinguished. Current results suggest that MultiCS conditioning provides a promising paradigm for investigating pre–post-learning changes under minimal influences of extinction and overlearning of simple stimulus features. Our data also revealed methodological pitfalls, such as the possibility of occurring artifacts when combining different acquisition systems for central and peripheral psychophysiological measures. PMID:26106318

Reduction in spontaneous firing of mouse excitatory layer 4 cortical neurons following visual classical conditioning

NASA Astrophysics Data System (ADS)

Bekisz, Marek; Shendye, Ninad; Raciborska, Ida; Wróbel, Andrzej; Waleszczyk, Wioletta J.

2017-08-01

The process of learning induces plastic changes in neuronal network of the brain. Our earlier studies on mice showed that classical conditioning in which monocular visual stimulation was paired with an electric shock to the tail enhanced GABA immunoreactivity within layer 4 of the monocular part of the primary visual cortex (V1), contralaterally to the stimulated eye. In the present experiment we investigated whether the same classical conditioning paradigm induces changes of neuronal excitability in this cortical area. Two experimental groups were used: mice that underwent 7-day visual classical conditioning and controls. Patch-clamp whole-cell recordings were performed from ex vivo slices of mouse V1. The slices were perfused with the modified artificial cerebrospinal fluid, the composition of which better mimics the brain interstitial fluid in situ and induces spontaneous activity. The neuronal excitability was characterized by measuring the frequency of spontaneous action potentials. We found that layer 4 star pyramidal cells located in the monocular representation of the "trained" eye in V1 had lower frequency of spontaneous activity in comparison with neurons from the same cortical region of control animals. Weaker spontaneous firing indicates decreased general excitability of star pyramidal neurons within layer 4 of the monocular representation of the "trained" eye in V1. Such effect could result from enhanced inhibitory processes accompanying learning in this cortical area.

Neural correlates of olfactory learning paradigms in an identified neuron in the honeybee brain.

PubMed

Mauelshagen, J

1993-02-01

1. Sensitization and classical odor conditioning of the proboscis extension reflex were functionally analyzed by repeated intracellular recordings from a single identified neuron (PE1-neuron) in the central bee brain. This neuron belongs to the class of "extrinsic cells" arising from the pedunculus of the mushroom bodies and has extensive arborizations in the median and lateral protocerebrum. The recordings were performed on isolated bee heads. 2. Two different series of physiological experiments were carried out with the use of a similar temporal succession of stimuli as in previous behavioral experiments. In the first series, one group of animals was used for a single conditioning trial [conditioned stimulus (CS), carnation; unconditioned stimulus (US), sucrose solution to the antennae and proboscis), a second group was used for sensitization (sensitizing stimulus, sucrose solution to the antennae and/or proboscis), and the third group served as control (no sucrose stimulation). In the second series, a differential conditioning paradigm (paired odor CS+, carnation; unpaired odor CS-, orange blossom) was applied to test the associative nature of the conditioning effect. 3. The PE1-neuron showed a characteristic burstlike odor response before the training procedures. The treatments resulted in different spike-frequency modulations of this response, which were specific for the nonassociative and associative stimulus paradigms applied. During differential conditioning, there are dynamic up and down modulations of spike frequencies and of the DC potentials underlying the responses to the CS+. Overall, only transient changes in the minute range were observed. 4. The results of the sensitization procedures suggest two qualitatively different US pathways. The comparison between sensitization and one-trial conditioning shows differential effects of nonassociative and associative stimulus paradigms on the response behavior of the PE1-neuron. The results of the differential conditioning procedure reveal that the effect observed for the one-trial conditioning paradigm is of an associative nature and that there might be modulations, which are specific for single and multiple trial conditioning procedures. It is hypothesized that the PE1-neuron is a possible element involved in the short-term acquisition, rather than in the long-term storage, of an associative olfactory memory in the honeybee.

A Gaze Independent Brain-Computer Interface Based on Visual Stimulation through Closed Eyelids

NASA Astrophysics Data System (ADS)

Hwang, Han-Jeong; Ferreria, Valeria Y.; Ulrich, Daniel; Kilic, Tayfun; Chatziliadis, Xenofon; Blankertz, Benjamin; Treder, Matthias

2015-10-01

A classical brain-computer interface (BCI) based on visual event-related potentials (ERPs) is of limited application value for paralyzed patients with severe oculomotor impairments. In this study, we introduce a novel gaze independent BCI paradigm that can be potentially used for such end-users because visual stimuli are administered on closed eyelids. The paradigm involved verbally presented questions with 3 possible answers. Online BCI experiments were conducted with twelve healthy subjects, where they selected one option by attending to one of three different visual stimuli. It was confirmed that typical cognitive ERPs can be evidently modulated by the attention of a target stimulus in eyes-closed and gaze independent condition, and further classified with high accuracy during online operation (74.58% ± 17.85 s.d.; chance level 33.33%), demonstrating the effectiveness of the proposed novel visual ERP paradigm. Also, stimulus-specific eye movements observed during stimulation were verified as reflex responses to light stimuli, and they did not contribute to classification. To the best of our knowledge, this study is the first to show the possibility of using a gaze independent visual ERP paradigm in an eyes-closed condition, thereby providing another communication option for severely locked-in patients suffering from complex ocular dysfunctions.

Signed reward prediction errors drive declarative learning

PubMed Central

Naert, Lien; Janssens, Clio; Talsma, Durk; Van Opstal, Filip; Verguts, Tom

2018-01-01

Reward prediction errors (RPEs) are thought to drive learning. This has been established in procedural learning (e.g., classical and operant conditioning). However, empirical evidence on whether RPEs drive declarative learning–a quintessentially human form of learning–remains surprisingly absent. We therefore coupled RPEs to the acquisition of Dutch-Swahili word pairs in a declarative learning paradigm. Signed RPEs (SRPEs; “better-than-expected” signals) during declarative learning improved recognition in a follow-up test, with increasingly positive RPEs leading to better recognition. In addition, classic declarative memory mechanisms such as time-on-task failed to explain recognition performance. The beneficial effect of SRPEs on recognition was subsequently affirmed in a replication study with visual stimuli. PMID:29293493

Signed reward prediction errors drive declarative learning.

PubMed

De Loof, Esther; Ergo, Kate; Naert, Lien; Janssens, Clio; Talsma, Durk; Van Opstal, Filip; Verguts, Tom

2018-01-01

Reward prediction errors (RPEs) are thought to drive learning. This has been established in procedural learning (e.g., classical and operant conditioning). However, empirical evidence on whether RPEs drive declarative learning-a quintessentially human form of learning-remains surprisingly absent. We therefore coupled RPEs to the acquisition of Dutch-Swahili word pairs in a declarative learning paradigm. Signed RPEs (SRPEs; "better-than-expected" signals) during declarative learning improved recognition in a follow-up test, with increasingly positive RPEs leading to better recognition. In addition, classic declarative memory mechanisms such as time-on-task failed to explain recognition performance. The beneficial effect of SRPEs on recognition was subsequently affirmed in a replication study with visual stimuli.

Using an abstract geometry in virtual reality to explore choice behaviour: visual flicker preferences in honeybees.

PubMed

Van De Poll, Matthew N; Zajaczkowski, Esmi L; Taylor, Gavin J; Srinivasan, Mandyam V; van Swinderen, Bruno

2015-11-01

Closed-loop paradigms provide an effective approach for studying visual choice behaviour and attention in small animals. Different flying and walking paradigms have been developed to investigate behavioural and neuronal responses to competing stimuli in insects such as bees and flies. However, the variety of stimulus choices that can be presented over one experiment is often limited. Current choice paradigms are mostly constrained as single binary choice scenarios that are influenced by the linear structure of classical conditioning paradigms. Here, we present a novel behavioural choice paradigm that allows animals to explore a closed geometry of interconnected binary choices by repeatedly selecting among competing objects, thereby revealing stimulus preferences in an historical context. We used our novel paradigm to investigate visual flicker preferences in honeybees (Apis mellifera) and found significant preferences for 20-25 Hz flicker and avoidance of higher (50-100 Hz) and lower (2-4 Hz) flicker frequencies. Similar results were found when bees were presented with three simultaneous choices instead of two, and when they were given the chance to select previously rejected choices. Our results show that honeybees can discriminate among different flicker frequencies and that their visual preferences are persistent even under different experimental conditions. Interestingly, avoided stimuli were more attractive if they were novel, suggesting that novelty salience can override innate preferences. Our recursive virtual reality environment provides a new approach to studying visual discrimination and choice behaviour in animals. © 2015. Published by The Company of Biologists Ltd.

Object-location training elicits an overlapping but temporally distinct transcriptional profile from contextual fear conditioning.

PubMed

Poplawski, Shane G; Schoch, Hannah; Wimmer, Mathieu; Hawk, Joshua D; Walsh, Jennifer L; Giese, Karl P; Abel, Ted

2014-12-01

Hippocampus-dependent learning is known to induce changes in gene expression, but information on gene expression differences between different learning paradigms that require the hippocampus is limited. The bulk of studies investigating RNA expression after learning use the contextual fear conditioning task, which couples a novel environment with a footshock. Although contextual fear conditioning has been useful in discovering gene targets, gene expression after spatial memory tasks has received less attention. In this study, we used the object-location memory task and studied gene expression at two time points after learning in a high-throughput manner using a microfluidic qPCR approach. We found that expression of the classic immediate-early genes changes after object-location training in a fashion similar to that observed after contextual fear conditioning. However, the temporal dynamics of gene expression are different between the two tasks, with object-location memory producing gene expression changes that last at least 2 hours. Our findings indicate that different training paradigms may give rise to distinct temporal dynamics of gene expression after learning. Copyright © 2014 Elsevier Inc. All rights reserved.

Object-Location Training Elicits an Overlapping but Temporally Distinct Transcriptional Profile from Contextual Fear Conditioning

PubMed Central

Wimmer, Mathieu; Hawk, Joshua D.; Walsh, Jennifer L.; Giese, Karl P.; Abel, Ted

2014-01-01

Hippocampus-dependent learning is known to induce changes in gene expression, but information on gene expression differences between different learning paradigms that require the hippocampus is limited. The bulk of studies investigating RNA expression after learning use the contextual fear conditioning task, which couples a novel environment with a footshock. Although contextual fear conditioning has been useful in discovering gene targets, gene expression after spatial memory tasks has received less attention. In this study, we used the object-location memory task and studied gene expression at two time points after learning in a high-throughput manner using a microfluidic qPCR approach. We found that expression of the classic immediate-early genes changes after object-location training in a fashion similar to that observed after contextual fear conditioning. However, the temporal dynamics of gene expression are different between the two tasks, with object-location memory producing gene expression changes that last at least 2 hours. Our findings indicate that different training paradigms may give rise to distinct temporal dynamics of gene expression after learning. PMID:25242102

Performance improvement of ERP-based brain-computer interface via varied geometric patterns.

PubMed

Ma, Zheng; Qiu, Tianshuang

2017-12-01

Recently, many studies have been focusing on optimizing the stimulus of an event-related potential (ERP)-based brain-computer interface (BCI). However, little is known about the effectiveness when increasing the stimulus unpredictability. We investigated a new stimulus type of varied geometric pattern where both complexity and unpredictability of the stimulus are increased. The proposed and classical paradigms were compared in within-subject experiments with 16 healthy participants. Results showed that the BCI performance was significantly improved for the proposed paradigm, with an average online written symbol rate increasing by 138% comparing with that of the classical paradigm. Amplitudes of primary ERP components, such as N1, P2a, P2b, N2, were also found to be significantly enhanced with the proposed paradigm. In this paper, a novel ERP BCI paradigm with a new stimulus type of varied geometric pattern is proposed. By jointly increasing the complexity and unpredictability of the stimulus, the performance of an ERP BCI could be considerably improved.

Ontogeny of classical and operant learning behaviors in zebrafish.

PubMed

Valente, André; Huang, Kuo-Hua; Portugues, Ruben; Engert, Florian

2012-03-20

The performance of developing zebrafish in both classical and operant conditioning assays was tested with a particular focus on the emergence of these learning behaviors during development. Strategically positioned visual cues paired with electroshocks were used in two fully automated assays to investigate both learning paradigms. These allow the evaluation of the behavioral performance of zebrafish continuously throughout development, from larva to adult. We found that learning improves throughout development, starts reliably around week 3, and reaches adult performance levels at week 6. Adult fish quickly learned to perform perfectly, and the expression of the learned behavior is manifestly controlled by vision. The memory is behaviorally expressed in adults for at least 6 h and retrievable for at least 12 h.

Ontogeny of classical and operant learning behaviors in zebrafish

PubMed Central

Valente, André; Huang, Kuo-Hua; Portugues, Ruben; Engert, Florian

2012-01-01

The performance of developing zebrafish in both classical and operant conditioning assays was tested with a particular focus on the emergence of these learning behaviors during development. Strategically positioned visual cues paired with electroshocks were used in two fully automated assays to investigate both learning paradigms. These allow the evaluation of the behavioral performance of zebrafish continuously throughout development, from larva to adult. We found that learning improves throughout development, starts reliably around week 3, and reaches adult performance levels at week 6. Adult fish quickly learned to perform perfectly, and the expression of the learned behavior is manifestly controlled by vision. The memory is behaviorally expressed in adults for at least 6 h and retrievable for at least 12 h. PMID:22434824

Asymptotic state discrimination and a strict hierarchy in distinguishability norms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chitambar, Eric; Hsieh, Min-Hsiu

2014-11-15

In this paper, we consider the problem of discriminating quantum states by local operations and classical communication (LOCC) when an arbitrarily small amount of error is permitted. This paradigm is known as asymptotic state discrimination, and we derive necessary conditions for when two multipartite states of any size can be discriminated perfectly by asymptotic LOCC. We use this new criterion to prove a gap in the LOCC and separable distinguishability norms. We then turn to the operational advantage of using two-way classical communication over one-way communication in LOCC processing. With a simple two-qubit product state ensemble, we demonstrate a strictmore » majorization of the two-way LOCC norm over the one-way norm.« less

Electrical stimulation of the rostral medial prefrontal cortex in rabbits inhibits the expression of conditioned eyelid responses but not their acquisition

PubMed Central

Leal-Campanario, Rocío; Fairén, Alfonso; Delgado-García, José M.; Gruart, Agnès

2007-01-01

We have studied the role of rostral medial prefrontal cortex (mPFC) on reflexively evoked blinks and on classically conditioned eyelid responses in alert-behaving rabbits. The rostral mPFC was identified by its afferent projections from the medial half of the thalamic mediodorsal nuclear complex. Classical conditioning consisted of a delay paradigm using a 370-ms tone as the conditioned stimulus (CS) and a 100-ms air puff directed at the left cornea as the unconditioned stimulus (US). The CS coterminated with the US. Electrical train stimulation of the contralateral rostral mPFC produced a significant inhibition of air-puff-evoked blinks. The same train stimulation of the rostral mPFC presented during the CS–US interval for 10 successive conditioning sessions significantly reduced the generation of conditioned responses (CRs) as compared with values reached by control animals. Interestingly, the percentage of CRs almost reached control values when train stimulation of the rostral mPFC was removed from the fifth conditioning session on. The electrical stimulation of the rostral mPFC in well conditioned animals produced a significant decrease in the percentage of CRs. Moreover, the stimulation of the rostral mPFC was also able to modify the kinematics (latency, amplitude, and velocity) of evoked CRs. These results suggest that the rostral mPFC is a potent inhibitor of reflexively evoked and classically conditioned eyeblinks but that activation prevents only the expression of CRs, not their latent acquisition. Functional and behavioral implications of this inhibitory role of the rostral mPFC are discussed. PMID:17592148

Donders revisited: Discrete or continuous temporal processing underlying reaction time distributions?

PubMed

Bao, Yan; Yang, Taoxi; Lin, Xiaoxiong; Pöppel, Ernst

2016-09-01

Differences of reaction times to specific stimulus configurations are used as indicators of cognitive processing stages. In this classical experimental paradigm, continuous temporal processing is implicitly assumed. Multimodal response distributions indicate, however, discrete time sampling, which is often masked by experimental conditions. Differences in reaction times reflect discrete temporal mechanisms that are pre-semantically implemented and suggested to be based on entrained neural oscillations. © 2016 The Institute of Psychology, Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Giorgio Agamben and the Abandonment Paradigm: A New Form of Student Diversion in Public Higher Education

ERIC Educational Resources Information Center

Harbour, Clifford P.; Wolgemuth, Jennifer R.

2013-01-01

This article proposes a new paradigm to understand recent government policies that pose new barriers to student participation and divert students out of public higher education. We explain how the classic diversion paradigm, exemplified by Clark (1960) and Brint and Karabel (1989), is unable to account for this new form of student diversion. We…

From Phosphorous to Arsenic: Changing the Classic Paradigm for the Structure of Biomolecules

PubMed Central

Knodle, Ryan; Agarwal, Pratima; Brown, Mark

2012-01-01

Biomolecules are composed primarily of the elements carbon, nitrogen, hydrogen, oxygen, sulfur, and phosphorus. The structured assembly of these elements forms the basis for proteins, nucleic acids and lipids. However, the recent discovery of a new bacterium, strain GFAJ-1 of the Halomonadaceae, has shaken the classic paradigms for the architecture of life. Mounting evidence supports the claim that these bacteria substitute arsenic for phosphorus in macromolecules. Herein, we provide a brief commentary and fuel the debate related to what may be a most unusual organism. PMID:24970138

From phosphorous to arsenic: changing the classic paradigm for the structure of biomolecules.

PubMed

Knodle, Ryan; Agarwal, Pratima; Brown, Mark

2012-05-30

Biomolecules are composed primarily of the elements carbon, nitrogen, hydrogen, oxygen, sulfur, and phosphorus. The structured assembly of these elements forms the basis for proteins, nucleic acids and lipids. However, the recent discovery of a new bacterium, strain GFAJ-1 of the Halomonadaceae, has shaken the classic paradigms for the architecture of life. Mounting evidence supports the claim that these bacteria substitute arsenic for phosphorus in macromolecules. Herein, we provide a brief commentary and fuel the debate related to what may be a most unusual organism.

Mixed-handedness advantages in episodic memory obtained under conditions of intentional learning extend to incidental learning.

PubMed

Christman, Stephen D; Butler, Michael

2011-10-01

The existence of handedness differences in the retrieval of episodic memories is well-documented, but virtually all have been obtained under conditions of intentional learning. Two experiments are reported that extend the presence of such handedness differences to memory retrieval under conditions of incidental learning. Experiment 1 used Craik and Tulving's (1975) classic levels-of-processing paradigm and obtained handedness differences under incidental and intentional conditions of deep processing, but not under conditions of shallow incidental processing. Experiment 2 looked at incidental memory for distracter items from a recognition memory task and again found a mixed-handed advantage. Results are discussed in terms of the relation between interhemispheric interaction, levels of processing, and episodic memory retrieval. Copyright © 2011 Elsevier Inc. All rights reserved.

Why trace and delay conditioning are sometimes (but not always) hippocampal dependent: A computational model

PubMed Central

Moustafa, Ahmed A.; Wufong, Ella; Servatius, Richard J.; Pang, Kevin C. H.; Gluck, Mark A.; Myers, Catherine E.

2013-01-01

A recurrent-network model provides a unified account of the hippocampal region in mediating the representation of temporal information in classical eyeblink conditioning. Much empirical research is consistent with a general conclusion that delay conditioning (in which the conditioned stimulus CS and unconditioned stimulus US overlap and co-terminate) is independent of the hippocampal system, while trace conditioning (in which the CS terminates before US onset) depends on the hippocampus. However, recent studies show that, under some circumstances, delay conditioning can be hippocampal-dependent and trace conditioning can be spared following hippocampal lesion. Here, we present an extension of our prior trial-level models of hippocampal function and stimulus representation that can explain these findings within a unified framework. Specifically, the current model includes adaptive recurrent collateral connections that aid in the representation of intra-trial temporal information. With this model, as in our prior models, we argue that the hippocampus is not specialized for conditioned response timing, but rather is a general-purpose system that learns to predict the next state of all stimuli given the current state of variables encoded by activity in recurrent collaterals. As such, the model correctly predicts that hippocampal involvement in classical conditioning should be critical not only when there is an intervening trace interval, but also when there is a long delay between CS onset and US onset. Our model simulates empirical data from many variants of classical conditioning, including delay and trace paradigms in which the length of the CS, the inter-stimulus interval, or the trace interval is varied. Finally, we discuss model limitations, future directions, and several novel empirical predictions of this temporal processing model of hippocampal function and learning. PMID:23178699

Predicting memory performance under conditions of proactive interference: immediate and delayed judgments of learning.

PubMed

Wahlheim, Christopher N

2011-07-01

Four experiments examined the monitoring accuracy of immediate and delayed judgments of learning (JOLs) under conditions of proactive interference (PI). PI was produced using paired-associate learning tasks that conformed to variations of classic A-B, A-D paradigms. Results revealed that the relative monitoring accuracy of interference items was better for delayed than for immediate JOLs. However, delayed JOLs were overconfident for interference items, but not for items devoid of interference. Intrusions retrieved prior to delayed JOLs produced inflated predictions of performance. These results show that delayed JOLs enhance monitoring accuracy in PI situations, except when intrusions are mistaken for target responses.

Kappa and Rater Accuracy: Paradigms and Parameters

ERIC Educational Resources Information Center

Conger, Anthony J.

2017-01-01

Drawing parallels to classical test theory, this article clarifies the difference between rater accuracy and reliability and demonstrates how category marginal frequencies affect rater agreement and Cohen's kappa. Category assignment paradigms are developed: comparing raters to a standard (index) versus comparing two raters to one another…

Autoshaping and paleostriatal lesions in the pigeon.

PubMed

Mitchell, J A

1983-07-01

Three experiments were conducted with the pigeon (Columbia livia) to investigate the effects of bilateral electrolytic lesions of the paleostriatum on classical conditioning paradigms. In Experiment 1 naive subjects were given autoshaping training to a white centre key light and it was found that paleostriatal pigeons showed higher peck rates than unoperated controls. A further group of naive paleostriatal pigeons showed higher rates of autoshaped responding but did not differ from controls on a successive autoshaping discrimination with colour (Experiment 2A) or striped (Experiment 2B) stimuli. In Experiment 3 paleostriatal pigeons performed better than controls on a go, no-go alternation. The higher response rates shown by paleostriatal pigeons during autoshaping could not readily be explained in terms of a (non-associative) motor disturbance such as a tremor which could have caused multiple key pecks to be emitted in view of the demonstrations of unimpaired discrimination (Experiment 2) and better alternation (Experiment 3). Instead, the results suggest that paleostriatal pigeons may show potentiated classical conditioning.

Vibrissae-evoked behavior and conditioning before functional ontogeny of the somatosensory vibrissae cortex.

PubMed

Landers, M S; Sullivan, R M

1999-06-15

The following experiments determined that the somatosensory whisker system is functional and capable of experience-dependent behavioral plasticity in the neonate before functional maturation of the somatosensory whisker cortex. First, unilateral whisker stimulation caused increased behavioral activity in both postnatal day (P) 3-4 and P8 pups, whereas stimulation-evoked cortical activity (14C 2-deoxyglucose autoradiography) was detectable only in P8 pups. Second, neonatal rat pups are capable of forming associations between whisker stimulation and a reinforcer. A classical conditioning paradigm (P3-P4) showed that the learning groups (paired whisker stimulation-shock or paired whisker stimulation-warm air stream) exhibited significantly higher behavioral responsiveness to whisker stimulation than controls. Finally, stimulus-evoked somatosensory cortical activity during testing [P8; using 14C 2-deoxyglucose (2-DG) autoradiography] was assessed after somatosensory conditioning from P1-P8. No learning-associated differences in stimulus-evoked cortical activity were detected between learning and nonlearning control groups. Together, these experiments demonstrate that the whisker system is functional in neonates and capable of experience-dependent behavioral plasticity. Furthermore, in contrast to adult somatosensory classical conditioning, these data suggest that the cortex is not required for associative somatosensory learning in neonates.

On the automatic activation of attitudes: a quarter century of evaluative priming research.

PubMed

Herring, David R; White, Katherine R; Jabeen, Linsa N; Hinojos, Michelle; Terrazas, Gabriela; Reyes, Stephanie M; Taylor, Jennifer H; Crites, Stephen L

2013-09-01

Evaluation is a fundamental concept in psychological science. Limitations of self-report measures of evaluation led to an explosion of research on implicit measures of evaluation. One of the oldest and most frequently used implicit measurement paradigms is the evaluative priming paradigm developed by Fazio, Sanbonmatsu, Powell, and Kardes (1986). This paradigm has received extensive attention in psychology and is used to investigate numerous phenomena ranging from prejudice to depression. The current review provides a meta-analysis of a quarter century of evaluative priming research: 73 studies yielding 125 independent effect sizes from 5,367 participants. Because judgments people make in evaluative priming paradigms can be used to tease apart underlying processes, this meta-analysis examined the impact of different judgments to test the classic encoding and response perspectives of evaluative priming. As expected, evidence for automatic evaluation was found, but the results did not exclusively support either of the classic perspectives. Results suggest that both encoding and response processes likely contribute to evaluative priming but are more nuanced than initially conceptualized by the classic perspectives. Additionally, there were a number of unexpected findings that influenced evaluative priming such as segmenting trials into discrete blocks. We argue that many of the findings of this meta-analysis can be explained with 2 recent evaluative priming perspectives: the attentional sensitization/feature-specific attention allocation and evaluation window perspectives. (c) 2013 APA, all rights reserved.

Decomposing Task-Switching Costs with the Diffusion Model

ERIC Educational Resources Information Center

Schmitz, Florian; Voss, Andreas

2012-01-01

In four experiments, task-switching processes were investigated with variants of the alternating runs paradigm and the explicit cueing paradigm. The classical diffusion model for binary decisions (Ratcliff, 1978) was used to dissociate different components of task-switching costs. Findings can be reconciled with the view that task-switching…

On the reality of the conjunction fallacy.

PubMed

Sides, Ashley; Osherson, Daniel; Bonini, Nicolao; Viale, Riccardo

2002-03-01

Attributing higher "probability" to a sentence of form p-and-q, relative to p, is a reasoning fallacy only if (1) the word probability carries its modern, technical meaning and (2) the sentence p is interpreted as a conjunct of the conjunction p-and-q. Legitimate doubts arise about both conditions in classic demonstrations of the conjunction fallacy. We used betting paradigms and unambiguously conjunctive statements to reduce these sources of ambiguity about conjunctive reasoning. Despite the precautions, conjunction fallacies were as frequent under betting instructions as under standard probability instructions.

Local classifiers for evoked potentials recorded from behaving rats.

PubMed

Jakuczun, Wit; Kublik, Ewa; Wójcik, Daniel K; Wróbel, Andrzej

2005-01-01

Dynamic states of the brain determine the way information is processed in local neural networks. We have applied classical conditioning paradigm in order to study whether habituated and aroused states can be differentiated in single barrel column of rat's somatosensory cortex by means of analysis of field potentials evoked by stimulation of a single vibrissa. A new method using local classifiers is presented which allows for reliable and meaningful classification of single evoked potentials which might be consequently attributed to different functional states of the cortical column.

An appraisal of the classic forest succession paradigm with the shade tolerance index

Treesearch

Jean Lienard; Ionut Florescu; Nikolay Strigul

2015-01-01

We revisit the classic theory of forest succession that relates shade tolerance and species replacement and assess its validity to understand patch-mosaic patterns of forested ecosystems of the USA. We introduce a macroscopic parameter called the “shade tolerance index” and compare it to the classic continuum index in southern Wisconsin forests. We exemplify shade...

Das CARNOTsche Paradigma und seine erkenntnistheoretischen Implikationen

NASA Astrophysics Data System (ADS)

Schöpf, Hans-Georg

Der vorliegende historisch-kritische Essay führt die Eigentümlichkeiten der klassischen phänomenologischen Thermodynamik auf das von CARNOT geschaffene Paradigma zurück und greift einige damit zusammenhängende Fragen auf.Translated AbstractCARNOT's Paradigm and its Epistemological ImplicationsThe present historic-critical essay traces the pecularities of classical phenomenological thermodynamics back to the paradigm, created by CARNOT, and takes up some questions to which this paradigm gives rise.

The effect of a dopamine antagonist on conditioning of sexual arousal in women.

PubMed

Brom, Mirte; Laan, Ellen; Everaerd, Walter; Spinhoven, Philip; Trimbos, Baptist; Both, Stephanie

2016-04-01

Dopamine (DA) plays a key role in reward-seeking behaviours. Accumulating evidence from animal and human studies suggests that human sexual reward learning may also depend on DA transmission. However, research on the role of DA in human sexual reward learning is completely lacking. To investigate whether DA antagonism attenuates classical conditioning of sexual response in humans. Healthy women were randomly allocated to one of two treatment conditions: haloperidol (n = 29) or placebo (n = 29). A differential conditioning paradigm was applied with genital vibrostimulation as unconditional stimulus (US) and neutral pictures as conditional stimuli (CSs). Genital arousal was assessed, and ratings of affective value and subjective sexual arousal were obtained. Haloperidol administration affected unconditional genital responding. However, no significant effects of medication were found for conditioned responding. No firm conclusions can be drawn about whether female sexual reward learning implicates DA transmission since the results do not lend themselves to unambiguous interpretation.

The Meaning of General Education: The Emergence of a Curriculum Paradigm.

ERIC Educational Resources Information Center

Miller, Gary E.

An historical and conceptual analysis of general education in the United States is presented, comprising the following chapters: (1) transformation and the search for meaning (including a discussion of the concept of general education); (2) the classical curriculum confronts democracy (democratic pressures on the classical curriculum; the Yale…

Homeostasis of exercise hyperpnea and optimal sensorimotor integration: the internal model paradigm.

PubMed

Poon, Chi-Sang; Tin, Chung; Yu, Yunguo

2007-10-15

Homeostasis is a basic tenet of biomedicine and an open problem for many physiological control systems. Among them, none has been more extensively studied and intensely debated than the dilemma of exercise hyperpnea - a paradoxical homeostatic increase of respiratory ventilation that is geared to metabolic demands instead of the normal chemoreflex mechanism. Classical control theory has led to a plethora of "feedback/feedforward control" or "set point" hypotheses for homeostatic regulation, yet so far none of them has proved satisfactory in explaining exercise hyperpnea and its interactions with other respiratory inputs. Instead, the available evidence points to a far more sophisticated respiratory controller capable of integrating multiple afferent and efferent signals in adapting the ventilatory pattern toward optimality relative to conflicting homeostatic, energetic and other objectives. This optimality principle parsimoniously mimics exercise hyperpnea, chemoreflex and a host of characteristic respiratory responses to abnormal gas exchange or mechanical loading/unloading in health and in cardiopulmonary diseases - all without resorting to a feedforward "exercise stimulus". Rather, an emergent controller signal encoding the projected metabolic level is predicted by the principle as an exercise-induced 'mental percept' or 'internal model', presumably engendered by associative learning (operant conditioning or classical conditioning) which achieves optimality through continuous identification of, and adaptation to, the causal relationship between respiratory motor output and resultant chemical-mechanical afferent feedbacks. This internal model self-tuning adaptive control paradigm opens a new challenge and exciting opportunity for experimental and theoretical elucidations of the mechanisms of respiratory control - and of homeostatic regulation and sensorimotor integration in general.

Developing and validating trace fear conditioning protocols in C57BL/6 mice.

PubMed

Burman, Michael A; Simmons, Cassandra A; Hughes, Miles; Lei, Lei

2014-01-30

Classical fear conditioning is commonly used to study the biology of fear, anxiety and memory. Previous research demonstrated that delay conditioning requires a neural circuit involving the amygdala, but not usually the hippocampus. Trace and contextual fear conditioning require the amygdala and hippocampus. While these paradigms were developed primarily using rat models, they are increasingly being used in mice. The current studies develop trace fear conditioning and control paradigms to allow for the assessment of trace and delay fear conditioning in C57BL/6N mice. Our initial protocol yielded clear delay and contextual conditioning. However, trace conditioning failed to differentiate from an unpaired group and was not hippocampus-dependent. These results suggested that the protocol needed to be modified to specifically accommodate trace conditioning the mice. In order to reduce unconditioned freezing and increase learning, the final protocol was developed by decreasing the intensity of the tone and by increasing the inter-trial interval. Our final protocol produced trace conditioned freezing that was significantly greater than that followed unpaired stimulus exposure and was disrupted by hippocampus lesions. A review of the literature produced 90 articles using trace conditioning in mice. Few of those articles used any kind of behavioral control group, which is required to rule out non-associative factors causing fearful behavior. Fewer used unpaired groups involving tones and shocks within a session, which is the optimal control group. Our final trace conditioning protocol can be used in future studies examining genetically modified C57BL/6N mice. Copyright © 2013 Elsevier B.V. All rights reserved.

Developing and Validating Trace Fear Conditioning Protocols in C57BL/6 Mice

PubMed Central

Burman, Michael A; Simmons, Cassandra A; Hughes, Miles; Lei, Lei

2013-01-01

Background Classical fear conditioning is commonly used to study the biology of fear, anxiety and memory. Previous research demonstrated that delay conditioning requires a neural circuit involving the amygdala, but not usually the hippocampus. Trace and contextual fear conditioning require the amygdala and hippocampus. While these paradigms were developed primarily using rat models, they are increasingly being used in mice. New Method The current studies develop trace fear conditioning and control paradigms to allow for the assessment of trace and delay fear conditioning in C57BL/6N mice. Our initial protocol yielded clear delay and contextual conditioning. However, trace conditioning failed to differentiate from an unpaired group and was not hippocampus-dependent. These results suggested that the protocol needed to be modified to specifically accommodate trace conditioning the mice. In order to reduce unconditioned freezing and increase learning, the final protocol was developed by decreasing the intensity of the tone and by increasing the inter-trial interval. Results Our final protocol produced trace conditioned freezing that was significantly greater than that followed unpaired stimulus exposure and was disrupted by hippocampus lesions. Comparison with Existing Methods A review of the literature produced 90 articles using trace conditioning in mice. Few of those articles used any kind of behavioral control group, which is required to rule out non-associative factors causing fearful behavior. Fewer used unpaired groups involving tones and shocks within a session, which is the optimal control group. Conclusions Our final trace conditioning protocol can be used in future studies examining genetically modified C57BL/6N mice. PMID:24269252

Recent language experience influences cross-language activation in bilinguals with different scripts

PubMed Central

Li, Chuchu; Wang, Min; Lin, Candise Y

2017-01-01

Purpose This study aimed to examine whether the phonological information in the non-target language is activated and its influence on bilingual processing. Approach Using the Stroop paradigm, Mandarin-English bilinguals named the ink color of Chinese characters in English in Experiment 1 and named the Chinese characters in addition to the color naming in English in Experiment 2. Twenty-four participants were recruited in each experiment. In both experiments, the visual stimuli included color characters (e.g. 红, hong2, red), homophones of the color characters (e.g. 洪, hong2, flood), characters that only shared the same syllable segment with the color characters (S+T−, e.g. 轰, hong1, boom), characters that shared the same tone but differed in segments with the color characters (S−T+, e.g. 瓶, ping2, bottle), and neutral characters (e.g. 牵, qian1, leading through). Data and analysis Planned t-tests were conducted in which participants’ naming accuracy rate and naming latency in each phonological condition were compared with the neutral condition. Findings Experiment 1 only showed the classic Stroop effect in the color character condition. In Experiment 2, in addition to the classic Stroop effect, the congruent homophone condition (e.g. 洪in red) showed a significant Stroop interference effect. These results suggested that for bilingual speakers with different scripts, phonological information in the non-target language may not be automatically activated even though the written words in the non-target language were visually presented. However, if the phonological information of the non-target language is activated in advance, it could lead to competition between the two languages, likely at both the phonological and lemma levels. Originality and significance This study is among the first to investigate whether the translation of a word is phonologically encoded in bilinguals using the Stroop paradigm. The findings improve our understanding of the underlying mechanism of bilingual processing. PMID:29056862

Functional imaging of conditioned aversive emotional responses in antisocial personality disorder.

PubMed

Schneider, F; Habel, U; Kessler, C; Posse, S; Grodd, W; Müller-Gärtner, H W

2000-01-01

Individuals with antisocial personality disorder (n = 12) and healthy controls (n = 12) were examined for cerebral regional activation involved in the processing of negative affect. A differential aversive classical conditioning paradigm was applied with odors as unconditioned stimuli and faces as conditioned stimuli. Functional magnetic resonance imaging (fMRI) based on echo-planar imaging was used while cerebral activity was studied during habituation, acquisition, and extinction. Individually defined cerebral regions were analyzed. Both groups indicated behavioral conditioning following subjective ratings of emotional valence to conditioned stimuli. Differential effects were found during acquisition in the amygdala and dorsolateral prefrontal cortex. Controls showed signal decreases, patients signal increases. These preliminary results revealed unexpected signal increases in cortical/subcortical areas of patients. The increases may result from an additional effort put in by these individuals to form negative emotional associations, a pattern of processing that may correspond to their characteristic deviant emotional behavior. Copyright 2000 S. Karger AG, Basel.

Impaired eye blink classical conditioning distinguishes dystonic patients with and without tremor.

PubMed

Antelmi, E; Di Stasio, F; Rocchi, L; Erro, R; Liguori, R; Ganos, C; Brugger, F; Teo, J; Berardelli, A; Rothwell, J; Bhatia, K P

2016-10-01

Tremor is frequently associated with dystonia, but its pathophysiology is still unclear. Dysfunctions of cerebellar circuits are known to play a role in the pathophysiology of action-induced tremors, and cerebellar impairment has frequently been associated to dystonia. However, a link between dystonic tremor and cerebellar abnormalities has not been demonstrated so far. Twenty-five patients with idiopathic isolated cervical dystonia, with and without tremor, were enrolled. We studied the excitability of inhibitory circuits in the brainstem by measuring the R2 blink reflex recovery cycle (BRC) and implicit learning mediated by the cerebellum by means of eyeblink classical conditioning (EBCC). Results were compared with those obtained in a group of age-matched healthy subjects (HS). Statistical analysis did not disclose any significant clinical differences among dystonic patients with and without tremor. Patients with dystonia (regardless of the presence of tremor) showed decreased inhibition of R2 blink reflex by conditioning pulses compared with HS. Patients with dystonic tremor showed a decreased number of conditioned responses in the EBCC paradigm compared to HS and dystonic patients without tremor. The present data show that cerebellar impairment segregates with the presence of tremor in patients with dystonia, suggesting that the cerebellum might have a role in the occurrence of dystonic tremor. Copyright © 2016 Elsevier Ltd. All rights reserved.

Does incongruence of lexicosemantic and prosodic information cause discernible cognitive conflict?

PubMed

Mitchell, Rachel L C

2006-12-01

We are often required to interpret discordant emotional signals. Whereas equivalent cognitive paradigms cause noticeable conflict via their behavioral and psychophysiological effects, the same may not necessarily be true for discordant emotions. Skin conductance responses (SCRs) and heart rates (HRs) were measured during a classic Stroop task and one in which the emotions conveyed by lexicosemantic content and prosody were congruent or incongruent. The participants' task was to identify the emotion conveyed by lexicosemantic content or prosody. No relationship was observed between HR and congruence. SCR was higher during incongruent than during congruent conditions of the experimental task (as well as in the classic Stroop task), but no difference in SCR was observed in a comparison between congruence effects during lexicosemantic emotion identification and those during prosodic emotion identification. It is concluded that incongruence between lexicosemantic and prosodic emotion does cause notable cognitive conflict. Functional neuroanatomic implications are discussed.

Neurobiological mechanisms underlying the blocking effect in aversive learning.

PubMed

Eippert, Falk; Gamer, Matthias; Büchel, Christian

2012-09-19

Current theories of classical conditioning assume that learning depends on the predictive relationship between events, not just on their temporal contiguity. Here we employ the classic experiment substantiating this reasoning-the blocking paradigm-in combination with functional magnetic resonance imaging (fMRI) to investigate whether human amygdala responses in aversive learning conform to these assumptions. In accordance with blocking, we demonstrate that significantly stronger behavioral and amygdala responses are evoked by conditioned stimuli that are predictive of the unconditioned stimulus than by conditioned stimuli that have received the same pairing with the unconditioned stimulus, yet have no predictive value. When studying the development of this effect, we not only observed that it was related to the strength of previous conditioned responses, but also that predictive compared with nonpredictive conditioned stimuli received more overt attention, as measured by fMRI-concurrent eye tracking, and that this went along with enhanced amygdala responses. We furthermore observed that prefrontal regions play a role in the development of the blocking effect: ventromedial prefrontal cortex (subgenual anterior cingulate) only exhibited responses when conditioned stimuli had to be established as nonpredictive for an outcome, whereas dorsolateral prefrontal cortex also showed responses when conditioned stimuli had to be established as predictive. Most importantly, dorsolateral prefrontal cortex connectivity to amygdala flexibly switched between positive and negative coupling, depending on the requirements posed by predictive relationships. Together, our findings highlight the role of predictive value in explaining amygdala responses and identify mechanisms that shape these responses in human fear conditioning.

Evaluative Conditioning with Facial Stimuli in Dementia Patients.

PubMed

Blessing, Andreas; Zöllig, Jacqueline; Weierstall, Roland; Dammann, Gerhard; Martin, Mike

2013-01-01

We present results of a study investigating evaluative learning in dementia patients with a classic evaluative conditioning paradigm. Picture pairs of three unfamiliar faces with liked, disliked, or neutral faces, that were rated prior to the presentation, were presented 10 times each to a group of dementia patients (N = 15) and healthy controls (N = 14) in random order. Valence ratings of all faces were assessed before and after presentation. In contrast to controls, dementia patients changed their valence ratings of unfamiliar faces according to their pairing with either a liked or disliked face, although they were not able to explicitly assign the picture pairs after the presentation. Our finding suggests preserved evaluative conditioning in dementia patients. However, the result has to be considered preliminary, as it is unclear which factors prevented the predicted rating changes in the expected direction in the control group.

Initial conditions for cosmological perturbations

NASA Astrophysics Data System (ADS)

Ashtekar, Abhay; Gupt, Brajesh

2017-02-01

Penrose proposed that the big bang singularity should be constrained by requiring that the Weyl curvature vanishes there. The idea behind this past hypothesis is attractive because it constrains the initial conditions for the universe in geometric terms and is not confined to a specific early universe paradigm. However, the precise statement of Penrose’s hypothesis is tied to classical space-times and furthermore restricts only the gravitational degrees of freedom. These are encapsulated only in the tensor modes of the commonly used cosmological perturbation theory. Drawing inspiration from the underlying idea, we propose a quantum generalization of Penrose’s hypothesis using the Planck regime in place of the big bang, and simultaneously incorporating tensor as well as scalar modes. Initial conditions selected by this generalization constrain the universe to be as homogeneous and isotropic in the Planck regime as permitted by the Heisenberg uncertainty relations.

Philosopher to Moderator: The Shifting Paradigm of "Ethos" in Education.

ERIC Educational Resources Information Center

Raign, Kathryn Rosser

The classical concept of "ethos" (the establishing of the speaker or writer's credibility, his or her moral character) has acquired many meanings over the centuries and has played an important role in determining the many shifting perceptions of the teacher's role, both in the classical period and the modern period. The issue can be…

Combining Speed Information Across Space

NASA Technical Reports Server (NTRS)

Verghese, Preeti; Stone, Leland S.

1995-01-01

We used speed discrimination tasks to measure the ability of observers to combine speed information from multiple stimuli distributed across space. We compared speed discrimination thresholds in a classical discrimination paradigm to those in an uncertainty/search paradigm. Thresholds were measured using a temporal two-interval forced-choice design. In the discrimination paradigm, the n gratings in each interval all moved at the same speed and observers were asked to choose the interval with the faster gratings. Discrimination thresholds for this paradigm decreased as the number of gratings increased. This decrease was not due to increasing the effective stimulus area as a control experiment that increased the area of a single grating did not show a similar improvement in thresholds. Adding independent speed noise to each of the n gratings caused thresholds to decrease at a rate similar to the original no-noise case, consistent with observers combining an independent sample of speed from each grating in both the added- and no-noise cases. In the search paradigm, observers were asked to choose the interval in which one of the n gratings moved faster. Thresholds in this case increased with the number of gratings, behavior traditionally attributed to an input bottleneck. However, results from the discrimination paradigm showed that the increase was not due to observers' inability to process these gratings. We have also shown that the opposite trends of the data in the two paradigms can be predicted by a decision theory model that combines independent samples of speed information across space. This demonstrates that models typically used in classical detection and discrimination paradigms are also applicable to search paradigms. As our model does not distinguish between samples in space and time, it predicts that discrimination performance should be the same regardless of whether the gratings are presented in two spatial intervals or two temporal intervals. Our last experiment largely confirmed this prediction.

Dark Matter and Cosmic Web Story

NASA Astrophysics Data System (ADS)

Einasto, Jaan

2014-01-01

The development of concepts of dark matter and cosmic web are described as paradigm changes in cosmology. As characteristic in paradigm shifts, there is no single discovery; the new concepts were developed step-by-step by many scientists. The book describes the classical cosmological paradigm, elaborated in the first half of the 20th century. Next the book describes problems in the classical picture, and steps to solve the discrepancies, which eventually led to the formation of the modern cosmological paradigm. The new paradigm tells that the Universe is dominated by dark matter and dark energy, that it has the structure in the form of the cosmic web, and that it has evolved through an inflationary initial stage. The story is told from the perspective of one of the participants of events. The book concentrates to the path of the research, difficulties encountered, and discussions in favour or against new concepts. A special flavour gives to the story the description of difficulties of doing revolutionary research in an occupied country behind the Iron Curtain -- as well as convincing scientists in the West -- and the development of Estonia towards a free country. The book is accompanied by a website (http://www.aai.ee/~einasto/DarkMatter) which contains additional material: copies of originals of some crucial papers, astronomical movies, and also movies which show the private life of the author.

Comparison of tactile, auditory, and visual modality for brain-computer interface use: a case study with a patient in the locked-in state.

PubMed

Kaufmann, Tobias; Holz, Elisa M; Kübler, Andrea

2013-01-01

This paper describes a case study with a patient in the classic locked-in state, who currently has no means of independent communication. Following a user-centered approach, we investigated event-related potentials (ERP) elicited in different modalities for use in brain-computer interface (BCI) systems. Such systems could provide her with an alternative communication channel. To investigate the most viable modality for achieving BCI based communication, classic oddball paradigms (1 rare and 1 frequent stimulus, ratio 1:5) in the visual, auditory and tactile modality were conducted (2 runs per modality). Classifiers were built on one run and tested offline on another run (and vice versa). In these paradigms, the tactile modality was clearly superior to other modalities, displaying high offline accuracy even when classification was performed on single trials only. Consequently, we tested the tactile paradigm online and the patient successfully selected targets without any error. Furthermore, we investigated use of the visual or tactile modality for different BCI systems with more than two selection options. In the visual modality, several BCI paradigms were tested offline. Neither matrix-based nor so-called gaze-independent paradigms constituted a means of control. These results may thus question the gaze-independence of current gaze-independent approaches to BCI. A tactile four-choice BCI resulted in high offline classification accuracies. Yet, online use raised various issues. Although performance was clearly above chance, practical daily life use appeared unlikely when compared to other communication approaches (e.g., partner scanning). Our results emphasize the need for user-centered design in BCI development including identification of the best stimulus modality for a particular user. Finally, the paper discusses feasibility of EEG-based BCI systems for patients in classic locked-in state and compares BCI to other AT solutions that we also tested during the study.

The Emerging Paradigm of Pebble Accretion

NASA Astrophysics Data System (ADS)

Ormel, Chris W.

Pebble accretion is the mechanism in which small particles ("pebbles") accrete onto big bodies big (planetesimals or planetary embryos) in gas-rich environments. In pebble accretion accretion , accretion occurs by settling and depends only on the mass of the gravitating body gravitating , not its radius. I give the conditions under which pebble accretion operates and show that the collisional cross section can become much larger than in the gas-free, ballistic, limit. In particular, pebble accretion requires the pre-existence of a massive planetesimal seed. When pebbles experience strong orbital decay by drift motions or are stirred by turbulence, the accretion efficiency is low and a great number of pebbles are needed to form Earth-mass cores. Pebble accretion is in many ways a more natural and versatile process than the classical, planetesimal-driven paradigm, opening up avenues to understand planet formation in solar and exoplanetary systems.

Tumor-associated macrophages as a paradigm of macrophage plasticity, diversity, and polarization: lessons and open questions.

PubMed

Mantovani, Alberto; Locati, Massimo

2013-07-01

Macrophages are present in all body compartments, including cancerous tissues, and their functions are profoundly affected by signals from the microenvironment under homeostatic and pathological conditions. Tumor-associated macrophages are a major cellular component of cancer-related inflammation and have served as a paradigm for the plasticity and functional polarization of mononuclear phagocytes. Tumor-associated macrophages can exert dual influence of cancer depending on the activation state, with classically activated (M1) and alternatively activated (M2) cells generally exerting antitumoral and protumoral functions, respectively. These are extremes in a continuum of polarization states in a universe of diversity. Tumor-associated macrophages affect virtually all aspects of tumor tissues, including stem cells, metabolism, angiogenesis, invasion, and metastasis. Progress has been made in defining signaling molecules, transcription factors, epigenetic changes, and repertoire of microRNAs underlying macrophage polarization. Preclinical and early clinical data suggest that macrophages may serve as tools for the development of innovative diagnostic and therapeutic strategies in cancer and chronic nonresolving inflammatory diseases.

When bees hamper the production of honey: lexical interference from associates in speech production.

PubMed

Abdel Rahman, Rasha; Melinger, Alissa

2007-05-01

In this article, the authors explore semantic context effects in speaking. In particular, the authors investigate a marked discrepancy between categorically and associatively induced effects; only categorical relationships have been reported to cause interference in object naming. In Experiments 1 and 2, a variant of the semantic blocking paradigm was used to induce two different types of semantic context effects. Pictures were either named in the context of categorically related objects (e.g., animals: bee, cow, fish) or in the context of associatively related objects from different semantic categories (e.g., apiary: bee, honey, bee keeper). Semantic interference effects were observed in both conditions, relative to an unrelated context. Experiment 3 replicated the classic effects of categorical interference and associative facilitation in a picture-word interference paradigm with the material used in Experiment 2. These findings suggest that associates are active lexical competitors and that the microstructure of lexicalization is highly flexible and adjustable to the semantic context in which the utterance takes place.

A new learning paradigm: learning using privileged information.

PubMed

Vapnik, Vladimir; Vashist, Akshay

2009-01-01

In the Afterword to the second edition of the book "Estimation of Dependences Based on Empirical Data" by V. Vapnik, an advanced learning paradigm called Learning Using Hidden Information (LUHI) was introduced. This Afterword also suggested an extension of the SVM method (the so called SVM(gamma)+ method) to implement algorithms which address the LUHI paradigm (Vapnik, 1982-2006, Sections 2.4.2 and 2.5.3 of the Afterword). See also (Vapnik, Vashist, & Pavlovitch, 2008, 2009) for further development of the algorithms. In contrast to the existing machine learning paradigm where a teacher does not play an important role, the advanced learning paradigm considers some elements of human teaching. In the new paradigm along with examples, a teacher can provide students with hidden information that exists in explanations, comments, comparisons, and so on. This paper discusses details of the new paradigm and corresponding algorithms, introduces some new algorithms, considers several specific forms of privileged information, demonstrates superiority of the new learning paradigm over the classical learning paradigm when solving practical problems, and discusses general questions related to the new ideas.

Effects of Extrinsic Mortality on the Evolution of Aging: A Stochastic Modeling Approach

PubMed Central

Shokhirev, Maxim Nikolaievich; Johnson, Adiv Adam

2014-01-01

The evolutionary theories of aging are useful for gaining insights into the complex mechanisms underlying senescence. Classical theories argue that high levels of extrinsic mortality should select for the evolution of shorter lifespans and earlier peak fertility. Non-classical theories, in contrast, posit that an increase in extrinsic mortality could select for the evolution of longer lifespans. Although numerous studies support the classical paradigm, recent data challenge classical predictions, finding that high extrinsic mortality can select for the evolution of longer lifespans. To further elucidate the role of extrinsic mortality in the evolution of aging, we implemented a stochastic, agent-based, computational model. We used a simulated annealing optimization approach to predict which model parameters predispose populations to evolve longer or shorter lifespans in response to increased levels of predation. We report that longer lifespans evolved in the presence of rising predation if the cost of mating is relatively high and if energy is available in excess. Conversely, we found that dramatically shorter lifespans evolved when mating costs were relatively low and food was relatively scarce. We also analyzed the effects of increased predation on various parameters related to density dependence and energy allocation. Longer and shorter lifespans were accompanied by increased and decreased investments of energy into somatic maintenance, respectively. Similarly, earlier and later maturation ages were accompanied by increased and decreased energetic investments into early fecundity, respectively. Higher predation significantly decreased the total population size, enlarged the shared resource pool, and redistributed energy reserves for mature individuals. These results both corroborate and refine classical predictions, demonstrating a population-level trade-off between longevity and fecundity and identifying conditions that produce both classical and non-classical lifespan effects. PMID:24466165

Does Classic School Curriculum Contribute to Morality? Integrating School Curriculum with Moral and Intellectual Education

ERIC Educational Resources Information Center

Segev, Arik

2017-01-01

Phillip Cam recently published a study on the separation between the teaching and learning of classic school curriculum (CSC) on the one hand and morality on the other. He suggests an approach to integrate them. The goal of this article was to suggest a complementary alternative approach, to Cam's. Based on a MacIntyrean paradigm, I argue that…

Transfer of Learning in Quantum Mechanics

NASA Astrophysics Data System (ADS)

Singh, Chandralekha

2005-09-01

We investigate the difficulties that undergraduate students in quantum mechanics courses have in transferring learning from previous courses or within the same course from one context to another by administering written tests and conducting individual interviews. Quantum mechanics is abstract and its paradigm is very different from the classical one. A good grasp of the principles of quantum mechanics requires creating and organizing a knowledge structure consistent with the quantum postulates. Previously learned concepts such as the principle of superposition and probability can be useful in quantum mechanics if students are given opportunity to build associations between new and prior knowledge. We also discuss the need for better alignment between quantum mechanics and modern physics courses taken previously because semi-classical models can impede internalization of the quantum paradigm in more advanced courses.

Changing the Paradigm for the Treatment and Development of New Therapies for FSGS

PubMed Central

Spino, Cathie; Jahnke, Jordan S.; Selewski, David T.; Massengill, Susan; Troost, Jonathan; Gipson, Debbie S.

2016-01-01

Focal segmental glomerulosclerosis (FSGS) is a renal pathology finding that represents a constellation of rare kidney diseases, which manifest as proteinuria, edema nephrotic syndrome, hypertension, and increased risk for kidney failure. Therapeutic options for FSGS are reviewed displaying the expected efficacy from 25 to 69% depending on specific therapy, patient characteristics, cost, and common side effects. This variability in treatment response is likely caused, in part, by the heterogeneity in the etiology and active molecular mechanisms of FSGS. Clinical trials in FSGS have been scant in number and slow to recruit, which may stem, in part, from reliance on classic clinical trial design paradigms. Traditional clinical trial designs based on the “learn and confirm” paradigm may not be appropriate for rare diseases, such as FSGS. Future drug development and testing will require novel approaches to trial designs that have the capacity to enrich study populations and adapt the trial in a planned way to gain efficiencies in trial completion timelines. A clinical trial simulation is provided that compares a classical and more modern design to determine the maximum tolerated dose in FSGS. PMID:27047908

Attitudes and defaults save lives and protect the environment jointly and compensatorily: understanding the behavioral efficacy of nudges and other structural interventions.

PubMed

Kaiser, Florian G; Arnold, Oliver; Otto, Siegmar

2014-09-01

A better understanding of when and why nudges (e.g., defaults, visibility or accessibility alterations) and other structural behavior-change measures work or fail can help avoid subsequent surprises such as unexpected political opposition. In this paper, we challenge the unilateral focus on structural interventions-which seemingly control people's behavioral decisions-as such a focus ignores the flipside-namely, attitudes or, as they are called in economics, preferences. We argue for a conceptual understanding of individual behavior that views personal attitudes and behavioral costs as its two separate compensatorily effective determinants. This classical understanding was reintroduced into attitude research as the Campbell paradigm. In the logic of the Campbell paradigm, a person's attitude becomes obvious in the face of the behavioral costs the person surmounts. Technically, individual attitudes reveal themselves in a set of cost-dependent transitively ordered performances. Behavioral costs in turn reflect the structural boundary conditions that are relevant as obstructive and/or supportive environmental forces that generically affect a specific behavior. So far, our research on people's attitudes toward environmental protection has demonstrated that the Campbell paradigm-and thus its conceptual account of individual behavior-holds true for approximately 95% of the people in a given society.

Differing Presynaptic Contributions to LTP and Associative Learning in Behaving Mice

PubMed Central

Madroñal, Noelia; Gruart, Agnès; Delgado-García, José M.

2009-01-01

The hippocampal CA3-CA1 synapse is an excellent experimental model for studying the interactions between short- and long-term plastic changes taking place following high-frequency stimulation (HFS) of Schaffer collaterals and during the acquisition and extinction of a classical eyeblink conditioning in behaving mice. Input/output curves and a full-range paired-pulse study enabled determining the optimal intensities and inter-stimulus intervals for evoking paired-pulse facilitation (PPF) or depression (PPD) at the CA3-CA1 synapse. Long-term potentiation (LTP) induced by HFS lasted ≈10 days. HFS-induced LTP evoked an initial depression of basal PPF. Recovery of PPF baseline values was a steady and progressive process lasting ≈20 days, i.e., longer than the total duration of the LTP. In a subsequent series of experiments, we checked whether PPF was affected similarly during activity-dependent synaptic changes. Animals were conditioned using a trace paradigm, with a tone as a conditioned stimulus (CS) and an electrical shock to the trigeminal nerve as an unconditioned stimulus (US). A pair of pulses (40 ms interval) was presented to the Schaffer collateral-commissural pathway to evoke field EPSPs (fEPSPs) during the CS-US interval. Basal PPF decreased steadily across conditioning sessions (i.e., in the opposite direction to that during LTP), reaching a minimum value during the 10th conditioning session. Thus, LTP and classical eyeblink conditioning share some presynaptic mechanisms, but with an opposite evolution. Furthermore, PPF and PPD might play a homeostatic role during long-term plastic changes at the CA3-CA1 synapse. PMID:19636387

Auditory Profiles of Classical, Jazz, and Rock Musicians: Genre-Specific Sensitivity to Musical Sound Features.

PubMed

Tervaniemi, Mari; Janhunen, Lauri; Kruck, Stefanie; Putkinen, Vesa; Huotilainen, Minna

2015-01-01

When compared with individuals without explicit training in music, adult musicians have facilitated neural functions in several modalities. They also display structural changes in various brain areas, these changes corresponding to the intensity and duration of their musical training. Previous studies have focused on investigating musicians with training in Western classical music. However, musicians involved in different musical genres may display highly differentiated auditory profiles according to the demands set by their genre, i.e., varying importance of different musical sound features. This hypothesis was tested in a novel melody paradigm including deviants in tuning, timbre, rhythm, melody transpositions, and melody contour. Using this paradigm while the participants were watching a silent video and instructed to ignore the sounds, we compared classical, jazz, and rock musicians' and non-musicians' accuracy of neural encoding of the melody. In all groups of participants, all deviants elicited an MMN response, which is a cortical index of deviance discrimination. The strength of the MMN and the subsequent attentional P3a responses reflected the importance of various sound features in each music genre: these automatic brain responses were selectively enhanced to deviants in tuning (classical musicians), timing (classical and jazz musicians), transposition (jazz musicians), and melody contour (jazz and rock musicians). Taken together, these results indicate that musicians with different training history have highly specialized cortical reactivity to sounds which violate the neural template for melody content.

Auditory Profiles of Classical, Jazz, and Rock Musicians: Genre-Specific Sensitivity to Musical Sound Features

PubMed Central

Tervaniemi, Mari; Janhunen, Lauri; Kruck, Stefanie; Putkinen, Vesa; Huotilainen, Minna

2016-01-01

When compared with individuals without explicit training in music, adult musicians have facilitated neural functions in several modalities. They also display structural changes in various brain areas, these changes corresponding to the intensity and duration of their musical training. Previous studies have focused on investigating musicians with training in Western classical music. However, musicians involved in different musical genres may display highly differentiated auditory profiles according to the demands set by their genre, i.e., varying importance of different musical sound features. This hypothesis was tested in a novel melody paradigm including deviants in tuning, timbre, rhythm, melody transpositions, and melody contour. Using this paradigm while the participants were watching a silent video and instructed to ignore the sounds, we compared classical, jazz, and rock musicians' and non-musicians' accuracy of neural encoding of the melody. In all groups of participants, all deviants elicited an MMN response, which is a cortical index of deviance discrimination. The strength of the MMN and the subsequent attentional P3a responses reflected the importance of various sound features in each music genre: these automatic brain responses were selectively enhanced to deviants in tuning (classical musicians), timing (classical and jazz musicians), transposition (jazz musicians), and melody contour (jazz and rock musicians). Taken together, these results indicate that musicians with different training history have highly specialized cortical reactivity to sounds which violate the neural template for melody content. PMID:26779055

AIDS, religious enthusiasm and spiritual insecurity in Africa.

PubMed

Ashforth, Adam

2011-01-01

The connection between the AIDS epidemic and the efflorescence of religious 'enthusiasm' (construed in both classical and contemporary senses) in Africa in recent decades is best understood, this paper argues, by reference to a concept of 'spiritual insecurity'. The article offers a general description of the condition of spiritual insecurity and argues that it is best studied within a relational realist paradigm. The article presents a critique of the concept of 'belief' as commonly used in the social science of religion, arguing instead for an opening of the study of social relations to include the universe of relations within which people experience the world, including their relations with entities such as spiritual beings that might otherwise be considered virtual.

Do different attention capture paradigms measure different types of capture?

PubMed

Roque, Nelson A; Wright, Timothy J; Boot, Walter R

2016-10-01

When something captures our attention, why does it do so? This topic has been hotly debated, with some arguing that attention is captured only by salient stimuli (bottom-up view) and others arguing capture is always due to a match between a stimulus and our goals (top-down view). Many different paradigms have provided evidence for 1 view or the other. If either of these strong views are correct, then capture represents a unitary phenomenon, and there should be a high correlation between capture in these paradigms. But if there are different types of capture (top-down, bottom-up), then some attention capture effects should be correlated and some should not. In 2 studies, we collected data from several paradigms used in support of claims of top-down and bottom-up capture in relatively large samples of participants. Contrary to either prediction, measures of capture were not strongly correlated. Results suggest that capture may in fact be strongly determined by idiosyncratic task demands and strategies. Relevant to this lack of relations among tasks, we observed that classic measures of attention capture demonstrated low reliability, especially among measures used to support bottom-up capture. Implications for the low reliability of capture measures are discussed. We also observed that the proportion of participants demonstrating a pattern of responses consistent with capture varied widely among classic measures of capture. Overall, results demonstrate that, even for relatively simple laboratory measures of attention, there are still important gaps in knowledge regarding what these paradigms measure and how they are related.

Lack of renewal effect in extinction of naturally acquired conditioned eyeblink responses, but possible dependency on physical context.

PubMed

Claassen, J; Mazilescu, L; Thieme, A; Bracha, V; Timmann, D

2016-01-01

Context dependency of extinction is well known and has extensively been studied in fear conditioning, but has rarely been assessed in eyeblink conditioning. One way to demonstrate context dependency of extinction is the renewal effect. ABA paradigms are most commonly used to show the renewal effect of extinguished learned fear: if acquisition takes place in context A, and extinction takes place in context B (extinction phase), learned responses will recover in subsequent extinction trials presented in context A (renewal phase). The renewal effect of the visual threat eyeblink response (VTER), a conditioned eyeblink response, which is naturally acquired in early infancy, was examined in a total of 48 young and healthy participants with two experiments using an ABA paradigm. Twenty paired trials were performed in context A (baseline trials), followed by 50 extinction trials in context B (extinction phase) and 50 extinction trials in context A (renewal phase). In 24 participants, contexts A and B were two different rooms, and in the other 24 participants, two different background colors (orange and blue) and noises were used. To rule out spontaneous recovery, an AAA design was used for comparison. There were significant effects of extinction in both experiments. No significant renewal effects were observed. In experiment 2, however, extinction was significantly less using orange background during extinction compared to the blue background. The present findings suggest that extinction of conditioned eyeblinks depends on the physical context. Findings add to the animal literature that context can play a role in the acquisition of classically conditioned eyeblink responses. Future studies, however, need to be performed to confirm the present findings. Lack of renewal effect may be explained by the highly overlearned character of the VTER.

Motivation and placebos: do different mechanisms occur in different contexts?

PubMed

Hyland, Michael E

2011-06-27

This paper challenges the common assumption that the mechanisms underlying short-term placebo paradigms (where there is no motivation for health improvement) and long-term placebo paradigms (where patients value improvement in their health) are the same. Three types of motivational theory are reviewed: (i) classical placebo motivation theory that the placebo response results from the desire for therapeutic improvement; (ii) goal activation model that expectancy-driven placebo responses are enhanced when the placebo response satisfies an activated goal; and (iii) motivational concordance model that the placebo response is the consequence of concordance between the placebo ritual and significant intrinsic motives. It is suggested that current data are consistent with the following theory: response expectancy, conditioning and goal activation are responsible for short-term placebo effects but long-term therapeutic change is achieved through the effects of goal satisfaction and affect on the inflammatory response system and hypothalamic-pituitary-adrenal axis. Empirical predictions of this new theory are outlined, including ways in which placebo effects can be combined with other psychologically mediated effects on short-term and long-term psychological and physiological state.

Motivation and placebos: do different mechanisms occur in different contexts?

PubMed Central

Hyland, Michael E.

2011-01-01

This paper challenges the common assumption that the mechanisms underlying short-term placebo paradigms (where there is no motivation for health improvement) and long-term placebo paradigms (where patients value improvement in their health) are the same. Three types of motivational theory are reviewed: (i) classical placebo motivation theory that the placebo response results from the desire for therapeutic improvement; (ii) goal activation model that expectancy-driven placebo responses are enhanced when the placebo response satisfies an activated goal; and (iii) motivational concordance model that the placebo response is the consequence of concordance between the placebo ritual and significant intrinsic motives. It is suggested that current data are consistent with the following theory: response expectancy, conditioning and goal activation are responsible for short-term placebo effects but long-term therapeutic change is achieved through the effects of goal satisfaction and affect on the inflammatory response system and hypothalamic–pituitary–adrenal axis. Empirical predictions of this new theory are outlined, including ways in which placebo effects can be combined with other psychologically mediated effects on short-term and long-term psychological and physiological state. PMID:21576140

Relationship between gastro-oesophageal reflux and airway diseases: the airway reflux paradigm.

PubMed

Pacheco-Galván, Adalberto; Hart, Simon P; Morice, Alyn H

2011-04-01

Our understanding of the relationship between gastro-oesophageal reflux and respiratory disease has recently undergone important changes. The previous paradigm of airway reflux as synonymous with the classic gastro-oesophageal reflux disease (GORD) causing heartburn has been overturned. Numerous epidemiological studies have shown a highly significant association of the acid, liquid, and gaseous reflux of GORD with conditions such as laryngeal diseases, chronic rhinosinusitis, treatment resistant asthma, COPD and even idiopathic pulmonary fibrosis. However, it has become clear from studies on cough hypersensitivity syndrome that much reflux of importance in the airways has been missed, since it is either non- or weakly acid and gaseous in composition. The evidence for such a relationship relies on the clinical history pointing to symptom associations with known precipitants of reflux. The tools for the diagnosis of extra-oesophageal reflux, in contrast to the oesophageal reflux of GORD, lack sensitivity and reproducibility. Unfortunately, methodology for detecting such reflux is only just becoming available and much additional work is required to properly delineate its role. Copyright © 2011 SEPAR. Published by Elsevier Espana. All rights reserved.

Learning With Mixed Hard/Soft Pointwise Constraints.

PubMed

Gnecco, Giorgio; Gori, Marco; Melacci, Stefano; Sanguineti, Marcello

2015-09-01

A learning paradigm is proposed and investigated, in which the classical framework of learning from examples is enhanced by the introduction of hard pointwise constraints, i.e., constraints imposed on a finite set of examples that cannot be violated. Such constraints arise, e.g., when requiring coherent decisions of classifiers acting on different views of the same pattern. The classical examples of supervised learning, which can be violated at the cost of some penalization (quantified by the choice of a suitable loss function) play the role of soft pointwise constraints. Constrained variational calculus is exploited to derive a representer theorem that provides a description of the functional structure of the optimal solution to the proposed learning paradigm. It is shown that such an optimal solution can be represented in terms of a set of support constraints, which generalize the concept of support vectors and open the doors to a novel learning paradigm, called support constraint machines. The general theory is applied to derive the representation of the optimal solution to the problem of learning from hard linear pointwise constraints combined with soft pointwise constraints induced by supervised examples. In some cases, closed-form optimal solutions are obtained.

Absolute pitch does not depend on early musical training.

PubMed

Ross, David A; Olson, Ingrid R; Gore, John C

2003-11-01

The etiology and defining characteristics of absolute pitch (AP) have been controversial. To test the importance of musical training in the development of this skill, we developed a new paradigm for identifying AP that is independent of a subject's musical experience. We confirm the efficacy of the paradigm using classically defined AP and non-AP musicians. We then present data from a nonmusician who nevertheless appears to possess AP. We conclude that musical training is not necessary for the development of AP.

A Whirlwind Tour of Computational Geometry.

ERIC Educational Resources Information Center

Graham, Ron; Yao, Frances

1990-01-01

Described is computational geometry which used concepts and results from classical geometry, topology, combinatorics, as well as standard algorithmic techniques such as sorting and searching, graph manipulations, and linear programing. Also included are special techniques and paradigms. (KR)

Classic-Ada(TM)

NASA Technical Reports Server (NTRS)

Valley, Lois

1989-01-01

The SPS product, Classic-Ada, is a software tool that supports object-oriented Ada programming with powerful inheritance and dynamic binding. Object Oriented Design (OOD) is an easy, natural development paradigm, but it is not supported by Ada. Following the DOD Ada mandate, SPS developed Classic-Ada to provide a tool which supports OOD and implements code in Ada. It consists of a design language, a code generator and a toolset. As a design language, Classic-Ada supports the object-oriented principles of information hiding, data abstraction, dynamic binding, and inheritance. It also supports natural reuse and incremental development through inheritance, code factoring, and Ada, Classic-Ada, dynamic binding and static binding in the same program. Only nine new constructs were added to Ada to provide object-oriented design capabilities. The Classic-Ada code generator translates user application code into fully compliant, ready-to-run, standard Ada. The Classic-Ada toolset is fully supported by SPS and consists of an object generator, a builder, a dictionary manager, and a reporter. Demonstrations of Classic-Ada and the Classic-Ada Browser were given at the workshop.

Spiking Neural Network With Distributed Plasticity Reproduces Cerebellar Learning in Eye Blink Conditioning Paradigms.

PubMed

Antonietti, Alberto; Casellato, Claudia; Garrido, Jesús A; Luque, Niceto R; Naveros, Francisco; Ros, Eduardo; D' Angelo, Egidio; Pedrocchi, Alessandra

2016-01-01

In this study, we defined a realistic cerebellar model through the use of artificial spiking neural networks, testing it in computational simulations that reproduce associative motor tasks in multiple sessions of acquisition and extinction. By evolutionary algorithms, we tuned the cerebellar microcircuit to find out the near-optimal plasticity mechanism parameters that better reproduced human-like behavior in eye blink classical conditioning, one of the most extensively studied paradigms related to the cerebellum. We used two models: one with only the cortical plasticity and another including two additional plasticity sites at nuclear level. First, both spiking cerebellar models were able to well reproduce the real human behaviors, in terms of both "timing" and "amplitude", expressing rapid acquisition, stable late acquisition, rapid extinction, and faster reacquisition of an associative motor task. Even though the model with only the cortical plasticity site showed good learning capabilities, the model with distributed plasticity produced faster and more stable acquisition of conditioned responses in the reacquisition phase. This behavior is explained by the effect of the nuclear plasticities, which have slow dynamics and can express memory consolidation and saving. We showed how the spiking dynamics of multiple interactive neural mechanisms implicitly drive multiple essential components of complex learning processes.  This study presents a very advanced computational model, developed together by biomedical engineers, computer scientists, and neuroscientists. Since its realistic features, the proposed model can provide confirmations and suggestions about neurophysiological and pathological hypotheses and can be used in challenging clinical applications.

The impact and determinants of the energy paradigm on economic growth in European Union.

PubMed

Andrei, Jean Vasile; Mieila, Mihai; Panait, Mirela

2017-01-01

Contemporary economies are strongly reliant on energy and analyzing the determining factors that trigger the changes in energy paradigm and their impact upon economic growth is a topical research subject. Our contention is that energy paradigm plays a major role in achieving the sustainable development of contemporary economies. In order to prove this the panel data methodology of research was employed, namely four panel unit root tests (LLC, IPS, F-ADF and F-PP) aiming to reveal the connections and relevance among 17 variables denoting energy influence on economic development. Moreover, it was introduced a specific indicator to express energy consumption per capita. Our findings extend the classical approach of the changes in energy paradigm and their impact upon economic growth and offer a comprehensive analysis which surpasses the practices and policy decisions in the field.

Bilateral Alternating Auditory Stimulations Facilitate Fear Extinction and Retrieval.

PubMed

Boukezzi, Sarah; Silva, Catarina; Nazarian, Bruno; Rousseau, Pierre-François; Guedj, Eric; Valenzuela-Moguillansky, Camila; Khalfa, Stéphanie

2017-01-01

Disruption of fear conditioning, its extinction and its retrieval are at the core of posttraumatic stress disorder (PTSD). Such deficits, especially fear extinction delay, disappear after alternating bilateral stimulations (BLS) during eye movement desensitization and reprocessing (EMDR) therapy. An animal model of fear recovery, based on auditory cued fear conditioning and extinction learning, recently showed that BLS facilitate fear extinction and fear extinction retrieval. Our goal was to determine if these previous results found in animals can be reproduced in humans. Twenty-two healthy participants took part in a classical fear conditioning, extinction, and extinction recall paradigm. Behavioral responses (fear expectations) as well as psychophysiological measures (skin conductance responses, SCRs) were recorded. The results showed a significant fear expectation decrease during fear extinction with BLS. Additionally, SCR for fear extinction retrieval were significantly lower with BLS. Our results demonstrate the importance of BLS to reduce negative emotions, and provide a successful model to further explore the neural mechanisms underlying the sole BLS effect in the EMDR.

Bilateral Alternating Auditory Stimulations Facilitate Fear Extinction and Retrieval

PubMed Central

Boukezzi, Sarah; Silva, Catarina; Nazarian, Bruno; Rousseau, Pierre-François; Guedj, Eric; Valenzuela-Moguillansky, Camila; Khalfa, Stéphanie

2017-01-01

Disruption of fear conditioning, its extinction and its retrieval are at the core of posttraumatic stress disorder (PTSD). Such deficits, especially fear extinction delay, disappear after alternating bilateral stimulations (BLS) during eye movement desensitization and reprocessing (EMDR) therapy. An animal model of fear recovery, based on auditory cued fear conditioning and extinction learning, recently showed that BLS facilitate fear extinction and fear extinction retrieval. Our goal was to determine if these previous results found in animals can be reproduced in humans. Twenty-two healthy participants took part in a classical fear conditioning, extinction, and extinction recall paradigm. Behavioral responses (fear expectations) as well as psychophysiological measures (skin conductance responses, SCRs) were recorded. The results showed a significant fear expectation decrease during fear extinction with BLS. Additionally, SCR for fear extinction retrieval were significantly lower with BLS. Our results demonstrate the importance of BLS to reduce negative emotions, and provide a successful model to further explore the neural mechanisms underlying the sole BLS effect in the EMDR. PMID:28659851

Adolescent social defeat alters N-methyl-D-aspartic acid receptor expression and impairs fear learning in adulthood.

PubMed

Novick, Andrew M; Mears, Mackenzie; Forster, Gina L; Lei, Yanlin; Tejani-Butt, Shanaz M; Watt, Michael J

2016-05-01

Repeated social defeat of adolescent male rats results in adult mesocortical dopamine hypofunction, impaired working memory, and increased contextual anxiety-like behavior. Given the role of glutamate in dopamine regulation, cognition, and fear and anxiety, we investigated potential changes to N-methyl-D-aspartic acid (NMDA) receptors following adolescent social defeat. As both NMDA receptors and mesocortical dopamine are implicated in the expression and extinction of conditioned fear, a separate cohort of rats was challenged with a classical fear conditioning paradigm to investigate whether fear learning is altered by adolescent defeat. Quantitative autoradiography was used to measure 3H-MK-801 binding to NMDA receptors in regions of the medial prefrontal cortex, caudate putamen, nucleus accumbens, amygdala and hippocampus. Assessment of fear learning was achieved using an auditory fear conditioning paradigm, with freezing toward the auditory tone used as a measure of conditioned fear. Compared to controls, adolescent social defeat decreased adult NMDA receptor expression in the infralimbic region of the prefrontal cortex and central amygdala, while increasing expression in the CA3 region of the hippocampus. Previously defeated rats also displayed decreased conditioned freezing during the recall and first extinction periods, which may be related to the observed decreases and increases in NMDA receptors within the central amygdala and CA3, respectively. The alteration in NMDA receptors seen following adolescent social defeat suggests that dysfunction of glutamatergic systems, combined with mesocortical dopamine deficits, likely plays a role in the some of the long-term behavioral consequences of social stressors in adolescence seen in both preclinical and clinical studies. Copyright © 2016 Elsevier B.V. All rights reserved.

Extinction of opiate reward reduces dendritic arborization and c-Fos expression in the nucleus accumbens core.

PubMed

Leite-Morris, Kimberly A; Kobrin, Kendra L; Guy, Marsha D; Young, Angela J; Heinrichs, Stephen C; Kaplan, Gary B

2014-04-15

Recurrent opiate use combined with environmental cues, in which the drug was administered, provokes cue-induced drug craving and conditioned drug reward. Drug abuse craving is frequently linked with stimuli from a prior drug-taking environment via classical conditioning and associative learning. We modeled the conditioned morphine reward process by using acquisition and extinction of conditioned place preference (CPP) in C57BL/6 mice. Mice were trained to associate a morphine injection with a drug context using a classical conditioning paradigm. In morphine conditioning (0, 0.25, 0.5, 1, 5, or 10 mg/kg) experimental mice acquired a morphine CPP dose response with 10mg/kg as most effective. During morphine CPP extinction experiments, mice were divided into three test groups: morphine CPP followed by extinction training, morphine CPP followed by sham extinction, and saline controls. Extinction of morphine CPP developed within one extinction experiment (4 days) that lasted over two more trials (another 8 days). However, the morphine CPP/sham extinction group retained a place preference that endured through all three extinction trials. Brains were harvested following CPP extinction and processed using Golgi-Cox impregnation. Changes in dendritic morphology and spine quantity were examined in the nucleus accumbens (NAc) Core and Shell neurons. In the NAcCore only, morphine CPP/extinguished mice produced less dendritic arborization, and a decrease in neuronal activity marker c-Fos compared to the morphine CPP/sham extinction group. Extinction of morphine CPP is associated with decreased structural complexity of dendrites in the NAcCore and may represent a substrate for learning induced structural plasticity relevant to addiction. Published by Elsevier B.V.

Role of Reuniens Nucleus Projections to the Medial Prefrontal Cortex and to the Hippocampal Pyramidal CA1 Area in Associative Learning

PubMed Central

Eleore, Lyndell; López-Ramos, Juan Carlos; Guerra-Narbona, Rafael; Delgado-García, José M.

2011-01-01

We studied the interactions between short- and long-term plastic changes taking place during the acquisition of a classical eyeblink conditioning and following high-frequency stimulation (HFS) of the reuniens nucleus in behaving mice. Synaptic changes in strength were studied at the reuniens-medial prefrontal cortex (mPFC) and the reuniens-CA1 synapses. Input/output curves and a paired-pulse study enabled determining the functional capabilities of the two synapses and the optimal intensities to be applied at the reuniens nucleus during classical eyeblink conditioning and for HFS applied to the reuniens nucleus. Animals were conditioned using a trace paradigm, with a tone as conditioned stimulus (CS) and an electric shock to the trigeminal nerve as unconditioned stimulus (US). A single pulse was presented to the reuniens nucleus to evoke field EPSPs (fEPSPs) in mPFC and CA1 areas during the CS-US interval. No significant changes in synaptic strength were observed at the reuniens-mPFC and reuniens-CA1 synapses during the acquisition of eyelid conditioned responses (CRs). Two successive HFS sessions carried out during the first two conditioning days decreased the percentage of CRs, without evoking any long-term potentiation (LTP) at the recording sites. HFS of the reuniens nucleus also prevented the proper acquisition of an object discrimination task. A subsequent study revealed that HFS of the reuniens nucleus evoked a significant decrease of paired-pulse facilitation. In conclusion, reuniens nucleus projections to prefrontal and hippocampal circuits seem to participate in the acquisition of associative learning through a mechanism that does not required the development of LTP. PMID:21858159

The University as a Community of Learners

ERIC Educational Resources Information Center

Daniel, Wallace

2014-01-01

Building on classical and recent studies of the learning paradigm of higher education, the author distinguishes between receiving ideas and using them and how universities might educate students to be more open to the world, open to discovery and creativity.

A normative inference approach for optimal sample sizes in decisions from experience

PubMed Central

Ostwald, Dirk; Starke, Ludger; Hertwig, Ralph

2015-01-01

“Decisions from experience” (DFE) refers to a body of work that emerged in research on behavioral decision making over the last decade. One of the major experimental paradigms employed to study experience-based choice is the “sampling paradigm,” which serves as a model of decision making under limited knowledge about the statistical structure of the world. In this paradigm respondents are presented with two payoff distributions, which, in contrast to standard approaches in behavioral economics, are specified not in terms of explicit outcome-probability information, but by the opportunity to sample outcomes from each distribution without economic consequences. Participants are encouraged to explore the distributions until they feel confident enough to decide from which they would prefer to draw from in a final trial involving real monetary payoffs. One commonly employed measure to characterize the behavior of participants in the sampling paradigm is the sample size, that is, the number of outcome draws which participants choose to obtain from each distribution prior to terminating sampling. A natural question that arises in this context concerns the “optimal” sample size, which could be used as a normative benchmark to evaluate human sampling behavior in DFE. In this theoretical study, we relate the DFE sampling paradigm to the classical statistical decision theoretic literature and, under a probabilistic inference assumption, evaluate optimal sample sizes for DFE. In our treatment we go beyond analytically established results by showing how the classical statistical decision theoretic framework can be used to derive optimal sample sizes under arbitrary, but numerically evaluable, constraints. Finally, we critically evaluate the value of deriving optimal sample sizes under this framework as testable predictions for the experimental study of sampling behavior in DFE. PMID:26441720

Hippocampal theta activity is selectively associated with contingency detection but not discrimination in rabbit discrimination-reversal eyeblink conditioning.

PubMed

Nokia, Miriam S; Wikgren, Jan

2010-04-01

The relative power of the hippocampal theta-band ( approximately 6 Hz) activity (theta ratio) is thought to reflect a distinct neural state and has been shown to affect learning rate in classical eyeblink conditioning in rabbits. We sought to determine if the theta ratio is mostly related to the detection of the contingency between the stimuli used in conditioning or also to the learning of more complex inhibitory associations when a highly demanding delay discrimination-reversal eyeblink conditioning paradigm is used. A high hippocampal theta ratio was not only associated with a fast increase in conditioned responding in general but also correlated with slow emergence of discriminative responding due to sustained responding to the conditioned stimulus not paired with an unconditioned stimulus. The results indicate that the neural state reflected by the hippocampal theta ratio is specifically linked to forming associations between stimuli rather than to the learning of inhibitory associations needed for successful discrimination. This is in line with the view that the hippocampus is responsible for contingency detection in the early phase of learning in eyeblink conditioning. (c) 2009 Wiley-Liss, Inc.

Using family paradigms to improve evidence-based practice.

PubMed

Hidecker, Mary Jo Cooley; Jones, Rebecca S; Imig, David R; Villarruel, Francisco A

2009-08-01

Evidence-based practice (EBP) describes clinical decision making using research, clinical experience, and client values. For family-centered practices, the client's family is integral to this process. This article proposes that using family paradigms, a family science framework, may help elicit and understand client/family values within family-centered EBP. This article describes the family paradigms framework: 4 classic paradigms of "closed," "random," "open," and "synchronous." Its applicability to family-centered EBP is proposed using augmentative and alternative communication examples. A family-centered approach to EBP requires families to be an integral part of clinical decision making, but some families may need assistance in enumerating their views and values. Family paradigms (which consider how a family uses its resources of time, space, energy, and material in the pursuit of its goals of control, affect, meaning, and content) may be a way to elicit family values and preferences relevant to clinical decisions. Family and client values can be incorporated throughout the EBP steps. Considering family paradigms may increase awareness and understanding of how families' views of their goals and resources affect clinical decisions. Further research is needed into both the processes and effectiveness of using family paradigms to conduct family-centered EBP.

Re-emerging conceptual integration: commentary on Berkowitz's "on the consideration of automatic as well as controlled psychological processes in aggression".

PubMed

Pahlavan, Farzaneh

2008-01-01

In recent decades, researchers in various areas of psychology have challenged the claims of a single mode of information processing, and developed dual-process models of social behaviors. Although these theories differ on a number of dimensions, they all share the basic assumption that two different modes of information processing operate in making decision and copying behavior. In essence, the common distinction in these perspectives is between controlled vs. automatic, conscious vs. unconscious, and affective vs. cognitive modes of processing. The purpose of Berkowitz's article is to go beyond the notion of automatic processes in order to use classic notions of conditioning and displacement to explain aggressive behavior. I assert that an explanatory framework for psychology of aggression must be anchored not only in the new but also classic theoretical paradigms. However, progress in psychology does not rest solely on the accumulation of theoretical insights. It demands a large body of empirical facts, with attention to incongruities, discordances, and conceptual clarifications. Copyright 2008 Wiley-Liss, Inc.

Africanized honeybees are slower learners than their European counterparts

NASA Astrophysics Data System (ADS)

Couvillon, Margaret J.; Degrandi-Hoffman, Gloria; Gronenberg, Wulfila

2010-02-01

Does cognitive ability always correlate with a positive fitness consequence? Previous research in both vertebrates and invertebrates provides mixed results. Here, we compare the learning and memory abilities of Africanized honeybees ( Apis mellifera scutellata hybrid) and European honeybees ( Apis mellifera ligustica). The range of the Africanized honeybee continues to expand, superseding the European honeybee, which led us to hypothesize that they might possess greater cognitive capabilities as revealed by a classical conditioning assay. Surprisingly, we found that fewer Africanized honeybees learn to associate an odor with a reward. Additionally, fewer Africanized honeybees remembered the association a day later. While Africanized honeybees are replacing European honeybees, our results show that they do so despite displaying a relatively poorer performance on an associative learning paradigm.

Paradigm shift in plant growth control.

PubMed

Körner, Christian

2015-06-01

For plants to grow they need resources and appropriate conditions that these resources are converted into biomass. While acknowledging the importance of co-drivers, the classical view is still that carbon, that is, photosynthetic CO2 uptake, ranks above any other drivers of plant growth. Hence, theory and modelling of growth traditionally is carbon centric. Here, I suggest that this view is not reflecting reality, but emerged from the availability of methods and process understanding at leaf level. In most cases, poorly understood processes of tissue formation and cell growth are governing carbon demand, and thus, CO2 uptake. Carbon can only be converted into biomass to the extent chemical elements other than carbon, temperature or cell turgor permit. Copyright © 2015. Published by Elsevier Ltd.

The Classical Theory of Light Colors: a Paradigm for Description of Particle Interactions

NASA Astrophysics Data System (ADS)

Mazilu, Nicolae; Agop, Maricel; Gatu, Irina; Iacob, Dan Dezideriu; Butuc, Irina; Ghizdovat, Vlad

2016-06-01

The color is an interaction property: of the interaction of light with matter. Classically speaking it is therefore akin to the forces. But while forces engendered the mechanical view of the world, the colors generated the optical view. One of the modern concepts of interaction between the fundamental particles of matter - the quantum chromodynamics - aims to fill the gap between mechanics and optics, in a specific description of strong interactions. We show here that this modern description of the particle interactions has ties with both the classical and quantum theories of light, regardless of the connection between forces and colors. In a word, the light is a universal model in the description of matter. The description involves classical Yang-Mills fields related to color.

Age-Dependent Decline of Endogenous Pain Control: Exploring the Effect of Expectation and Depression

PubMed Central

Grashorn, Wiebke; Sprenger, Christian; Forkmann, Katarina; Wrobel, Nathalie; Bingel, Ulrike

2013-01-01

Although chronic pain affects all age ranges, it is particularly common in the elderly. One potential explanation for the high prevalence of chronic pain in the older population is impaired functioning of the descending pain inhibitory system which can be studied in humans using conditioned pain modulation (CPM) paradigms. In this study we investigated (i) the influence of age on CPM and (ii) the role of expectations, depression and gender as potential modulating variables of an age-related change in CPM. 64 healthy volunteers of three different age groups (young = 20–40 years, middle-aged = 41–60 years, old = 61–80 years) were studied using a classical CPM paradigm that combined moderate heat pain stimuli to the right forearm as test stimuli (TS) and immersion of the contralateral foot into ice water as the conditioning stimulus (CS). The CPM response showed an age-dependent decline with strong CPM responses in young adults but no significant CPM responses in middle-aged and older adults. These age-related changes in CPM responses could not be explained by expectations of pain relief or depression. Furthermore, changes in CPM responses did not differ between men and women. Our results strongly support the notion of a genuine deterioration of descending pain inhibitory mechanisms with age. PMID:24086595

Pavlovian conditioning and cross-sensitization studies raise challenges to the hypothesis that overeating is an addictive behavior.

PubMed

Harb, M R; Almeida, O F X

2014-04-29

Elevated glucocorticoid levels and sign tracking (ST) in Pavlovian conditioning are potential biomarkers of compulsive behaviors such as addiction. As overeating is sometimes viewed as a form of addictive behavior, we hypothesized that murine Pavlovian sign trackers would have a greater propensity to overeat and develop obesity. Using a food reward in the classical conditioning paradigm, we show that ST behavior is a robust conditioned response but not a predictor of eating and growth trajectories in mice, thus challenging the view that the development of obesity and drug addiction depend on identical mechanisms. This interpretation was supported by experiments which showed that overweight mice do not display cross-sensitization to an addictive drug (morphine), and conversely, that overweight morphine-sensitized animals do not overconsume a highly rewarding food. Although the rewarding/motivational effects of both food and drugs of abuse are mediated by similar neurochemical mechanisms, obesity and drug addiction represent a summation of other dysfunctional input and output pathways that lead to the emergence of two distinct disorders, each of which would deserve a specific pharmacotherapeutic approach.

Pavlovian conditioning and cross-sensitization studies raise challenges to the hypothesis that overeating is an addictive behavior

PubMed Central

Harb, M R; Almeida, O F X

2014-01-01

Elevated glucocorticoid levels and sign tracking (ST) in Pavlovian conditioning are potential biomarkers of compulsive behaviors such as addiction. As overeating is sometimes viewed as a form of addictive behavior, we hypothesized that murine Pavlovian sign trackers would have a greater propensity to overeat and develop obesity. Using a food reward in the classical conditioning paradigm, we show that ST behavior is a robust conditioned response but not a predictor of eating and growth trajectories in mice, thus challenging the view that the development of obesity and drug addiction depend on identical mechanisms. This interpretation was supported by experiments which showed that overweight mice do not display cross-sensitization to an addictive drug (morphine), and conversely, that overweight morphine-sensitized animals do not overconsume a highly rewarding food. Although the rewarding/motivational effects of both food and drugs of abuse are mediated by similar neurochemical mechanisms, obesity and drug addiction represent a summation of other dysfunctional input and output pathways that lead to the emergence of two distinct disorders, each of which would deserve a specific pharmacotherapeutic approach. PMID:24780921

The impact and determinants of the energy paradigm on economic growth in European Union

PubMed Central

Mieila, Mihai; Panait, Mirela

2017-01-01

Contemporary economies are strongly reliant on energy and analyzing the determining factors that trigger the changes in energy paradigm and their impact upon economic growth is a topical research subject. Our contention is that energy paradigm plays a major role in achieving the sustainable development of contemporary economies. In order to prove this the panel data methodology of research was employed, namely four panel unit root tests (LLC, IPS, F-ADF and F-PP) aiming to reveal the connections and relevance among 17 variables denoting energy influence on economic development. Moreover, it was introduced a specific indicator to express energy consumption per capita. Our findings extend the classical approach of the changes in energy paradigm and their impact upon economic growth and offer a comprehensive analysis which surpasses the practices and policy decisions in the field. PMID:28301505

An online hybrid brain-computer interface combining multiple physiological signals for webpage browse.

PubMed

Long Chen; Zhongpeng Wang; Feng He; Jiajia Yang; Hongzhi Qi; Peng Zhou; Baikun Wan; Dong Ming

2015-08-01

The hybrid brain computer interface (hBCI) could provide higher information transfer rate than did the classical BCIs. It included more than one brain-computer or human-machine interact paradigms, such as the combination of the P300 and SSVEP paradigms. Research firstly constructed independent subsystems of three different paradigms and tested each of them with online experiments. Then we constructed a serial hybrid BCI system which combined these paradigms to achieve the functions of typing letters, moving and clicking cursor, and switching among them for the purpose of browsing webpages. Five subjects were involved in this study. They all successfully realized these functions in the online tests. The subjects could achieve an accuracy above 90% after training, which met the requirement in operating the system efficiently. The results demonstrated that it was an efficient system capable of robustness, which provided an approach for the clinic application.

Quantum gravity extension of the inflationary scenario.

PubMed

Agullo, Ivan; Ashtekar, Abhay; Nelson, William

2012-12-21

Since the standard inflationary paradigm is based on quantum field theory on classical space-times, it excludes the Planck era. Using techniques from loop quantum gravity, the paradigm is extended to a self-consistent theory from the Planck scale to the onset of slow roll inflation, covering some 11 orders of magnitude in energy density and curvature. This preinflationary dynamics also opens a small window for novel effects, e.g., a source for non-Gaussianities, which could extend the reach of cosmological observations to the deep Planck regime of the early Universe.

The "where is it?" reflex: autoshaping the orienting response.

PubMed

Buzsáki, G

1982-05-01

The goal of this review is to compare two divergent lines of research on signal-centered behavior: the orienting reflex (OR) and autoshaping. A review of conditioning experiments in animals and humans suggests that the novelty hypothesis of the OR is no longer tenable. Only stimuli that represent biological "relevance" elicit ORs. A stimulus may be relevant a priori (i.e., unconditioned) or as a result of conditioning. Exposure to a conditioned stimulus (CS) that predicts a positive reinforcer causes the animal to orient to it throughout conditioning. Within the CS-US interval, the initial CS-directed orienting response is followed by US-directed tendencies. Experimental evidence is shown that the development and maintenance of the conditioned OR occur in a similar fashion both in response-independent (classical) and response-dependent (instrumental) paradigms. It is proposed that the conditioned OR and the signal-directed autoshaped response are identical. Signals predicting aversive events repel the subject from the source of the CS. It is suggested that the function of the CS is not only to signal the probability of US occurrence, but also to serve as a spatial cue to guide the animal in the environment.

The "where is it?" reflex: autoshaping the orienting response.

PubMed Central

Buzsáki, G

1982-01-01

The goal of this review is to compare two divergent lines of research on signal-centered behavior: the orienting reflex (OR) and autoshaping. A review of conditioning experiments in animals and humans suggests that the novelty hypothesis of the OR is no longer tenable. Only stimuli that represent biological "relevance" elicit ORs. A stimulus may be relevant a priori (i.e., unconditioned) or as a result of conditioning. Exposure to a conditioned stimulus (CS) that predicts a positive reinforcer causes the animal to orient to it throughout conditioning. Within the CS-US interval, the initial CS-directed orienting response is followed by US-directed tendencies. Experimental evidence is shown that the development and maintenance of the conditioned OR occur in a similar fashion both in response-independent (classical) and response-dependent (instrumental) paradigms. It is proposed that the conditioned OR and the signal-directed autoshaped response are identical. Signals predicting aversive events repel the subject from the source of the CS. It is suggested that the function of the CS is not only to signal the probability of US occurrence, but also to serve as a spatial cue to guide the animal in the environment. PMID:7097153

Phencyclidine and Scopolamine for Modeling Amnesia in Rodents: Direct Comparison with the Use of Barnes Maze Test and Contextual Fear Conditioning Test in Mice.

PubMed

Malikowska-Racia, Natalia; Podkowa, Adrian; Sałat, Kinga

2018-04-21

Nowadays cognitive impairments are a growing unresolved medical issue which may accompany many diseases and therapies, furthermore, numerous researchers investigate various neurobiological aspects of human memory to find possible ways to improve it. Until any other method is discovered, in vivo studies remain the only available tool for memory evaluation. At first, researchers need to choose a model of amnesia which may strongly influence observed results. Thereby a deeper insight into a model itself may increase the quality and reliability of results. The most common method to impair memory in rodents is the pretreatment with drugs that disrupt learning and memory. Taking this into consideration, we compared the activity of agents commonly used for this purpose. We investigated effects of phencyclidine (PCP), a non-competitive NMDA receptor antagonist, and scopolamine (SCOP), an antagonist of muscarinic receptors, on short-term spatial memory and classical fear conditioning in mice. PCP (3 mg/kg) and SCOP (1 mg/kg) were administrated intraperitoneally 30 min before behavioral paradigms. To assess the influence of PCP and SCOP on short-term spatial memory, the Barnes maze test in C57BL/J6 mice was used. Effects on classical conditioning were evaluated using contextual fear conditioning test. Additionally, spontaneous locomotor activity of mice was measured. These two tests were performed in CD-1 mice. Our study reports that both tested agents disturbed short-term spatial memory in the Barnes maze test, however, SCOP revealed a higher activity. Surprisingly, learning in contextual fear conditioning test was impaired only by SCOP. Graphical Abstract ᅟ.

Macrophage polarization in virus-host interactions

USDA-ARS?s Scientific Manuscript database

Macrophage involvement in viral infections and antiviral states is common. However, this involvement has not been well-studied in the paradigm of macrophage polarization, which typically has been categorized by the dichotomy of classical (M1) and alternative (M2) statuses. Recent studies have reveal...

Non-target adjacent stimuli classification improves performance of classical ERP-based brain computer interface

NASA Astrophysics Data System (ADS)

Ceballos, G. A.; Hernández, L. F.

2015-04-01

Objective. The classical ERP-based speller, or P300 Speller, is one of the most commonly used paradigms in the field of Brain Computer Interfaces (BCI). Several alterations to the visual stimuli presentation system have been developed to avoid unfavorable effects elicited by adjacent stimuli. However, there has been little, if any, regard to useful information contained in responses to adjacent stimuli about spatial location of target symbols. This paper aims to demonstrate that combining the classification of non-target adjacent stimuli with standard classification (target versus non-target) significantly improves classical ERP-based speller efficiency. Approach. Four SWLDA classifiers were trained and combined with the standard classifier: the lower row, upper row, right column and left column classifiers. This new feature extraction procedure and the classification method were carried out on three open databases: the UAM P300 database (Universidad Autonoma Metropolitana, Mexico), BCI competition II (dataset IIb) and BCI competition III (dataset II). Main results. The inclusion of the classification of non-target adjacent stimuli improves target classification in the classical row/column paradigm. A gain in mean single trial classification of 9.6% and an overall improvement of 25% in simulated spelling speed was achieved. Significance. We have provided further evidence that the ERPs produced by adjacent stimuli present discriminable features, which could provide additional information about the spatial location of intended symbols. This work promotes the searching of information on the peripheral stimulation responses to improve the performance of emerging visual ERP-based spellers.

The use of repetition suppression paradigms in developmental cognitive neuroscience.

PubMed

Nordt, Marisa; Hoehl, Stefanie; Weigelt, Sarah

2016-07-01

Repetition suppression paradigms allow a more detailed look at brain functioning than classical paradigms and have been applied vigorously in adult cognitive neuroscience. These paradigms are well suited for studies in the field of developmental cognitive neuroscience as they can be applied without collecting a behavioral response and across all age groups. Furthermore, repetition suppression paradigms can be employed in various neuroscience techniques, such as functional magnetic resonance imaging (fMRI), functional near-infrared spectroscopy (fNIRS), electroencephalography (EEG) and magnetoencephalography (MEG). In the present article we review studies using repetition suppression paradigms in developmental cognitive neuroscience covering the age range from infancy to adolescence. Our first goal is to point out characteristics of developmental repetition suppression effects. In doing so, we discuss the relationship of the direction of repetition effects (suppression vs enhancement) with developmental factors, and address the question how the direction of repetition effects might be related to looking-time effects in behavioral infant paradigms, the most prominently used behavioral measure in infant research. To highlight the potential of repetition suppression paradigms, our second goal is to provide an overview on the insights recently obtained by applying repetition paradigms in neurodevelopmental studies, including research on children with autism spectrum disorders (ASDs). We conclude that repetition suppression paradigms are valuable tools for investigating neurodevelopmental processes, while at the same time we highlight the necessity for further studies that disentangle methodological and developmental factors. Copyright © 2016 Elsevier Ltd. All rights reserved.

Social Pavlovian conditioning: Short- and long-term effects and the role of anxiety and depressive symptoms

PubMed Central

Wilhelm, Frank H.; Boger, Sabrina; Georgii, Claudio; Klimesch, Wolfgang; Blechert, Jens

2017-01-01

Abstract Today’s stressors largely arise from social interactions rather than from physical threat. However, the dominant laboratory model of emotional learning relies on physical stimuli (e.g. electric shock) whereas adequate models of social conditioning are missing, possibly due to more subtle and multilayered biobehavioral responses to such stimuli. To fill this gap, we acquired a broad set of measures during conditioning to negative social unconditioned stimuli, also taking into account long-term maintenance of conditioning and inter-individual differences. Fifty-nine healthy participants underwent a classical conditioning task with videos of actors expressing disapproving (US-neg) or neutral (US-neu) statements. Static images of the corresponding actors with a neutral facial expression served as CS+ and CS−, predicting US-neg and US-neu, respectively. Autonomic and facial-muscular measures confirmed differential unconditioned responding whereas experiential CS ratings, event-related potentials, and evoked theta oscillations confirmed differential conditioned responding. Conditioning was maintained at 1 month and 1 year follow-ups on experiential ratings, especially in individuals with elevated anxiety and depressive symptoms, documenting the efficiency of social conditioning and its clinical relevance. This novel, ecologically improved conditioning paradigm uncovered a remarkably efficient multi-layered social learning mechanism that may represent a risk factor for anxiety and depression. PMID:27614767

Curriculum Development for Technology-Based Entrepreneurship Education: A Cross-Disciplinary and Cross-Cultural Approach

ERIC Educational Resources Information Center

Kazakeviciute, Agne; Urbone, Renata; Petraite, Monika

2016-01-01

University-based entrepreneurship education is facing a paradigm shift between the classical "business school" and the contemporary cross-disciplinary "technology venturing" approach, mainly advocated by engineering schools and other communities outside business schools. The conflict is between structured "business…

Illusion-related brain activations: a new virtual reality mirror box system for use during functional magnetic resonance imaging.

PubMed

Diers, Martin; Kamping, Sandra; Kirsch, Pinar; Rance, Mariela; Bekrater-Bodmann, Robin; Foell, Jens; Trojan, Joerg; Fuchs, Xaver; Bach, Felix; Maaß, Heiko; Cakmak, Hüseyin; Flor, Herta

2015-01-12

Extended viewing of movements of one's intact limb in a mirror as well as motor imagery have been shown to decrease pain in persons with phantom limb pain or complex regional pain syndrome and to increase the movement ability in hemiparesis following stroke. In addition, mirrored movements differentially activate sensorimotor cortex in amputees with and without phantom limb pain. However, using a so-called mirror box has technical limitations, some of which can be overcome by virtual reality applications. We developed a virtual reality mirror box application and evaluated its comparability to a classical mirror box setup. We applied both paradigms to 20 healthy controls and analyzed vividness and authenticity of the illusion as well as brain activation patterns. In both conditions, subjects reported similar intensities for the sensation that movements of the virtual left hand felt as if they were executed by their own left hand. We found activation in the primary sensorimotor cortex contralateral to the actual movement, with stronger activation for the virtual reality 'mirror box' compared to the classical mirror box condition, as well as activation in the primary sensorimotor cortex contralateral to the mirrored/virtual movement. We conclude that a virtual reality application of the mirror box is viable and that it might be useful for future research. Copyright © 2014 Elsevier B.V. All rights reserved.

RETHINKING ACTIVE LEARNING AS A PARADIGM OF OUR TIMES: TOWARDS POETICIZING AND HUMANIZING NATURAL SCIENCES IN THE AGE OF STEM

PubMed Central

Uskoković, Vuk

2018-01-01

Though practiced since ancient times, active learning has emerged as the dominant educational paradigm in the 1990s. Methodologically, it is more suitable to teach critical thinking skills compared to the classical lecturing approach. On the other hand, most university settings, including those focusing heavily on STEM (Science-Engineering-Technology-Mathematics), have embraced it unreservedly, offering no forums to analyze its pros and cons and thus provide conditions for its progress. This constitutes a fundamental paradox. In this essay, specific drawbacks associated with the practical applications of this educational paradigm are discussed. They include the promotion of mediocrity through classroom “democratization”; the suppression of solitary reflections and introspectiveness, along with the creative potentials associated therewith; the inhibition of extraordinariness through excessive teamwork; and the incompatibility with the dominant learning assessment strategies. It is argued that the absorption of ideas stemming from domains distant from pedagogy and one’s field of research are needed to revitalize the current state of active learning practice. Proposed solutions include the revival of the magic of live lecturing through training teachers in spoken poetry and performance arts; integrating research projects into teaching time; and restructuring the concept of the classroom toward a space and context more reflective of life and more conducive to the learning experience. Continued discussion over the weaknesses of active learning practices are needed to ensure the unhindered progress of this teaching methodology that is currently unrivaled in its popularity and prospect. PMID:29899595

Impaired visuocortical discrimination learning of socially conditioned stimuli in social anxiety

PubMed Central

Mühlberger, Andreas; Pauli, Paul; Wieser, Matthias J.

2015-01-01

In search of causative factors of social anxiety disorder (SAD), classical conditioning has been discussed as a potential trigger mechanism for many years. Recent findings suggest that the social relevance of the unconditioned stimulus (US) might play a major role in learning theories of SAD. Thus, this study applied a social conditioning paradigm with disorder-relevant US to examine the electrocortical correlates of affective learning. Twenty-four high socially anxious (HSA) and 23 age- and gender-matched low socially anxious (LSA) subjects were conditioned to 3 different faces flickering at a frequency of 15 Hz which were paired with auditory insults, compliments or neutral comments (US). The face-evoked electrocortical response was measured via steady-state visually evoked potentials and subjective measures of valence and arousal were obtained. Results revealed a significant interaction of social anxiety and conditioning, with LSA showing highest cortical activity to faces paired with insults and lowest activity to faces paired with compliments, while HSA did not differentiate between faces. No group differences were discovered in the affective ratings. The findings indicate a potentially impaired ability of HSA to discriminate between relevant and irrelevant social stimuli, which may constitute a perpetuating factor of SAD. PMID:25338634

Semantic Classical Conditioning and Brain-Computer Interface Control: Encoding of Affirmative and Negative Thinking

PubMed Central

Ruf, Carolin A.; De Massari, Daniele; Furdea, Adrian; Matuz, Tamara; Fioravanti, Chiara; van der Heiden, Linda; Halder, Sebastian; Birbaumer, Niels

2013-01-01

The aim of the study was to investigate conditioned electroencephalography (EEG) responses to factually correct and incorrect statements in order to enable binary communication by means of a brain-computer interface (BCI). In two experiments with healthy participants true and false statements (serving as conditioned stimuli, CSs) were paired with two different tones which served as unconditioned stimuli (USs). The features of the USs were varied and tested for their effectiveness to elicit differentiable conditioned reactions (CRs). After acquisition of the CRs, these CRs to true and false statements were classified offline using a radial basis function kernel support vector machine. A mean single-trial classification accuracy of 50.5% was achieved for differentiating conditioned “yes” versus “no” thinking and mean accuracies of 65.4% for classification of “yes” and 68.8% for “no” thinking (both relative to baseline) were found using the best US. Analysis of the area under the curve of the conditioned EEG responses revealed significant differences between conditioned “yes” and “no” answers. Even though improvements are necessary, these first results indicate that the semantic conditioning paradigm could be a useful basis for further research regarding BCI communication in patients in the complete locked-in state. PMID:23471568

Functionality limit of classical simulated annealing

NASA Astrophysics Data System (ADS)

Hasegawa, M.

2015-09-01

By analyzing the system dynamics in the landscape paradigm, optimization function of classical simulated annealing is reviewed on the random traveling salesman problems. The properly functioning region of the algorithm is experimentally determined in the size-time plane and the influence of its boundary on the scalability test is examined in the standard framework of this method. From both results, an empirical choice of temperature length is plausibly explained as a minimum requirement that the algorithm maintains its scalability within its functionality limit. The study exemplifies the applicability of computational physics analysis to the optimization algorithm research.

Active Brownian particles escaping a channel in single file.

PubMed

Locatelli, Emanuele; Baldovin, Fulvio; Orlandini, Enzo; Pierno, Matteo

2015-02-01

Active particles may happen to be confined in channels so narrow that they cannot overtake each other (single-file conditions). This interesting situation reveals nontrivial physical features as a consequence of the strong interparticle correlations developed in collective rearrangements. We consider a minimal two-dimensional model for active Brownian particles with the aim of studying the modifications introduced by activity with respect to the classical (passive) single-file picture. Depending on whether their motion is dominated by translational or rotational diffusion, we find that active Brownian particles in single file may arrange into clusters that are continuously merging and splitting (active clusters) or merely reproduce passive-motion paradigms, respectively. We show that activity conveys to self-propelled particles a strategic advantage for trespassing narrow channels against external biases (e.g., the gravitational field).

Active Brownian particles escaping a channel in single file

NASA Astrophysics Data System (ADS)

Locatelli, Emanuele; Baldovin, Fulvio; Orlandini, Enzo; Pierno, Matteo

2015-02-01

Active particles may happen to be confined in channels so narrow that they cannot overtake each other (single-file conditions). This interesting situation reveals nontrivial physical features as a consequence of the strong interparticle correlations developed in collective rearrangements. We consider a minimal two-dimensional model for active Brownian particles with the aim of studying the modifications introduced by activity with respect to the classical (passive) single-file picture. Depending on whether their motion is dominated by translational or rotational diffusion, we find that active Brownian particles in single file may arrange into clusters that are continuously merging and splitting (active clusters) or merely reproduce passive-motion paradigms, respectively. We show that activity conveys to self-propelled particles a strategic advantage for trespassing narrow channels against external biases (e.g., the gravitational field).

Three-Week Isolation Does Not Lead to Depressive-Like Disorders in Rats.

PubMed

Gorlova, A V; Pavlov, D A; Zubkov, E A; Morozova, A Yu; Inozemtsev, A N; Chekhonin, V P

2018-06-19

We studied the effects of social isolation for 1, 2 or 3 weeks on behavioral reactions of male rats. As social isolation is a common model for inducing depressive-like state in rodents, classical tests for depressive-like behavioral features were conducted: Porsolt forced swimming test and tests for anhedonia and social interest. None of the experimental groups showed statistically significant disorders in comparison with the control group kept under standard conditions. Thus, social isolation for up to 3 weeks did not cause behavioral abnormalities in male rats. Single housing can be used in other models of induction of depressive-like states, but the use of this paradigm as an independent model for the development of depressive-like behavior requires longer period of social isolation.

Behavioral rehabilitation of the eye closure reflex in senescent rats using a real-time biosignal acquisition system.

PubMed

Prueckl, R; Taub, A H; Herreros, I; Hogri, R; Magal, A; Bamford, S A; Giovannucci, A; Almog, R Ofek; Shacham-Diamand, Y; Verschure, P F M J; Mintz, M; Scharinger, J; Silmon, A; Guger, C

2011-01-01

In this paper the replacement of a lost learning function of rats through a computer-based real-time recording and feedback system is shown. In an experiment two recording electrodes and one stimulation electrode were implanted in an anesthetized rat. During a classical-conditioning paradigm, which includes tone and airpuff stimulation, biosignals were recorded and the stimulation events detected. A computational model of the cerebellum acquired the association between the stimuli and gave feedback to the brain of the rat using deep brain stimulation in order to close the eyelid of the rat. The study shows that replacement of a lost brain function using a direct bidirectional interface to the brain is realizable and can inspire future research for brain rehabilitation.

DEVS representation of dynamical systems - Event-based intelligent control. [Discrete Event System Specification

NASA Technical Reports Server (NTRS)

Zeigler, Bernard P.

1989-01-01

It is shown how systems can be advantageously represented as discrete-event models by using DEVS (discrete-event system specification), a set-theoretic formalism. Such DEVS models provide a basis for the design of event-based logic control. In this control paradigm, the controller expects to receive confirming sensor responses to its control commands within definite time windows determined by its DEVS model of the system under control. The event-based contral paradigm is applied in advanced robotic and intelligent automation, showing how classical process control can be readily interfaced with rule-based symbolic reasoning systems.

Teaching thermal physics in the paradigms project

NASA Astrophysics Data System (ADS)

Roundy, David

2011-10-01

Thermal physics is probably the most disliked course in the physics major curriculum, with students feeling that they are being led through a mathematical maze, leading to an unsatisfactory conclusion. Classical thermodynamics involves scary derivatives, while statistical mechanics leads to lengthy summations and is difficult to apply to interacting systems. It is unsurprising that students find themselves failing to see the physics for the math. In this talk, I will discuss my experiences teaching the Energy and Entropy paradigm, and will introduce materials we have developed to aide student understanding of partial derivatives and their relationship to experimental observables.

Proboscis Conditioning Experiments with Honeybees, Apis Mellifera Caucasica, with Butyric Acid and DEET Mixture as Conditioned and Unconditioned Stimuli

PubMed Central

Abramson, Charles I.; Giray, Tugrul; Mixson, T. Andrew; Nolf, Sondra L.; Wells, Harrington; Kence, Aykut; Kence, Meral

2010-01-01

Three experiments are described investigating whether olfactory repellents DEET and butyric acid can support the classical conditioning of proboscis extension in the honeybee, Apis mellifera caucasica (Hymenoptera: Apidae). In the first experiment DEET and butyric acid readily led to standard acquisition and extinction effects, which are comparable to the use of cinnamon as a conditioned stimulus. These results demonstrate that the odor of DEET or butyric acid is not intrinsically repellent to honey bees. In a second experiment, with DEET and butyric acid mixed with sucrose as an unconditioned stimulus, proboscis conditioning was not established. After several trials, few animals responded to the unconditioned stimulus. These results demonstrate that these chemicals are gustatory repellents when in direct contact. In the last experiment a conditioned suppression paradigm was used. Exposing animals to butyric acid or DEET when the proboscis was extended by direct sucrose stimulation or by learning revealed that retraction of the proboscis was similar to another novel odor, lavender, and in all cases greatest when the animal was not permitted to feed. These results again demonstrate that DEET or butyric acid are not olfactory repellents, and in addition, conditioned suppression is influenced by feeding state of the bee. PMID:20879917

Proboscis conditioning experiments with honeybees, Apis mellifera caucasica, with butyric acid and DEET mixture as conditioned and unconditioned stimuli.

PubMed

Abramson, Charles I; Giray, Tugrul; Mixson, T Andrew; Nolf, Sondra L; Wells, Harrington; Kence, Aykut; Kence, Meral

2010-01-01

Three experiments are described investigating whether olfactory repellents DEET and butyric acid can support the classical conditioning of proboscis extension in the honeybee, Apis mellifera caucasica (Hymenoptera: Apidae). In the first experiment DEET and butyric acid readily led to standard acquisition and extinction effects, which are comparable to the use of cinnamon as a conditioned stimulus. These results demonstrate that the odor of DEET or butyric acid is not intrinsically repellent to honey bees. In a second experiment, with DEET and butyric acid mixed with sucrose as an unconditioned stimulus, proboscis conditioning was not established. After several trials, few animals responded to the unconditioned stimulus. These results demonstrate that these chemicals are gustatory repellents when in direct contact. In the last experiment a conditioned suppression paradigm was used. Exposing animals to butyric acid or DEET when the proboscis was extended by direct sucrose stimulation or by learning revealed that retraction of the proboscis was similar to another novel odor, lavender, and in all cases greatest when the animal was not permitted to feed. These results again demonstrate that DEET or butyric acid are not olfactory repellents, and in addition, conditioned suppression is influenced by feeding state of the bee.

Nonlinear dynamics and quantum entanglement in optomechanical systems.

PubMed

Wang, Guanglei; Huang, Liang; Lai, Ying-Cheng; Grebogi, Celso

2014-03-21

To search for and exploit quantum manifestations of classical nonlinear dynamics is one of the most fundamental problems in physics. Using optomechanical systems as a paradigm, we address this problem from the perspective of quantum entanglement. We uncover strong fingerprints in the quantum entanglement of two common types of classical nonlinear dynamical behaviors: periodic oscillations and quasiperiodic motion. There is a transition from the former to the latter as an experimentally adjustable parameter is changed through a critical value. Accompanying this process, except for a small region about the critical value, the degree of quantum entanglement shows a trend of continuous increase. The time evolution of the entanglement measure, e.g., logarithmic negativity, exhibits a strong dependence on the nature of classical nonlinear dynamics, constituting its signature.

Reverse spin-crossover and high-pressure kinetics of the heme iron center relevant for the operation of heme proteins under deep-sea conditions.

PubMed

Troeppner, Oliver; Lippert, Rainer; Shubina, Tatyana E; Zahl, Achim; Jux, Norbert; Ivanović-Burmazović, Ivana

2014-10-20

By design of a heme model complex with a binding pocket of appropriate size and flexibility, and by elucidating its kinetics and thermodynamics under elevated pressures, some of the pressure effects are demonstrated relevant for operation of heme-proteins under deep-sea conditions. Opposite from classical paradigms of the spin-crossover and reaction kinetics, a pressure increase can cause deceleration of the small-molecule binding to the vacant coordination site of the heme-center in a confined space and stabilize a high-spin state of its Fe center. This reverse high-pressure behavior can be achieved only if the volume changes related to the conformational transformation of the cavity can offset the volume changes caused by the substrate binding. It is speculated that based on these criteria nature could make a selection of structures of heme pockets that assist in reducing metabolic activity and enzymatic side reactions under extreme pressure conditions. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Variable Oscillator Underlies the Measurement of Time Intervals in the Rostral Medial Prefrontal Cortex during Classical Eyeblink Conditioning in Rabbits.

PubMed

Caro-Martín, C Rocío; Leal-Campanario, Rocío; Sánchez-Campusano, Raudel; Delgado-García, José M; Gruart, Agnès

2015-11-04

We were interested in determining whether rostral medial prefrontal cortex (rmPFC) neurons participate in the measurement of conditioned stimulus-unconditioned stimulus (CS-US) time intervals during classical eyeblink conditioning. Rabbits were conditioned with a delay paradigm consisting of a tone as CS. The CS started 50, 250, 500, 1000, or 2000 ms before and coterminated with an air puff (100 ms) directed at the cornea as the US. Eyelid movements were recorded with the magnetic search coil technique and the EMG activity of the orbicularis oculi muscle. Firing activities of rmPFC neurons were recorded across conditioning sessions. Reflex and conditioned eyelid responses presented a dominant oscillatory frequency of ≈12 Hz. The firing rate of each recorded neuron presented a single peak of activity with a frequency dependent on the CS-US interval (i.e., ≈12 Hz for 250 ms, ≈6 Hz for 500 ms, and≈3 Hz for 1000 ms). Interestingly, rmPFC neurons presented their dominant firing peaks at three precise times evenly distributed with respect to CS start and also depending on the duration of the CS-US interval (only for intervals of 250, 500, and 1000 ms). No significant neural responses were recorded at very short (50 ms) or long (2000 ms) CS-US intervals. rmPFC neurons seem not to encode the oscillatory properties characterizing conditioned eyelid responses in rabbits, but are probably involved in the determination of CS-US intervals of an intermediate range (250-1000 ms). We propose that a variable oscillator underlies the generation of working memories in rabbits. The way in which brains generate working memories (those used for the transient processing and storage of newly acquired information) is still an intriguing question. Here, we report that the firing activities of neurons located in the rostromedial prefrontal cortex recorded in alert behaving rabbits are controlled by a dynamic oscillator. This oscillator generated firing frequencies in a variable band of 3-12 Hz depending on the conditioned stimulus-unconditioned stimulus intervals (1 s, 500 ms, 250 ms) selected for classical eyeblink conditioning of behaving rabbits. Shorter (50 ms) and longer (2 s) intervals failed to activate the oscillator and prevented the acquisition of conditioned eyelid responses. This is an unexpected mechanism to generate sustained firing activities in neural circuits generating working memories. Copyright © 2015 the authors 0270-6474/15/3514809-13$15.00/0.

[Is the brain the creator of psychic phenomena or is a paradigm shift inevitable?].

PubMed

Bonilla, Ernesto

2014-06-01

Every day new scientific information is appearing that cannot be explained using the classical Newtonian model and is calling for the emergence of a new paradigm that would include the explanation of such phenomena as telepathy, clairvoyance, presentiment, precognition, out of the body experiences, psychic healing, after-death communication, near-death experiences and reincarnation. The materialist paradigm which considers the brain as the sole cause of consciousness and psychic phenomena has been challenged by a new paradigm that seems to demonstrate that there is not a cause-effect relationship between brain activity and psychic phenomena but only a correlation between them, since these phenomena can be experienced without the body and appear to have an extra-cerebral origin (cosmic field, cosmic consciousness?). Of course, the brain is intensely involved in the manifestation of consciousness in our daily life but this is not equivalent to affirm that brain creates consciousness. Recent findings force us to consider a non-physical, spiritual and transpersonal aspect of reality.

Placebo Effects and Informed Consent.

PubMed

Alfano, Mark

2015-01-01

The concepts of placebos and placebo effects refer to extremely diverse phenomena. I recommend dissolving the concepts of placebos and placebo effects into loosely related groups of specific mechanisms, including (potentially among others) expectation-fulfillment, classical conditioning, and attentional-somatic feedback loops. If this approach is on the right track, it has three main implications for the ethics of informed consent. First, because of the expectation-fulfillment mechanism, the process of informing cannot be considered independently from the potential effects of treatment. Obtaining informed consent influences the effects of treatment. This provides support for the authorized concealment and authorized deception paradigms, and perhaps even for outright deceptive placebo use. Second, doctors may easily fail to consider the potential benefits of conditioning, leading them to misjudge the trade-off between beneficence and autonomy. Third, how attentional-somatic feedback loops play out depends not only on the content of the informing process but also on its framing. This suggests a role for libertarian paternalism in clinical practice.

Circadian Rhythms in Fear Conditioning: An Overview of Behavioral, Brain System, and Molecular Interactions

PubMed Central

Stork, Oliver

2017-01-01

The formation of fear memories is a powerful and highly evolutionary conserved mechanism that serves the behavioral adaptation to environmental threats. Accordingly, classical fear conditioning paradigms have been employed to investigate fundamental molecular processes of memory formation. Evidence suggests that a circadian regulation mechanism allows for a timestamping of such fear memories and controlling memory salience during both their acquisition and their modification after retrieval. These mechanisms include an expression of molecular clocks in neurons of the amygdala, hippocampus, and medial prefrontal cortex and their tight interaction with the intracellular signaling pathways that mediate neural plasticity and information storage. The cellular activities are coordinated across different brain regions and neural circuits through the release of glucocorticoids and neuromodulators such as acetylcholine, which integrate circadian and memory-related activation. Disturbance of this interplay by circadian phase shifts or traumatic experience appears to be an important factor in the development of stress-related psychopathology, considering these circadian components are of critical importance for optimizing therapeutic approaches to these disorders. PMID:28698810

Psychology in Mathematics Education: Past, Present, and Future

ERIC Educational Resources Information Center

Steffe, Leslie P.

2017-01-01

Starting with Woodworth and Thorndike's classical experiment published in 1901, major periods in mathematics education throughout 20th century and on into the current century are reviewed in terms of competing epistemological and psychological paradigms that were operating within as well as across the major periods. The periods were marked by…

Childhood Hodgkin Lymphoma Treatment (PDQ®)—Health Professional Version

Cancer.gov

In childhood Hodgkin lymphoma, current treatment uses risk-adapted, response-based paradigms to determine the length and intensity of treatment. Get detailed information about newly diagnosed and recurrent classical and nodular lymphocyte predominant Hodgkin lymphoma, including presentation, diagnosis and staging, prognosis, and treatment in this summary for clinicians.

Alienation and the Ontology of Social Structure.

ERIC Educational Resources Information Center

Segalman, Ralph

Theoretical models of social structure are analyzed in light of modern work patterns, social affiliations, and social attitudes. It is hypothesized that previous paradigms for society were based on classic theory which analyzed the then emergent forms of social structure and relationships. Because social structures and relationships have changed,…

The Need for Alternative Paradigms in Science and Engineering Education

ERIC Educational Resources Information Center

Baggi, Dennis L.

2007-01-01

There are two main claims in this article. First, that the classic pillars of engineering education, namely, traditional mathematics and differential equations, are merely a particular, if not old-fashioned, representation of a broader mathematical vision, which spans from Turing machine programming and symbolic productions sets to sub-symbolic…

Civic Education for Sustainable Development

ERIC Educational Resources Information Center

Ohlmeier, Bernhard

2015-01-01

Education for sustainable development (ESD) often fails to consider the political dimension. To address this gap, this paper focuses on a specific political approach to ESD. The model presented is derived from the four sustainable growth targets of German Development Policy. Instead of relying on a neo-classical or neo-liberal economic paradigm,…

Voluntary inhibition of pain avoidance behavior: an fMRI study.

PubMed

Lynn, Margaret T; Demanet, Jelle; Krebs, Ruth M; Van Dessel, Pieter; Brass, Marcel

2016-04-01

Behavioral inhibition has classically been considered to rely upon a neural network centered at the right inferior frontal cortex [rIFC; Aron et al. (8:170-177, 2004; 18:177-185, 2014)]. However, the vast majority of inhibition studies have entailed exogenous stop signals instructing participants to withhold responding. More recent work has begun to examine the neural underpinnings of endogenous inhibition, revealing a distinct cortical basis in the dorsal fronto-median cortex [dFMC; Brass and Haggard (27:9141-9145, 2007); Kühn et al. (30:2834-3843, 2009)]. Yet, contrary to everyday experiences of voluntary behavioral suppression, the paradigms employed to investigate action inhibition have thus far been somewhat artificial, and involve little persuasive motivation to act. Accordingly, the present fMRI study seeks to compare and contrast intentional with instructed inhibition in a novel pain paradigm that recruits 'hot' incentive response systems. Participants received increasing thermal stimulation to their inner wrists, and were required to occasionally withhold their natural impulse to withdraw from the compelling pain sensation at peak temperature, in both instructed and free-choice conditions. Consistent with previous research, we observed inhibition-related activity in the dFMC and the rIFC. However, these regions displayed equivalent activation levels for both inhibition types. These data extend previous research by demonstrating that under ecologically valid conditions with a strong motivation to act, both stopping networks operate in concert to enable suppression of unwanted behavior.

Something old, something new and something borrowed: emerging paradigm of insulin-like growth factor type 1 receptor (IGF-1R) signaling regulation.

PubMed

Girnita, Leonard; Worrall, Claire; Takahashi, Shin-Ichiro; Seregard, Stefan; Girnita, Ada

2014-07-01

The insulin-like growth factor type 1 receptor (IGF-1R) plays a key role in the development and progression of cancer; however, therapeutics targeting it have had disappointing results in the clinic. As a receptor tyrosine kinase (RTK), IGF-1R is traditionally described as an ON/OFF system, with ligand stabilizing the ON state and exclusive kinase-dependent signaling activation. Newly added to the traditional model, ubiquitin-mediated receptor downregulation and degradation was originally described as a response to ligand/receptor interaction and thus inseparable from kinase signaling activation. Yet, the classical model has proven over-simplified and insufficient to explain experimental evidence accumulated over the last decade, including kinase-independent signaling, unbalanced signaling, or dissociation between signaling and receptor downregulation. Based on the recent findings that IGF-1R "borrows" components of G-protein coupled receptor (GPCR) signaling, including β-arrestins and G-protein-related kinases, we discuss the emerging paradigm for the IGF-1R as a functional RTK/GPCR hybrid, which integrates the kinase signaling with the IGF-1R canonical GPCR characteristics. The contradictions to the classical IGF-1R signaling concept as well as the design of anti-IGF-1R therapeutics treatment are considered in the light of this paradigm shift and we advocate recognition of IGF-1R as a valid target for cancer treatment.

Towards a new paradigm of microscopic colitis: Incomplete and variant forms

PubMed Central

Guagnozzi, Danila; Landolfi, Stefania; Vicario, Maria

2016-01-01

Microscopic colitis (MC) is a chronic inflammatory bowel disease that has emerged in the last three decades as a leading cause of chronic watery diarrhoea. MC classically includes two main subtypes: lymphocytic colitis (LC) and collagenous colitis (CC). Other types of histopathological changes in the colonic mucosa have been described in patients with chronic diarrhoea, without fulfilling the conventional histopathological criteria for MC diagnosis. Whereas those unclassified alterations remained orphan for a long time, the use of the term incomplete MC (MCi) is nowadays universally accepted. However, it is still unresolved whether CC, LC and MCi should be considered as one clinical entity or if they represent three related conditions. In contrast to classical MC, the real epidemiological impact of MCi remains unknown, because only few epidemiological studies and case reports have been described. MCi presents clinical characteristics indistinguishable from complete MC with a good response to budesonide and cholestiramine. Although a number of medical treatments have been assayed in MC patients, currently, there is no causal treatment approach for MC and MCi, and only empirical strategies have been performed. Further studies are needed in order to identify their etiopathogenic mechanisms, and to better classify and treat MC. PMID:27784958

Theory, Scientific Evidence, and the Communibiological Paradigm: Reflections on Misguided Criticism.

ERIC Educational Resources Information Center

Beatty, Michael J.; McCroskey, James C.

2000-01-01

Replies to C. M. Condit's responses to the authors' articles and comments advancing a communibiological paradigm. Argues that a general misidentification of the level of abstraction (paradigm not theory) drives Condit's complaints about communibiology, and outlines several misrepresentations of the authors' position. (SR)

A novel manipulation method of human body ownership using an fMRI-compatible master-slave system.

PubMed

Hara, Masayuki; Salomon, Roy; van der Zwaag, Wietske; Kober, Tobias; Rognini, Giulio; Nabae, Hiroyuki; Yamamoto, Akio; Blanke, Olaf; Higuchi, Toshiro

2014-09-30

Bodily self-consciousness has become an important topic in cognitive neuroscience aiming to understand how the brain creates a unified sensation of the self in a body. Specifically, full body illusion (FBI) in which changes in bodily self-consciousness are experimentally introduced by using visual-tactile stimulation has led to improve understanding of these mechanisms. This paper introduces a novel approach to the classic FBI paradigm using a robotic master-slave system which allows us to examine interactions between action and the sense of body ownership in behavioral and MRI experiments. In the proposed approach, the use of the robotic master-slave system enables unique stimulation in which experimental participants can administer tactile cues on their own back using active self-touch. This active self-touch has never been employed in FBI experiments and it allows to test the role of sensorimotor integration and agency (the feeling of control over our actions) in FBI paradigms. The objective of this study is to propose a robotic-haptic platform allowing a new FBI paradigm including the active self-touch in MRI environments. This paper, first, describes the design concept and the performance of the prototype device in the fMRI environment (for 3T and 7T MRI scanners). In addition, the prototype device is applied to a classic FBI experiment, and we verify that the use of the prototype device succeeded in inducing the FBI. These results indicate that the proposed approach has a potential to drive advances in our understanding of human body ownership and agency by allowing novel manipulation and paradigms. Copyright © 2014 Elsevier B.V. All rights reserved.

Eyeblink Conditioning in Healthy Adults: A Positron Emission Tomography Study

PubMed Central

Andreasen, Nancy C.; Liu, Dawei; Freeman, John H.; Boles Ponto, Laura L.; O’Leary, Daniel S.

2013-01-01

Eyeblink conditioning is a paradigm commonly used to investigate the neural mechanisms underlying motor learning. It involves the paired presentation of a toneconditioning stimulus which precedes and co-terminates with an airpuff unconditioned stimulus. Following repeated paired presentations a conditioned eyeblink develops which precedes the airpuff. This type of learning has been intensively studied and the cerebellum is known to be essential in both humans and animals. The study presented here was designed to investigate the role of the cerebellum during eyeblink conditioning in humans using positron emission tomography (PET). The sample includes 20 subjects (10 male and 10 female) with an average age of 29.2 years. PET imaging was used to measure regional cerebral blood flow (rCBF) changes occurring during the first, second, and third blocks of conditioning. In addition, stimuli-specific rCBF to unpaired tones and airpuffs (“pseudoconditioning”) was used as a baseline level that was subtracted from each block. Conditioning was performed using three, 15-trial blocks of classical eyeblink conditioning with the last five trials in each block imaged. As expected, subjects quickly acquired conditioned responses. A comparison between the conditioning tasks and the baseline task revealed that during learning there was activation of the cerebellum and recruitment of several higher cortical regions. Specifically, large peaks were noted in cerebellar lobules IV/V, the frontal lobes, and cingulate gyri. PMID:22430943

Scale-independent inflation and hierarchy generation

DOE PAGES

Ferreira, Pedro G.; Hill, Christopher T.; Ross, Graham G.

2016-10-20

We discuss models involving two scalar fields coupled to classical gravity that satisfy the general criteria: (i) the theory has no mass input parameters, (ii) classical scale symmetry is broken only throughmore » $$-\\frac{1}{12}\\varsigma \\phi^2 R$$ couplings where $$\\varsigma$$ departs from the special conformal value of $1$; (iii) the Planck mass is dynamically generated by the vacuum expectations values (VEVs) of the scalars (iv) there is a stage of viable inflation associated with slow roll in the two--scalar potential; (v) the final vacuum has a small to vanishing cosmological constant and an hierarchically small ratio of the VEVs and the ratio of the scalar masses to the Planck scale. In addition, this assumes the paradigm of classical scale symmetry as a custodial symmetry of large hierarchies.« less

A nonmusical paradigm for identifying absolute pitch possessors

NASA Astrophysics Data System (ADS)

Ross, David A.; Olson, Ingrid R.; Marks, Lawrence E.; Gore, John C.

2004-09-01

The ability to identify and reproduce sounds of specific frequencies is remarkable and uncommon. The etiology and defining characteristics of this skill, absolute pitch (AP), have been very controversial. One theory suggests that AP requires a specific type of early musical training and that the ability to encode and remember tones depends on these learned musical associations. An alternate theory argues that AP may be strongly dependent on hereditary factors and relatively independent of musical experience. To date, it has been difficult to test these hypotheses because all previous paradigms for identifying AP have required subjects to employ knowledge of musical nomenclature. As such, these tests are insensitive to the possibility of discovering AP in either nonmusicians or musicians of non-Western training. Based on previous literature in pitch memory, a paradigm is presented that is intended to distinguish between AP possessors and nonpossessors independent of the subjects' musical experience. The efficacy of this method is then tested with 20 classically defined AP possessors and 22 nonpossessors. Data from these groups strongly support the validity of the paradigm. The use of a nonmusical paradigm to identify AP may facilitate research into many aspects of this phenomenon.

A nonmusical paradigm for identifying absolute pitch possessors.

PubMed

Ross, David A; Olson, Ingrid R; Marks, Lawrence E; Gore, John C

2004-09-01

The ability to identify and reproduce sounds of specific frequencies is remarkable and uncommon. The etiology and defining characteristics of this skill, absolute pitch (AP), have been very controversial. One theory suggests that AP requires a specific type of early musical training and that the ability to encode and remember tones depends on these learned musical associations. An alternate theory argues that AP may be strongly dependent on hereditary factors and relatively independent of musical experience. To date, it has been difficult to test these hypotheses because all previous paradigms for identifying AP have required subjects to employ knowledge of musical nomenclature. As such, these tests are insensitive to the possibility of discovering AP in either nonmusicians or musicians of non-Western training. Based on previous literature in pitch memory, a paradigm is presented that is intended to distinguish between AP possessors and nonpossessors independent of the subjects' musical experience. The efficacy of this method is then tested with 20 classically defined AP possessors and 22 nonpossessors. Data from these groups strongly support the validity of the paradigm. The use of a nonmusical paradigm to identify AP may facilitate research into many aspects of this phenomenon.

Is All Motivation Good for Learning? Dissociable Influences of Approach and Avoidance Motivation in Declarative Memory

ERIC Educational Resources Information Center

Murty, Vishnu P.; LaBar, Kevin S.; Hamilton, Derek A.; Adcock, R. Alison

2011-01-01

The present study investigated the effects of approach versus avoidance motivation on declarative learning. Human participants navigated a virtual reality version of the Morris water task, a classic spatial memory paradigm, adapted to permit the experimental manipulation of motivation during learning. During this task, participants were instructed…

From Aristotle to Disney World: Cinematic Paradigms and Perceptual Shifts.

ERIC Educational Resources Information Center

Barry, Ann Marie

This paper contrasts classical Aristotelian narrative, which encouraged intellectual reflection and came to dominate Hollywood film by the 1930s, with the pulsating images which began to appear in the 1980 as a result of MTV's influence on films. The discussion focuses on two major Hollywood films: "Grapes of Wrath" (1940) and "Top…

Making an Art of Creativity: The Cognitive Science of Duchamp and Dada

ERIC Educational Resources Information Center

Prager, Phillip Andrew

2012-01-01

Dada is the infant terrible of art history, an anarchic movement that is typically referred to as nihilistic, pathological, and firmly enshrined within the modernist paradigm and the context of WWI. Through the lens of classical, romantic, and psychoanalytic notions, it certainly appears almost antithetical to creativity. Yet from a cognitive…

Back to the Future: The Idea of a University Revisited

ERIC Educational Resources Information Center

O'Byrne, Darren; Bond, Christopher

2014-01-01

We begin this paper by outlining the "classical" debate on the idea of a university. We then proceed to show how this intellectual ideal has been compromised by successive processes of reform privileging paradigms of managerialism and commodification at the expense of intellectualism in shaping and defining UK higher education, with…

Hemispheric Differences in Processing Dichotic Meaningful and Non-Meaningful Words

ERIC Educational Resources Information Center

Yasin, Ifat

2007-01-01

Classic dichotic-listening paradigms reveal a right-ear advantage (REA) for speech sounds as compared to non-speech sounds. This REA is assumed to be associated with a left-hemisphere dominance for meaningful speech processing. This study objectively probed the relationship between ear advantage and hemispheric dominance in a dichotic-listening…

Development of Attentional Control of Verbal Auditory Perception from Middle to Late Childhood: Comparisons to Healthy Aging

ERIC Educational Resources Information Center

Passow, Susanne; Müller, Maike; Westerhausen, René; Hugdahl, Kenneth; Wartenburger, Isabell; Heekeren, Hauke R.; Lindenberger, Ulman; Li, Shu-Chen

2013-01-01

Multitalker situations confront listeners with a plethora of competing auditory inputs, and hence require selective attention to relevant information, especially when the perceptual saliency of distracting inputs is high. This study augmented the classical forced-attention dichotic listening paradigm by adding an interaural intensity manipulation…

In the eye of the cyclops: The classic case of cospeciation and why paradigms are important

USDA-ARS?s Scientific Manuscript database

Scientific disagreements due to empirical problems - not enough data, not enough of the critical type of data, problems in analyzing the data - are generally short-lived and resolved in the next cycle of data production. Those disagreements are thus transitory. Persistent scientific conflicts do n...

Emergence of Global Shape Processing Continues through Adolescence

ERIC Educational Resources Information Center

Scherf, K. Suzanne; Behrmann, Marlene; Kimchi, Ruth; Luna, Beatriz

2009-01-01

The developmental trajectory of perceptual organization in humans is unclear. This study investigated perceptual grouping abilities across a wide age range (8-30 years) using a classic compound letter global/local (GL) task and a more fine-grained microgenetic prime paradigm (MPP) with both few- and many-element hierarchical displays. In the GL…

Parafoveal Preprocessing in Reading Revisited: Evidence from a Novel Preview Manipulation

ERIC Educational Resources Information Center

Gagl, Benjamin; Hawelka, Stefan; Richlan, Fabio; Schuster, Sarah; Hutzler, Florian

2014-01-01

The study investigated parafoveal preprocessing by the means of the classical invisible boundary paradigm and a novel manipulation of the parafoveal previews (i.e., visual degradation). Eye movements were investigated on 5-letter target words with constraining (i.e., highly informative) initial letters or similarly constraining final letters.…

Teaching Bayesian Statistics to Undergraduate Students through Debates

ERIC Educational Resources Information Center

Stewart, Sepideh; Stewart, Wayne

2014-01-01

This paper describes a lecturer's approach to teaching Bayesian statistics to students who were only exposed to the classical paradigm. The study shows how the lecturer extended himself by making use of ventriloquist dolls to grab hold of students' attention and embed important ideas in revealing the differences between the Bayesian and classical…

Toward a brain-computer interface for Alzheimer's disease patients by combining classical conditioning and brain state classification.

PubMed

Liberati, Giulia; Dalboni da Rocha, Josué Luiz; van der Heiden, Linda; Raffone, Antonino; Birbaumer, Niels; Olivetti Belardinelli, Marta; Sitaram, Ranganatha

2012-01-01

Brain-computer interfaces (BCIs) provide alternative methods for communicating and acting on the world, since messages or commands are conveyed from the brain to an external device without using the normal output pathways of peripheral nerves and muscles. Alzheimer's disease (AD) patients in the most advanced stages, who have lost the ability to communicate verbally, could benefit from a BCI that may allow them to convey basic thoughts (e.g., "yes" and "no") and emotions. There is currently no report of such research, mostly because the cognitive deficits in AD patients pose serious limitations to the use of traditional BCIs, which are normally based on instrumental learning and require users to self-regulate their brain activation. Recent studies suggest that not only self-regulated brain signals, but also involuntary signals, for instance related to emotional states, may provide useful information about the user, opening up the path for so-called "affective BCIs". These interfaces do not necessarily require users to actively perform a cognitive task, and may therefore be used with patients who are cognitively challenged. In the present hypothesis paper, we propose a paradigm shift from instrumental learning to classical conditioning, with the aim of discriminating "yes" and "no" thoughts after associating them to positive and negative emotional stimuli respectively. This would represent a first step in the development of a BCI that could be used by AD patients, lending a new direction not only for communication, but also for rehabilitation and diagnosis.

Atypical dust species in the ejecta of classical novae

NASA Astrophysics Data System (ADS)

Helton, L. A.; Evans, A.; Woodward, C. E.; Gehrz, R. D.

2011-03-01

A classical nova outburst arises from a thermonuclear runaway in the hydrogen-rich material accreted onto the surface of a white dwarf in a binary system. These explosions can produce copious amounts of heavy element enriched material that are ejected violently into the surrounding interstellar medium. In some novae, conditions in the ejecta are suitable for the formation of dust of various compositions, including silicates, amorphous carbon, silicon carbide, and hydrocarbons. Multiple dust grain types are sometimes produced in the same system. CO formation in novae may not reach saturation, thus invalidating the usual paradigm in which the C:O ratio determines the dust species. A few novae, such as V705 Cas and DZ Cru, have exhibited emission features near 6, 8, and 11 μmthat are similar to "Unidentified Infrared" (UIR) features, but with significant differences in position and band structure. Here, we present Spitzer IRS spectra of two recent dusty novae, V2361 Cyg and V2362 Cyg, that harbor similar peculiar emission structures superimposed on features arising from carbonaceous grains. In other astronomical objects, such as star forming regions and young stellar objects, emission peaks at 6.2, 7.7, and 11.3 μmhave been associated with polycyclic aromatic hydrocarbon (PAH) complexes. We suggest that hydrogenated amorphous carbon (HAC) may be the source of these features in novae based upon the spectral behavior of the emission features and the conditions under which the dust formed.

A Human Alcohol Self-Administration Paradigm to Model Individual Differences in Impaired Control over Alcohol Use

PubMed Central

Leeman, Robert F.; Corbin, William R.; Nogueira, Christine; Krishnan-Sarin, Suchitra; Potenza, Marc N.; O’Malley, Stephanie S.

2014-01-01

We developed an alcohol self-administration paradigm to model individual differences in impaired control. The paradigm includes moderate drinking guidelines meant to model limits on alcohol consumption, which are typically exceeded by people with impaired control. Possible payment reductions provided a disincentive for excessive drinking. Alcohol use above the guideline, despite possible pay reductions, was considered to be indicative of impaired control. Heavy-drinking 21–25 year-olds (N = 39) were randomized to an experimental condition including the elements of the impaired control paradigm or to a free-drinking condition without these elements. Alcohol self-administration was compared between these two conditions to establish the internal validity of the experimental paradigm. In both conditions, participants self-administered beer and non-alcoholic beverages for 3 hours in a bar setting with 1–3 other participants. Experimental condition participants self-administered significantly fewer beers and drank to lower blood-alcohol concentrations (BACs) on average than those in the free-drinking condition. Experimental condition participants were more likely than free-drinking condition participants to intersperse non-alcoholic beverages with beer and to drink at a slower pace. Although experimental condition participants drank more moderately than those in the free-drinking condition overall, their range of drinking was considerable (BAC range = .024–.097) with several participants drinking excessively. A lower initial subjective response to alcohol and earlier age of alcohol use onset were associated with greater alcohol self-administration in the experimental condition. Given the variability in response, the impaired control laboratory paradigm may have utility for preliminary tests of novel interventions in future studies and for identifying individual differences in problem-drinking risk. PMID:23937598

Evidence for instantaneous e-vector detection in the honeybee using an associative learning paradigm

PubMed Central

Sakura, Midori; Okada, Ryuichi; Aonuma, Hitoshi

2012-01-01

Many insects use the polarization pattern of the sky for obtaining compass information during orientation or navigation. E-vector information is collected by a specialized area in the dorsal-most part of the compound eye, the dorsal rim area (DRA). We tested honeybees' capability of learning certain e-vector orientations by using a classical conditioning paradigm with the proboscis extension reflex. When one e-vector orientation (CS+) was associated with sugar water, while another orientation (CS−) was not rewarded, the honeybees could discriminate CS+ from CS−. Bees whose DRA was inactivated by painting did not learn CS+. When ultraviolet (UV) polarized light (350 nm) was used for CS, the bees discriminated CS+ from CS−, but no discrimination was observed in blue (442 nm) or green light (546 nm). Our data indicate that honeybees can learn and discriminate between different e-vector orientations, sensed by the UV receptors of the DRA, suggesting that bees can determine their flight direction from polarized UV skylight during foraging. Fixing the bees' heads during the experiments did not prevent learning, indicating that they use an ‘instantaneous’ algorithm of e-vector detection; that is, the bees do not need to actively scan the sky with their DRAs (‘sequential’ method) to determine e-vector orientation. PMID:21733901

Attitudes and Defaults Save Lives and Protect the Environment Jointly and Compensatorily: Understanding the Behavioral Efficacy of Nudges and Other Structural Interventions

PubMed Central

Kaiser, Florian G.; Arnold, Oliver; Otto, Siegmar

2014-01-01

A better understanding of when and why nudges (e.g., defaults, visibility or accessibility alterations) and other structural behavior-change measures work or fail can help avoid subsequent surprises such as unexpected political opposition. In this paper, we challenge the unilateral focus on structural interventions—which seemingly control people's behavioral decisions—as such a focus ignores the flipside—namely, attitudes or, as they are called in economics, preferences. We argue for a conceptual understanding of individual behavior that views personal attitudes and behavioral costs as its two separate compensatorily effective determinants. This classical understanding was reintroduced into attitude research as the Campbell paradigm. In the logic of the Campbell paradigm, a person's attitude becomes obvious in the face of the behavioral costs the person surmounts. Technically, individual attitudes reveal themselves in a set of cost-dependent transitively ordered performances. Behavioral costs in turn reflect the structural boundary conditions that are relevant as obstructive and/or supportive environmental forces that generically affect a specific behavior. So far, our research on people’s attitudes toward environmental protection has demonstrated that the Campbell paradigm—and thus its conceptual account of individual behavior—holds true for approximately 95% of the people in a given society. PMID:25379277

Voluntary saccadic eye movements in humans studied with a double-cue paradigm.

PubMed

Sheliga, B M; Brown, V J; Miles, F A

2002-07-01

In the classic double-step paradigm, subjects are required to make a saccade to a visual target that is briefly presented at one location and then shifted to a new location before the subject has responded. The saccades in this situation are "reflexive" in that they are made in response to the appearance of the target itself. In the present experiments we adapted the double-step paradigm to study "voluntary" saccades. For this, several identical targets were always visible and subjects were given a cue to indicate that they should make a saccade to one of them. This cue was then changed to indicate another of the targets before the subject had responded: double-cue (DC) paradigm. The saccadic eye movements in our DC paradigm had many features in common with those in the double-step paradigm and we show that apparent differences can be attributed to the spatio-temporal arrangements of the cues/targets rather than to any intrinsic differences in the programming of these two kinds of eye movements. For example, a feature of our DC paradigm that is not seen in the usual double-step paradigm is that the second cue could cause transient delays of the initial saccade, and these delays still occurred when the second cue was reflexive--provided that it was at the fovea (as in our DC paradigm) and not in the periphery (as in the usual double-step paradigm). Thus, the critical factor for the delay was the retinal (foveal) location of the second cue/target--not whether it was cognitive or reflexive--and we argue that the second cue/target is here acting as a distractor. We conclude that the DC paradigm can be used to study the programming of voluntary saccades in the same way that the double-step paradigm can be used to study reflexive saccades.

Teaching and Demonstrating Classical Conditioning.

ERIC Educational Resources Information Center

Sparrow, John; Fernald, Peter

1989-01-01

Discusses classroom demonstrations of classical conditioning and notes tendencies to misrepresent Pavlov's procedures. Describes the design and construction of the conditioner that is used for demonstrating classical conditioning. Relates how students experience conditioning, generalization, extinction, discrimination, and spontaneous recovery.…

CPM Test-Retest Reliability: "Standard" vs "Single Test-Stimulus" Protocols.

PubMed

Granovsky, Yelena; Miller-Barmak, Adi; Goldstein, Oren; Sprecher, Elliot; Yarnitsky, David

2016-03-01

Assessment of pain inhibitory mechanisms using conditioned pain modulation (CPM) is relevant clinically in prediction of pain and analgesic efficacy. Our objective is to provide necessary estimates of intersession CPM reliability, to enable transformation of the CPM paradigm into a clinical tool. Two cohorts of young healthy subjects (N = 65) participated in two dual-session studies. In Study I, a Bath-Thermode CPM protocol was used, with hot water immersion and contact heat as conditioning- and test-stimuli, respectively, in a classical parallel CPM design introducing test-stimulus first, and then the conditioning- and repeated test-stimuli in parallel. Study II consisted of two CPM protocols: 1) Two-Thermodes, one for each of the stimuli, in the same parallel design as above, and 2) single test-stimulus (STS) protocol with a single administration of a contact heat test-stimulus, partially overlapped in time by a remote shorter contact heat as conditioning stimulus. Test-retest reliability was assessed within 3-7 days. The STS-CPM had superior reliability intraclass correlation (ICC 2 ,: 1  = 0.59) over Bath-Thermode (ICC 2 ,: 1  = 0.34) or Two-Thermodes (ICC 2 ,: 1  = 0.21) protocols. The hand immersion conditioning pain had higher reliability than thermode pain (ICC 2 ,: 1  = 0.76 vs ICC 2 ,: 1  = 0.16). Conditioned test-stimulus pain scores were of good (ICC 2 ,: 1  = 0.62) or fair (ICC 2 ,: 1  = 0.43) reliability for the Bath-Thermode and the STS, respectively, but not for the Two-Thermodes protocol (ICC 2 ,: 1  = 0.20). The newly developed STS-CPM paradigm was more reliable than other CPM protocols tested here, and should be further investigated for its clinical relevance. It appears that large contact size of the conditioning-stimulus and use of single rather than dual test-stimulus pain contribute to augmentation of CPM reliability. © 2015 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Investigating motion sickness using the conditioned taste aversion paradigm

NASA Technical Reports Server (NTRS)

Fox, Robert A.

1991-01-01

The avoidance of foods which are associated with uncomfortable or aversive internal states has long been recognized. Many people are aware, either directly or via anecdotal reports, of individuals who avoid foods which were eaten just before the onset of sickness. Awareness of this phenomenon can be traced to the writings of John Locke. The disruption of diet during cancer therapy is sometimes ascribed to the attribution of an unpleasant quality to foods eaten preceding the sickness induced by therapy itself. In addition, it has long been recognized by the manufacturers of rodent poisons that animals avoid the injection of food treated with nonlethal doses of poison. An important part of the laboratory study of this phenomenon was directed toward studying the role learning plays in this type of avoidance behavior. Following the lead of Garcia and his associates, this avoidance has come to be interpreted as arising from a form of classical conditioning. In typical laboratory studies of this bahavior, a novel food is ingested just prior to exposure to some stimulus, commonly poisoning or irradiation, which produces illness. Following the terminology of classical conditioning, it is common to describe this procedure as one of 'pairing' a conditioned stimulus (CS), the novel food, with an unconditioned stimulus (US), the illness induced by toxicosis or irradiation. Avoidance of the food in succeeding feeding opportunities is viewed as a learned response or a conditioned taste aversion (CTA). Garcia et al. asserted that motion sickness could produce 'gustatory' aversions, but passive motion was first reported as an US to establish CTA by Green and Rachlin. The purpose is to review the manner in which CTA has been used to study motion sickness. Numerous reviews concentrating on other aspects of CTA are available in the existing literature. Readers are encouraged to consult the various papers and edited books for extensive information on other aspects of this literature.

Timing and Causality in the Generation of Learned Eyelid Responses

PubMed Central

Sánchez-Campusano, Raudel; Gruart, Agnès; Delgado-García, José M.

2011-01-01

The cerebellum-red nucleus-facial motoneuron (Mn) pathway has been reported as being involved in the proper timing of classically conditioned eyelid responses. This special type of associative learning serves as a model of event timing for studying the role of the cerebellum in dynamic motor control. Here, we have re-analyzed the firing activities of cerebellar posterior interpositus (IP) neurons and orbicularis oculi (OO) Mns in alert behaving cats during classical eyeblink conditioning, using a delay paradigm. The aim was to revisit the hypothesis that the IP neurons (IPns) can be considered a neuronal phase-modulating device supporting OO Mns firing with an emergent timing mechanism and an explicit correlation code during learned eyelid movements. Optimized experimental and computational tools allowed us to determine the different causal relationships (temporal order and correlation code) during and between trials. These intra- and inter-trial timing strategies expanding from sub-second range (millisecond timing) to longer-lasting ranges (interval timing) expanded the functional domain of cerebellar timing beyond motor control. Interestingly, the results supported the above-mentioned hypothesis. The causal inferences were influenced by the precise motor and pre-motor spike timing in the cause-effect interval, and, in addition, the timing of the learned responses depended on cerebellar–Mn network causality. Furthermore, the timing of CRs depended upon the probability of simulated causal conditions in the cause-effect interval and not the mere duration of the inter-stimulus interval. In this work, the close relation between timing and causality was verified. It could thus be concluded that the firing activities of IPns may be related more to the proper performance of ongoing CRs (i.e., the proper timing as a consequence of the pertinent causality) than to their generation and/or initiation. PMID:21941469

Hearing the shape of the Ising model with a programmable superconducting-flux annealer.

PubMed

Vinci, Walter; Markström, Klas; Boixo, Sergio; Roy, Aidan; Spedalieri, Federico M; Warburton, Paul A; Severini, Simone

2014-07-16

Two objects can be distinguished if they have different measurable properties. Thus, distinguishability depends on the Physics of the objects. In considering graphs, we revisit the Ising model as a framework to define physically meaningful spectral invariants. In this context, we introduce a family of refinements of the classical spectrum and consider the quantum partition function. We demonstrate that the energy spectrum of the quantum Ising Hamiltonian is a stronger invariant than the classical one without refinements. For the purpose of implementing the related physical systems, we perform experiments on a programmable annealer with superconducting flux technology. Departing from the paradigm of adiabatic computation, we take advantage of a noisy evolution of the device to generate statistics of low energy states. The graphs considered in the experiments have the same classical partition functions, but different quantum spectra. The data obtained from the annealer distinguish non-isomorphic graphs via information contained in the classical refinements of the functions but not via the differences in the quantum spectra.

Common Schools: Classical Schools Citizenship Education in a Pluralistic State

ERIC Educational Resources Information Center

Pitts, Timothy Wade

2011-01-01

In the current political climate, where many politicians in both Europe and United States have proclaimed that multi-cultural education has failed as an educational paradigm, there is a growing fear that the very idea of a democratic, multicultural society is untenable over time. In this dissertation, I explore three responses to the question of…

Do U Txt? Event-Related Potentials to Semantic Anomalies in Standard and Texted English

ERIC Educational Resources Information Center

Berger, Natalie I.; Coch, Donna

2010-01-01

Texted English is a hybrid, technology-based language derived from standard English modified to facilitate ease of communication via instant and text messaging. We compared semantic processing of texted and standard English sentences by recording event-related potentials in a classic semantic incongruity paradigm designed to elicit an N400 effect.…

Waiting for the Paradigm Shift: What We Did and Why We Did It.

ERIC Educational Resources Information Center

Borelli, Jan G.

1995-01-01

Public schools are failing because they still provide a classical, rather than an applied, education that prepares students for the real world beyond high school. An Oklahoma high school has revamped its ninth-grade math curriculum to include only algebra and geometry (using calculators and real-world applications) and requires four years of math…

HRD as an Emergent and Negotiated Evolution: An Ethnographic Case Study in the British National Health Service.

ERIC Educational Resources Information Center

Sambrook, Sally

2001-01-01

Using a contingency framework, three stages in the evolution of human resource development (HRD) in the National Health Service were identified: tell (training enacted within the classical management paradigm); sell (a competence approach to development for all employees); and gel (strategic HRD linked to corporate goals and future needs).…

A Forced-Attention Dichotic Listening fMRI Study on 113 Subjects

ERIC Educational Resources Information Center

Kompus, Kristiina; Specht, Karsten; Ersland, Lars; Juvodden, Hilde T.; van Wageningen, Heidi; Hugdahl, Kenneth; Westerhausen, Rene

2012-01-01

We report fMRI and behavioral data from 113 subjects on attention and cognitive control using a variant of the classic dichotic listening paradigm with pairwise presentations of consonant-vowel syllables. The syllable stimuli were presented in a block-design while subjects were in the MR scanner. The subjects were instructed to pay attention to…

New Frontiers in the Intrarenal Renin-Angiotensin System: A Critical Review of Classical and New Paradigms

PubMed Central

Zhuo, Jia L.; Ferrao, Fernanda M.; Zheng, Yun; Li, Xiao C.

2013-01-01

The renin-angiotensin system (RAS) is well-recognized as one of the oldest and most important regulators of arterial blood pressure, cardiovascular, and renal function. New frontiers have recently emerged in the RAS research well beyond its classic paradigm as a potent vasoconstrictor, an aldosterone release stimulator, or a sodium-retaining hormone. First, two new members of the RAS have been uncovered, which include the renin/(Pro)renin receptor (PRR) and angiotensin-converting enzyme 2 (ACE2). Recent studies suggest that prorenin may act on the PRR independent of the classical ACE/ANG II/AT1 receptor axis, whereas ACE2 may degrade ANG II to generate ANG (1–7), which activates the Mas receptor. Second, there is increasing evidence that ANG II may function as an intracellular peptide to activate intracellular and/or nuclear receptors. Third, currently there is a debate on the relative contribution of systemic versus intrarenal RAS to the physiological regulation of blood pressure and the development of hypertension. The objectives of this article are to review and discuss the new insights and perspectives derived from recent studies using novel transgenic mice that either overexpress or are deficient of one key enzyme, ANG peptide, or receptor of the RAS. This information may help us better understand how ANG II acts, both independently or through interactions with other members of the system, to regulate the kidney function and blood pressure in health and disease. PMID:24273531

Ahead of the Curve; Hidden breakthroughs in the biosciences

NASA Astrophysics Data System (ADS)

Levin, Michael; Adams, Dany Spencer

2016-12-01

This unique book is a compendium of carefully curated published papers in the biosciences, which have (or will) precipitate a profound change in prevailing paradigms and research programs. A mix of new and classic papers, it shows the limitations of current thought or identifies novel vistas for investigations that have not yet been explored. The purpose of the book is to highlight scientific gems, most unrecognized, that suggest revisions to key pillars of thought in the biological sciences and further the education of young scientists. This will be achieved by including reprints of papers that demonstrate counter-paradigm, novel directions for future research featuring commentary from current, notable researchers in a variety of areas.

Resolving Risks in Individual Astronauts: A New Paradigm for Critical Path Exposures

NASA Technical Reports Server (NTRS)

Richmond, Robert C.

2005-01-01

The limited number of astronauts available for risk-assessment prevents classic epidemiologic study, and thereby requires alternative approach to assessing risks within individual astronauts exposed to toxic agents identified within the Bioastronautics Critical Path Roadmap (BCPR). Developing a system of noninvasive real-time biodosimetry that provides large datasets for analyses before, during, and after missions for simultaneously determining 1) the kinds of toxic insult, 2) the degree of that insult, both within tissues absorbing that insult, would be usehl for resolving statistically significant risk-assessment in individual astronauts. Therefore, a currently achievable multiparametric paradigm is presented for use in analyzing gene-expression and protein-expression so as to establish predictive outcomes.

Trace conditioning in insects—keep the trace!

PubMed Central

Dylla, Kristina V.; Galili, Dana S.; Szyszka, Paul; Lüdke, Alja

2013-01-01

Trace conditioning is a form of associative learning that can be induced by presenting a conditioned stimulus (CS) and an unconditioned stimulus (US) following each other, but separated by a temporal gap. This gap distinguishes trace conditioning from classical delay conditioning, where the CS and US overlap. To bridge the temporal gap between both stimuli and to form an association between CS and US in trace conditioning, the brain must keep a neural representation of the CS after its termination—a stimulus trace. Behavioral and physiological studies on trace and delay conditioning revealed similarities between the two forms of learning, like similar memory decay and similar odor identity perception in invertebrates. On the other hand differences were reported also, like the requirement of distinct brain structures in vertebrates or disparities in molecular mechanisms in both vertebrates and invertebrates. For example, in commonly used vertebrate conditioning paradigms the hippocampus is necessary for trace but not for delay conditioning, and Drosophila delay conditioning requires the Rutabaga adenylyl cyclase (Rut-AC), which is dispensable in trace conditioning. It is still unknown how the brain encodes CS traces and how they are associated with a US in trace conditioning. Insects serve as powerful models to address the mechanisms underlying trace conditioning, due to their simple brain anatomy, behavioral accessibility and established methods of genetic interference. In this review we summarize the recent progress in insect trace conditioning on the behavioral and physiological level and emphasize similarities and differences compared to delay conditioning. Moreover, we examine proposed molecular and computational models and reassess different experimental approaches used for trace conditioning. PMID:23986710

Development of an aversive Pavlovian-to-instrumental transfer task in rat

PubMed Central

Campese, Vincent; McCue, Margaret; Lázaro-Muñoz, Gabriel; LeDoux, Joseph E.; Cain, Christopher K.

2013-01-01

Pavlovian-to-instrumental transfer (PIT) is an effect whereby a classically conditioned stimulus (CS) enhances ongoing instrumental responding. PIT has been extensively studied with appetitive conditioning but barely at all with aversive conditioning. Although it's been argued that conditioned suppression is a form of aversive PIT, this effect is fundamentally different from appetitive PIT because the CS suppresses, instead of facilitates, responding. Five experiments investigated the importance of a variety of factors on aversive PIT in a rodent Sidman avoidance paradigm in which ongoing shuttling behavior (unsignaled active avoidance or USAA) was facilitated by an aversive CS. Experiment 1 demonstrated a basic PIT effect. Experiment 2 found that a moderate amount of USAA extinction produces the strongest PIT with shuttling rates best at around 2 responses per minute prior to the CS. Experiment 3 tested a protocol in which the USAA behavior was required to reach the 2-response per minute mark in order to trigger the CS presentation and found that this produced robust and reliable PIT. Experiment 4 found that the Pavlovian conditioning US intensity was not a major determinant of PIT strength. Experiment 5 demonstrated that if the CS and US were not explicitly paired during Pavlovian conditioning, PIT did not occur, showing that CS-US learning is required. Together, these studies demonstrate a robust, reliable and stable aversive PIT effect that is amenable to analysis of neural circuitry. PMID:24324417

Nudging and informed consent.

PubMed

Cohen, Shlomo

2013-01-01

Libertarian paternalism's notion of "nudging" refers to steering individual decision making so as to make choosers better off without breaching their free choice. If successful, this may offer an ideal synthesis between the duty to respect patient autonomy and that of beneficence, which at times favors paternalistic influence. A growing body of literature attempts to assess the merits of nudging in health care. However, this literature deals almost exclusively with health policy, while the question of the potential benefit of nudging for the practice of informed consent has escaped systematic analysis. This article focuses on this question. While it concedes that nudging could amount to improper exploitation of cognitive weaknesses, it defends the practice of nudging in a wide range of other conditions. The conclusion is that, when ethically legitimate, nudging offers an important new paradigm for informed consent, with a special potential to overcome the classical dilemma between paternalistic beneficence and respect for autonomy.

When anticipation beats accuracy: Threat alters memory for dynamic scenes.

PubMed

Greenstein, Michael; Franklin, Nancy; Martins, Mariana; Sewack, Christine; Meier, Markus A

2016-05-01

Threat frequently leads to the prioritization of survival-relevant processes. Much of the work examining threat-related processing advantages has focused on the detection of static threats or long-term memory for details. In the present study, we examined immediate memory for dynamic threatening situations. We presented participants with visually neutral, dynamic stimuli using a representational momentum (RM) paradigm, and manipulated threat conceptually. Although the participants in both the threatening and nonthreatening conditions produced classic RM effects, RM was stronger for scenarios involving threat (Exps. 1 and 2). Experiments 2 and 3 showed that this effect does not generalize to the nonthreatening objects within a threatening scene, and that it does not extend to arousing happy situations. Although the increased RM effect for threatening objects by definition reflects reduced accuracy, we argue that this reduced accuracy may be offset by a superior ability to predict, and thereby evade, a moving threat.

Mindfulness Enhances Episodic Memory Performance: Evidence from a Multimethod Investigation

PubMed Central

Goodman, Robert J.; Ryan, Richard M.; Anālayo, Bhikkhu

2016-01-01

Training in mindfulness, classically described as a receptive attentiveness to present events and experiences, has been shown to improve attention and working memory. Both are key to long-term memory formation, and the present three-study series used multiple methods to examine whether mindfulness would enhance episodic memory, a key form of long-term memory. In Study 1 (N = 143), a self-reported state of mindful attention predicted better recognition performance in the Remember-Know (R-K) paradigm. In Study 2 (N = 93), very brief training in a focused attention form of mindfulness also produced better recognition memory performance on the R-K task relative to a randomized, well-matched active control condition. Study 3 (N = 57) extended these findings by showing that relative to randomized active and inactive control conditions the effect of very brief mindfulness training generalized to free-recall memory performance. This study also found evidence for mediation of the mindfulness training—episodic memory relation by intrinsic motivation. These findings indicate that mindful attention can beneficially impact motivation and episodic memory, with potential implications for educational and occupational performance. PMID:27115491

Mindfulness Enhances Episodic Memory Performance: Evidence from a Multimethod Investigation.

PubMed

Brown, Kirk Warren; Goodman, Robert J; Ryan, Richard M; Anālayo, Bhikkhu

2016-01-01

Training in mindfulness, classically described as a receptive attentiveness to present events and experiences, has been shown to improve attention and working memory. Both are key to long-term memory formation, and the present three-study series used multiple methods to examine whether mindfulness would enhance episodic memory, a key form of long-term memory. In Study 1 (N = 143), a self-reported state of mindful attention predicted better recognition performance in the Remember-Know (R-K) paradigm. In Study 2 (N = 93), very brief training in a focused attention form of mindfulness also produced better recognition memory performance on the R-K task relative to a randomized, well-matched active control condition. Study 3 (N = 57) extended these findings by showing that relative to randomized active and inactive control conditions the effect of very brief mindfulness training generalized to free-recall memory performance. This study also found evidence for mediation of the mindfulness training-episodic memory relation by intrinsic motivation. These findings indicate that mindful attention can beneficially impact motivation and episodic memory, with potential implications for educational and occupational performance.

Condition Monitoring for Helicopter Data. Appendix A

NASA Technical Reports Server (NTRS)

Wen, Fang; Willett, Peter; Deb, Somnath

2000-01-01

In this paper the classical "Westland" set of empirical accelerometer helicopter data is analyzed with the aim of condition monitoring for diagnostic purposes. The goal is to determine features for failure events from these data, via a proprietary signal processing toolbox, and to weigh these according to a variety of classification algorithms. As regards signal processing, it appears that the autoregressive (AR) coefficients from a simple linear model encapsulate a great deal of information in a relatively few measurements; it has also been found that augmentation of these by harmonic and other parameters can improve classification significantly. As regards classification, several techniques have been explored, among these restricted Coulomb energy (RCE) networks, learning vector quantization (LVQ), Gaussian mixture classifiers and decision trees. A problem with these approaches, and in common with many classification paradigms, is that augmentation of the feature dimension can degrade classification ability. Thus, we also introduce the Bayesian data reduction algorithm (BDRA), which imposes a Dirichlet prior on training data and is thus able to quantify probability of error in an exact manner, such that features may be discarded or coarsened appropriately.

Unique genetic loci identified for emotional behavior in control and chronic stress conditions.

PubMed

Carhuatanta, Kimberly A K; Shea, Chloe J A; Herman, James P; Jankord, Ryan

2014-01-01

An individual's genetic background affects their emotional behavior and response to stress. Although studies have been conducted to identify genetic predictors for emotional behavior or stress response, it remains unknown how prior stress history alters the interaction between an individual's genome and their emotional behavior. Therefore, the purpose of this study is to identify chromosomal regions that affect emotional behavior and are sensitive to stress exposure. We utilized the BXD behavioral genetics mouse model to identify chromosomal regions that predict fear learning and emotional behavior following exposure to a control or chronic stress environment. 62 BXD recombinant inbred strains and C57BL/6 and DBA/2 parental strains underwent behavioral testing including a classical fear conditioning paradigm and the elevated plus maze. Distinct quantitative trait loci (QTLs) were identified for emotional learning, anxiety and locomotion in control and chronic stress populations. Candidate genes, including those with already known functions in learning and stress were found to reside within the identified QTLs. Our data suggest that chronic stress history reveals novel genetic predictors of emotional behavior.

Learning to breathe? Feedforward regulation of the inspiratory motor drive.

PubMed

Zaman, Jonas; Van den Bergh, Omer; Fannes, Stien; Van Diest, Ilse

2014-09-15

Claims have been made that breathing is in part controlled by feedforward regulation. In a classical conditioning paradigm, we investigated anticipatory increases in the inspiratory motor drive as measured by inspiratory occlusion pressure (P100). In an acquisition phase, an experimental group (N=13) received a low-intensity resistive load (5 cmH2O/l/s) for three consecutive inspirations as Conditioned Stimulus (CS), preceding a load of a stronger intensity (20 cmH2O/l/s) for three subsequent inspirations as unconditioned stimulus (US). The control group (N=11) received the low-intensity load for six consecutive inspirations. In a post-acquisition phase both groups received the low-intensity load for six consecutive inspirations. Responses to the CS-load only differed between groups during the first acquisition trials and a strong increase in P100 during the US-loads was observed, which habituated across the experiment. Our results suggest that the disruption caused by adding low to moderate resistive loads to three consecutive inspirations results in a short-lasting anticipatory increase in inspiratory motor drive. Copyright © 2014 Elsevier B.V. All rights reserved.

Reprint of "Learning to breathe? Feedforward regulation of the inspiratory motor drive".

PubMed

Zaman, Jonas; Van den Bergh, Omer; Fannes, Stien; Van Diest, Ilse

2014-12-01

Claims have been made that breathing is in part controlled by feedforward regulation. In a classical conditioning paradigm, we investigated anticipatory increases in the inspiratory motor drive as measured by inspiratory occlusion pressure (P100). In an acquisition phase, an experimental group (N = 13) received a low-intensity resistive load (5 cmH2O/l/s) for three consecutive inspirations as Conditioned Stimulus (CS), preceding a load of a stronger intensity (20 cmH2O/l/s) for three subsequent inspirations as unconditioned stimulus (US). The control group (N = 11) received the low-intensity load for six consecutive inspirations. In a post-acquisition phase both groups received the low-intensity load for six consecutive inspirations. Responses to the CS-load only differed between groups during the first acquisition trials and a strong increase in P100 during the US-loads was observed, which habituated across the experiment. Our results suggest that the disruption caused by adding low to moderate resistive loads to three consecutive inspirations results in a short-lasting anticipatory increase in inspiratory motor drive. Copyright © 2014 Elsevier B.V. All rights reserved.

Unique genetic loci identified for emotional behavior in control and chronic stress conditions

PubMed Central

Carhuatanta, Kimberly A. K.; Shea, Chloe J. A.; Herman, James P.; Jankord, Ryan

2014-01-01

An individual's genetic background affects their emotional behavior and response to stress. Although studies have been conducted to identify genetic predictors for emotional behavior or stress response, it remains unknown how prior stress history alters the interaction between an individual's genome and their emotional behavior. Therefore, the purpose of this study is to identify chromosomal regions that affect emotional behavior and are sensitive to stress exposure. We utilized the BXD behavioral genetics mouse model to identify chromosomal regions that predict fear learning and emotional behavior following exposure to a control or chronic stress environment. 62 BXD recombinant inbred strains and C57BL/6 and DBA/2 parental strains underwent behavioral testing including a classical fear conditioning paradigm and the elevated plus maze. Distinct quantitative trait loci (QTLs) were identified for emotional learning, anxiety and locomotion in control and chronic stress populations. Candidate genes, including those with already known functions in learning and stress were found to reside within the identified QTLs. Our data suggest that chronic stress history reveals novel genetic predictors of emotional behavior. PMID:25374516

A Classical Conditioning Procedure for the Hearing Assessment of Multiply Handicapped Persons.

ERIC Educational Resources Information Center

Lancioni, Giulio E.; And Others

1989-01-01

Hearing assessments of multiply handicapped children/adolescents were conducted using classical conditioning (with an air puff as unconditioned stimulus) and operant conditioning (with a modified visual reinforcement audiometry procedure or edible reinforcement). Findings indicate that classical conditioning was successful with 21 of the 23…

Conditioning of Attitudes Using a Backward Conditioning Paradigm. Language, Personality, Social and Cross-Cultural Study and Measurement of the Human A-R-D (Motivational) System.

ERIC Educational Resources Information Center

Brewer, Barbara A.; Gross, Michael C.

In order to test whether meaning will transfer when a backward conditioning paradigm is utilized, Staats' language conditioning procedure, including the pairing of unconditioned stimulus (UCS) evaluative words with conditioned stimulus (CS) nonsense syllables, was modified so that the UCS words preceded the CS nonsense syllables on each trial.…

Development of Nonword and Irregular Word Lists for Australian Grade 3 Students Using Rasch Analysis

ERIC Educational Resources Information Center

Callinan, Sarah; Cunningham, Everarda; Theiler, Stephen

2014-01-01

Many tests used in educational settings to identify learning difficulties endeavour to pick up only the lowest performers. Yet these tests are generally developed within a Classical Test Theory (CTT) paradigm that assumes that data do not have significant skew. Rasch analysis is more tolerant of skew and was used to validate two newly developed…

From Musical Detectives to DJs: Expanding Aural Skills and Analysis through Engaging Popular Music and Culture

ERIC Educational Resources Information Center

Tobias, Evan S.

2015-01-01

Many music educators address aural skills and analysis by drawing on strategies designed for the realm of Western classical music. Focusing solely on aural skills and analysis within paradigms of Western music can limit students' musical learning and engagement to particular ways of knowing music. To diversify and broaden the types of aural skills…

To Be or Not to Be...a Frog: The Frog Prince and Shifting Paradigms.

ERIC Educational Resources Information Center

Crane, Lisa Marie

1997-01-01

Discusses three modern variations of the classic "Frog Prince" folk tale: "Pondlarker" (Fred Gwynne); "The Frog Prince Continued" (Jon Scieszka); and "The Prince of the Pond" (Donna Jo Napoli). Notes that these variants create a world in which frogs can have values, wisdom, and emotion, and in which frogs can influence the ways of humanity. (RS)

The physiognomic unity of sign, word, and gesture.

PubMed

Cornejo, Carlos; Musa, Roberto

2017-01-01

Goldin-Meadow & Brentari (G-M&B) are implicitly going against the dominant paradigm in language research, namely, the "speech as written language" metaphor that portrays vocal sounds and bodily signs as means of delivering stable word meanings. We argue that Heinz Werner's classical research on the physiognomic properties of language supports and complements their view of sign and gesture as a unified system.

Quasi-classical modeling of molecular quantum-dot cellular automata multidriver gates

NASA Astrophysics Data System (ADS)

Rahimi, Ehsan; Nejad, Shahram Mohammad

2012-05-01

Molecular quantum-dot cellular automata (mQCA) has received considerable attention in nanoscience. Unlike the current-based molecular switches, where the digital data is represented by the on/off states of the switches, in mQCA devices, binary information is encoded in charge configuration within molecular redox centers. The mQCA paradigm allows high device density and ultra-low power consumption. Digital mQCA gates are the building blocks of circuits in this paradigm. Design and analysis of these gates require quantum chemical calculations, which are demanding in computer time and memory. Therefore, developing simple models to probe mQCA gates is of paramount importance. We derive a semi-classical model to study the steady-state output polarization of mQCA multidriver gates, directly from the two-state approximation in electron transfer theory. The accuracy and validity of this model are analyzed using full quantum chemistry calculations. A complete set of logic gates, including inverters and minority voters, are implemented to provide an appropriate test bench in the two-dot mQCA regime. We also briefly discuss how the QCADesigner tool could find its application in simulation of mQCA devices.

Changes in complex spike activity during classical conditioning

PubMed Central

Rasmussen, Anders; Jirenhed, Dan-Anders; Wetmore, Daniel Z.; Hesslow, Germund

2014-01-01

The cerebellar cortex is necessary for adaptively timed conditioned responses (CRs) in eyeblink conditioning. During conditioning, Purkinje cells acquire pause responses or “Purkinje cell CRs” to the conditioned stimuli (CS), resulting in disinhibition of the cerebellar nuclei (CN), allowing them to activate motor nuclei that control eyeblinks. This disinhibition also causes inhibition of the inferior olive (IO), via the nucleo-olivary pathway (N-O). Activation of the IO, which relays the unconditional stimulus (US) to the cortex, elicits characteristic complex spikes in Purkinje cells. Although Purkinje cell activity, as well as stimulation of the CN, is known to influence IO activity, much remains to be learned about the way that learned changes in simple spike firing affects the IO. In the present study, we analyzed changes in simple and complex spike firing, in extracellular Purkinje cell records, from the C3 zone, in decerebrate ferrets undergoing training in a conditioning paradigm. In agreement with the N-O feedback hypothesis, acquisition resulted in a gradual decrease in complex spike activity during the conditioned stimulus, with a delay that is consistent with the long N-O latency. Also supporting the feedback hypothesis, training with a short interstimulus interval (ISI), which does not lead to acquisition of a Purkinje cell CR, did not cause a suppression of complex spike activity. In contrast, observations that extinction did not lead to a recovery in complex spike activity and the irregular patterns of simple and complex spike activity after the conditioned stimulus are less conclusive. PMID:25140129

Inconsistent-handed advantage in episodic memory extends to paragraph-level materials.

PubMed

Prichard, Eric C; Christman, Stephen D

2017-09-01

Past research using handedness as a proxy for functional access to the right hemisphere demonstrates that individuals who are mixed/inconsistently handed outperform strong/consistently handed individuals when performing episodic recall tasks. However, research has generally been restricted to stimuli presented in a list format. In the present paper, we present two studies in which participants were presented with paragraph-level material and then asked to recall material from the passages. The first study was based on a classic study looking at retroactive interference with prose materials. The second was modelled on a classic experiment looking at perspective taking and the content of memory. In both studies, the classic effects were replicated and the general finding that mixed/inconsistent-handers outperform strong/consistent-handers was replicated. This suggests that considering degree of handedness may be an empirically useful means of reducing error variance in paradigms looking at memory for prose level material.

Anorexia nervosa in children and adolescents: diagnosis, treatment and the role of the pediatrician.

PubMed

Silber, T J

2013-02-01

The diagnosis and treatment of anorexia nervosa (AN) in children and adolescents has some commonality but also differs from that of this condition in adults. A new understanding of AN is emerging: research data from the fields of epidemiology, genetics, and brain biology, suggest that there may be an underlying brain diathesis predisposing towards AN. It is now proposed that that what starts as a harmless diet, once it turns into a more prolonged food restriction may trigger an eating disorder in a genetically neurobiologically predisposed population. The condition may be then perpetuated by the biochemical changes induced by weight loss, ketosis, and the impact of the ensuing malnutrition on the brain (starvation illness). This change of paradigm from a psychological understanding to a neurobiological conceptualization calls for an early intervention to assure nutritional rehabilitation as soon as an eating disorder is suspected in children, without needing to wait for all the classical features of the diagnosis as seen in adults. This new model is agnostic about the origins of the disease and questions the classic assumption of "an underlying family pathology". It gives strong support to treatments such as Family Based Treatment, also referred to as the "Maudsley method". Essentially this consists of empowering parents to monitor and supervise the nutritional rehabilitation of their children. Hence pediatricians no longer need to be bystanders when treating these children and adolescents. They now have a clearly defined role: early diagnosticians, clinical monitors (of potential medical complications), nutrition advisors, and as members of a multidisciplinary team, patient and family advocates and educators.

Tactile and bone-conduction auditory brain computer interface for vision and hearing impaired users.

PubMed

Rutkowski, Tomasz M; Mori, Hiromu

2015-04-15

The paper presents a report on the recently developed BCI alternative for users suffering from impaired vision (lack of focus or eye-movements) or from the so-called "ear-blocking-syndrome" (limited hearing). We report on our recent studies of the extents to which vibrotactile stimuli delivered to the head of a user can serve as a platform for a brain computer interface (BCI) paradigm. In the proposed tactile and bone-conduction auditory BCI novel multiple head positions are used to evoke combined somatosensory and auditory (via the bone conduction effect) P300 brain responses, in order to define a multimodal tactile and bone-conduction auditory brain computer interface (tbcaBCI). In order to further remove EEG interferences and to improve P300 response classification synchrosqueezing transform (SST) is applied. SST outperforms the classical time-frequency analysis methods of the non-linear and non-stationary signals such as EEG. The proposed method is also computationally more effective comparing to the empirical mode decomposition. The SST filtering allows for online EEG preprocessing application which is essential in the case of BCI. Experimental results with healthy BCI-naive users performing online tbcaBCI, validate the paradigm, while the feasibility of the concept is illuminated through information transfer rate case studies. We present a comparison of the proposed SST-based preprocessing method, combined with a logistic regression (LR) classifier, together with classical preprocessing and LDA-based classification BCI techniques. The proposed tbcaBCI paradigm together with data-driven preprocessing methods are a step forward in robust BCI applications research. Copyright © 2014 Elsevier B.V. All rights reserved.

E-health beyond technology: analyzing the paradigm shift that lies beneath.

PubMed

Moerenhout, Tania; Devisch, Ignaas; Cornelis, Gustaaf C

2018-03-01

Information and computer technology has come to play an increasingly important role in medicine, to the extent that e-health has been described as a disruptive innovation or revolution in healthcare. The attention is very much focused on the technology itself, and advances that have been made in genetics and biology. This leads to the question: What is changing in medicine today concerning e-health? To what degree could these changes be characterized as a 'revolution'? We will apply the work of Thomas Kuhn, Larry Laudan, Michel Foucault and other philosophers-which offers an alternative understanding of progress and revolution in medicine to the classic discovery-oriented approach-to our analysis. Nowadays, the long-standing curative or reactive paradigm in medicine is facing a crisis due to an aging population, a significant increase in chronic diseases and the development of more expensive diagnostic tools and therapies. This promotes the evolution towards a new paradigm with an emphasis on preventive medicine. E-health constitutes an essential part of this new paradigm that seeks to solve the challenges presented by an aging population, skyrocketing costs and so forth. Our approach changes the focus from the technology itself toward the underlying paradigm shift in medicine. We will discuss the relevance of this approach by applying it to the surge in digital self-tracking through health apps and wearables: the recognition of the underlying paradigm shift leads to a more comprehensive understanding of self-tracking than a solely discovery-oriented or technology-focused view can provide.

Default Mode Network (DMN) Deactivation during Odor-Visual Association

PubMed Central

Karunanayaka, Prasanna R.; Wilson, Donald A.; Tobia, Michael J.; Martinez, Brittany; Meadowcroft, Mark; Eslinger, Paul J.; Yang, Qing X.

2017-01-01

Default mode network (DMN) deactivation has been shown to be functionally relevant for goal-directed cognition. In this study, we investigated the DMN’s role during olfactory processing using two complementary functional magnetic resonance imaging (fMRI) paradigms with identical timing, visual-cue stimulation and response monitoring protocols. Twenty-nine healthy, non-smoking, right-handed adults (mean age = 26±4 yrs., 16 females) completed an odor-visual association fMRI paradigm that had two alternating odor+visual and visual-only trial conditions. During odor+visual trials, a visual cue was presented simultaneously with an odor, while during visual-only trial conditions the same visual cue was presented alone. Eighteen of the 29 participants (mean age = 27.0 ± 6.0 yrs.,11 females) also took part in a control no-odor fMRI paradigm that consisted of visual-only trial conditions which were identical to the visual-only trials in the odor-visual association paradigm. We used Independent Component Analysis (ICA), extended unified structural equation modeling (euSEM), and psychophysiological interaction (PPI) to investigate the interplay between the DMN and olfactory network. In the odor-visual association paradigm, DMN deactivation was evoked by both the odor+visual and visual-only trial conditions. In contrast, the visual-only trials in the no-odor paradigm did not evoke consistent DMN deactivation. In the odor-visual association paradigm, the euSEM and PPI analyses identified a directed connectivity between the DMN and olfactory network which was significantly different between odor+visual and visual-only trial conditions. The results support a strong interaction between the DMN and olfactory network and highlights DMN’s role in task-evoked brain activity and behavioral responses during olfactory processing. PMID:27785847

Quantum Corrections in Nanoplasmonics: Shape, Scale, and Material

NASA Astrophysics Data System (ADS)

Christensen, Thomas; Yan, Wei; Jauho, Antti-Pekka; Soljačić, Marin; Mortensen, N. Asger

2017-04-01

The classical treatment of plasmonics is insufficient at the nanometer-scale due to quantum mechanical surface phenomena. Here, an extension of the classical paradigm is reported which rigorously remedies this deficiency through the incorporation of first-principles surface response functions—the Feibelman d parameters—in general geometries. Several analytical results for the leading-order plasmonic quantum corrections are obtained in a first-principles setting; particularly, a clear separation of the roles of shape, scale, and material is established. The utility of the formalism is illustrated by the derivation of a modified sum rule for complementary structures, a rigorous reformulation of Kreibig's phenomenological damping prescription, and an account of the small-scale resonance shifting of simple and noble metal nanostructures.

Fixed or adapted conditioning intensity for repeated conditioned pain modulation.

PubMed

Hoegh, M; Petersen, K K; Graven-Nielsen, T

2017-12-29

Aims Conditioned pain modulation (CPM) is used to assess descending pain modulation through a test stimulation (TS) and a conditioning stimulation (CS). Due to potential carry-over effects, sequential CPM paradigms might alter the intensity of the CS, which potentially can alter the CPM-effect. This study aimed to investigate the difference between a fixed and adaptive CS intensity on CPM-effect. Methods On the dominant leg of 20 healthy subjects the cuff pressure detection threshold (PDT) was recorded as TS and the pain tolerance threshold (PTT) was assessed on the non-dominant leg for estimating the CS. The difference in PDT before and during CS defined the CPM-effect. The CPM-effect was assessed four times using a CS with intensities of 70% of baseline PTT (fixed) or 70% of PTT measured throughout the session (adaptive). Pain intensity of the conditioning stimulus was assessed on a numeric rating scale (NRS). Data were analyzed with repeated-measures ANOVA. Results No difference was found comparing the four PDTs assessed before CSs for the fixed and the adaptive paradigms. The CS pressure intensity for the adaptive paradigm was increasing during the four repeated assessments (P < 0.01). The pain intensity was similar during the fixed (NRS: 5.8±0.5) and the adjusted paradigm (NRS: 6.0±0.4). The CPM-effect was higher using the fixed condition compared with the adaptive condition (P < 0.05). Conclusions The current study found that sequential CPM paradigms using a fixed conditioning stimulus produced an increased CPM-effect compared with adaptive and increasing conditioning intensities.

Suppressing flashes of items surrounding targets during calibration of a P300-based brain-computer interface improves performance

NASA Astrophysics Data System (ADS)

Frye, G. E.; Hauser, C. K.; Townsend, G.; Sellers, E. W.

2011-04-01

Since the introduction of the P300 brain-computer interface (BCI) speller by Farwell and Donchin in 1988, the speed and accuracy of the system has been significantly improved. Larger electrode montages and various signal processing techniques are responsible for most of the improvement in performance. New presentation paradigms have also led to improvements in bit rate and accuracy (e.g. Townsend et al (2010 Clin. Neurophysiol. 121 1109-20)). In particular, the checkerboard paradigm for online P300 BCI-based spelling performs well, has started to document what makes for a successful paradigm, and is a good platform for further experimentation. The current paper further examines the checkerboard paradigm by suppressing items which surround the target from flashing during calibration (i.e. the suppression condition). In the online feedback mode the standard checkerboard paradigm is used with a stepwise linear discriminant classifier derived from the suppression condition and one classifier derived from the standard checkerboard condition, counter-balanced. The results of this research demonstrate that using suppression during calibration produces significantly more character selections/min ((6.46) time between selections included) than the standard checkerboard condition (5.55), and significantly fewer target flashes are needed per selection in the SUP condition (5.28) as compared to the RCP condition (6.17). Moreover, accuracy in the SUP and RCP conditions remained equivalent (~90%). Mean theoretical bit rate was 53.62 bits/min in the suppression condition and 46.36 bits/min in the standard checkerboard condition (ns). Waveform morphology also showed significant differences in amplitude and latency.

Adaptation in human visual cortex as a mechanism for rapid discrimination of aversive stimuli.

PubMed

Keil, Andreas; Stolarova, Margarita; Moratti, Stephan; Ray, William J

2007-06-01

The ability to react rapidly and efficiently to adverse stimuli is crucial for survival. Neuroscience and behavioral studies have converged to show that visual information associated with aversive content is processed quickly and accurately and is associated with rapid amplification of the neural responses. In particular, unpleasant visual information has repeatedly been shown to evoke increased cortical activity during early visual processing between 60 and 120 ms following the onset of a stimulus. However, the nature of these early responses is not well understood. Using neutral versus unpleasant colored pictures, the current report examines the time course of short-term changes in the human visual cortex when a subject is repeatedly exposed to simple grating stimuli in a classical conditioning paradigm. We analyzed changes in amplitude and synchrony of large-scale oscillatory activity across 2 days of testing, which included baseline measurements, 2 conditioning sessions, and a final extinction session. We found a gradual increase in amplitude and synchrony of very early cortical oscillations in the 20-35 Hz range across conditioning sessions, specifically for conditioned stimuli predicting aversive visual events. This increase for conditioned stimuli affected stimulus-locked cortical oscillations at a latency of around 60-90 ms and disappeared during extinction. Our findings suggest that reorganization of neural connectivity on the level of the visual cortex acts to optimize early perception of specific features indicative of emotional relevance.

Pavlovian conditioned approach, extinction, and spontaneous recovery to an audiovisual cue paired with an intravenous heroin infusion.

PubMed

Peters, Jamie; De Vries, Taco J

2014-01-01

Novel stimuli paired with exposure to addictive drugs can elicit approach through Pavlovian learning. While such approach behavior, or sign tracking, has been documented for cocaine and alcohol, it has not been shown to occur with opiate drugs like heroin. Most Pavlovian conditioned approach paradigms use an operandum as the sign, so that sign tracking can be easily automated. We were interested in assessing whether approach behavior occurs to an audiovisual cue paired with an intravenous heroin infusion. If so, would this behavior exhibit characteristics of other Pavlovian conditioned behaviors, such as extinction and spontaneous recovery? Rats were repeatedly exposed to an audiovisual cue, similar to that used in standard self-administration models, along with an intravenous heroin infusion. Sign tracking was measured in an automated fashion by analyzing motion pixels within the cue zone during each cue presentation. We were able to observe significant sign tracking after only five pairings of the conditioned stimulus (CS) with the unconditioned stimulus (US). This behavior rapidly extinguished over 2 days, but exhibited pronounced spontaneous recovery 3 weeks later. We conclude that sign tracking measured by these methods exhibits all the characteristics of a classically conditioned behavior. This model can be used to examine the Pavlovian component of drug memories, alone, or in combination with self-administration methods.

Quantum-correlation breaking channels, quantum conditional probability and Perron-Frobenius theory

NASA Astrophysics Data System (ADS)

Chruściński, Dariusz

2013-03-01

Using the quantum analog of conditional probability and classical Bayes theorem we discuss some aspects of particular entanglement breaking channels: quantum-classical and classical-classical channels. Applying the quantum analog of Perron-Frobenius theorem we generalize the recent result of Korbicz et al. (2012) [8] on full and spectrum broadcasting from quantum-classical channels to arbitrary quantum channels.

Early life stress paradigms in rodents: potential animal models of depression?

PubMed

Schmidt, Mathias V; Wang, Xiao-Dong; Meijer, Onno C

2011-03-01

While human depressive illness is indeed uniquely human, many of its symptoms may be modeled in rodents. Based on human etiology, the assumption has been made that depression-like behavior in rats and mice can be modulated by some of the powerful early life programming effects that are known to occur after manipulations in the first weeks of life. Here we review the evidence that is available in literature for early life manipulation as risk factors for the development of depression-like symptoms such as anhedonia, passive coping strategies, and neuroendocrine changes. Early life paradigms that were evaluated include early handling, separation, and deprivation protocols, as well as enriched and impoverished environments. We have also included a small number of stress-related pharmacological models. We find that for most early life paradigms per se, the actual validity for depression is limited. A number of models have not been tested with respect to classical depression-like behaviors, while in many cases, the outcome of such experiments is variable and depends on strain and additional factors. Because programming effects confer vulnerability rather than disease, a number of paradigms hold promise for usefulness in depression research, in combination with the proper genetic background and adult life challenges.

Kappa and Rater Accuracy: Paradigms and Parameters.

PubMed

Conger, Anthony J

2017-12-01

Drawing parallels to classical test theory, this article clarifies the difference between rater accuracy and reliability and demonstrates how category marginal frequencies affect rater agreement and Cohen's kappa (κ). Category assignment paradigms are developed: comparing raters to a standard (index) versus comparing two raters to one another (concordance), using both nonstochastic and stochastic category membership. Using a probability model to express category assignments in terms of rater accuracy and random error, it is shown that observed agreement (Po) depends only on rater accuracy and number of categories; however, expected agreement (Pe) and κ depend additionally on category frequencies. Moreover, category frequencies affect Pe and κ solely through the variance of the category proportions, regardless of the specific frequencies underlying the variance. Paradoxically, some judgment paradigms involving stochastic categories are shown to yield higher κ values than their nonstochastic counterparts. Using the stated probability model, assignments to categories were generated for 552 combinations of paradigms, rater and category parameters, category frequencies, and number of stimuli. Observed means and standard errors for Po, Pe, and κ were fully consistent with theory expectations. Guidelines for interpretation of rater accuracy and reliability are offered, along with a discussion of alternatives to the basic model.

Activity in Face-Responsive Brain Regions is Modulated by Invisible, Attended Faces: Evidence from Masked Priming

PubMed Central

Eger, Evelyn; Dolan, Raymond; Henson, Richard N.

2009-01-01

It is often assumed that neural activity in face-responsive regions of primate cortex correlates with conscious perception of faces. However, whether such activity occurs without awareness is still debated. Using functional magnetic resonance imaging (fMRI) in conjunction with a novel masked face priming paradigm, we observed neural modulations that could not be attributed to perceptual awareness. More specifically, we found reduced activity in several classic face-processing regions, including the “fusiform face area,” “occipital face area,” and superior temporal sulcus, when a face was preceded by a briefly flashed image of the same face, relative to a different face, even when 2 images of the same face differed. Importantly, unlike most previous studies, which have minimized awareness by using conditions of inattention, the present results occurred when the stimuli (the primes) were attended. By contrast, when primes were perceived consciously, in a long-lag priming paradigm, we found repetition-related activity increases in additional frontal and parietal regions. These data not only demonstrate that fMRI activity in face-responsive regions can be modulated independently of perceptual awareness, but also document where such subliminal face-processing occurs (i.e., restricted to face-responsive regions of occipital and temporal cortex) and to what extent (i.e., independent of the specific image). PMID:18400791

Effects of stop-signal probability in the stop-signal paradigm: the N2/P3 complex further validated.

PubMed

Ramautar, J R; Kok, A; Ridderinkhof, K R

2004-11-01

The aim of this study was to examine the effects of frequency of occurrence of stop signals in the stop-signal paradigm. Presenting stop signals less frequently resulted in faster reaction times to the go stimulus and a lower probability of inhibition. Also, go stimuli elicited larger and somewhat earlier P3 responses when stop signals occurred less frequently. Since the amplitude effect was more pronounced on trials when go signals were followed by fast than slow reactions, it probably reflected a stronger set to produce fast responses. N2 and P3 components to stop signals were observed to be larger and of longer latency when stop signals occurred less frequently. The amplitude enhancement of these N2 and P3 components were more pronounced for unsuccessful than for successful stop-signal trials. Moreover, the successfully inhibited stop trials elicited a frontocentral P3 whereas unsuccessfully inhibited stop trials elicited a more posterior P3 that resembled the classical P3b. P3 amplitude in the unsuccessfully inhibited condition also differed between waveforms synchronized with the stop signal and waveforms synchronized with response onset whereas N2 amplitude did not. Taken together these findings suggest that N2 reflected a greater significance of failed inhibitions after low probability stop signals while P3 reflected continued processing of the erroneous response after response execution.

Extending In Vitro Conditioning in "Aplysia" to Analyze Operant and Classical Processes in the Same Preparation

ERIC Educational Resources Information Center

Brembs, Bjorn; Baxter, Douglas A.; Byrne, John H.

2004-01-01

Operant and classical conditioning are major processes shaping behavioral responses in all animals. Although the understanding of the mechanisms of classical conditioning has expanded significantly, the understanding of the mechanisms of operant conditioning is more limited. Recent developments in "Aplysia" are helping to narrow the gap in the…

Color congruity effect: where do colors and numbers interact in synesthesia?

PubMed

Cohen Kadosh, Roi; Henik, Avishai

2006-02-01

The traditional size congruity paradigm is a Stroop-like situation where participants are asked to compare the values of two digits and ignore the irrelevant physical sizes of the digits (e.g., 3 5). Here a color congruity paradigm was employed and the irrelevant physical sizes were replaced by irrelevant colors. MM, a digit-color synesthete, yielded the classical congruity effect. Namely, she was slower to identify numerically larger numbers when they deviated from her synesthetic experience than when they matched it. In addition, the effect of color on her comparative judgments was modulated by numerical distance. In contrast, performance of non-synesthetes was not affected by the colors. On the basis of neurophysiological studies of magnitude comparison and interference between numerical and physical information, it is proposed that the interaction between colors and digits in MM occurs at the conceptual level. Moreover, by using the current paradigm it is possible to determine the stage at which color-digit binding in synesthesia occurs.

The virtual mirror: a new interaction paradigm for augmented reality environments.

PubMed

Bichlmeier, Christoph; Heining, Sandro Michael; Feuerstein, Marco; Navab, Nassir

2009-09-01

Medical augmented reality (AR) has been widely discussed within the medical imaging as well as computer aided surgery communities. Different systems for exemplary medical applications have been proposed. Some of them produced promising results. One major issue still hindering AR technology to be regularly used in medical applications is the interaction between physician and the superimposed 3-D virtual data. Classical interaction paradigms, for instance with keyboard and mouse, to interact with visualized medical 3-D imaging data are not adequate for an AR environment. This paper introduces the concept of a tangible/controllable Virtual Mirror for medical AR applications. This concept intuitively augments the direct view of the surgeon with all desired views on volumetric medical imaging data registered with the operation site without moving around the operating table or displacing the patient. We selected two medical procedures to demonstrate and evaluate the potentials of the Virtual Mirror for the surgical workflow. Results confirm the intuitiveness of this new paradigm and its perceptive advantages for AR-based computer aided interventions.

Solitons Experience for Black Hole Production in Ultrarelativistic Particle Collisions

NASA Astrophysics Data System (ADS)

Ya. Aref'eva, I.

2012-11-01

We discuss the analogy between soliton scattering in quantum field theory and black hole/wormholes (BH/WH) production in ultrarelativistic particle collisions in gravity. It is a common wisdom of the current paradigm suggests that BH/WH formation in particles collisions will happen when a center-mass energy of colliding particles is sufficiently above the Planck scale (the transplanckian region) and the BH/WH production can be estimated by the classical geometrical cross section. We compare the background of this paradigm with the functional integral method to scattering amplitudes and, in particular, we stress the analogy of the BH production in collision of ultrarelativistic particle and appearance of breathers poles in the scattering amplitudes in the Sin-Gordon model.

Solitons Experience for Black Hole Production in Ultrarelativistic Particle Collisions

NASA Astrophysics Data System (ADS)

Aref'eva, I. Ya.

2013-06-01

We discuss the analogy between soliton scattering in quantum field theory and black hole/wormholes (BH/WH) production in ultrarelativistic particle collisions in gravity. It is a common wisdom of the current paradigm suggests that BH/WH formation in particles collisions will happen when a center-mass energy of colliding particles is sufficiently above the Planck scale (the transplanckian region) and the BH/WH production can be estimated by the classical geometrical cross section. We compare the background of this paradigm with the functional integral method to scattering amplitudes and, in particular, we stress the analogy of the BH production in collision of ultrarelativistic particle and appearance of breathers poles in the scattering amplitudes in the Sin-Gordon model.

Vaccine development for emerging virulent infectious diseases.

PubMed

Maslow, Joel N

2017-10-04

The recent outbreak of Zaire Ebola virus in West Africa altered the classical paradigm of vaccine development and that for emerging infectious diseases (EIDs) in general. In this paper, the precepts of vaccine discovery and advancement through pre-clinical and clinical assessment are discussed in the context of the recent Ebola virus, Middle East Respiratory Syndrome coronavirus (MERS-CoV), and Zika virus outbreaks. Clinical trial design for diseases with high mortality rates and/or high morbidity in the face of a global perception of immediate need and the factors that drive design in the face of a changing epidemiology are presented. Vaccines for EIDs thus present a unique paradigm to standard development precepts. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rapid prefrontal cortex activation towards aversively paired faces and enhanced contingency detection are observed in highly trait-anxious women under challenging conditions

PubMed Central

Rehbein, Maimu Alissa; Wessing, Ida; Zwitserlood, Pienie; Steinberg, Christian; Eden, Annuschka Salima; Dobel, Christian; Junghöfer, Markus

2015-01-01

Relative to healthy controls, anxiety-disorder patients show anomalies in classical conditioning that may either result from, or provide a risk factor for, clinically relevant anxiety. Here, we investigated whether healthy participants with enhanced anxiety vulnerability show abnormalities in a challenging affective-conditioning paradigm, in which many stimulus-reinforcer associations had to be acquired with only few learning trials. Forty-seven high and low trait-anxious females underwent MultiCS conditioning, in which 52 different neutral faces (CS+) were paired with an aversive noise (US), while further 52 faces (CS−) remained unpaired. Emotional learning was assessed by evaluative (rating), behavioral (dot-probe, contingency report), and neurophysiological (magnetoencephalography) measures before, during, and after learning. High and low trait-anxious groups did not differ in evaluative ratings or response priming before or after conditioning. High trait-anxious women, however, were better than low trait-anxious women at reporting CS+/US contingencies after conditioning, and showed an enhanced prefrontal cortex (PFC) activation towards CS+ in the M1 (i.e., 80–117 ms) and M170 time intervals (i.e., 140–160 ms) during acquisition. These effects in MultiCS conditioning observed in individuals with elevated trait anxiety are consistent with theories of enhanced conditionability in anxiety vulnerability. Furthermore, they point towards increased threat monitoring and detection in highly trait-anxious females, possibly mediated by alterations in visual working memory. PMID:26113814

Continuous-variable quantum network coding for coherent states

NASA Astrophysics Data System (ADS)

Shang, Tao; Li, Ke; Liu, Jian-wei

2017-04-01

As far as the spectral characteristic of quantum information is concerned, the existing quantum network coding schemes can be looked on as the discrete-variable quantum network coding schemes. Considering the practical advantage of continuous variables, in this paper, we explore two feasible continuous-variable quantum network coding (CVQNC) schemes. Basic operations and CVQNC schemes are both provided. The first scheme is based on Gaussian cloning and ADD/SUB operators and can transmit two coherent states across with a fidelity of 1/2, while the second scheme utilizes continuous-variable quantum teleportation and can transmit two coherent states perfectly. By encoding classical information on quantum states, quantum network coding schemes can be utilized to transmit classical information. Scheme analysis shows that compared with the discrete-variable paradigms, the proposed CVQNC schemes provide better network throughput from the viewpoint of classical information transmission. By modulating the amplitude and phase quadratures of coherent states with classical characters, the first scheme and the second scheme can transmit 4{log _2}N and 2{log _2}N bits of information by a single network use, respectively.

The sound of music: differentiating musicians using a fast, musical multi-feature mismatch negativity paradigm.

PubMed

Vuust, Peter; Brattico, Elvira; Seppänen, Miia; Näätänen, Risto; Tervaniemi, Mari

2012-06-01

Musicians' skills in auditory processing depend highly on instrument, performance practice, and on level of expertise. Yet, it is not known though whether the style/genre of music might shape auditory processing in the brains of musicians. Here, we aimed at tackling the role of musical style/genre on modulating neural and behavioral responses to changes in musical features. Using a novel, fast and musical sounding multi-feature paradigm, we measured the mismatch negativity (MMN), a pre-attentive brain response, to six types of musical feature change in musicians playing three distinct styles of music (classical, jazz, rock/pop) and in non-musicians. Jazz and classical musicians scored higher in the musical aptitude test than band musicians and non-musicians, especially with regards to tonal abilities. These results were extended by the MMN findings: jazz musicians had larger MMN-amplitude than all other experimental groups across the six different sound features, indicating a greater overall sensitivity to auditory outliers. In particular, we found enhanced processing of pith and sliding up to pitches in jazz musicians only. Furthermore, we observed a more frontal MMN to pitch and location compared to the other deviants in jazz musicians and left lateralization of the MMN to timbre in classical musicians. These findings indicate that the characteristics of the style/genre of music played by musicians influence their perceptual skills and the brain processing of sound features embedded in a musical context. Musicians' brain is hence shaped by the type of training, musical style/genre, and listening experiences. Copyright © 2012 Elsevier Ltd. All rights reserved.

Comparing Language Lateralization Determined by Dichotic Listening and fMRI Activation in Frontal and Temporal Lobes in Children with Epilepsy

ERIC Educational Resources Information Center

Fernandes, M. A.; Smith, M. L.; Logan, W.; Crawley, A.; McAndrews, M. P.

2006-01-01

We investigated the relationship between ear advantage scores on the Fused Dichotic Words Test (FDWT), and laterality of activation in fMRI using a verb generation paradigm in fourteen children with epilepsy. The magnitude of the laterality index (LI), based on spatial extent and magnitude of activation in classical language areas (BA 44/45,…

Negative Priming Effect after Inhibition of Weight/Number Interference in a Piaget-Like Task

ERIC Educational Resources Information Center

Schirlin, Olivier; Houde, Olivier

2007-01-01

Piagetian tasks have more to do with the child's ability to inhibit interference than they do with the ability to grasp their underlying logic. Here we used a chronometric paradigm with 11-year-olds, who succeed in Piaget's conservation-of-weight task, to test the role of cognitive inhibition in a priming version of this classical task. The…

Driving Student-Centred Calculus: Results of a Comprehensive Case Study for Kaizen Learning in the Sultanate of Oman

ERIC Educational Resources Information Center

Heim, Bernhard; Rupp, Florian; Viet, Nils; Stockhausen, Paul v.; Gallenkämper, Jonas; Kreuzer, Judith

2015-01-01

The art of teaching freshmen students is undergoing a rapid paradigm change. Classical forms of teaching are not applicable any more and an unmanageable offer of new multimedia tools and concepts is glutting the market. Moreover, compared to previous courses, the class size triples. In view of these challenges, we implemented a new teaching…

Model-Driven Analysis of Eyeblink Classical Conditioning Reveals the Underlying Structure of Cerebellar Plasticity and Neuronal Activity.

PubMed

Antonietti, Alberto; Casellato, Claudia; D'Angelo, Egidio; Pedrocchi, Alessandra

The cerebellum plays a critical role in sensorimotor control. However, how the specific circuits and plastic mechanisms of the cerebellum are engaged in closed-loop processing is still unclear. We developed an artificial sensorimotor control system embedding a detailed spiking cerebellar microcircuit with three bidirectional plasticity sites. This proved able to reproduce a cerebellar-driven associative paradigm, the eyeblink classical conditioning (EBCC), in which a precise time relationship between an unconditioned stimulus (US) and a conditioned stimulus (CS) is established. We challenged the spiking model to fit an experimental data set from human subjects. Two subsequent sessions of EBCC acquisition and extinction were recorded and transcranial magnetic stimulation (TMS) was applied on the cerebellum to alter circuit function and plasticity. Evolutionary algorithms were used to find the near-optimal model parameters to reproduce the behaviors of subjects in the different sessions of the protocol. The main finding is that the optimized cerebellar model was able to learn to anticipate (predict) conditioned responses with accurate timing and success rate, demonstrating fast acquisition, memory stabilization, rapid extinction, and faster reacquisition as in EBCC in humans. The firing of Purkinje cells (PCs) and deep cerebellar nuclei (DCN) changed during learning under the control of synaptic plasticity, which evolved at different rates, with a faster acquisition in the cerebellar cortex than in DCN synapses. Eventually, a reduced PC activity released DCN discharge just after the CS, precisely anticipating the US and causing the eyeblink. Moreover, a specific alteration in cortical plasticity explained the EBCC changes induced by cerebellar TMS in humans. In this paper, for the first time, it is shown how closed-loop simulations, using detailed cerebellar microcircuit models, can be successfully used to fit real experimental data sets. Thus, the changes of the model parameters in the different sessions of the protocol unveil how implicit microcircuit mechanisms can generate normal and altered associative behaviors.The cerebellum plays a critical role in sensorimotor control. However, how the specific circuits and plastic mechanisms of the cerebellum are engaged in closed-loop processing is still unclear. We developed an artificial sensorimotor control system embedding a detailed spiking cerebellar microcircuit with three bidirectional plasticity sites. This proved able to reproduce a cerebellar-driven associative paradigm, the eyeblink classical conditioning (EBCC), in which a precise time relationship between an unconditioned stimulus (US) and a conditioned stimulus (CS) is established. We challenged the spiking model to fit an experimental data set from human subjects. Two subsequent sessions of EBCC acquisition and extinction were recorded and transcranial magnetic stimulation (TMS) was applied on the cerebellum to alter circuit function and plasticity. Evolutionary algorithms were used to find the near-optimal model parameters to reproduce the behaviors of subjects in the different sessions of the protocol. The main finding is that the optimized cerebellar model was able to learn to anticipate (predict) conditioned responses with accurate timing and success rate, demonstrating fast acquisition, memory stabilization, rapid extinction, and faster reacquisition as in EBCC in humans. The firing of Purkinje cells (PCs) and deep cerebellar nuclei (DCN) changed during learning under the control of synaptic plasticity, which evolved at different rates, with a faster acquisition in the cerebellar cortex than in DCN synapses. Eventually, a reduced PC activity released DCN discharge just after the CS, precisely anticipating the US and causing the eyeblink. Moreover, a specific alteration in cortical plasticity explained the EBCC changes induced by cerebellar TMS in humans. In this paper, for the first time, it is shown how closed-loop simulations, using detailed cerebellar microcircuit models, can be successfully used to fit real experimental data sets. Thus, the changes of the model parameters in the different sessions of the protocol unveil how implicit microcircuit mechanisms can generate normal and altered associative behaviors.

Sex Hormones Modulate the Relationship Between Global Advantage, Lateralization, and Interhemispheric Connectivity in a Navon Paradigm

PubMed Central

Harris, TiAnni

2018-01-01

Abstract Sex, stimulus material, and attention condition have previously been related to global advantage (GA; faster responses to global targets than to local targets) on the one hand and lateralization during global–local processing on the other hand. It is presumed that the lateralization of brain functions is either related to the inhibitory influence of the dominant on the nondominant hemisphere or reduced excitation between hemispheres. However, a direct relationship between the GA and lateralization and interhemispheric connectivity has not been previously established. In this study, 58 participants (29 men, 29 naturally cycling women) completed a Navon paradigm, modulating attention condition (divided vs. focused) and stimulus material (letters vs. shapes) during functional magnetic resonance imaging. The size of the GA effect, lateralization indices, interhemispheric connectivity, and sex hormone levels were assessed. In summary, this study suggests that interhemispheric connectivity during global–local processing is affected by sex and material. Furthermore, the relationship between interhemispheric connectivity, lateralization, and behavior was modulated by sex and sex hormones. Results suggest (1) differential roles of interhemispheric connectivity for lateralization in men and women and (2) differential roles of lateralization for behavior in men and women. Importantly, the classic assumption that a more negative connectivity leads to stronger lateralization, which in turn leads to a stronger GA effect, was observed in men, whereas the opposite pattern was found in women. The relationship between connectivity and lateralization was mediated through testosterone levels, whereas the relationship between lateralization and behavior was mediated through progesterone levels. Results are discussed in light of differential functions of inhibitory and excitatory interhemispheric processes in men and women. PMID:29226703

Different requirements for cAMP response element binding protein in positive and negative reinforcing properties of drugs of abuse.

PubMed

Walters, C L; Blendy, J A

2001-12-01

Addiction is a complex process that relies on the ability of an organism to integrate positive and negative properties of drugs of abuse. Therefore, studying the reinforcing as well as aversive components of drugs of abuse in a single model system will enable us to understand the role of final common mediators, such as cAMP response element-binding protein (CREB), in the addiction process. To this end, we analyzed mice with a mutation in the alpha and Delta isoforms of the CREB gene. Previously we have shown that CREB(alphaDelta) mutant mice in a mixed genetic background show attenuated signs of physical dependence, as measured by the classic signs of withdrawal. We have generated a uniform genetically stable F1 hybrid (129SvEv/C57BL/6) mouse line harboring the CREB mutation. We have found the functional activity of CREB in these F1 hybrid mice to be dramatically reduced compared with their wild-type littermates. These mice maintain a reduced withdrawal phenotype after chronic morphine. We are now poised to examine a number of complex behavioral phenotypes related to addiction in a well defined CREB-deficient mouse model. We demonstrate that the aversive properties of morphine are still present in CREB mutant mice despite a reduction of physical withdrawal. On the other hand, these mice do not respond to the reinforcing properties of morphine in a conditioned place preference paradigm. In contrast, CREB mutant mice demonstrate an enhanced response to the reinforcing properties of cocaine compared with their wild-type controls in both conditioned place preference and sensitization behaviors. These data may provide the first paradigm for differential vulnerability to various drugs of abuse.

Differential Transcriptional Response to Nonassociative and Associative Components of Classical Fear Conditioning in the Amygdala and Hippocampus

ERIC Educational Resources Information Center

Isiegas, Carolina; Stein, Joel; Hellman, Kevin; Hannenhalli, Sridhar; Abel, Ted; Keeley, Michael B.; Wood, Marcelo A.

2006-01-01

Classical fear conditioning requires the recognition of conditioned stimuli (CS) and the association of the CS with an aversive stimulus. We used Affymetrix oligonucleotide microarrays to characterize changes in gene expression compared to naive mice in both the amygdala and the hippocampus 30 min after classical fear conditioning and 30 min after…

The effect of changing the secondary task in dual-task paradigms for measuring listening effort.

PubMed

Picou, Erin M; Ricketts, Todd A

2014-01-01

The purpose of this study was to evaluate the effect of changing the secondary task in dual-task paradigms that measure listening effort. Specifically, the effects of increasing the secondary task complexity or the depth of processing on a paradigm's sensitivity to changes in listening effort were quantified in a series of two experiments. Specific factors investigated within each experiment were background noise and visual cues. Participants in Experiment 1 were adults with normal hearing (mean age 23 years) and participants in Experiment 2 were adults with mild sloping to moderately severe sensorineural hearing loss (mean age 60.1 years). In both experiments, participants were tested using three dual-task paradigms. These paradigms had identical primary tasks, which were always monosyllable word recognition. The secondary tasks were all physical reaction time measures. The stimulus for the secondary task varied by paradigm and was a (1) simple visual probe, (2) a complex visual probe, or (3) the category of word presented. In this way, the secondary tasks mainly varied from the simple paradigm by either complexity or depth of speech processing. Using all three paradigms, participants were tested in four conditions, (1) auditory-only stimuli in quiet, (2) auditory-only stimuli in noise, (3) auditory-visual stimuli in quiet, and (4) auditory-visual stimuli in noise. During auditory-visual conditions, the talker's face was visible. Signal-to-noise ratios used during conditions with background noise were set individually so word recognition performance was matched in auditory-only and auditory-visual conditions. In noise, word recognition performance was approximately 80% and 65% for Experiments 1 and 2, respectively. For both experiments, word recognition performance was stable across the three paradigms, confirming that none of the secondary tasks interfered with the primary task. In Experiment 1 (listeners with normal hearing), analysis of median reaction times revealed a significant main effect of background noise on listening effort only with the paradigm that required deep processing. Visual cues did not change listening effort as measured with any of the three dual-task paradigms. In Experiment 2 (listeners with hearing loss), analysis of median reaction times revealed expected significant effects of background noise using all three paradigms, but no significant effects of visual cues. None of the dual-task paradigms were sensitive to the effects of visual cues. Furthermore, changing the complexity of the secondary task did not change dual-task paradigm sensitivity to the effects of background noise on listening effort for either group of listeners. However, the paradigm whose secondary task involved deeper processing was more sensitive to the effects of background noise for both groups of listeners. While this paradigm differed from the others in several respects, depth of processing may be partially responsible for the increased sensitivity. Therefore, this paradigm may be a valuable tool for evaluating other factors that affect listening effort.

Pedunculopontine tegmental nucleus lesions impair stimulus--reward learning in autoshaping and conditioned reinforcement paradigms.

PubMed

Inglis, W L; Olmstead, M C; Robbins, T W

2000-04-01

The role of the pedunculopontine tegmental nucleus (PPTg) in stimulus-reward learning was assessed by testing the effects of PPTg lesions on performance in visual autoshaping and conditioned reinforcement (CRf) paradigms. Rats with PPTg lesions were unable to learn an association between a conditioned stimulus (CS) and a primary reward in either paradigm. In the autoshaping experiment, PPTg-lesioned rats approached the CS+ and CS- with equal frequency, and the latencies to respond to the two stimuli did not differ. PPTg lesions also disrupted discriminated approaches to an appetitive CS in the CRf paradigm and completely abolished the acquisition of responding with CRf. These data are discussed in the context of a possible cognitive function of the PPTg, particularly in terms of lesion-induced disruptions of attentional processes that are mediated by the thalamus.

Elevated Arc/Arg 3.1 protein expression in the basolateral amygdala following auditory trace-cued fear conditioning.

PubMed

Chau, Lily S; Prakapenka, Alesia; Fleming, Stephen A; Davis, Ashley S; Galvez, Roberto

2013-11-01

The underlying neuronal mechanisms of learning and memory have been heavily explored using associative learning paradigms. Two of the more commonly employed learning paradigms have been contextual and delay fear conditioning. In fear conditioning, a subject learns to associate a neutral stimulus (conditioned stimulus; CS), such as a tone or the context of the room, with a fear provoking stimulus (unconditioned stimulus; US), such as a mild footshock. Utilizing these two paradigms, various analyses have elegantly demonstrated that the amygdala plays a role in both fear-related associative learning paradigms. However, the amygdala's involvement in trace fear conditioning, a forebrain-dependent fear associative learning paradigm that has been suggested to tap into higher cognitive processes, has not been closely investigated. Furthermore, to our knowledge, the specific amygdala nuclei involved with trace fear conditioning has not been examined. The present study used Arc expression as an activity marker to determine the amygdala's involvement in trace fear associative learning and to further explore involvement of specific amygdalar nuclei. Arc is an immediate early gene that has been shown to be associated with neuronal activation and is believed to be necessary for neuronal plasticity. Findings from the present study demonstrated that trace-conditioned mice, compared to backward-conditioned (stimulation-control), delay-conditioned and naïve mice, exhibited elevated amygdalar Arc expression in the basolateral (BLA) but not the central (CeA) or the lateral amygdala (LA). These findings are consistent with previous reports demonstrating that the amygdala plays a critical role in trace conditioning. Furthermore, these findings parallel studies demonstrating hippocampal-BLA activation following contextual fear conditioning, suggesting that trace fear conditioning and contextual fear conditioning may involve similar amygdala nuclei. Together, findings from this study demonstrate similarities in the pathway for trace and contextual fear conditioning, and further suggest possible underlying mechanisms for acquisition and consolidation of these two types of fear-related learning. Copyright © 2013 Elsevier Inc. All rights reserved.

A paradigm shift in orthognathic surgery? A comparison of navigation, computer-aided designed/computer-aided manufactured splints, and "classic" intermaxillary splints to surgical transfer of virtual orthognathic planning.

PubMed

Zinser, Max J; Sailer, Hermann F; Ritter, Lutz; Braumann, Bert; Maegele, Marc; Zöller, Joachim E

2013-12-01

Advances in computers and imaging have permitted the adoption of 3-dimensional (3D) virtual planning protocols in orthognathic surgery, which may allow a paradigm shift when the virtual planning can be transferred properly. The purpose of this investigation was to compare the versatility and precision of innovative computer-aided designed and computer-aided manufactured (CAD/CAM) surgical splints, intraoperative navigation, and "classic" intermaxillary occlusal splints for surgical transfer of virtual orthognathic planning. The protocols consisted of maxillofacial imaging, diagnosis, virtual orthognathic planning, and surgical planning transfer using newly designed CAD/CAM splints (approach A), navigation (approach B), and intermaxillary occlusal splints (approach C). In this prospective observational study, all patients underwent bimaxillary osteotomy. Eight patients were treated using approach A, 10 using approach B, and 12 using approach C. These techniques were evaluated by applying 13 hard and 7 soft tissue parameters to compare the virtual orthognathic planning (T0) with the postoperative result (T1) using 3D cephalometry and image fusion (ΔT1 vs T0). The highest precision (ΔT1 vs T0) for the maxillary planning transfer was observed with CAD/CAM splints (<0.23 mm; P > .05) followed by surgical "waferless" navigation (<0.61 mm, P < .05) and classic intermaxillary occlusal splints (<1.1 mm; P < .05). Only the innovative CAD/CAM splints kept the condyles in their central position in the temporomandibular joint. However, no technique enables a precise prediction of the mandible and soft tissue. CAD/CAM splints and surgical navigation provide a reliable, innovative, and precise approach for the transfer of virtual orthognathic planning. These computer-assisted techniques may offer an alternate approach to the use of classic intermaxillary occlusal splints. Copyright © 2013 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Listening to classical music ameliorates unilateral neglect after stroke.

PubMed

Tsai, Pei-Luen; Chen, Mei-Ching; Huang, Yu-Ting; Lin, Keh-Chung; Chen, Kuan-Lin; Hsu, Yung-Wen

2013-01-01

OBJECTIVE. We determined whether listening to excerpts of classical music ameliorates unilateral neglect (UN) in stroke patients. METHOD. In this within-subject study, we recruited and separately tested 16 UN patients with a right-hemisphere stroke under three conditions within 1 wk. In each condition, participants were asked to complete three subtests of the Behavioral Inattention Test while listening to classical music, white noise, or nothing. All conditions and the presentation of the tests were counterbalanced across participants. Visual analog scales were used to provide self-reported ratings of arousal and mood. RESULTS. Participants generally had the highest scores under the classical music condition and the lowest scores under the silence condition. In addition, most participants rated their arousal as highest after listening to classical music. CONCLUSION. Listening to classical music may improve visual attention in stroke patients with UN. Future research with larger study populations is necessary to validate these findings. Copyright © 2013 by the American Occupational Therapy Association, Inc.

Dissociable Learning Processes Underlie Human Pain Conditioning

PubMed Central

Zhang, Suyi; Mano, Hiroaki; Ganesh, Gowrishankar; Robbins, Trevor; Seymour, Ben

2016-01-01

Summary Pavlovian conditioning underlies many aspects of pain behavior, including fear and threat detection [1], escape and avoidance learning [2], and endogenous analgesia [3]. Although a central role for the amygdala is well established [4], both human and animal studies implicate other brain regions in learning, notably ventral striatum and cerebellum [5]. It remains unclear whether these regions make different contributions to a single aversive learning process or represent independent learning mechanisms that interact to generate the expression of pain-related behavior. We designed a human parallel aversive conditioning paradigm in which different Pavlovian visual cues probabilistically predicted thermal pain primarily to either the left or right arm and studied the acquisition of conditioned Pavlovian responses using combined physiological recordings and fMRI. Using computational modeling based on reinforcement learning theory, we found that conditioning involves two distinct types of learning process. First, a non-specific “preparatory” system learns aversive facial expressions and autonomic responses such as skin conductance. The associated learning signals—the learned associability and prediction error—were correlated with fMRI brain responses in amygdala-striatal regions, corresponding to the classic aversive (fear) learning circuit. Second, a specific lateralized system learns “consummatory” limb-withdrawal responses, detectable with electromyography of the arm to which pain is predicted. Its related learned associability was correlated with responses in ipsilateral cerebellar cortex, suggesting a novel computational role for the cerebellum in pain. In conclusion, our results show that the overall phenotype of conditioned pain behavior depends on two dissociable reinforcement learning circuits. PMID:26711494

Brain response to visceral aversive conditioning: a functional magnetic resonance imaging study.

PubMed

Yágüez, Lidia; Coen, Steven; Gregory, Lloyd J; Amaro, Edson; Altman, Christian; Brammer, Michael J; Bullmore, Edward T; Williams, Steven C R; Aziz, Qasim

2005-06-01

Brain-imaging studies to date have confounded visceral pain perception with anticipation. We used functional magnetic resonance imaging of the human brain to study the neuroanatomic network involved in aversive conditioning of visceral pain and, thus, anticipation. Eight healthy volunteers (5 male) participated in the study. We used a classic conditioning paradigm in which 3 neutral stimuli (differently colored circles) that acted as conditioned stimuli were paired with painful esophageal distention, air puff to the wrist, or nothing, which acted as unconditioned stimuli. Neural activity was measured during learning, anticipation (pairing only 50% of conditioned stimuli with their unconditioned stimuli), and extinction (unpaired conditioned stimuli) phases. For magnetic resonance imaging, axial slices depicting blood oxygen level-dependent contrast were acquired with a 1.5-T system. Neural responses during the learning phase included areas commonly associated with visceral pain (anterior cingulate cortex, insula, and primary and secondary somatosensory cortices) and innocuous somatosensory perception (primary and secondary somatosensory cortices and insula). During the anticipation and extinction phases of aversive stimulation, brain activity resembled that seen during actual painful esophageal stimulation. In contrast, anticipation and extinction of the innocuous somatic stimulus failed to show that effect. We have shown that actual and anticipated visceral pain elicit similar cortical responses. These results have implications for the design and interpretation of brain-imaging studies of visceral pain. They not only contribute to our understanding of the processing of visceral pain, but also have clinical implications for the management of chronic pain states.

Plastic Synaptic Networks of the Amygdala for the Acquisition, Expression, and Extinction of Conditioned Fear

PubMed Central

Pape, Hans-Christian; Pare, Denis

2009-01-01

The last ten years have witnessed a surge of interest for the mechanisms underlying the acquisition and extinction of classically conditioned fear responses. In part, this results from the realization that abnormalities in fear learning mechanisms likely participate to the development and/or maintenance of human anxiety disorders. The simplicity and robustness of this learning paradigm, coupled to the fact that the underlying circuitry is evolutionarily well conserved makes it an ideal model to study the basic biology of memory and identify genetic factors and neuronal systems that regulate the normal and pathological expressions of learned fear. Critical advances have been made in determining how modified neuronal functions upon fear acquisition become stabilized during fear memory consolidation and how these processes are controlled in the course of fear memory extinction. With these advances, came the realization that activity in remote neuronal networks must be coordinated for these events to take place. In this paper, we review these mechanisms of coordinated network activity and the molecular cascades leading to enduring fear memory, and allowing for their extinction. We will focus on Pavlovian fear conditioning as a model and the amygdala as a key component for the acquisition and extinction of fear responses. PMID:20393190

Cholinergic modulation of stimulus-driven attentional capture.

PubMed

Boucart, Muriel; Michael, George Andrew; Bubicco, Giovanna; Ponchel, Amelie; Waucquier, Nawal; Deplanque, Dominique; Deguil, Julie; Bordet, Régis

2015-04-15

Distraction is one of the main problems encountered by people with degenerative diseases that are associated with reduced cortical cholinergic innervations. We examined the effects of donepezil, a cholinesterase inhibitor, on stimulus-driven attentional capture. Reflexive attention shifts to a distractor are usually elicited by abrupt peripheral changes. This bottom-up shift of attention to a salient item is thought to be the result of relatively inflexible hardwired mechanisms. Thirty young male participants were randomly allocated to one of two groups: placebo first/donepezil second session or the opposite. They were asked to locate a target appearing above and below fixation whilst a peripheral distractor moved abruptly (motion-jitter attentional capture condition) or not (baseline condition). A classical attentional capture effect was observed under placebo: moving distractors interfered with the task in slowing down response times as compared to the baseline condition with fixed distractors. Increased interference from moving distractors was found under donepezil. We suggest that attentional capture in our paradigm likely involved low level mechanisms such as automatic reflexive orienting. Peripheral motion-jitter elicited a rapid reflexive orienting response initiated by a cholinergic signal from the brainstem pedunculo-pontine nucleus that activates nicotinic receptors in the superior colliculus. Copyright © 2015 Elsevier B.V. All rights reserved.

Higher threat avoidance costs reduce avoidance behaviour which in turn promotes fear extinction in humans.

PubMed

Rattel, Julina A; Miedl, Stephan F; Blechert, Jens; Wilhelm, Frank H

2017-09-01

Theoretical models specifying the underlying mechanisms of the development and maintenance of anxiety and related disorders state that fear responses acquired through classical Pavlovian conditioning are maintained by repeated avoidance behaviour; thus, it is assumed that avoidance prevents fear extinction. The present study investigated behavioural avoidance decisions as a function of avoidance costs in a naturalistic fear conditioning paradigm. Ecologically valid avoidance costs - manipulated between participant groups - were represented via time-delays during a detour in a gamified computer task. After differential acquisitions of shock-expectancy to a predictive conditioned stimulus (CS+), participants underwent extinction where they could either take a risky shortcut, while anticipating shock signaled by the CS+, or choose a costly avoidance option (lengthy detour); thus, they were faced with an approach-avoidance conflict. Groups with higher avoidance costs (longer detours) showed lower proportions of avoiders. Avoiders gave heightened shock-expectancy ratings post-extinction, demonstrating 'protecting from extinction', i.e. failure to extinguish. Moreover, there was an indirect effect of avoidance costs on protection from extinction through avoidance behaviour. No moderating role of trait-anxiety was found. Theoretical implications of avoidance behaviour are discussed, considering the involvement of instrumental learning in the maintenance of fear responses. Copyright © 2016 Elsevier Ltd. All rights reserved.

Diffusion and related transport mechanisms in brain tissue

NASA Astrophysics Data System (ADS)

Nicholson, Charles

2001-07-01

Diffusion plays a crucial role in brain function. The spaces between cells can be likened to the water phase of a foam and many substances move within this complicated region. Diffusion in this interstitial space can be accurately modelled with appropriate modifications of classical equations and quantified from measurements based on novel micro-techniques. Besides delivering glucose and oxygen from the vascular system to brain cells, diffusion also moves informational substances between cells, a process known as volume transmission. Deviations from expected results reveal how local uptake, degradation or bulk flow may modify the transport of molecules. Diffusion is also essential to many therapies that deliver drugs to the brain. The diffusion-generated concentration distributions of well-chosen molecules also reveal the structure of brain tissue. This structure is represented by the volume fraction (void space) and the tortuosity (hindrance to diffusion imposed by local boundaries or local viscosity). Analysis of these parameters also reveals how the local geometry of the brain changes with time or under pathological conditions. Theoretical and experimental approaches borrow from classical diffusion theory and from porous media concepts. Earlier studies were based on radiotracers but the recent methods use a point-source paradigm coupled with micro-sensors or optical imaging of macromolecules labelled with fluorescent tags. These concepts and methods are likely to be applicable elsewhere to measure diffusion properties in very small volumes of highly structured but delicate material.

Are horses capable of mirror self-recognition? A pilot study.

PubMed

Baragli, Paolo; Demuru, Elisa; Scopa, Chiara; Palagi, Elisabetta

2017-01-01

Mirror Self-Recognition (MSR) unveils complex cognitive, social and emotional skills and it has been found only in humans and few other species, such as great apes, dolphins, elephants and magpies. In this pilot study, we tested if horses show the capacity of MSR. Four subjects living socially under naturalistic conditions were selected for the experiment. We adopted the classical mark test, which consists in placing a coloured mark on an out-of-view body part, visible only through mirror inspection. If the animal considers the image as its own, it will use its reflection to detect the mark and will try to explore it. We enhanced the classical paradigm by introducing a double-check control. Only in the presence of the reflecting surface, animals performed tactile and olfactory exploration of the mirror and looked behind it. These behaviors suggest that subjects were trying to associate multiple sensory cues (visual, tactile and olfactory) to the image in the mirror. The lack of correspondence between the collected stimuli in front of the mirror and the response to the colored mark lead us to affirm that horses are able to perceive that the reflected image is incongruent when compared with the memorized information of a real horse. However, without replication of data, the self-directed behavior towards the colored marks showed by our horses cannot be sufficient per se to affirm that horses are capable of self-recognition.

Analysis and Synthesis of Adaptive Neural Elements and Assemblies

DTIC Science & Technology

1992-12-14

network, a learning rule (activity-dependent neuromodulation ), which has been proposed as a cellular mechanism for classical conditioning , was...activity-dependent neuromodulation ), which has been proposed as a cellular mechanism for classical conditioning, was demonstrated to support many...network, a learning rule (activity-dependent neuromodulation ), which has been proposed as a cellular mechanism for classical conditioning, was

A Continuous False Belief Task Reveals Egocentric Biases in Children and Adolescents with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Begeer, Sander; Bernstein, Daniel M.; van Wijhe, Jonas; Scheeren, Anke M.; Koot, Hans M.

2012-01-01

This study reports on a new false belief measure in a sample of 124 children and adolescents with or without high functioning autism (HFASD). In the classic paradigm, a participant predicts in which of two discrete locations a deceived protagonist will look for an object. In the current Sandbox task, the object is buried and reburied in a sandbox,…

Synergetics in Science and Education

ERIC Educational Resources Information Center

Steklova, I.

2004-01-01

The natural crisis in contemporary culture, conditioned by the emergence of a new cultural paradigm, makes it essential to look for methodological and theoretical foundations of a possible new scientific paradigm, one closely linked to issues in education. In this article, the author presents basic conditions for the self-organization and…

A Closer Examination of the Structured Written Disclosure Procedure.

ERIC Educational Resources Information Center

Sloan, Denise M.; Marx, Brian P.

2004-01-01

The current study examined psychological and physical health outcomes of the written disclosure paradigm and the hypothesis that the principles of therapeutic exposure account for the beneficial effects of the paradigm. Participants were randomly assigned to either a written disclosure condition or a control condition. Reactivity to the writing…

Quantum annealing with parametrically driven nonlinear oscillators

NASA Astrophysics Data System (ADS)

Puri, Shruti

While progress has been made towards building Ising machines to solve hard combinatorial optimization problems, quantum speedups have so far been elusive. Furthermore, protecting annealers against decoherence and achieving long-range connectivity remain important outstanding challenges. With the hope of overcoming these challenges, I introduce a new paradigm for quantum annealing that relies on continuous variable states. Unlike the more conventional approach based on two-level systems, in this approach, quantum information is encoded in two coherent states that are stabilized by parametrically driving a nonlinear resonator. I will show that a fully connected Ising problem can be mapped onto a network of such resonators, and outline an annealing protocol based on adiabatic quantum computing. During the protocol, the resonators in the network evolve from vacuum to coherent states representing the ground state configuration of the encoded problem. In short, the system evolves between two classical states following non-classical dynamics. As will be supported by numerical results, this new annealing paradigm leads to superior noise resilience. Finally, I will discuss a realistic circuit QED realization of an all-to-all connected network of parametrically driven nonlinear resonators. The continuous variable nature of the states in the large Hilbert space of the resonator provides new opportunities for exploring quantum phase transitions and non-stoquastic dynamics during the annealing schedule.

General Relativity without paradigm of space-time covariance, and resolution of the problem of time

NASA Astrophysics Data System (ADS)

Soo, Chopin; Yu, Hoi-Lai

2014-01-01

The framework of a theory of gravity from the quantum to the classical regime is presented. The paradigm shift from full space-time covariance to spatial diffeomorphism invariance, together with clean decomposition of the canonical structure, yield transparent physical dynamics and a resolution of the problem of time. The deep divide between quantum mechanics and conventional canonical formulations of quantum gravity is overcome with a Schrödinger equation for quantum geometrodynamics that describes evolution in intrinsic time. Unitary time development with gauge-invariant temporal ordering is also viable. All Kuchar observables become physical; and classical space-time, with direct correlation between its proper times and intrinsic time intervals, emerges from constructive interference. The framework not only yields a physical Hamiltonian for Einstein's theory, but also prompts natural extensions and improvements towards a well behaved quantum theory of gravity. It is a consistent canonical scheme to discuss Horava-Lifshitz theories with intrinsic time evolution, and of the many possible alternatives that respect 3-covariance (rather than the more restrictive 4-covariance of Einstein's theory), Horava's "detailed balance" form of the Hamiltonian constraint is essentially pinned down by this framework. Issues in quantum gravity that depend on radiative corrections and the rigorous definition and regularization of the Hamiltonian operator are not addressed in this work.

Increasing Working Memory Load Reduces Processing of Cross-Modal Task-Irrelevant Stimuli Even after Controlling for Task Difficulty and Executive Capacity

PubMed Central

Simon, Sharon S.; Tusch, Erich S.; Holcomb, Phillip J.; Daffner, Kirk R.

2016-01-01

The classic account of the load theory (LT) of attention suggests that increasing cognitive load leads to greater processing of task-irrelevant stimuli due to competition for limited executive resource that reduces the ability to actively maintain current processing priorities. Studies testing this hypothesis have yielded widely divergent outcomes. The inconsistent results may, in part, be related to variability in executive capacity (EC) and task difficulty across subjects in different studies. Here, we used a cross-modal paradigm to investigate whether augmented working memory (WM) load leads to increased early distracter processing, and controlled for the potential confounders of EC and task difficulty. Twenty-three young subjects were engaged in a primary visual WM task, under high and low load conditions, while instructed to ignore irrelevant auditory stimuli. Demands of the high load condition were individually titrated to make task difficulty comparable across subjects with differing EC. Event-related potentials (ERPs) were used to measure neural activity in response to stimuli presented in both the task relevant modality (visual) and task-irrelevant modality (auditory). Behavioral results indicate that the load manipulation and titration procedure of the primary visual task were successful. ERPs demonstrated that in response to visual target stimuli, there was a load-related increase in the posterior slow wave, an index of sustained attention and effort. Importantly, under high load, there was a decrease of the auditory N1 in response to distracters, a marker of early auditory processing. These results suggest that increased WM load is associated with enhanced attentional engagement and protection from distraction in a cross-modal setting, even after controlling for task difficulty and EC. Our findings challenge the classic LT and offer support for alternative models. PMID:27536226

Neural cascade of conflict processing: not just time-on-task

PubMed Central

McKay, Cameron C.; van den Berg, Berry; Woldorff, Marty G.

2017-01-01

In visual conflict tasks (e.g., Stroop or flanker), response times (RTs) are generally longer on incongruent trials relative to congruent ones. Two event-related-potential (ERP) components classically associated with the processing of stimulus conflict are the fronto-central, incongruency-related negativity (Ninc) and the posterior late-positive complex (LPC), which are derived from the ERP difference waves for incongruent minus congruent trials. It has been questioned, however, whether these effects, or other neural measures of incongruency (e.g., fMRI responses in the anterior cingulate), reflect true conflict processing, or whether such effects derive mainly from differential time-on-task. To address this question, we leveraged high-temporal-resolution ERP measures of brain activity during two behavioral tasks. The first task, a modified Erikson flanker paradigm (with congruent and incongruent trials), was used to evoke the classic RT and ERP effects associated with conflict. In the second, a non-conflict comparison condition, participants visually discriminated a single stimulus (with easy and hard discrimination conditions). Behaviorally, the parameters were titrated to yield similar RT effects of conflict and difficulty (27 ms). Neurally, both within-task contrasts showed an initial fronto-central negative-polarity wave (N2-latency effect), but they then diverged. In the difficulty difference wave, the initial negativity led directly into the posterior LPC, whereas in the incongruency contrast the initial negativity was followed a by a second fronto-central negative peak (Ninc), which was then followed by a considerably longer-latency LPC. These results provide clear evidence that the longer processing for incongruent stimulus inputs do not just reflect time-on-task or difficulty, but include a true conflict-processing component. PMID:28017818

Increasing Working Memory Load Reduces Processing of Cross-Modal Task-Irrelevant Stimuli Even after Controlling for Task Difficulty and Executive Capacity.

PubMed

Simon, Sharon S; Tusch, Erich S; Holcomb, Phillip J; Daffner, Kirk R

2016-01-01

The classic account of the load theory (LT) of attention suggests that increasing cognitive load leads to greater processing of task-irrelevant stimuli due to competition for limited executive resource that reduces the ability to actively maintain current processing priorities. Studies testing this hypothesis have yielded widely divergent outcomes. The inconsistent results may, in part, be related to variability in executive capacity (EC) and task difficulty across subjects in different studies. Here, we used a cross-modal paradigm to investigate whether augmented working memory (WM) load leads to increased early distracter processing, and controlled for the potential confounders of EC and task difficulty. Twenty-three young subjects were engaged in a primary visual WM task, under high and low load conditions, while instructed to ignore irrelevant auditory stimuli. Demands of the high load condition were individually titrated to make task difficulty comparable across subjects with differing EC. Event-related potentials (ERPs) were used to measure neural activity in response to stimuli presented in both the task relevant modality (visual) and task-irrelevant modality (auditory). Behavioral results indicate that the load manipulation and titration procedure of the primary visual task were successful. ERPs demonstrated that in response to visual target stimuli, there was a load-related increase in the posterior slow wave, an index of sustained attention and effort. Importantly, under high load, there was a decrease of the auditory N1 in response to distracters, a marker of early auditory processing. These results suggest that increased WM load is associated with enhanced attentional engagement and protection from distraction in a cross-modal setting, even after controlling for task difficulty and EC. Our findings challenge the classic LT and offer support for alternative models.

Hippocampal Non-Theta-Contingent Eyeblink Classical Conditioning: A Model System for Neurobiological Dysfunction

PubMed Central

Cicchese, Joseph J.; Berry, Stephen D.

2016-01-01

Typical information processing is thought to depend on the integrity of neurobiological oscillations that may underlie coordination and timing of cells and assemblies within and between structures. The 3–7 Hz bandwidth of hippocampal theta rhythm is associated with cognitive processes essential to learning and depends on the integrity of cholinergic, GABAergic, and glutamatergic forebrain systems. Since several significant psychiatric disorders appear to result from dysfunction of medial temporal lobe (MTL) neurochemical systems, preclinical studies on animal models may be an important step in defining and treating such syndromes. Many studies have shown that the amount of hippocampal theta in the rabbit strongly predicts the acquisition rate of classical eyeblink conditioning and that impairment of this system substantially slows the rate of learning and attainment of asymptotic performance. Our lab has developed a brain–computer interface that makes eyeblink training trials contingent upon the explicit presence or absence of hippocampal theta. The behavioral benefit of theta-contingent training has been demonstrated in both delay and trace forms of the paradigm with a two- to fourfold increase in learning speed over non-theta states. The non-theta behavioral impairment is accompanied by disruption of the amplitude and synchrony of hippocampal local field potentials, multiple-unit excitation, and single-unit response patterns dependent on theta state. Our findings indicate a significant electrophysiological and behavioral impact of the pretrial state of the hippocampus that suggests an important role for this MTL system in associative learning and a significant deleterious impact in the absence of theta. Here, we focus on the impairments in the non-theta state, integrate them into current models of psychiatric disorders, and suggest how improvement in our understanding of neurobiological oscillations is critical for theories and treatment of psychiatric pathology. PMID:26903886

A Self-Control Versus a Counterconditioning Paradigm for Systematic Desensitization: An Experimental Comparison

ERIC Educational Resources Information Center

Spiegler, Michael D.; And Others

1976-01-01

A comparison was made between the traditional counterconditioning paradigm and a self-control paradigm of systematic desensitization. College students reporting high test anxiety and indicating interest in receiving treatment were assigned to counterconditioning, self-control, or wait-list control conditions. As predicted, self-control procedures…

Quantum-Classical Hybrid for Information Processing

NASA Technical Reports Server (NTRS)

Zak, Michail

2011-01-01

Based upon quantum-inspired entanglement in quantum-classical hybrids, a simple algorithm for instantaneous transmissions of non-intentional messages (chosen at random) to remote distances is proposed. The idea is to implement instantaneous transmission of conditional information on remote distances via a quantum-classical hybrid that preserves superposition of random solutions, while allowing one to measure its state variables using classical methods. Such a hybrid system reinforces the advantages, and minimizes the limitations, of both quantum and classical characteristics. Consider n observers, and assume that each of them gets a copy of the system and runs it separately. Although they run identical systems, the outcomes of even synchronized runs may be different because the solutions of these systems are random. However, the global constrain must be satisfied. Therefore, if the observer #1 (the sender) made a measurement of the acceleration v(sub 1) at t =T, then the receiver, by measuring the corresponding acceleration v(sub 1) at t =T, may get a wrong value because the accelerations are random, and only their ratios are deterministic. Obviously, the transmission of this knowledge is instantaneous as soon as the measurements have been performed. In addition to that, the distance between the observers is irrelevant because the x-coordinate does not enter the governing equations. However, the Shannon information transmitted is zero. None of the senders can control the outcomes of their measurements because they are random. The senders cannot transmit intentional messages. Nevertheless, based on the transmitted knowledge, they can coordinate their actions based on conditional information. If the observer #1 knows his own measurements, the measurements of the others can be fully determined. It is important to emphasize that the origin of entanglement of all the observers is the joint probability density that couples their actions. There is no centralized source, or a sender of the signal, because each receiver can become a sender as well. An observer receives a signal by performing certain measurements synchronized with the measurements of the others. This means that the signal is uniformly and simultaneously distributed over the observers in a decentralized way. The signals transmit no intentional information that would favor one agent over another. All the sequence of signals received by different observers are not only statistically equivalent, but are also point-by-point identical. It is important to assume that each agent knows that the other agent simultaneously receives the identical signals. The sequences of the signals are true random, so that no agent could predict the next step with the probability different from those described by the density. Under these quite general assumptions, the entangled observers-agents can perform non-trivial tasks that include transmission of conditional information from one agent to another, simple paradigm of cooperation, etc. The problem of behavior of intelligent agents correlated by identical random messages in a decentralized way has its own significance: it simulates evolutionary behavior of biological and social systems correlated only via simultaneous sensoring sequences of unexpected events.

Rational snacking: young children's decision-making on the marshmallow task is moderated by beliefs about environmental reliability.

PubMed

Kidd, Celeste; Palmeri, Holly; Aslin, Richard N

2013-01-01

Children are notoriously bad at delaying gratification to achieve later, greater rewards (e.g., Piaget, 1970)-and some are worse at waiting than others. Individual differences in the ability-to-wait have been attributed to self-control, in part because of evidence that long-delayers are more successful in later life (e.g., Shoda, Mischel, & Peake, 1990). Here we provide evidence that, in addition to self-control, children's wait-times are modulated by an implicit, rational decision-making process that considers environmental reliability. We tested children (M=4;6, N=28) using a classic paradigm-the marshmallow task (Mischel, 1974)-in an environment demonstrated to be either unreliable or reliable. Children in the reliable condition waited significantly longer than those in the unreliable condition (p<0.0005), suggesting that children's wait-times reflected reasoned beliefs about whether waiting would ultimately pay off. Thus, wait-times on sustained delay-of-gratification tasks (e.g., the marshmallow task) may not only reflect differences in self-control abilities, but also beliefs about the stability of the world. Copyright © 2012 Elsevier B.V. All rights reserved.

Short-term total sleep deprivation alters delay-conditioned memory in the rat.

PubMed

Tripathi, Shweta; Jha, Sushil K

2016-06-01

Short-term sleep deprivation soon after training may impair memory consolidation. Also, a particular sleep stage or its components increase after learning some tasks, such as negative and positive reinforcement tasks, avoidance tasks, and spatial learning tasks, and so forth. It suggests that discrete memory types may require specific sleep stage or its components for their optimal processing. The classical conditioning paradigms are widely used to study learning and memory but the role of sleep in a complex conditioned learning is unclear. Here, we have investigated the effects of short-term sleep deprivation on the consolidation of delay-conditioned memory and the changes in sleep architecture after conditioning. Rats were trained for the delay-conditioned task (for conditioning, house-light [conditioned stimulus] was paired with fruit juice [unconditioned stimulus]). Animals were divided into 3 groups: (a) sleep deprived (SD); (b) nonsleep deprived (NSD); and (c) stress control (SC) groups. Two-way ANOVA revealed a significant interaction between groups and days (training and testing) during the conditioned stimulus-unconditioned stimulus presentation. Further, Tukey post hoc comparison revealed that the NSD and SC animals exhibited significant increase in performances during testing. The SD animals, however, performed significantly less during testing. Further, we observed that wakefulness and NREM sleep did not change after training and testing. Interestingly, REM sleep increased significantly on both days compared to baseline more specifically during the initial 4-hr time window after conditioning. Our results suggest that the consolidation of delay-conditioned memory is sleep-dependent and requires augmented REM sleep during an explicit time window soon after training. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Keeping the doctor in the loop: Ayurvedic pharmaceuticals in Kerala.

PubMed

Kudlu, Chithprabha

2016-12-01

Ethnographic inquiry into Ayurvedic commodification in Kerala revealed the prevalence of a distinct regional pharmaceutical market dominated by physician-manufacturers, oriented towards supplying classical medicines to Ayurvedic doctors. This stands in sharp contrast to mainstream Ayurveda that is observed to have undergone biomedicalization and pharmaceuticalization. This paper argues that Kerala's classical-medicine-centric pharmaceutical market constitutes an alternative modernity because it provided Kerala Ayurveda with a different route to modernization impervious to the biomedical regime, as well as endowing it with the institutional power to safeguard its regional identity. Although physician-entrepreneurs are its key architects, it is sustained by value regimes shaped by a unique regional medico-cultural milieu. Even when industrially produced, classical medicines remain embedded within Ayurveda's socio-technical network; unlike proprietary drugs sold as individual product-identities through non-Ayurvedic channels, they travel together as a pharmacopeia, distributed through exclusive doctor-mediated agencies. This clinic-centric distribution format is best conceptualized as an open-source business model as it made low-margin generics viable by packaging them with therapies and services. Besides ensuring better access and affordability, it provided resistance to pharmaceuticalization and intellectual property concentration. By keeping the doctor in the loop, it prevented medicines from degenerating into de-contextualized commodities; the service component of Ayurveda therein preserved went on become the unique selling point in the health-tourism market. The tourism-inspired proliferation of Brand Kerala eventually triggered a paradigm shift in mainstream Ayurveda - shifting focus from 'pharmaceuticals' to 'services' and from 'illness' to 'wellness'. Furthermore, interacting with hybrid Ayurvedas in transnational markets, Kerala Ayurveda co-produces new alterities countervailing the structurally dominant biomedical paradigm.

Psychophysiology of Delayed Extinction and Reconsideration in Humans

DTIC Science & Technology

2012-02-01

modify or block it. The aim of this project is to create an experimental assay in the form of an optimal Pavlovian differential fear conditioning ...The aim of this project is to create an experimental assay in the form of an optimal Pavlovian differential fear conditioning paradigm. Animal...open label study examining the relative efficacies of pharmacological and non- drug interventions within a fear conditioning paradigm. At the time of

What can robots tell us about brains? A synthetic approach towards the study of learning and problem solving.

PubMed

Voegtlin, T; Verschure, P F

1999-01-01

This paper argues for the development of synthetic approaches towards the study of brain and behavior as a complement to the more traditional empirical mode of research. As an example we present our own work on learning and problem solving which relates to the behavioral paradigms of classical and operant conditioning. We define the concept of learning in the context of behavior and lay out the basic methodological requirements a model needs to satisfy, which includes evaluations using robots. In addition, we define a number of design principles neuronal models should obey to be considered relevant. We present in detail the construction of a neural model of short- and long-term memory which can be applied to an artificial behaving system. The presented model (DAC4) provides a novel self-consistent implementation of these processes, which satisfies our principles. This model will be interpreted towards the present understanding of the neuronal substrate of memory.

On the Design of a CADS for Shoulder Pain Pathology

NASA Astrophysics Data System (ADS)

de Ipiña, K. López; Hernández, M. C.; Martínez, E.; Vaquero, C.

A musculoskeletal disorder is a condition of the musculoskeletal system, which consists in part of it being injured continuously over time. Shoulder disorders are one of the most common musculoskeletal cases attended in primary health care services. Shoulder disorders cause pain and limit the ability to perform many routine activities, affecting about 15-25 % of the general population. Several clinical tests have been described to aid diagnosis of shoulder disorders. However, the current literature acknowledges a lack of concordance in clinical assessment, even among musculoskeletal specialists. We are working on the design of a Computer-Aided Decision Support (CADS) system for Shoulder Pain Pathology. The paper presents the results of our efforts to build a CADS system testing several classical classification paradigms, feature reduction methods (PCA) and K-means unsupervised clustering. The small database size imposes the use of robust covariance matrix estimation methods to improve the system performance. Finally, the system was evaluated by a medical specialist.

Synthetic tactile perception induced by transcranial alternating-current stimulation can substitute for natural sensory stimulus in behaving rabbits.

PubMed

Márquez-Ruiz, Javier; Ammann, Claudia; Leal-Campanario, Rocío; Ruffini, Giulio; Gruart, Agnès; Delgado-García, José M

2016-01-21

The use of brain-derived signals for controlling external devices has long attracted the attention from neuroscientists and engineers during last decades. Although much effort has been dedicated to establishing effective brain-to-computer communication, computer-to-brain communication feedback for "closing the loop" is now becoming a major research theme. While intracortical microstimulation of the sensory cortex has already been successfully used for this purpose, its future application in humans partly relies on the use of non-invasive brain stimulation technologies. In the present study, we explore the potential use of transcranial alternating-current stimulation (tACS) for synthetic tactile perception in alert behaving animals. More specifically, we determined the effects of tACS on sensory local field potentials (LFPs) and motor output and tested its capability for inducing tactile perception using classical eyeblink conditioning in the behaving animal. We demonstrated that tACS of the primary somatosensory cortex vibrissa area could indeed substitute natural stimuli during training in the associative learning paradigm.

The core planar cell polarity gene, Vangl2, maintains apical-basal organisation of the corneal epithelium.

PubMed

Panzica, D Alessio; Findlay, Amy S; van Ladesteijn, Rianne; Collinson, J Martin

2017-08-17

The role of the core planar cell polarity (PCP) pathway protein, Vangl2, was investigated in the corneal epithelium of the mammalian eye, a paradigm anatomical model of planar cell migration. The gene was conditionally knocked out in vivo and knocked down by siRNA, followed by immunohistochemical, behavioural and morphological analysis of corneal epithelial cells. The primary defects observed in vivo were of apical-basal organisation of the corneal epithelium, with abnormal stratification throughout life, mislocalisation of the cell membrane protein, Scribble, to the basal side of cells, and partial loss of the epithelial basement membrane. Planar defects in migration after wounding and in the presence of an applied electric field were noted. However, knockdown of Vangl2 also retarded cell migration in individual cells that had no contact with their neighbours, which precluded a classic PCP mechanism. It is concluded that some of the planar polarity phenotypes in PCP mutants may arise from disruption of apical-basal polarity. © 2017 Anatomical Society.

Caring Cooperators and Powerful Punishers: Differential Effects of Induced Care and Power Motivation on Different Types of Economic Decision Making.

PubMed

Chierchia, G; Lesemann, F H Parianen; Snower, D; Vogel, M; Singer, T

2017-09-11

Standard economic theory postulates that decisions are driven by stable context-insensitive preferences, while motivation psychology suggests they are driven by distinct context-sensitive motives with distinct evolutionary goals and characteristic psycho-physiological and behavioral patterns. To link these fields and test how distinct motives could differentially predict different types of economic decisions, we experimentally induced participants with either a Care or a Power motive, before having them take part in a suite of classic game theoretical paradigms involving monetary exchange. We show that the Care induction alone raised scores on a latent factor of cooperation-related behaviors, relative to a control condition, while, relative to Care, Power raised scores on a punishment-related factor. These findings argue against context-insensitive stable preferences and theories of strong reciprocity and in favor of a motive-based approach to economic decision making: Care and Power motivation have a dissociable fingerprint in shaping either cooperative or punishment behaviors.

Cognitive assessment of mice strains heterozygous for cell-adhesion genes reveals strain-specific alterations in timing.

PubMed

Gallistel, C R; Tucci, Valter; Nolan, Patrick M; Schachner, Melitta; Jakovcevski, Igor; Kheifets, Aaron; Barboza, Luendro

2014-03-05

We used a fully automated system for the behavioural measurement of physiologically meaningful properties of basic mechanisms of cognition to test two strains of heterozygous mutant mice, Bfc (batface) and L1, and their wild-type littermate controls. Both of the target genes are involved in the establishment and maintenance of synapses. We find that the Bfc heterozygotes show reduced precision in their representation of interval duration, whereas the L1 heterozygotes show increased precision. These effects are functionally specific, because many other measures made on the same mice are unaffected, namely: the accuracy of matching temporal investment ratios to income ratios in a matching protocol, the rate of instrumental and classical conditioning, the latency to initiate a cued instrumental response, the trials on task and the impulsivity in a switch paradigm, the accuracy with which mice adjust timed switches to changes in the temporal constraints, the days to acquisition, and mean onset time and onset variability in the circadian anticipation of food availability.

Cognitive assessment of mice strains heterozygous for cell-adhesion genes reveals strain-specific alterations in timing

PubMed Central

Gallistel, C. R.; Tucci, Valter; Nolan, Patrick M.; Schachner, Melitta; Jakovcevski, Igor; Kheifets, Aaron; Barboza, Luendro

2014-01-01

We used a fully automated system for the behavioural measurement of physiologically meaningful properties of basic mechanisms of cognition to test two strains of heterozygous mutant mice, Bfc (batface) and L1, and their wild-type littermate controls. Both of the target genes are involved in the establishment and maintenance of synapses. We find that the Bfc heterozygotes show reduced precision in their representation of interval duration, whereas the L1 heterozygotes show increased precision. These effects are functionally specific, because many other measures made on the same mice are unaffected, namely: the accuracy of matching temporal investment ratios to income ratios in a matching protocol, the rate of instrumental and classical conditioning, the latency to initiate a cued instrumental response, the trials on task and the impulsivity in a switch paradigm, the accuracy with which mice adjust timed switches to changes in the temporal constraints, the days to acquisition, and mean onset time and onset variability in the circadian anticipation of food availability. PMID:24446498

Design of pharmaceutical products to meet future patient needs requires modification of current development paradigms and business models.

PubMed

Stegemann, S; Baeyens, J-P; Becker, R; Maio, M; Bresciani, M; Shreeves, T; Ecker, F; Gogol, M

2014-06-01

Drugs represent the most common intervention strategy for managing acute and chronic medical conditions. In light of demographic change and the increasing age of patients, the classic model of drug research and development by the pharmaceutical industry and drug prescription by physicians is reaching its limits. Different stakeholders, e.g. industry, regulatory authorities, health insurance systems, physicians etc., have at least partially differing interests regarding the process of healthcare provision. The primary responsibility for the correct handling of medication and adherence to treatment schedules lies with the recipient of a drug-based therapy, i.e. the patient. It is thus necessary to interactively involve elderly patients, as well as the other stakeholders, in the development of medication and medication application devices, and in clinical trials. This approach will provide the basis for developing a strategy that better meets patients' needs, thus resulting in improved adherence to treatment schedules and better therapeutic outcomes.

The New ISR Paradigm

DTIC Science & Technology

2011-05-02

researchers define only two distinct methods. In a conserved spread network, the quantity of information that enters a network remains constant at...any given time. In such a network, information can only be in one place at any given time. A classic example is that ofa pitcher of water poured into...serious of pipes and joints; once the water passes through one pipe, that pipe empties while others in the network are filled with water as it passes

Quantification of alcohol drinking patterns in mice.

PubMed

Eisenhardt, Manuela; Leixner, Sarah; Spanagel, Rainer; Bilbao, Ainhoa

2015-11-01

The use of mice in alcohol research provides an excellent model system for a better understanding of the genetics and neurobiology of alcohol addiction. Almost 60 years ago, alcohol researchers began to test strains of mice for alcohol preference and intake. In particular, various voluntary alcohol drinking paradigms in the home cage were developed. In mouse models of voluntary oral alcohol consumption, animals have concurrent access to water and either one or several concentrated alcohol solutions in their home cages. Although these models have high face validity, many experimental conditions require a more precise monitoring of alcohol consumption in mice in order to capture the role of specific strains or genes, or any other manipulation on alcohol drinking behavior. Therefore, we have developed a fully automated, highly precise monitoring system for alcohol drinking in mice in the home cage. This system is now commercially available. We show that this drinkometer system allows for detecting differences in drinking behavior (i) in transgenic mice, (ii) following alcohol deprivation, and (iii) following stress applications that are usually not detected by classical home-cage drinking paradigms. In conclusion, our drinkometer system allows disturbance-free and high resolution monitoring of alcohol drinking behavior. In particular, micro-drinking and circadian drinking patterns can be monitored in genetically modified and inbred strains of mice after environmental and pharmacological manipulation, and therefore this system represents an improvement in measuring behavioral features that are of relevance for the development of alcohol use disorders. © 2015 Society for the Study of Addiction.

Testing effects of free recall on organization in whole/part and part/whole transfer.

PubMed

Bacso, Sarah A; Marmurek, Harvey H C

2016-11-01

Testing of to-be-learned material facilitates subsequent learning of new material. We investigated this forward effect of testing in two experiments using the whole/part and part/whole transfer paradigms with categorized word lists. Learning was assessed for recall of individual words, higher order categories, and category clustering. In each experiment participants learned two lists in which the number of tests on the first list was varied. The first list contained either twice as many items as the second list (whole/part paradigm) or half as many items as the second list (part/whole paradigm). In the experimental condition, the part list contained half the items of the whole list. In the control condition, the two lists were unique. In the whole/part paradigm, learning of the part list was poorer in the experimental than in the control condition. Although testing during whole list learning facilitated learning of the part list, it did not moderate the negative transfer effect. In the part/whole paradigm, learning of the whole list was better in the experimental than in the control condition, and this positive transfer effect was strengthened by repeated testing of the part list. The findings are discussed in the context of discrimination and encoding explanations of the forward effect of testing. Copyright © 2016 Elsevier B.V. All rights reserved.

The Eyes Know Time: A Novel Paradigm to Reveal the Development of Temporal Memory

ERIC Educational Resources Information Center

Pathman, Thanujeni; Ghetti, Simona

2014-01-01

Temporal memory in 7-year-olds, 10-year-olds, and young adults (N = 78) was examined introducing a novel eye-movement paradigm. Participants learned object sequences and were tested under three conditions: temporal order, temporal context, and recognition. Age-related improvements in accuracy were found across conditions; accuracy in the temporal…

Using the Social Web to Supplement Classical Learning

NASA Astrophysics Data System (ADS)

Trausan-Matu, Stefan; Posea, Vlad; Rebedea, Traian; Chiru, Costin

The paper describes a complex e-learning experiment that has involved over 700 students that attended the Human-Computer Interaction course at the “Politehnica” University of Bucharest during the last 4 years. The experiment consisted in using social web technologies like blogs and chat conferences to engage students in collaborative learning. The paper presents the learning scenario, the problems encountered and the tools developed for solving these problems and assisting tutors in evaluating the activity of the students. The results of the experiment and of using the blog and chat analysis tools are also covered. Moreover, we show the benefits of using such a scenario for the learning community formed by the students that attended this course in order to supplement the classical teaching and learning paradigm.

Agile IT: Thinking in User-Centric Models

NASA Astrophysics Data System (ADS)

Margaria, Tiziana; Steffen, Bernhard

We advocate a new teaching direction for modern CS curricula: extreme model-driven development (XMDD), a new development paradigm designed to continuously involve the customer/application expert throughout the whole systems' life cycle. Based on the `One-Thing Approach', which works by successively enriching and refining one single artifact, system development becomes in essence a user-centric orchestration of intuitive service functionality. XMDD differs radically from classical software development, which, in our opinion is no longer adequate for the bulk of application programming - in particular when it comes to heterogeneous, cross organizational systems which must adapt to rapidly changing market requirements. Thus there is a need for new curricula addressing this model-driven, lightweight, and cooperative development paradigm that puts the user process in the center of the development and the application expert in control of the process evolution.

Dissociable Learning Processes Underlie Human Pain Conditioning.

PubMed

Zhang, Suyi; Mano, Hiroaki; Ganesh, Gowrishankar; Robbins, Trevor; Seymour, Ben

2016-01-11

Pavlovian conditioning underlies many aspects of pain behavior, including fear and threat detection [1], escape and avoidance learning [2], and endogenous analgesia [3]. Although a central role for the amygdala is well established [4], both human and animal studies implicate other brain regions in learning, notably ventral striatum and cerebellum [5]. It remains unclear whether these regions make different contributions to a single aversive learning process or represent independent learning mechanisms that interact to generate the expression of pain-related behavior. We designed a human parallel aversive conditioning paradigm in which different Pavlovian visual cues probabilistically predicted thermal pain primarily to either the left or right arm and studied the acquisition of conditioned Pavlovian responses using combined physiological recordings and fMRI. Using computational modeling based on reinforcement learning theory, we found that conditioning involves two distinct types of learning process. First, a non-specific "preparatory" system learns aversive facial expressions and autonomic responses such as skin conductance. The associated learning signals-the learned associability and prediction error-were correlated with fMRI brain responses in amygdala-striatal regions, corresponding to the classic aversive (fear) learning circuit. Second, a specific lateralized system learns "consummatory" limb-withdrawal responses, detectable with electromyography of the arm to which pain is predicted. Its related learned associability was correlated with responses in ipsilateral cerebellar cortex, suggesting a novel computational role for the cerebellum in pain. In conclusion, our results show that the overall phenotype of conditioned pain behavior depends on two dissociable reinforcement learning circuits. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

The changing face of P300 BCIs: a comparison of stimulus changes in a P300 BCI involving faces, emotion, and movement.

PubMed

Jin, Jing; Allison, Brendan Z; Kaufmann, Tobias; Kübler, Andrea; Zhang, Yu; Wang, Xingyu; Cichocki, Andrzej

2012-01-01

One of the most common types of brain-computer interfaces (BCIs) is called a P300 BCI, since it relies on the P300 and other event-related potentials (ERPs). In the canonical P300 BCI approach, items on a monitor flash briefly to elicit the necessary ERPs. Very recent work has shown that this approach may yield lower performance than alternate paradigms in which the items do not flash but instead change in other ways, such as moving, changing colour or changing to characters overlaid with faces. The present study sought to extend this research direction by parametrically comparing different ways to change items in a P300 BCI. Healthy subjects used a P300 BCI across six different conditions. Three conditions were similar to our prior work, providing the first direct comparison of characters flashing, moving, and changing to faces. Three new conditions also explored facial motion and emotional expression. The six conditions were compared across objective measures such as classification accuracy and bit rate as well as subjective measures such as perceived difficulty. In line with recent studies, our results indicated that the character flash condition resulted in the lowest accuracy and bit rate. All four face conditions (mean accuracy >91%) yielded significantly better performance than the flash condition (mean accuracy = 75%). Objective results reaffirmed that the face paradigm is superior to the canonical flash approach that has dominated P300 BCIs for over 20 years. The subjective reports indicated that the conditions that yielded better performance were not considered especially burdensome. Therefore, although further work is needed to identify which face paradigm is best, it is clear that the canonical flash approach should be replaced with a face paradigm when aiming at increasing bit rate. However, the face paradigm has to be further explored with practical applications particularly with locked-in patients.

Classical-Conditioning Demonstrations for Elementary and Advanced Courses.

ERIC Educational Resources Information Center

Abramson, Charles I.; And Others

1996-01-01

Describes two new exercises in classical conditioning that use earthworms and houseflies. The animals are available year-round and pose no risk to the students or instructor. The conditioned stimuli are odorants. These elicit a conditioned response of contraction in worms or proboscis extension in flies. (MJP)

Re'class'ification of 'quant'ified classical simulated annealing

NASA Astrophysics Data System (ADS)

Tanaka, Toshiyuki

2009-12-01

We discuss a classical reinterpretation of quantum-mechanics-based analysis of classical Markov chains with detailed balance, that is based on the quantum-classical correspondence. The classical reinterpretation is then used to demonstrate that it successfully reproduces a sufficient condition for cooling schedule in classical simulated annealing, which has the inverse-logarithmic scaling.

AD/HD and the Capture of Attention by Briefly Exposed Delay-Related Cues: Evidence from a Conditioning Paradigm

ERIC Educational Resources Information Center

Sonuga-Barke, Edmund J. S.; De Houwer, Jan; De Ruiter, Karen; Ajzenstzen, Michal; Holland, Sarah

2004-01-01

Background: The selective attention of children with attention deficit/hyperactivity disorder (AD/HD) to briefly exposed delay-related cues was examined in two experiments using a dot-probe conditioning paradigm. Method: Colour cues were paired with negatively (i.e., imposition of delay) and positively valenced cues (i.e., escape from or avoidance…

Holistic Integrative Analysis of International Change: A Commentary on Teaching Emergent Futures (Proteus Monograph Series. Volume 1, Issue 3)

DTIC Science & Technology

2008-01-01

especially by comparing the late nineteenth century holistic sociology tradition of Max Weber, Emile Durkheim , and others to the single disciplinary...this developmentally, as Max Weber, Emile Durkheim (1973), and others previously quoted, have said, and also emergently as societal paths, as Hayek...Art of War: Sun Tzu. Boston: Shambhala. Classics. Drucker, Peter. “Management’s New Paradigms.” Forbes. October 5th, 1998: 152-162. Durkheim , Emile

Iplt--image processing library and toolkit for the electron microscopy community.

PubMed

Philippsen, Ansgar; Schenk, Andreas D; Stahlberg, Henning; Engel, Andreas

2003-01-01

We present the foundation for establishing a modular, collaborative, integrated, open-source architecture for image processing of electron microscopy images, named iplt. It is designed around object oriented paradigms and implemented using the programming languages C++ and Python. In many aspects it deviates from classical image processing approaches. This paper intends to motivate developers within the community to participate in this on-going project. The iplt homepage can be found at http://www.iplt.org.

An alternative approach for neural network evolution with a genetic algorithm: crossover by combinatorial optimization.

PubMed

García-Pedrajas, Nicolás; Ortiz-Boyer, Domingo; Hervás-Martínez, César

2006-05-01

In this work we present a new approach to crossover operator in the genetic evolution of neural networks. The most widely used evolutionary computation paradigm for neural network evolution is evolutionary programming. This paradigm is usually preferred due to the problems caused by the application of crossover to neural network evolution. However, crossover is the most innovative operator within the field of evolutionary computation. One of the most notorious problems with the application of crossover to neural networks is known as the permutation problem. This problem occurs due to the fact that the same network can be represented in a genetic coding by many different codifications. Our approach modifies the standard crossover operator taking into account the special features of the individuals to be mated. We present a new model for mating individuals that considers the structure of the hidden layer and redefines the crossover operator. As each hidden node represents a non-linear projection of the input variables, we approach the crossover as a problem on combinatorial optimization. We can formulate the problem as the extraction of a subset of near-optimal projections to create the hidden layer of the new network. This new approach is compared to a classical crossover in 25 real-world problems with an excellent performance. Moreover, the networks obtained are much smaller than those obtained with classical crossover operator.

Bayesian prediction of placebo analgesia in an instrumental learning model

PubMed Central

Jung, Won-Mo; Lee, Ye-Seul; Wallraven, Christian; Chae, Younbyoung

2017-01-01

Placebo analgesia can be primarily explained by the Pavlovian conditioning paradigm in which a passively applied cue becomes associated with less pain. In contrast, instrumental conditioning employs an active paradigm that might be more similar to clinical settings. In the present study, an instrumental conditioning paradigm involving a modified trust game in a simulated clinical situation was used to induce placebo analgesia. Additionally, Bayesian modeling was applied to predict the placebo responses of individuals based on their choices. Twenty-four participants engaged in a medical trust game in which decisions to receive treatment from either a doctor (more effective with high cost) or a pharmacy (less effective with low cost) were made after receiving a reference pain stimulus. In the conditioning session, the participants received lower levels of pain following both choices, while high pain stimuli were administered in the test session even after making the decision. The choice-dependent pain in the conditioning session was modulated in terms of both intensity and uncertainty. Participants reported significantly less pain when they chose the doctor or the pharmacy for treatment compared to the control trials. The predicted pain ratings based on Bayesian modeling showed significant correlations with the actual reports from participants for both of the choice categories. The instrumental conditioning paradigm allowed for the active choice of optional cues and was able to induce the placebo analgesia effect. Additionally, Bayesian modeling successfully predicted pain ratings in a simulated clinical situation that fits well with placebo analgesia induced by instrumental conditioning. PMID:28225816

Differentiation of subsequent memory effects between retrieval practice and elaborative study.

PubMed

Liu, Yi; Rosburg, Timm; Gao, Chuanji; Weber, Christine; Guo, Chunyan

2017-07-01

Retrieval practice enhances memory retention more than re-studying. The underlying mechanisms of this retrieval practice effect have remained widely unclear. According to the elaborative retrieval hypothesis, activation of elaborative information occurs to a larger extent during testing than re-studying. In contrast, the episodic context account has suggested that recollecting prior episodic information (especially the temporal context) contributes to memory retention. To adjudicate the distinction between these two accounts, the present study used the classical retrieval practice effect paradigm to compare retrieval practice and elaborative study. In an initial behavioral experiment, retrieval practice produced greater retention than elaboration and re-studying in a one-week delayed test. In a subsequent event-related potential (ERP) experiment, retrieval practice resulted in reliably superior accuracy in the delayed test compared to elaborative study. In the ERPs, a frontally distributed subsequent memory effect (SME), starting at 300ms, occurred in the elaborative study condition, but not in the retrieval practice condition. A parietal SME emerged in the retrieval practice condition from 500 to 700ms, but was absent in the elaborative study condition. After 700ms, a late SME was present in the retrieval practice condition, but not in the elaborative study condition. Moreover, SMEs lasted longer in retrieval practice than in elaboration. The frontal SME in the elaborative study condition might be related to semantic processing or working memory-based elaboration, whereas the parietal and widespread SME in the retrieval practice condition might be associated with episodic recollection processes. These findings contradict the elaborative retrieval theory, and suggest that contextual recollection rather than activation of semantic information contributes to the retrieval practice effect, supporting the episodic context account. Copyright © 2017. Published by Elsevier B.V.

A model of amygdala-hippocampal-prefrontal interaction in fear conditioning and extinction in animals

PubMed Central

Moustafa, Ahmed A.; Gilbertson, Mark W.; Orr, Scott P.; Herzallah, Mohammad M.; Servatius, Richard. J.; Myers, Catherine E.

2012-01-01

Empirical research has shown that the amygdala, hippocampus, and ventromedial prefrontal cortex (vmPFC) are involved in fear conditioning. However, the functional contribution of each brain area and the nature of their interactions are not clearly understood. Here, we extend existing neural network models of the functional roles of the hippocampus in classical conditioning to include interactions with the amygdala and prefrontal cortex. We apply the model to fear conditioning, in which animals learn physiological (e.g. heart rate) and behavioral (e.g. freezing) responses to stimuli that have been paired with a highly aversive event (e.g. electrical shock). The key feature of our model is that learning of these conditioned responses in the central nucleus of the amygdala is modulated by two separate processes, one from basolateral amygdala and signaling a positive prediction error, and one from the vmPFC, via the intercalated cells of the amygdala, and signaling a negative prediction error. In addition, we propose that hippocampal input to both vmPFC and basolateral amygdala is essential for contextual modulation of fear acquisition and extinction. The model is sufficient to account for a body of data from various animal fear conditioning paradigms, including acquisition, extinction, reacquisition, and context specificity effects. Consistent with studies on lesioned animals, our model shows that damage to the vmPFC impairs extinction, while damage to the hippocampus impairs extinction in a different context (e.g., a different conditioning chamber from that used in initial training in animal experiments). We also discuss model limitations and predictions, including the effects of number of training trials on fear conditioning. PMID:23164732

Classical Conditioning of Eyelid and Mystacial Vibrissae Responses in Conscious Mice

ERIC Educational Resources Information Center

Delgado-Garcia, Jose Maria; Troncoso, Julieta; Munera, Alejandro

2004-01-01

The murine vibrissae sensorimotor system has been scrutinized as a target of motor learning through trace classical conditioning. Conditioned eyelid responses were acquired by using weak electrical whisker-pad stimulation as conditioned stimulus (CS) and strong electrical periorbital stimulation as unconditioned stimulus (US). In addition,…

Individual Differences in Behavioural Despair Predict Brain GSK-3beta Expression in Mice: The Power of a Modified Swim Test

PubMed Central

Markova, Nataliia; Shevtsova, Elena; Bakhmet, Anastassia; Steinbusch, Harry M.

2016-01-01

While deficient brain plasticity is a well-established pathophysiologic feature of depression, little is known about disorder-associated enhanced cognitive processing. Here, we studied a novel mouse paradigm that potentially models augmented learning of adverse memories during development of a depressive-like state. We used a modification of the classic two-day protocol of a mouse Porsolt test with an additional session occurring on Day 5 following the initial exposure. Unexpectedly, floating behaviour and brain glycogen synthase kinase-3 beta (GSK-3beta) mRNA levels, a factor of synaptic plasticity as well as a marker of distress and depression, were increased during the additional swimming session that was prevented by imipramine. Observed increases of GSK-3beta mRNA in prefrontal cortex during delayed testing session correlated with individual parameters of behavioural despair that was not found in the classic Porsolt test. Repeated swim exposure was accompanied by a lower pGSK-3beta/GSK-3beta ratio. A replacement of the second or the final swim sessions with exposure to the context of testing resulted in increased GSK-3beta mRNA level similar to the effects of swimming, while exclusion of the second testing prevented these changes. Together, our findings implicate the activation of brain GSK-3beta expression in enhanced contextual conditioning of adverse memories, which is associated with an individual susceptibility to a depressive syndrome. PMID:27478647

Individual Differences in Behavioural Despair Predict Brain GSK-3beta Expression in Mice: The Power of a Modified Swim Test.

PubMed

Strekalova, Tatyana; Markova, Nataliia; Shevtsova, Elena; Zubareva, Olga; Bakhmet, Anastassia; Steinbusch, Harry M; Bachurin, Sergey; Lesch, Klaus-Peter

2016-01-01

While deficient brain plasticity is a well-established pathophysiologic feature of depression, little is known about disorder-associated enhanced cognitive processing. Here, we studied a novel mouse paradigm that potentially models augmented learning of adverse memories during development of a depressive-like state. We used a modification of the classic two-day protocol of a mouse Porsolt test with an additional session occurring on Day 5 following the initial exposure. Unexpectedly, floating behaviour and brain glycogen synthase kinase-3 beta (GSK-3beta) mRNA levels, a factor of synaptic plasticity as well as a marker of distress and depression, were increased during the additional swimming session that was prevented by imipramine. Observed increases of GSK-3beta mRNA in prefrontal cortex during delayed testing session correlated with individual parameters of behavioural despair that was not found in the classic Porsolt test. Repeated swim exposure was accompanied by a lower pGSK-3beta/GSK-3beta ratio. A replacement of the second or the final swim sessions with exposure to the context of testing resulted in increased GSK-3beta mRNA level similar to the effects of swimming, while exclusion of the second testing prevented these changes. Together, our findings implicate the activation of brain GSK-3beta expression in enhanced contextual conditioning of adverse memories, which is associated with an individual susceptibility to a depressive syndrome.

Are horses capable of mirror self-recognition? A pilot study

PubMed Central

Demuru, Elisa; Scopa, Chiara; Palagi, Elisabetta

2017-01-01

Mirror Self-Recognition (MSR) unveils complex cognitive, social and emotional skills and it has been found only in humans and few other species, such as great apes, dolphins, elephants and magpies. In this pilot study, we tested if horses show the capacity of MSR. Four subjects living socially under naturalistic conditions were selected for the experiment. We adopted the classical mark test, which consists in placing a coloured mark on an out-of-view body part, visible only through mirror inspection. If the animal considers the image as its own, it will use its reflection to detect the mark and will try to explore it. We enhanced the classical paradigm by introducing a double-check control. Only in the presence of the reflecting surface, animals performed tactile and olfactory exploration of the mirror and looked behind it. These behaviors suggest that subjects were trying to associate multiple sensory cues (visual, tactile and olfactory) to the image in the mirror. The lack of correspondence between the collected stimuli in front of the mirror and the response to the colored mark lead us to affirm that horses are able to perceive that the reflected image is incongruent when compared with the memorized information of a real horse. However, without replication of data, the self-directed behavior towards the colored marks showed by our horses cannot be sufficient per se to affirm that horses are capable of self-recognition. PMID:28510577

Improvement of encoding and retrieval in normal and pathological aging with word-picture paradigm.

PubMed

Iodice, Rosario; Meilán, Juan José G; Carro, Juan

2015-01-01

During the aging process, there is a progressive deficit in the encoding of new information and its retrieval. Different strategies are used in order to maintain, optimize or diminish these deficits in people with and without dementia. One of the classic techniques is paired-associate learning (PAL), which is based on improving the encoding of memories, but it has yet to be used to its full potential in people with dementia. In this study, our aim is to corroborate the importance of PAL tasks as instrumental tools for creating contextual cues, during both the encoding and retrieval phases of memory. Additionally, we aim to identify the most effective form of presenting the related items. Pairs of stimuli were shown to healthy elderly people and to patients with moderate and mild Alzheimer's disease. The encoding conditions were as follows: word/word, picture/picture, picture/word, and word/picture. Associative cued recall of the second item in the pair shows that retrieval is higher for the word/picture condition in the two groups of patients with dementia when compared to the other conditions, while word/word is the least effective in all cases. These results confirm that PAL is an effective tool for creating contextual cues during both the encoding and retrieval phases in people with dementia when the items are presented using the word/picture condition. In this way, the encoding and retrieval deficit can be reduced in these people.

Learning to experience side effects after antidepressant intake - Results from a randomized, controlled, double-blind study.

PubMed

Rheker, Julia; Winkler, Alexander; Doering, Bettina K; Rief, Winfried

2017-02-01

Side effects play a key role in patients' failure to take antidepressants. There is evidence that verbal suggestions and informed consent elicit expectations that can in turn trigger the occurrence of side effects. Prior experience or learning mechanisms are also assumed to contribute to the development of side effects, although their role has not been thoroughly investigated. In this study, we examined whether an antidepressant's side effects can be learned via Pavlovian conditioning. Participants (n = 39) were randomly allocated to one of two groups and were exposed to a classical conditioning procedure. During acquisition, 19 participants received amitriptyline and 20 participants received a placebo pill. Pills were taken for four nights together with a novel-tasting drink. After a washout phase, both groups received a placebo pill together with the novel-tasting drink (evocation). Side effects were assessed via the Generic Assessment of Side Effects Scale prior to acquisition (baseline), after acquisition, and after evocation. A score of antidepressant-specific side effects was calculated. Participants taking amitriptyline reported significantly more antidepressant-specific side effects after acquisition compared to both baseline and the placebo group. After evocation, participants who underwent the conditioning procedure with amitriptyline reported significantly more antidepressant-specific side effects than those who never received amitriptyline, even though both groups received a placebo. Our results indicate that antidepressant side effects can be learned using a conditioning paradigm and evoked via a placebo pill when applied with the same contextual factors as the verum.

Comparisons of musculoskeletal complaints and data entry between a sitting and a sit-stand workstation paradigm.

PubMed

Husemann, Britta; Von Mach, Carolin Yvonne; Borsotto, Daniel; Zepf, Kirsten Isabel; Scharnbacher, Jutta

2009-06-01

Seated working positions are often regarded as a cause for discomfort in the musculoskeletal system. Performing work in different working positions--that is, alternating between sitting and standing (sit-stand workstation paradigm)--could help reduce physical complaints. The questions were whether performing office work partly in a standing position leads to reduced complaints and whether standing would change the efficiency of data entry office work. We investigated the effect of a sit-stand workstation paradigmd during experimental data entry office work on physical and psychological complaints and data entry efficiency by conducting a randomized controlled trial with 60 male participants ages 18 to 35 years. In this experiment, musculoskeletal complaints were reduced by a sit-stand workstation paradigm. A trend could be identified indicating a small but nonsignificant loss of efficiency in data entry while standing. A sit-stand workstation paradigm reduces musculoskeletal complaints without considerably affecting data entry efficiency under the presented study conditions (young male participants, short duration, fixed and controlled sit-stand workstation paradigm, simulated experimental working condition). According to the present data, implementing a sit-stand workstation paradigm can be an effective workplace health intervention to reduce musculoskeletal complaints. This experiment encourages further studies on the effectiveness of a sit-stand workstation paradigm. Experimental research and field studies that prove the reduction of complaints when introducing a sit-stand workstation paradigm in the workplace could be the basis for evidence-based recommendations regarding such interventions.

Contextual fear conditioning in zebrafish.

PubMed

Kenney, Justin W; Scott, Ian C; Josselyn, Sheena A; Frankland, Paul W

2017-10-01

Zebrafish are a genetically tractable vertebrate that hold considerable promise for elucidating the molecular basis of behavior. Although numerous recent advances have been made in the ability to precisely manipulate the zebrafish genome, much less is known about many aspects of learning and memory in adult fish. Here, we describe the development of a contextual fear conditioning paradigm using an electric shock as the aversive stimulus. We find that contextual fear conditioning is modulated by shock intensity, prevented by an established amnestic agent (MK-801), lasts at least 14 d, and exhibits extinction. Furthermore, fish of various background strains (AB, Tu, and TL) are able to acquire fear conditioning, but differ in fear extinction rates. Taken together, we find that contextual fear conditioning in zebrafish shares many similarities with the widely used contextual fear conditioning paradigm in rodents. Combined with the amenability of genetic manipulation in zebrafish, we anticipate that our paradigm will prove to be a useful complementary system in which to examine the molecular basis of vertebrate learning and memory. © 2017 Kenney et al.; Published by Cold Spring Harbor Laboratory Press.

Measuring listening effort: driving simulator vs. simple dual-task paradigm

PubMed Central

Wu, Yu-Hsiang; Aksan, Nazan; Rizzo, Matthew; Stangl, Elizabeth; Zhang, Xuyang; Bentler, Ruth

2014-01-01

Objectives The dual-task paradigm has been widely used to measure listening effort. The primary objectives of the study were to (1) investigate the effect of hearing aid amplification and a hearing aid directional technology on listening effort measured by a complicated, more real world dual-task paradigm, and (2) compare the results obtained with this paradigm to a simpler laboratory-style dual-task paradigm. Design The listening effort of adults with hearing impairment was measured using two dual-task paradigms, wherein participants performed a speech recognition task simultaneously with either a driving task in a simulator or a visual reaction-time task in a sound-treated booth. The speech materials and road noises for the speech recognition task were recorded in a van traveling on the highway in three hearing aid conditions: unaided, aided with omni directional processing (OMNI), and aided with directional processing (DIR). The change in the driving task or the visual reaction-time task performance across the conditions quantified the change in listening effort. Results Compared to the driving-only condition, driving performance declined significantly with the addition of the speech recognition task. Although the speech recognition score was higher in the OMNI and DIR conditions than in the unaided condition, driving performance was similar across these three conditions, suggesting that listening effort was not affected by amplification and directional processing. Results from the simple dual-task paradigm showed a similar trend: hearing aid technologies improved speech recognition performance, but did not affect performance in the visual reaction-time task (i.e., reduce listening effort). The correlation between listening effort measured using the driving paradigm and the visual reaction-time task paradigm was significant. The finding showing that our older (56 to 85 years old) participants’ better speech recognition performance did not result in reduced listening effort was not consistent with literature that evaluated younger (approximately 20 years old), normal hearing adults. Because of this, a follow-up study was conducted. In the follow-up study, the visual reaction-time dual-task experiment using the same speech materials and road noises was repeated on younger adults with normal hearing. Contrary to findings with older participants, the results indicated that the directional technology significantly improved performance in both speech recognition and visual reaction-time tasks. Conclusions Adding a speech listening task to driving undermined driving performance. Hearing aid technologies significantly improved speech recognition while driving, but did not significantly reduce listening effort. Listening effort measured by dual-task experiments using a simulated real-world driving task and a conventional laboratory-style task was generally consistent. For a given listening environment, the benefit of hearing aid technologies on listening effort measured from younger adults with normal hearing may not be fully translated to older listeners with hearing impairment. PMID:25083599

Using virtual reality to rehabilitate neglect.

PubMed

Sedda, A; Borghese, N A; Ronchetti, M; Mainetti, R; Pasotti, F; Beretta, G; Bottini, G

2013-01-01

Virtual Reality (VR) platforms gained a lot of attention in the rehabilitation field due to their ability to engage patients and the opportunity they offer to use real world scenarios. As neglect is characterized by an impairment in exploring space that greatly affects daily living, VR could be a powerful tool compared to classical paper and pencil tasks and computer training. Nevertheless, available platforms are costly and obstructive. Here we describe a low cost platform for neglect rehabilitation, that using consumer equipments allows the patient to train at home in an intensive fashion. We tested the platform on IB, a chronic neglect patient, who did not benefit from classical rehabilitation. Our results show that IB improved both in terms of neglect and attention. Importantly, these ameliorations lasted at a follow up evaluation 5 months after the last treatment session and generalized to everyday life activities. VR platforms built using equipment technology and following theoretical principles on brain functioning may induce greater ameliorations in visuo-spatial deficits than classical paradigms possibly thanks to the real world scenarios in association with the "visual feedback" of the patient's own body operating in the virtual environment.

Quantum Dynamics in the HMF Model

NASA Astrophysics Data System (ADS)

Plestid, Ryan; O'Dell, Duncan

2017-04-01

The Hamiltonian Mean Field (HMF) model represents a paradigm in the study of long-range interactions but has never been realized in a lab. Recently Shutz and Morigi (PRL 113) have come close but ultimately fallen short. Their proposal relied on cavity-induced interactions between atoms. If a design using cold atoms is to be successful, an understanding of quantum effects is essential. I will outline the natural quantum generalization of the HMF assuming a BEC by using a generalized Gross-Pitaevskii equation (gGPE). I will show how quantum effects modify features which are well understood in the classical model. More specifically, by working in the semi-classical regime (strong interparticle interactions) we can identify the universal features predicted by catastrophe theory dressed with quantum interference effects. The stationary states of gGPE can be solved exactly and are found to be described by self-consistent Mathieu functions. Finally, I will discuss the connection between the classical description of the dynamics in terms of the Vlassov equation, and the gGPE. We would like to thank the Government of Ontario's OGS program, NSERC, and the Perimeter Institute of Theoretical Physics.

Towards secure quantum key distribution protocol for wireless LANs: a hybrid approach

NASA Astrophysics Data System (ADS)

Naik, R. Lalu; Reddy, P. Chenna

2015-12-01

The primary goals of security such as authentication, confidentiality, integrity and non-repudiation in communication networks can be achieved with secure key distribution. Quantum mechanisms are highly secure means of distributing secret keys as they are unconditionally secure. Quantum key distribution protocols can effectively prevent various attacks in the quantum channel, while classical cryptography is efficient in authentication and verification of secret keys. By combining both quantum cryptography and classical cryptography, security of communications over networks can be leveraged. Hwang, Lee and Li exploited the merits of both cryptographic paradigms for provably secure communications to prevent replay, man-in-the-middle, and passive attacks. In this paper, we propose a new scheme with the combination of quantum cryptography and classical cryptography for 802.11i wireless LANs. Since quantum cryptography is premature in wireless networks, our work is a significant step forward toward securing communications in wireless networks. Our scheme is known as hybrid quantum key distribution protocol. Our analytical results revealed that the proposed scheme is provably secure for wireless networks.

Pharmacological Targeting of the Host-Pathogen Interaction: Alternatives to Classical Antibiotics to Combat Drug-Resistant Superbugs

PubMed Central

Munguia, Jason; Nizet, Victor

2017-01-01

The rise of multidrug-resistant pathogens and the dearth of new antibiotic development place an existential strain on successful infectious disease therapy. Breakthrough strategies that go beyond classical antibiotic mechanisms are needed to combat this looming public health catastrophe. Reconceptualizing antibiotic therapy in the richer context of the host-pathogen interaction is required for innovative solutions. By defining specific virulence factors, the essence of a pathogen, and pharmacologically neutralizing their activities, one can block disease progression and sensitize microbes to immune clearance. Likewise, host-directed strategies to boost phagocyte bactericidal activity, enhance leukocyte recruitment, or reverse pathogen-induced immunosuppression seek to replicate the success of cancer immunotherapy in the field of infectious diseases. The answer to the threat of multidrug-resistant pathogens lies “outside-the-box” of current antibiotic paradigms. PMID:28283200

Quantum-like model of processing of information in the brain based on classical electromagnetic field.

PubMed

Khrennikov, Andrei

2011-09-01

We propose a model of quantum-like (QL) processing of mental information. This model is based on quantum information theory. However, in contrast to models of "quantum physical brain" reducing mental activity (at least at the highest level) to quantum physical phenomena in the brain, our model matches well with the basic neuronal paradigm of the cognitive science. QL information processing is based (surprisingly) on classical electromagnetic signals induced by joint activity of neurons. This novel approach to quantum information is based on representation of quantum mechanics as a version of classical signal theory which was recently elaborated by the author. The brain uses the QL representation (QLR) for working with abstract concepts; concrete images are described by classical information theory. Two processes, classical and QL, are performed parallely. Moreover, information is actively transmitted from one representation to another. A QL concept given in our model by a density operator can generate a variety of concrete images given by temporal realizations of the corresponding (Gaussian) random signal. This signal has the covariance operator coinciding with the density operator encoding the abstract concept under consideration. The presence of various temporal scales in the brain plays the crucial role in creation of QLR in the brain. Moreover, in our model electromagnetic noise produced by neurons is a source of superstrong QL correlations between processes in different spatial domains in the brain; the binding problem is solved on the QL level, but with the aid of the classical background fluctuations. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Differential modulation of changes in hippocampal-septal synaptic excitability by the amygdala as a function of either elemental or contextual fear conditioning in mice.

PubMed

Desmedt, A; Garcia, R; Jaffard, R

1998-01-01

Recent data obtained using a classic fear conditioning paradigm showed a dissociation between the retention of associations relative to contextual information (dependent on the hippocampal formation) and the retention of elemental associations (dependent on the amygdala). Furthermore, it was reported that conditioned emotional responses (CERs) could be dissociated from the recollection of the learning experience (declarative memory) in humans and from modifications of the hippocampal-septal excitability in animals. Our aim was to determine whether these two systems ("behavioral expression" system and "factual memory" system) interact by examining the consequences of amygdalar lesions (1) on the modifications of hippocampal-septal excitability and (2) on the behavioral expression of fear (freezing) resulting from an aversive conditioning during reexposure to conditional stimuli (CSs). During conditioning, to modulate the predictive nature of the context and of a discrete stimulus (tone) on the unconditional stimulus (US) occurrence, the phasic discrete CS was paired with the US or randomly distributed with regard to the US. After the lesion, the CER was dramatically reduced during reexposure to the CSs, whatever the type of acquisition. However, the changes in hippocampal-septal excitability persisted but were altered. For controls, a decrease in septal excitability was observed during reexposure to the conditioning context only for the "unpaired group" (predictive context case). Conversely, among lesioned subjects this decrease was observed in the "paired group" (predictive discrete CS case), whereas this decrease was significantly reduced in the unpaired group with respect to the matched control group. The amplitude and the direction of these modifications suggest a differential modulation of hippocampal-septal excitability by the amygdala to amplify the contribution of the more predictive association signaling the occurrence of the aversive event.

Associative Learning in Invertebrates

PubMed Central

Hawkins, Robert D.; Byrne, John H.

2015-01-01

This work reviews research on neural mechanisms of two types of associative learning in the marine mollusk Aplysia, classical conditioning of the gill- and siphon-withdrawal reflex and operant conditioning of feeding behavior. Basic classical conditioning is caused in part by activity-dependent facilitation at sensory neuron–motor neuron (SN–MN) synapses and involves a hybrid combination of activity-dependent presynaptic facilitation and Hebbian potentiation, which are coordinated by trans-synaptic signaling. Classical conditioning also shows several higher-order features, which might be explained by the known circuit connections in Aplysia. Operant conditioning is caused in part by a different type of mechanism, an intrinsic increase in excitability of an identified neuron in the central pattern generator (CPG) for feeding. However, for both classical and operant conditioning, adenylyl cyclase is a molecular site of convergence of the two signals that are associated. Learning in other invertebrate preparations also involves many of the same mechanisms, which may contribute to learning in vertebrates as well. PMID:25877219

A unifying paradigm for naphthoquinone-based meroterpenoid (bio)synthesis

NASA Astrophysics Data System (ADS)

Miles, Zachary D.; Diethelm, Stefan; Pepper, Henry P.; Huang, David M.; George, Jonathan H.; Moore, Bradley S.

2017-12-01

Bacterial meroterpenoids constitute an important class of natural products with diverse biological properties and therapeutic potential. The biosynthetic logic for their production is unknown and defies explanation via classical biochemical paradigms. A large subgroup of naphthoquinone-based meroterpenoids exhibits a substitution pattern of the polyketide-derived aromatic core that seemingly contradicts the established reactivity pattern of polyketide phenol nucleophiles and terpene diphosphate electrophiles. We report the discovery of a hitherto unprecedented enzyme-promoted α-hydroxyketone rearrangement catalysed by vanadium-dependent haloperoxidases to account for these discrepancies in the merochlorin and napyradiomycin class of meroterpenoid antibiotics, and we demonstrate that the α-hydroxyketone rearrangement is potentially a conserved biosynthetic reaction in this molecular class. The biosynthetic α-hydroxyketone rearrangement was applied in a concise total synthesis of naphthomevalin, a prominent member of the napyradiomycin meroterpenes, and sheds further light on the mechanism of this unifying enzymatic transformation.

Decomposing task-switching costs with the diffusion model.

PubMed

Schmitz, Florian; Voss, Andreas

2012-02-01

In four experiments, task-switching processes were investigated with variants of the alternating runs paradigm and the explicit cueing paradigm. The classical diffusion model for binary decisions (Ratcliff, 1978) was used to dissociate different components of task-switching costs. Findings can be reconciled with the view that task-switching processes take place in successive phases as postulated by multiple-components models of task switching (e.g., Mayr & Kliegl, 2003; Ruthruff, Remington, & Johnston, 2001). At an earlier phase, task-set reconfiguration (Rogers & Monsell, 1995) or cue-encoding (Schneider & Logan, 2005) takes place, at a later phase, the response is selected in accord with constraints set in the first phase. Inertia effects (Allport, Styles, & Hsieh, 1994; Allport & Wylie, 2000) were shown to affect this later stage. Additionally, findings support the notion that response caution contributes to both global as well as to local switching costs when task switches are predictable.

A sample implementation for parallelizing Divide-and-Conquer algorithms on the GPU.

PubMed

Mei, Gang; Zhang, Jiayin; Xu, Nengxiong; Zhao, Kunyang

2018-01-01

The strategy of Divide-and-Conquer (D&C) is one of the frequently used programming patterns to design efficient algorithms in computer science, which has been parallelized on shared memory systems and distributed memory systems. Tzeng and Owens specifically developed a generic paradigm for parallelizing D&C algorithms on modern Graphics Processing Units (GPUs). In this paper, by following the generic paradigm proposed by Tzeng and Owens, we provide a new and publicly available GPU implementation of the famous D&C algorithm, QuickHull, to give a sample and guide for parallelizing D&C algorithms on the GPU. The experimental results demonstrate the practicality of our sample GPU implementation. Our research objective in this paper is to present a sample GPU implementation of a classical D&C algorithm to help interested readers to develop their own efficient GPU implementations with fewer efforts.

Practiced musical style shapes auditory skills.

PubMed

Vuust, Peter; Brattico, Elvira; Seppänen, Miia; Näätänen, Risto; Tervaniemi, Mari

2012-04-01

Musicians' processing of sounds depends highly on instrument, performance practice, and level of expertise. Here, we measured the mismatch negativity (MMN), a preattentive brain response, to six types of musical feature change in musicians playing three distinct styles of music (classical, jazz, and rock/pop) and in nonmusicians using a novel, fast, and musical sounding multifeature MMN paradigm. We found MMN to all six deviants, showing that MMN paradigms can be adapted to resemble a musical context. Furthermore, we found that jazz musicians had larger MMN amplitude than all other experimental groups across all sound features, indicating greater overall sensitivity to auditory outliers. Furthermore, we observed a tendency toward shorter latency of the MMN to all feature changes in jazz musicians compared to band musicians. These findings indicate that the characteristics of the style of music played by musicians influence their perceptual skills and the brain processing of sound features embedded in music. © 2012 New York Academy of Sciences.

Giant Viruses of Amoebae: A Journey Through Innovative Research and Paradigm Changes.

PubMed

Colson, Philippe; La Scola, Bernard; Raoult, Didier

2017-09-29

Giant viruses of amoebae were discovered serendipitously in 2003; they are visible via optical microscopy, making them bona fide microbes. Their lifestyle, structure, and genomes break the mold of classical viruses. Giant viruses of amoebae are complex microorganisms. Their genomes harbor between 444 and 2,544 genes, including many that are unique to viruses, and encode translation components; their virions contain >100 proteins as well as mRNAs. Mimiviruses have a specific mobilome, including virophages, provirophages, and transpovirons, and can resist virophages through a system known as MIMIVIRE (mimivirus virophage resistance element). Giant viruses of amoebae bring upheaval to the definition of viruses and tend to separate the current virosphere into two categories: very simple viruses and viruses with complexity similar to that of other microbes. This new paradigm is propitious for enhanced detection and characterization of giant viruses of amoebae, and a particular focus on their role in humans is warranted.

FAST TRACK COMMUNICATION: Quantum anomalies and linear response theory

NASA Astrophysics Data System (ADS)

Sela, Itamar; Aisenberg, James; Kottos, Tsampikos; Cohen, Doron

2010-08-01

The analysis of diffusive energy spreading in quantized chaotic driven systems leads to a universal paradigm for the emergence of a quantum anomaly. In the classical approximation, a driven chaotic system exhibits stochastic-like diffusion in energy space with a coefficient D that is proportional to the intensity ɛ2 of the driving. In the corresponding quantized problem the coherent transitions are characterized by a generalized Wigner time tɛ, and a self-generated (intrinsic) dephasing process leads to nonlinear dependence of D on ɛ2.

Synchronisation of chaos and its applications

NASA Astrophysics Data System (ADS)

Eroglu, Deniz; Lamb, Jeroen S. W.; Pereira, Tiago

2017-07-01

Dynamical networks are important models for the behaviour of complex systems, modelling physical, biological and societal systems, including the brain, food webs, epidemic disease in populations, power grids and many other. Such dynamical networks can exhibit behaviour in which deterministic chaos, exhibiting unpredictability and disorder, coexists with synchronisation, a classical paradigm of order. We survey the main theory behind complete, generalised and phase synchronisation phenomena in simple as well as complex networks and discuss applications to secure communications, parameter estimation and the anticipation of chaos.

[Visual hygiene in LED lighting. Modern scientific imaginations].

PubMed

Deynego, V N; Kaptsov, V A

2014-01-01

There are considered a classic and modern paradigm of perception of light and its impact on human health. To consider the perception of light as a complex self-organizing synergistic system of compression of information in the process of its sequencing was supposed. This allowed to develop a complex of interrelated measures, which may become the basis for modern hygiene, and determine requirements for the led lamp with biologically adequate spectrum of the light, for which there were obtained patents in Russia, Europe and USA.

Purists need not apply: the case for pragmatism in mixed methods research.

PubMed

Florczak, Kristine L

2014-10-01

The purpose of this column is to describe several different ways of conducting mixed method research. The paradigms that underpin both qualitative and quantitative research are also considered along with a cursory review of classical pragmatism as it relates conducting mixed methods studies. Finally, the idea of loosely coupled systems as a means to support mixed methods studies is proposed along with several caveats to researchers who desire to use this new way of obtaining knowledge. © The Author(s) 2014.

Systems Analysis - a new paradigm and decision support tools for the water framework directive

NASA Astrophysics Data System (ADS)

Bruen, M.

2008-05-01

In the early days of Systems Analysis the focus was on providing tools for optimisation, modelling and simulation for use by experts. Now there is a recognition of the need to develop and disseminate tools to assist in making decisions, negotiating compromises and communicating preferences that can easily be used by stakeholders without the need for specialist training. The Water Framework Directive (WFD) requires public participation and thus provides a strong incentive for progress in this direction. This paper places the new paradigm in the context of the classical one and discusses some of the new approaches which can be used in the implementation of the WFD. These include multi-criteria decision support methods suitable for environmental problems, adaptive management, cognitive mapping, social learning and cooperative design and group decision-making. Concordance methods (such as ELECTRE) and the Analytical Hierarchy Process (AHP) are identified as multi-criteria methods that can be readily integrated into Decision Support Systems (DSS) that deal with complex environmental issues with very many criteria, some of which are qualitative. The expanding use of the new paradigm provides an opportunity to observe and learn from the interaction of stakeholders with the new technology and to assess its effectiveness.

Osteoporosis: Modern Paradigms for Last Century’s Bones †

PubMed Central

Kruger, Marlena C.; Wolber, Frances M.

2016-01-01

The skeleton is a metabolically active organ undergoing continuously remodelling. With ageing and menopause the balance shifts to increased resorption, leading to a reduction in bone mineral density and disruption of bone microarchitecture. Bone mass accretion and bone metabolism are influenced by systemic hormones as well as genetic and lifestyle factors. The classic paradigm has described osteoporosis as being a “brittle bone” disease that occurs in post-menopausal, thin, Caucasian women with low calcium intakes and/or vitamin D insufficiency. However, a study of black women in Africa demonstrated that higher proportions of body fat did not protect bone health. Isoflavone interventions in Asian postmenopausal women have produced inconsistent bone health benefits, due in part to population heterogeneity in enteric bacterial metabolism of daidzein. A comparison of women and men in several Asian countries identified significant differences between countries in the rate of bone health decline, and a high incidence rate of osteoporosis in both sexes. These studies have revealed significant differences in genetic phenotypes, debunking long-held beliefs and leading to new paradigms in study design. Current studies are now being specifically designed to assess genotype differences between Caucasian, Asian, African, and other phenotypes, and exploring alternative methodology to measure bone architecture. PMID:27322315

Osteoporosis: Modern Paradigms for Last Century's Bones.

PubMed

Kruger, Marlena C; Wolber, Frances M

2016-06-17

The skeleton is a metabolically active organ undergoing continuously remodelling. With ageing and menopause the balance shifts to increased resorption, leading to a reduction in bone mineral density and disruption of bone microarchitecture. Bone mass accretion and bone metabolism are influenced by systemic hormones as well as genetic and lifestyle factors. The classic paradigm has described osteoporosis as being a "brittle bone" disease that occurs in post-menopausal, thin, Caucasian women with low calcium intakes and/or vitamin D insufficiency. However, a study of black women in Africa demonstrated that higher proportions of body fat did not protect bone health. Isoflavone interventions in Asian postmenopausal women have produced inconsistent bone health benefits, due in part to population heterogeneity in enteric bacterial metabolism of daidzein. A comparison of women and men in several Asian countries identified significant differences between countries in the rate of bone health decline, and a high incidence rate of osteoporosis in both sexes. These studies have revealed significant differences in genetic phenotypes, debunking long-held beliefs and leading to new paradigms in study design. Current studies are now being specifically designed to assess genotype differences between Caucasian, Asian, African, and other phenotypes, and exploring alternative methodology to measure bone architecture.

Examining the sex- and circadian dependency of a learning phenotype in mice with glycine transporter 1 deletion in two Pavlovian conditioning paradigms

PubMed Central

Dubroqua, Sylvain; Boison, Detlev; Feldon, Joram; Möhler, Hanns; Yee, Benjamin K.

2011-01-01

Behavioural characterisation of transgenic mice has been instrumental in search of therapeutic targets for the modulation of cognitive function. However, little effort has been devoted to phenotypic characterisation across environmental conditions and genomic differences such as sex and strain, which is essential to translational research. The present study is an effort in this direction. It scrutinised the stability and robustness of the phenotype of enhanced Pavlovian conditioning reported in mice with forebrain neuronal deletion of glycine transporter 1 by evaluating the possible presence of sex and circadian dependency, and its consistency across aversive and appetitive conditioning paradigms. The Pavlovian phenotype was essentially unaffected by the time of testing between the two circadian phases, but it was modified by sex in both conditioning paradigms. We observed that the effect size of the phenotype was strongest in female mice tested during the dark phase in the aversive paradigm. Critically, the presence of the phenotype in female mutants was accompanied by an increase in resistance to extinction. Similarly, enhanced conditioned responding once again emerged solely in female mutants in the appetitive conditioning experiment, which was again associated with an increased resistance to extinction across days, but male mutants exhibited an opposite trend towards facilitation of extinction. The present study has thus added hitherto unknown qualifications and specifications of a previously reported memory enhancing phenotype in this mouse line by identifying the determinants of the magnitude and direction of the expressed phenotype. This in-depth comparative approach is of value to the interpretation of behavioural findings in general. PMID:21596148

Evaluating Brain-Computer Interface Performance in an ALS Population: Checkerboard and Color Paradigms.

PubMed

Ryan, David B; Colwell, Kenneth A; Throckmorton, Chandra S; Collins, Leslie M; Caves, Kevin; Sellers, Eric W

2018-03-01

The objective of this study was to investigate the performance of 3 brain-computer interface (BCI) paradigms in an amyotrophic lateral sclerosis (ALS) population (n = 11). Using a repeated-measures design, participants completed 3 BCI conditions: row/column (RCW), checkerboard (CBW), and gray-to-color (CBC). Based on previous studies, it is hypothesized that the CBC and CBW conditions will result in higher accuracy, information transfer rate, waveform amplitude, and user preference over the RCW condition. An offline dynamic stopping simulation will also increase information transfer rate. Higher mean accuracy was observed in the CBC condition (89.7%), followed by the CBW (84.3%) condition, and lowest in the RCW condition (78.7%); however, these differences did not reach statistical significance ( P = .062). Eight of the eleven participants preferred the CBC and the remaining three preferred the CBW conditions. The offline dynamic stopping simulation significantly increased information transfer rate ( P = .005) and decreased accuracy ( P < .000). The findings of this study suggest that color stimuli provide a modest improvement in performance and that participants prefer color stimuli over monochromatic stimuli. Given these findings, BCI paradigms that use color stimuli should be considered for individuals who have ALS.

Classical conditioning for preserving the effects of short melatonin treatment in children with delayed sleep: a pilot study.

PubMed

van Maanen, Annette; Meijer, Anne Marie; Smits, Marcel G; Oort, Frans J

2017-01-01

Melatonin treatment is effective in treating sleep onset problems in children with delayed melatonin onset, but effects usually disappear when treatment is discontinued. In this pilot study, we investigated whether classical conditioning might help in preserving treatment effects of melatonin in children with sleep onset problems, with and without comorbid attention deficit hyperactivity disorder (ADHD) or autism. After a baseline week, 16 children (mean age: 9.92 years, 31% ADHD/autism) received melatonin treatment for 3 weeks and then gradually discontinued the treatment. Classical conditioning was applied by having children drink organic lemonade while taking melatonin and by using a dim red light lamp that was turned on when children went to bed. Results were compared with a group of 41 children (mean age: 9.43 years, 34% ADHD/autism) who received melatonin without classical conditioning. Melatonin treatment was effective in advancing dim light melatonin onset and reducing sleep onset problems, and positive effects were found on health and behavior problems. After stopping melatonin, sleep returned to baseline levels. We found that for children without comorbidity in the experimental group, sleep latency and sleep start delayed less in the stop week, which suggests an effect of classical conditioning. However, classical conditioning seems counterproductive in children with ADHD or autism. Further research is needed to establish these results and to examine other ways to preserve melatonin treatment effects, for example, by applying morning light.

Adult-onset hypothyroidism enhances fear memory and upregulates mineralocorticoid and glucocorticoid receptors in the amygdala.

PubMed

Montero-Pedrazuela, Ana; Fernández-Lamo, Iván; Alieva, María; Pereda-Pérez, Inmaculada; Venero, César; Guadaño-Ferraz, Ana

2011-01-01

Hypothyroidism is the most common hormonal disease in adults, which is frequently accompanied by learning and memory impairments and emotional disorders. However, the deleterious effects of thyroid hormones deficiency on emotional memory are poorly understood and often underestimated. To evaluate the consequences of hypothyroidism on emotional learning and memory, we have performed a classical Pavlovian fear conditioning paradigm in euthyroid and adult-thyroidectomized Wistar rats. In this experimental model, learning acquisition was not impaired, fear memory was enhanced, memory extinction was delayed and spontaneous recovery of fear memory was exacerbated in hypothyroid rats. The potentiation of emotional memory under hypothyroidism was associated with an increase of corticosterone release after fear conditioning and with higher expression of glucocorticoid and mineralocorticoid receptors in the lateral and basolateral nuclei of the amygdala, nuclei that are critically involved in the circuitry of fear memory. Our results demonstrate for the first time that adult-onset hypothyroidism potentiates fear memory and also increases vulnerability to develop emotional memories. Furthermore, our findings suggest that enhanced corticosterone signaling in the amygdala is involved in the pathophysiological mechanisms of fear memory potentiation. Therefore, we recommend evaluating whether inappropriate regulation of fear in patients with post-traumatic stress and other mental disorders is associated with abnormal levels of thyroid hormones, especially those patients refractory to treatment.

Framing faces: Frame alignment impacts holistic face perception.

PubMed

Curby, Kim M; Entenman, Robert

2016-11-01

Traditional accounts of face perception emphasise the importance of the prototypical configuration of features within faces. However, here we probe influences of more general perceptual grouping mechanisms on holistic face perception. Participants made part-matching judgments about composite faces presented in intact external oval frames or frames made from misaligned oval parts. This manipulation served to disrupt basic perceptual grouping cues that facilitate the grouping of the two face halves together. This manipulation also produced an external face contour like that in the standard misaligned condition used within the classic composite face task. Notably, by introducing a discontinuity in the external contour, grouping of the face halves into a cohesive unit was discouraged, but face configuration was preserved. Conditions where both the face parts and the frames were misaligned together, as in the typical composite task paradigm, or where just the internal face parts where misaligned, were also included. Disrupting only the face frame similarly disrupted holistic face perception as disrupting both the frame and face configuration. However, misaligned face parts presented in aligned frames also incurred a cost to holistic perception. These findings provide support for the contribution of general-purpose perceptual grouping mechanisms to holistic face perception and are presented and discussed in the context of an enhanced object-based selection account of holistic perception.

FracFit: A Robust Parameter Estimation Tool for Anomalous Transport Problems

NASA Astrophysics Data System (ADS)

Kelly, J. F.; Bolster, D.; Meerschaert, M. M.; Drummond, J. D.; Packman, A. I.

2016-12-01

Anomalous transport cannot be adequately described with classical Fickian advection-dispersion equations (ADE). Rather, fractional calculus models may be used, which capture non-Fickian behavior (e.g. skewness and power-law tails). FracFit is a robust parameter estimation tool based on space- and time-fractional models used to model anomalous transport. Currently, four fractional models are supported: 1) space fractional advection-dispersion equation (sFADE), 2) time-fractional dispersion equation with drift (TFDE), 3) fractional mobile-immobile equation (FMIE), and 4) tempered fractional mobile-immobile equation (TFMIE); additional models may be added in the future. Model solutions using pulse initial conditions and continuous injections are evaluated using stable distribution PDFs and CDFs or subordination integrals. Parameter estimates are extracted from measured breakthrough curves (BTCs) using a weighted nonlinear least squares (WNLS) algorithm. Optimal weights for BTCs for pulse initial conditions and continuous injections are presented, facilitating the estimation of power-law tails. Two sample applications are analyzed: 1) continuous injection laboratory experiments using natural organic matter and 2) pulse injection BTCs in the Selke river. Model parameters are compared across models and goodness-of-fit metrics are presented, assisting model evaluation. The sFADE and time-fractional models are compared using space-time duality (Baeumer et. al., 2009), which links the two paradigms.

Neural population-level memory traces in the mouse hippocampus.

PubMed

Chen, Guifen; Wang, L Phillip; Tsien, Joe Z

2009-12-16

One of the fundamental goals in neurosciences is to elucidate the formation and retrieval of brain's associative memory traces in real-time. Here, we describe real-time neural ensemble transient dynamics in the mouse hippocampal CA1 region and demonstrate their relationships with behavioral performances during both learning and recall. We employed the classic trace fear conditioning paradigm involving a neutral tone followed by a mild foot-shock 20 seconds later. Our large-scale recording and decoding methods revealed that conditioned tone responses and tone-shock association patterns were not present in CA1 during the first pairing, but emerged quickly after multiple pairings. These encoding patterns showed increased immediate-replay, correlating tightly with increased immediate-freezing during learning. Moreover, during contextual recall, these patterns reappeared in tandem six-to-fourteen times per minute, again correlating tightly with behavioral recall. Upon traced tone recall, while various fear memories were retrieved, the shock traces exhibited a unique recall-peak around the 20-second trace interval, further signifying the memory of time for the expected shock. Therefore, our study has revealed various real-time associative memory traces during learning and recall in CA1, and demonstrates that real-time memory traces can be decoded on a moment-to-moment basis over any single trial.

Habituation of visual evoked responses in neonates and fetuses: A MEG study

PubMed Central

Matuz, Tamara; Govindan, Rathinaswamy B.; Preissl, Hubert; Siegel, Eric R.; Muenssinger, Jana; Murphy, Pamela; Ware, Maureen; Lowery, Curtis L.; Eswaran, Hari

2013-01-01

In this study we aimed to develop a habituation paradigm that allows the investigation of response decrement and response recovery and examine its applicability for measuring the habituation of the visually evoked responses (VERs) in neonatal and fetal magnetoencephalographic recordings. Two paradigms, one with a long and one with a short inter-train interval (ITI), were developed and tested in separate studies. Both paradigms consisted of a train of four light flashes; each train being followed by a 500 Hz burst tone. Healthy pregnant women underwent two prenatal measurements and returned with their babies for a neonatal investigation. The amplitudes of the neonatal VERs in the long-ITI condition showed within-train response decrement. An increased response to the auditory dishabituator was found confirming response recovery. In the short-ITI condition, neonatal amplitude decrement could not be demonstrated while response recovery was present. In both ITI conditions, the response rate of the cortical responses was much lower in the fetuses than in the neonates. Fetal VERs in the long-ITI condition indicate amplitude decline from the first to the second flash with no further decrease. The long-ITI paradigm might be useful to investigate habituation of the VERs in neonates and fetuses, although the latter requires precaution. PMID:22483416

Considerations for Using Genetic and Epigenetic Information in Occupational Health Risk Assessment and Standard Setting

PubMed Central

Schulte, P. A.; Whittaker, C.; Curran, C. P.

2015-01-01

Risk assessment forms the basis for both occupational health decision-making and the development of occupational exposure limits (OELs). Although genetic and epigenetic data have not been widely used in risk assessment and ultimately, standard setting, it is possible to envision such uses. A growing body of literature demonstrates that genetic and epigenetic factors condition biological responses to occupational and environmental hazards or serve as targets of them. This presentation addresses the considerations for using genetic and epigenetic information in risk assessments, provides guidance on using this information within the classic risk assessment paradigm, and describes a framework to organize thinking about such uses. The framework is a 4 × 4 matrix involving the risk assessment functions (hazard identification, dose-response modeling, exposure assessment, and risk characterization) on one axis and inherited and acquired genetic and epigenetic data on the other axis. The cells in the matrix identify how genetic and epigenetic data can be used for each risk assessment function. Generally, genetic and epigenetic data might be used as endpoints in hazard identification, as indicators of exposure, as effect modifiers in exposure assessment and dose-response modeling, as descriptors of mode of action, and to characterize toxicity pathways. Vast amounts of genetic and epigenetic data may be generated by high-throughput technologies. These data can be useful for assessing variability and reducing uncertainty in extrapolations, and they may serve as the foundation upon which identification of biological perturbations would lead to a new paradigm of toxicity pathway-based risk assessments. PMID:26583908

How and Why Affective and Reactive Virtual Agents Will Bring New Insights on Social Cognitive Disorders in Schizophrenia? An Illustration with a Virtual Card Game Paradigm

PubMed Central

Oker, Ali; Prigent, Elise; Courgeon, Matthieu; Eyharabide, Victoria; Urbach, Mathieu; Bazin, Nadine; Amorim, Michel-Ange; Passerieux, Christine; Martin, Jean-Claude; Brunet-Gouet, Eric

2015-01-01

In recent decades, many studies have shown that schizophrenia is associated with severe social cognitive impairments affecting key components, such as the recognition of emotions, theory of mind, attributional style, and metacognition. Most studies investigated each construct separately, precluding analysis of the interactive and immersive nature of real-life situation. Specialized batteries of tests are under investigation to assess social cognition, which is thought now as a link between neurocognitive disorders and impaired functioning. However, this link accounts for a limited part of the variance of real-life functioning. To fill this gap, advances in virtual reality and affective computing have made it possible to carry out experimental investigations of naturalistic social cognition, in controlled conditions, with good reproducibility. This approach is illustrated with the description of a new paradigm based on an original virtual card game in which subjects interpret emotional displays from a female virtual agent, and decipher her helping intentions. Independent variables concerning emotional expression in terms of valence and intensity were manipulated. We show how several useful dependant variables, ranging from classic experimental psychology data to metacognition or subjective experiences records, may be extracted from a single experiment. Methodological issues about the immersion into a simulated intersubjective situation are considered. The example of this new flexible experimental setting, with regards to the many constructs recognized in social neurosciences, constitutes a rationale for focusing on this potential intermediate link between standardized tests and real-life functioning, and also for using it as an innovative media for cognitive remediation. PMID:25870549

How and why affective and reactive virtual agents will bring new insights on social cognitive disorders in schizophrenia? An illustration with a virtual card game paradigm.

PubMed

Oker, Ali; Prigent, Elise; Courgeon, Matthieu; Eyharabide, Victoria; Urbach, Mathieu; Bazin, Nadine; Amorim, Michel-Ange; Passerieux, Christine; Martin, Jean-Claude; Brunet-Gouet, Eric

2015-01-01

In recent decades, many studies have shown that schizophrenia is associated with severe social cognitive impairments affecting key components, such as the recognition of emotions, theory of mind, attributional style, and metacognition. Most studies investigated each construct separately, precluding analysis of the interactive and immersive nature of real-life situation. Specialized batteries of tests are under investigation to assess social cognition, which is thought now as a link between neurocognitive disorders and impaired functioning. However, this link accounts for a limited part of the variance of real-life functioning. To fill this gap, advances in virtual reality and affective computing have made it possible to carry out experimental investigations of naturalistic social cognition, in controlled conditions, with good reproducibility. This approach is illustrated with the description of a new paradigm based on an original virtual card game in which subjects interpret emotional displays from a female virtual agent, and decipher her helping intentions. Independent variables concerning emotional expression in terms of valence and intensity were manipulated. We show how several useful dependant variables, ranging from classic experimental psychology data to metacognition or subjective experiences records, may be extracted from a single experiment. Methodological issues about the immersion into a simulated intersubjective situation are considered. The example of this new flexible experimental setting, with regards to the many constructs recognized in social neurosciences, constitutes a rationale for focusing on this potential intermediate link between standardized tests and real-life functioning, and also for using it as an innovative media for cognitive remediation.

Contrast Enhancement without Transient Map Expansion for Species-Specific Vocalizations in Core Auditory Cortex during Learning.

PubMed

Shepard, Kathryn N; Chong, Kelly K; Liu, Robert C

2016-01-01

Tonotopic map plasticity in the adult auditory cortex (AC) is a well established and oft-cited measure of auditory associative learning in classical conditioning paradigms. However, its necessity as an enduring memory trace has been debated, especially given a recent finding that the areal expansion of core AC tuned to a newly relevant frequency range may arise only transiently to support auditory learning. This has been reinforced by an ethological paradigm showing that map expansion is not observed for ultrasonic vocalizations (USVs) or for ultrasound frequencies in postweaning dams for whom USVs emitted by pups acquire behavioral relevance. However, whether transient expansion occurs during maternal experience is not known, and could help to reveal the generality of cortical map expansion as a correlate for auditory learning. We thus mapped the auditory cortices of maternal mice at postnatal time points surrounding the peak in pup USV emission, but found no evidence of frequency map expansion for the behaviorally relevant high ultrasound range in AC. Instead, regions tuned to low frequencies outside of the ultrasound range show progressively greater suppression of activity in response to the playback of ultrasounds or pup USVs for maternally experienced animals assessed at their pups' postnatal day 9 (P9) to P10, or postweaning. This provides new evidence for a lateral-band suppression mechanism elicited by behaviorally meaningful USVs, likely enhancing their population-level signal-to-noise ratio. These results demonstrate that tonotopic map enlargement has limits as a construct for conceptualizing how experience leaves neural memory traces within sensory cortex in the context of ethological auditory learning.

Comparison of Balance Performance Between Thai Classical Dancers and Non-Dancers.

PubMed

Krityakiarana, Warin; Jongkamonwiwat, Nopporn

2016-01-01

Thai classical dance is a traditional dramatic art, the technique of which has many features in common with South East Asian performing art. The choreographic patterns consist of various forms of balance control together with limb movements in slow rhythm. The grace and beauty of the dancer are dependent on how well the limb movements curve and angle. The relationship of whole body proportion and balance control in various patterns of support base is also important. The purpose of this study was to compare balance abilities between Thai classical dancers and non-dancers in different balance conditions. Twenty-five Thai classical dancers and 25 non-dancers performed the modified Sensory Organization Test (mSOT) and were further challenged by adding dynamic head tilts (DHTs) in four different directions during mSOT. Mixed model ANOVA was applied to determine the equilibrium score in each balance condition and also the interaction between dancer and non-dancer groups. It was found that Thai classical dancers achieved better equilibrium scores in all mSOT conditions except the least challenging one. Moreover, additional multitask conditions (mSOT+DHT) were revealed to profoundly affect differences between dancers and controls. In conclusion, Thai classical dancers demonstrated a better ability to maintain postural stability during different challenging postural tests. This information suggests various ways of putting the practice of Thai classical dance to use in the future.

Beyond singular values and loop shapes

NASA Technical Reports Server (NTRS)

Stein, G.

1985-01-01

The status of singular value loop-shaping as a design paradigm for multivariable feedback systems is reviewed. It shows that this paradigm is an effective design tool whenever the problem specifications are spacially round. The tool can be arbitrarily conservative, however, when they are not. This happens because singular value conditions for robust performance are not tight (necessary and sufficient) and can severely overstate actual requirements. An alternate paradign is discussed which overcomes these limitations. The alternative includes a more general problem formulation, a new matrix function mu, and tight conditions for both robust stability and robust performance. The state of the art currently permits analysis of feedback systems within this new paradigm. Synthesis remains a subject of research.

Beyond desertification: New paradigms for dryland landscapes

USDA-ARS?s Scientific Manuscript database

The dryland desertification paradigm focuses on losses of ecosystem services accompanying transitions from grasslands to systems dominated by bare ground or woody plants unpalatable for domestic livestock. However, recent studies reveal complex transitions across a range of environmental conditions ...

Touchscreen-paradigm for mice reveals cross-species evidence for an antagonistic relationship of cognitive flexibility and stability

PubMed Central

Richter, S. Helene; Vogel, Anne S.; Ueltzhöffer, Kai; Muzzillo, Chiara; Vogt, Miriam A.; Lankisch, Katja; Armbruster-Genç, Diana J. N.; Riva, Marco A.; Fiebach, Christian J.; Gass, Peter; Vollmayr, Barbara

2014-01-01

The abilities to either flexibly adjust behavior according to changing demands (cognitive flexibility) or to maintain it in the face of potential distractors (cognitive stability) are critical for adaptive behavior in many situations. Recently, a novel human paradigm has found individual differences of cognitive flexibility and stability to be related to common prefrontal networks. The aims of the present study were, first, to translate this paradigm from humans to mice and, second, to test conceptual predictions of a computational model of prefrontal working memory mechanisms, the Dual State Theory, which assumes an antagonistic relation between cognitive flexibility and stability. Mice were trained in a touchscreen-paradigm to discriminate visual cues. The task involved “ongoing” and cued “switch” trials. In addition distractor cues were interspersed to test the ability to resist distraction, and an ambiguous condition assessed the spontaneous switching between two possible responses without explicit cues. While response times did not differ substantially between conditions, error rates (ER) increased from the “ongoing” baseline condition to the most complex condition, where subjects were required to switch between two responses in the presence of a distracting cue. Importantly, subjects switching more often spontaneously were found to be more distractible by task irrelevant cues, but also more flexible in situations, where switching was required. These results support a dichotomy of cognitive flexibility and stability as predicted by the Dual State Theory. Furthermore, they replicate critical aspects of the human paradigm, which indicates the translational potential of the testing procedure and supports the use of touchscreen procedures in preclinical animal research. PMID:24834036

Aberrant approach-avoidance conflict resolution following repeated cocaine pre-exposure.

PubMed

Nguyen, David; Schumacher, Anett; Erb, Suzanne; Ito, Rutsuko

2015-10-01

Addiction is characterized by persistence to seek drug reinforcement despite negative consequences. Drug-induced aberrations in approach and avoidance processing likely facilitate the sustenance of addiction pathology. Currently, the effects of repeated drug exposure on the resolution of conflicting approach and avoidance motivational signals have yet to be thoroughly investigated. The present study sought to investigate the effects of cocaine pre-exposure on conflict resolution using novel approach-avoidance paradigms. We used a novel mixed-valence conditioning paradigm to condition cocaine-pre-exposed rats to associate visuo-tactile cues with either the delivery of sucrose reward or shock punishment in the arms in which the cues were presented. Following training, exploration of an arm containing a superimposition of the cues was assessed as a measure of conflict resolution behavior. We also used a mixed-valence runway paradigm wherein cocaine-pre-exposed rats traversed an alleyway toward a goal compartment to receive a pairing of sucrose reward and shock punishment. Latency to enter the goal compartment across trials was taken as a measure of motivational conflict. Our results reveal that cocaine pre-exposure attenuated learning for the aversive cue association in our conditioning paradigm and enhanced preference for mixed-valence stimuli in both paradigms. Repeated cocaine pre-exposure allows appetitive approach motivations to gain greater influence over behavioral output in the context of motivational conflict, due to aberrant positive and negative incentive motivational processing.

On parametrized cold dense matter equation-of-state inference

NASA Astrophysics Data System (ADS)

Riley, Thomas E.; Raaijmakers, Geert; Watts, Anna L.

2018-07-01

Constraining the equation of state of cold dense matter in compact stars is a major science goal for observing programmes being conducted using X-ray, radio, and gravitational wave telescopes. We discuss Bayesian hierarchical inference of parametrized dense matter equations of state. In particular, we generalize and examine two inference paradigms from the literature: (i) direct posterior equation-of-state parameter estimation, conditioned on observations of a set of rotating compact stars; and (ii) indirect parameter estimation, via transformation of an intermediary joint posterior distribution of exterior spacetime parameters (such as gravitational masses and coordinate equatorial radii). We conclude that the former paradigm is not only tractable for large-scale analyses, but is principled and flexible from a Bayesian perspective while the latter paradigm is not. The thematic problem of Bayesian prior definition emerges as the crux of the difference between these paradigms. The second paradigm should in general only be considered as an ill-defined approach to the problem of utilizing archival posterior constraints on exterior spacetime parameters; we advocate for an alternative approach whereby such information is repurposed as an approximative likelihood function. We also discuss why conditioning on a piecewise-polytropic equation-of-state model - currently standard in the field of dense matter study - can easily violate conditions required for transformation of a probability density distribution between spaces of exterior (spacetime) and interior (source matter) parameters.

On parametrised cold dense matter equation of state inference

NASA Astrophysics Data System (ADS)

Riley, Thomas E.; Raaijmakers, Geert; Watts, Anna L.

2018-04-01

Constraining the equation of state of cold dense matter in compact stars is a major science goal for observing programmes being conducted using X-ray, radio, and gravitational wave telescopes. We discuss Bayesian hierarchical inference of parametrised dense matter equations of state. In particular we generalise and examine two inference paradigms from the literature: (i) direct posterior equation of state parameter estimation, conditioned on observations of a set of rotating compact stars; and (ii) indirect parameter estimation, via transformation of an intermediary joint posterior distribution of exterior spacetime parameters (such as gravitational masses and coordinate equatorial radii). We conclude that the former paradigm is not only tractable for large-scale analyses, but is principled and flexible from a Bayesian perspective whilst the latter paradigm is not. The thematic problem of Bayesian prior definition emerges as the crux of the difference between these paradigms. The second paradigm should in general only be considered as an ill-defined approach to the problem of utilising archival posterior constraints on exterior spacetime parameters; we advocate for an alternative approach whereby such information is repurposed as an approximative likelihood function. We also discuss why conditioning on a piecewise-polytropic equation of state model - currently standard in the field of dense matter study - can easily violate conditions required for transformation of a probability density distribution between spaces of exterior (spacetime) and interior (source matter) parameters.

Unconscious classical conditioning of sexual arousal: evidence for the conditioning of female genital arousal to subliminally presented sexual stimuli.

PubMed

Both, Stephanie; Spiering, Mark; Laan, Ellen; Belcome, Sarah; van den Heuvel, Birre; Everaerd, Walter

2008-01-01

Although the assumption that sexual behavior is at least partly learned is common across theories of sexual behavior, classical conditioning of sexual response in women has been seldom studied. The study of unconscious classical conditioning of appetitive sexual responses in women. Vaginal pulse amplitude assessed by vaginal photoplethysmography, and ratings of sexual affective value. Pavlovian conditioning was examined in 18 sexually functional women by using two erotic pictures as conditional stimuli (CSs) and genital vibrotactile stimulation as unconditional stimulus (US). During the acquisition phase, the CSs were presented briefly (30 ms) and were masked by an immediately following masking stimulus. Only one CS (the CS+) was followed by the US during the acquisition phase. Conditioned responses were assessed during the extinction phase with supraliminal presentations of the CS+ and the CS-. Vaginal pulse amplitude was higher in response to the CS+ than during the CS- during the first extinction trial. There was no conditioning effect on ratings of affective value. The experiment demonstrates evidence for unconscious conditioning of genital responses in women, but no evidence for evaluative conditioning. The results add to the limited evidence for classical conditioning of sexual arousal in women, and to increasing evidence for associative emotional learning without awareness.

Making Classical Conditioning Understandable through a Demonstration Technique.

ERIC Educational Resources Information Center

Gibb, Gerald D.

1983-01-01

One lemon, an assortment of other fruits and vegetables, a tennis ball, and a Galvanic Skin Response meter are needed to implement this approach to teaching about classical conditioning in introductory psychology courses. (RM)

Acute psychophysiological stress impairs human associative learning.

PubMed

Ehlers, M R; Todd, R M

2017-11-01

Addiction is increasingly discussed asa disorder of associative learning processes, with both operant and classical conditioning contributing to the development of maladaptive habits. Stress has long been known to promote drug taking and relapse and has further been shown to shift behavior from goal-directed actions towards more habitual ones. However, it remains to be investigated how acute stress may influence simple associative learning processes that occur before a habit can be established. In the present study, healthy young adults were exposed to either acute stress or a control condition half an hour before performing simple classical and operant conditioning tasks. Psychophysiological measures confirmed successful stress induction. Results of the operant conditioning task revealed reduced instrumental responding under delayed acute stress that resembled behavioral responses to lower levels of reward. The classical conditioning experiment revealed successful conditioning in both experimental groups; however, explicit knowledge of conditioning as indicated by stimulus ratings differentiated the stress and control groups. These findings suggest that operant and classical conditioning are differentially influenced by the delayed effects of acute stress with important implications for the understanding of how new habitual behaviors are initially established. Copyright © 2017 Elsevier Inc. All rights reserved.

Specific Stimuli Induce Specific Adaptations: Sensorimotor Training vs. Reactive Balance Training

PubMed Central

Freyler, Kathrin; Krause, Anne; Gollhofer, Albert; Ritzmann, Ramona

2016-01-01

Typically, balance training has been used as an intervention paradigm either as static or as reactive balance training. Possible differences in functional outcomes between the two modalities have not been profoundly studied. The objective of the study was to investigate the specificity of neuromuscular adaptations in response to two balance intervention modalities within test and intervention paradigms containing characteristics of both profiles: classical sensorimotor training (SMT) referring to a static ledger pivoting around the ankle joint vs. reactive balance training (RBT) using externally applied perturbations to deteriorate body equilibrium. Thirty-eight subjects were assigned to either SMT or RBT. Before and after four weeks of intervention training, postural sway and electromyographic activities of shank and thigh muscles were recorded and co-contraction indices (CCI) were calculated. We argue that specificity of training interventions could be transferred into corresponding test settings containing properties of SMT and RBT, respectively. The results revealed that i) postural sway was reduced in both intervention groups in all test paradigms; magnitude of changes and effect sizes differed dependent on the paradigm: when training and paradigm coincided most, effects were augmented (P<0.05). ii) These specificities were accompanied by segmental modulations in the amount of CCI, with a greater reduction within the CCI of thigh muscles after RBT compared to the shank muscles after SMT (P<0.05). The results clearly indicate the relationship between test and intervention specificity in balance performance. Hence, specific training modalities of postural control cause multi-segmental and context-specific adaptations, depending upon the characteristics of the trained postural strategy. In relation to fall prevention, perturbation training could serve as an extension to SMT to include the proximal segment, and thus the control of structures near to the body’s centre of mass, into training. PMID:27911944

Quantum Bohmian model for financial market

NASA Astrophysics Data System (ADS)

Choustova, Olga Al.

2007-01-01

We apply methods of quantum mechanics for mathematical modeling of price dynamics at the financial market. The Hamiltonian formalism on the price/price-change phase space describes the classical-like evolution of prices. This classical dynamics of prices is determined by “hard” conditions (natural resources, industrial production, services and so on). These conditions are mathematically described by the classical financial potential V(q), where q=(q1,…,qn) is the vector of prices of various shares. But the information exchange and market psychology play important (and sometimes determining) role in price dynamics. We propose to describe such behavioral financial factors by using the pilot wave (Bohmian) model of quantum mechanics. The theory of financial behavioral waves takes into account the market psychology. The real trajectories of prices are determined (through the financial analogue of the second Newton law) by two financial potentials: classical-like V(q) (“hard” market conditions) and quantum-like U(q) (behavioral market conditions).

Utility of the Hebb-Williams Maze Paradigm for Translational Research in Fragile X Syndrome: A Direct Comparison of Mice and Humans.

PubMed

Boutet, Isabelle; Collin, Charles A; MacLeod, Lindsey S; Messier, Claude; Holahan, Matthew R; Berry-Kravis, Elizabeth; Gandhi, Reno M; Kogan, Cary S

2018-01-01

To generate meaningful information, translational research must employ paradigms that allow extrapolation from animal models to humans. However, few studies have evaluated translational paradigms on the basis of defined validation criteria. We outline three criteria for validating translational paradigms. We then evaluate the Hebb-Williams maze paradigm (Hebb and Williams, 1946; Rabinovitch and Rosvold, 1951) on the basis of these criteria using Fragile X syndrome (FXS) as model disease. We focused on this paradigm because it allows direct comparison of humans and animals on tasks that are behaviorally equivalent (criterion #1) and because it measures spatial information processing, a cognitive domain for which FXS individuals and mice show impairments as compared to controls (criterion #2). We directly compared the performance of affected humans and mice across different experimental conditions and measures of behavior to identify which conditions produce comparable patterns of results in both species. Species differences were negligible for Mazes 2, 4, and 5 irrespective of the presence of visual cues, suggesting that these mazes could be used to measure spatial learning in both species. With regards to performance on the first trial, which reflects visuo-spatial problem solving, Mazes 5 and 9 without visual cues produced the most consistent results. We conclude that the Hebb-Williams mazes paradigm has the potential to be utilized in translational research to measure comparable cognitive functions in FXS humans and animals (criterion #3).

Cognitive effort is modulated outside of the explicit awareness of conflict frequency: Evidence from pupillometry.

PubMed

Diede, Nathaniel T; Bugg, Julie M

2017-05-01

Classic theories of cognitive control conceptualized controlled processes as slow, strategic, and willful, with automatic processes being fast and effortless. The context-specific proportion compatibility (CSPC) effect, the reduction in the compatibility effect in a context (e.g., location) associated with a high relative to low likelihood of conflict, challenged classic theories by demonstrating fast and flexible control that appears to operate outside of conscious awareness. Two theoretical questions yet to be addressed are whether the CSPC effect is accompanied by context-dependent variation in effort, and whether the exertion of effort depends on explicit awareness of context-specific task demands. To address these questions, pupil diameter was measured during a CSPC paradigm. Stimuli were randomly presented in either a mostly compatible location or a mostly incompatible location. Replicating prior research, the CSPC effect was found. The novel finding was that pupil diameter was greater in the mostly incompatible location compared to the mostly compatible location, despite participants' lack of awareness of context-specific task demands. Additionally, this difference occurred regardless of trial type or a preceding switch in location. These patterns support the view that context (location) dictates selection of optimal attentional settings in the CSPC paradigm, and varying levels of effort and performance accompany these settings. Theoretically, these patterns imply that cognitive control may operate fast, flexibly, and outside of awareness, but not effortlessly. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A trial of scheduled deep brain stimulation for Tourette syndrome: moving away from continuous deep brain stimulation paradigms.

PubMed

Okun, Michael S; Foote, Kelly D; Wu, Samuel S; Ward, Herbert E; Bowers, Dawn; Rodriguez, Ramon L; Malaty, Irene A; Goodman, Wayne K; Gilbert, Donald M; Walker, Harrison C; Mink, Jonathan W; Merritt, Stacy; Morishita, Takashi; Sanchez, Justin C

2013-01-01

To collect the information necessary to design the methods and outcome variables for a larger trial of scheduled deep brain stimulation (DBS) for Tourette syndrome. We performed a small National Institutes of Health-sponsored clinical trials planning study of the safety and preliminary efficacy of implanted DBS in the bilateral centromedian thalamic region. The study used a cranially contained constant-current device and a scheduled, rather than the classic continuous, DBS paradigm. Baseline vs 6-month outcomes were collected and analyzed. In addition, we compared acute scheduled vs acute continuous vs off DBS. A university movement disorders center. Five patients with implanted DBS. A 50% improvement in the Yale Global Tic Severity Scale (YGTSS) total score. RESULTS Participating subjects had a mean age of 34.4 (range, 28-39) years and a mean disease duration of 28.8 years. No significant adverse events or hardware-related issues occurred. Baseline vs 6-month data revealed that reductions in the YGTSS total score did not achieve the prestudy criterion of a 50% improvement in the YGTSS total score on scheduled stimulation settings. However, statistically significant improvements were observed in the YGTSS total score (mean [SD] change, -17.8 [9.4]; P=.01), impairment score (-11.3 [5.0]; P=.007), and motor score (-2.8 [2.2]; P=.045); the Modified Rush Tic Rating Scale Score total score (-5.8 [2.9]; P=.01); and the phonic tic severity score (-2.2 [2.6]; P=.04). Continuous, off, and scheduled stimulation conditions were assessed blindly in an acute experiment at 6 months after implantation. The scores in all 3 conditions showed a trend for improvement. Trends for improvement also occurred with continuous and scheduled conditions performing better than the off condition. Tic suppression was commonly seen at ventral (deep) contacts, and programming settings resulting in tic suppression were commonly associated with a subjective feeling of calmness. This study provides safety and proof of concept that a scheduled DBS approach could improve motor and vocal tics in Tourette syndrome. Refinements in neurostimulator battery life, outcome measure selection, and flexibility in programming settings can be used to enhance outcomes in a future larger study. Scheduled stimulation holds promise as a potential first step for shifting movement and neuropsychiatric disorders toward more responsive neuromodulation approaches. clinicaltrials.gov Identifier: NCT01329198.

Where Do Epigenetics and Developmental Origins Take the Field of Developmental Psychopathology?

PubMed

Nigg, Joel T

2016-04-01

The time is ripe for upgrading or rethinking the assumed paradigms for how we study developmental psychopathology. The classic transactional models appear robust but need specification in terms of biological and psychosocial processes. That specification is increasingly tractable due to developments in genetics, epigenetics, the measurement of psychosocial processes, and theory and data on developmental origins of health and disease. This essay offers a high-level view of where the field has been and where it may be going in regard to nosology and conceptions of etiology. Remarks seek to consider rapidly evolving contexts not only for children, but also for the science itself due to progress in our field and in neighboring fields. Illustrations are provided as to how syndromal nosology can be enriched and advanced by careful integration with biologically relevant behavioral dimensions and application of quantitative methods. It is concluded that a revised, forward-looking, transactional model of abnormal child psychology will incorporate prenatal and postnatal developmental programming, epigenetic mechanisms and their associated genotype x environment interactions, and inflammatory processes as a potential common mediator influencing numerous health and mental health conditions.

Wavelet multiresolution complex network for decoding brain fatigued behavior from P300 signals

NASA Astrophysics Data System (ADS)

Gao, Zhong-Ke; Wang, Zi-Bo; Yang, Yu-Xuan; Li, Shan; Dang, Wei-Dong; Mao, Xiao-Qian

2018-09-01

Brain-computer interface (BCI) enables users to interact with the environment without relying on neural pathways and muscles. P300 based BCI systems have been extensively used to achieve human-machine interaction. However, the appearance of fatigue symptoms during operation process leads to the decline in classification accuracy of P300. Characterizing brain cognitive process underlying normal and fatigue conditions constitutes a problem of vital importance in the field of brain science. We in this paper propose a novel wavelet decomposition based complex network method to efficiently analyze the P300 signals recorded in the image stimulus test based on classical 'Oddball' paradigm. Initially, multichannel EEG signals are decomposed into wavelet coefficient series. Then we construct complex network by treating electrodes as nodes and determining the connections according to the 2-norm distances between wavelet coefficient series. The analysis of topological structure and statistical index indicates that the properties of brain network demonstrate significant distinctions between normal status and fatigue status. More specifically, the brain network reconfiguration in response to the cognitive task in fatigue status is reflected as the enhancement of the small-worldness.

Conscious and unconscious thought in risky choice: testing the capacity principle and the appropriate weighting principle of unconscious thought theory.

PubMed

Ashby, Nathaniel J S; Glöckner, Andreas; Dickert, Stephan

2011-01-01

Daily we make decisions ranging from the mundane to the seemingly pivotal that shape our lives. Assuming rationality, all relevant information about one's options should be thoroughly examined in order to make the best choice. However, some findings suggest that under specific circumstances thinking too much has disadvantageous effects on decision quality and that it might be best to let the unconscious do the busy work. In three studies we test the capacity assumption and the appropriate weighting principle of Unconscious Thought Theory using a classic risky choice paradigm and including a "deliberation with information" condition. Although we replicate an advantage for unconscious thought (UT) over "deliberation without information," we find that "deliberation with information" equals or outperforms UT in risky choices. These results speak against the generality of the assumption that UT has a higher capacity for information integration and show that this capacity assumption does not hold in all domains. Furthermore, we show that "deliberate thought with information" leads to more differentiated knowledge compared to UT which speaks against the generality of the appropriate weighting assumption.

A Unified Theory of Sepsis-Induced Acute Kidney Injury: Inflammation, microcirculatory dysfunction, bioenergetics and the tubular cell adaptation to injury

PubMed Central

Gomez, Hernando; Ince, Can; De Backer, Daniel; Pickkers, Peter; Payen, Didier; Hotchkiss, John; Kellum, John A.

2014-01-01

Given that the leading clinical conditions associated with Acute kidney injury (AKI), namely, sepsis, major surgery, heart failure and hypovolemia, are all associated with shock, it is tempting to attribute all AKI to ischemia on the basis of macro-hemodynamic changes. However, an increasing body of evidence has suggested that in many patients, AKI can occur in the absence of overt signs of global renal hypoperfusion. Indeed, sepsis-induced AKI can occur in the setting of normal or even increased renal blood flow. Accordingly, renal injury may not be entirely explained solely on the basis of the classic paradigm of hypoperfusion, and thus other mechanisms must come into play. Herein, we put forward a “unifying theory” to explain the interplay between inflammation and oxidative stress, microvascular dysfunction, and the adaptive response of the tubular epithelial cell to the septic insult. We propose that this response is mostly adaptive in origin, that it is driven by mitochondria and that it ultimately results in and explains the clinical phenotype of sepsis induced AKI. PMID:24346647

Similarities and Differences in Diagnostic Criterion.

PubMed

Wei, Zhengde; Zhang, Xiaochu

2017-01-01

In this chapter, the main content is to discuss the similarities and differences in diagnostic criteria between substance and non-substance addictions. Firstly, diagnostic criteria of substance addiction were introduced, mainly focused on Diagnostic and Statistical Manual for the Mental Disorders, fifth edition (DSM-5). Then, we described the diagnostic criteria of several non-substance addictions, including gambling disorder, internet addiction, food addiction and hypersexual disorder. Depending on the proof, substance and non-substance addictions have many similarities in symptoms. Though the proposed diagnostic criteria of many non-substance addictions are currently most useful as survey instruments to access the prevalence of the problem, there is little or no validating proof for these diagnostic criteria. Finally, animal model is useful tool for addiction research. But, present animal models for gambling studying do not meet enough diagnostic criteria and could not be regarded as gambling disorder. By introducing the animal models evolved to resemble the diagnostic criteria of substance addiction and two classical paradigms for substance addiction, self-administration and conditioned place preference, we hope it is helpful to improve the validation of animal model of gambling disorder.

Feeding Behavior of Aplysia: A Model System for Comparing Cellular Mechanisms of Classical and Operant Conditioning

ERIC Educational Resources Information Center

Baxter, Douglas A.; Byrne, John H.

2006-01-01

Feeding behavior of Aplysia provides an excellent model system for analyzing and comparing mechanisms underlying appetitive classical conditioning and reward operant conditioning. Behavioral protocols have been developed for both forms of associative learning, both of which increase the occurrence of biting following training. Because the neural…

The auditory oddball paradigm revised to improve bedside detection of consciousness in behaviorally unresponsive patients.

PubMed

Morlet, Dominique; Ruby, Perrine; André-Obadia, Nathalie; Fischer, Catherine

2017-11-01

Active paradigms requiring subjects to engage in a mental task on request have been developed to detect consciousness in behaviorally unresponsive patients. Using auditory ERPs, the active condition consists in orienting patient's attention toward oddball stimuli. In comparison with passive listening, larger P300 in the active condition identifies voluntary processes. However, contrast between these two conditions is usually too weak to be detected at the individual level. To improve test sensitivity, we propose as a control condition to actively divert the subject's attention from the auditory stimuli with a mental imagery task that has been demonstrated to be within the grasp of the targeted patients: navigate in one's home. Twenty healthy subjects were presented with a two-tone oddball paradigm in the three following condition: (a) passive listening, (b) mental imagery, (c) silent counting of deviant stimuli. Mental imagery proved to be more efficient than passive listening to lessen P300 response to deviant tones as compared with the active counting condition. An effect of attention manipulation (oriented vs. diverted) was observed in 19/20 subjects, of whom 18 showed the expected P300 effect and 1 showed an effect restricted to the N2 component. The only subject showing no effect also proved insufficient engagement in the tasks. Our study demonstrated the efficiency of diverting attention using mental imagery to improve the sensitivity of the active oddball paradigm. Using recorded instructions and requiring a small number of electrodes, the test was designed to be conveniently and economically used at the patient's bedside. © 2017 Society for Psychophysiological Research.

[Taxonomic theory for non-classical systematics].

PubMed

Pavlinov, I Ia

2012-01-01

Outlined briefly are basic principles of construing general taxonomic theory for biological systematics considered in the context of non-classical scientific paradigm. The necessity of such kind of theory is substantiated, and some key points of its elaboration are exposed: its interpretation as a framework concept for the partial taxonomic theories in various schools of systematics; elaboration of idea of cognitive situation including three interrelated components, namely subject, object, and epistemic ones; its construing as a content-wisely interpreted quasi-axiomatics, with strong structuring of its conceptual space including demarcation between axioms and inferring rules; its construing as a "conceptual pyramid" of concepts of various levels of generality; inclusion of a basic model into definition of the taxonomic system (classification) regulating its content. Two problems are indicated as fundamental: definition of taxonomic diversity as a subject domain for the systematics as a whole; definition of onto-epistemological status of taxonomic system (classification) in general and of taxa in particular.

Optimally stopped variational quantum algorithms

NASA Astrophysics Data System (ADS)

Vinci, Walter; Shabani, Alireza

2018-04-01

Quantum processors promise a paradigm shift in high-performance computing which needs to be assessed by accurate benchmarking measures. In this article, we introduce a benchmark for the variational quantum algorithm (VQA), recently proposed as a heuristic algorithm for small-scale quantum processors. In VQA, a classical optimization algorithm guides the processor's quantum dynamics to yield the best solution for a given problem. A complete assessment of the scalability and competitiveness of VQA should take into account both the quality and the time of dynamics optimization. The method of optimal stopping, employed here, provides such an assessment by explicitly including time as a cost factor. Here, we showcase this measure for benchmarking VQA as a solver for some quadratic unconstrained binary optimization. Moreover, we show that a better choice for the cost function of the classical routine can significantly improve the performance of the VQA algorithm and even improve its scaling properties.

Pharmacological Targeting of the Host-Pathogen Interaction: Alternatives to Classical Antibiotics to Combat Drug-Resistant Superbugs.

PubMed

Munguia, Jason; Nizet, Victor

2017-05-01

The rise of multidrug-resistant pathogens and the dearth of new antibiotic development place an existential strain on successful infectious disease therapy. Breakthrough strategies that go beyond classical antibiotic mechanisms are needed to combat this looming public health catastrophe. Reconceptualizing antibiotic therapy in the richer context of the host-pathogen interaction is required for innovative solutions. By defining specific virulence factors, the essence of a pathogen, and pharmacologically neutralizing their activities, one can block disease progression and sensitize microbes to immune clearance. Likewise, host-directed strategies to boost phagocyte bactericidal activity, enhance leukocyte recruitment, or reverse pathogen-induced immunosuppression seek to replicate the success of cancer immunotherapy in the field of infectious diseases. The answer to the threat of multidrug-resistant pathogens lies 'outside the box' of current antibiotic paradigms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Quantum simulator review

NASA Astrophysics Data System (ADS)

Bednar, Earl; Drager, Steven L.

2007-04-01

Quantum information processing's objective is to utilize revolutionary computing capability based on harnessing the paradigm shift offered by quantum computing to solve classically hard and computationally challenging problems. Some of our computationally challenging problems of interest include: the capability for rapid image processing, rapid optimization of logistics, protecting information, secure distributed simulation, and massively parallel computation. Currently, one important problem with quantum information processing is that the implementation of quantum computers is difficult to realize due to poor scalability and great presence of errors. Therefore, we have supported the development of Quantum eXpress and QuIDD Pro, two quantum computer simulators running on classical computers for the development and testing of new quantum algorithms and processes. This paper examines the different methods used by these two quantum computing simulators. It reviews both simulators, highlighting each simulators background, interface, and special features. It also demonstrates the implementation of current quantum algorithms on each simulator. It concludes with summary comments on both simulators.

Colour in a larger perspective: the rebirth of Gestalt psychology.

PubMed

Spillmann, L

1997-01-01

This overview takes the reader from the classical contrast and assimilation studies of the past to today's colour research, in a broad sense, with its renewed emphasis on the phenomenological qualities of visual perception. It shows how the shift in paradigm from local to global effects in single-unit recordings prompted a reappraisal of appearance in visual experiments, not just in colour, but in the perception of motion, texture, and depth as well. Gestalt ideas placed in the context of modern concepts are shown to inspire psychophysicists, neurophysiologists, and computational vision scientists alike. Feedforward, horizontal interactions, and feedback are discussed as potential neuronal mechanisms to account for phenomena such as uniform surfaces, filling-in, and grouping arising from processes beyond the classical receptive field. A look forward towards future developments in the field of figure-ground segregation (Gestalt formation) concludes the article.

From transistor to trapped-ion computers for quantum chemistry.

PubMed

Yung, M-H; Casanova, J; Mezzacapo, A; McClean, J; Lamata, L; Aspuru-Guzik, A; Solano, E

2014-01-07

Over the last few decades, quantum chemistry has progressed through the development of computational methods based on modern digital computers. However, these methods can hardly fulfill the exponentially-growing resource requirements when applied to large quantum systems. As pointed out by Feynman, this restriction is intrinsic to all computational models based on classical physics. Recently, the rapid advancement of trapped-ion technologies has opened new possibilities for quantum control and quantum simulations. Here, we present an efficient toolkit that exploits both the internal and motional degrees of freedom of trapped ions for solving problems in quantum chemistry, including molecular electronic structure, molecular dynamics, and vibronic coupling. We focus on applications that go beyond the capacity of classical computers, but may be realizable on state-of-the-art trapped-ion systems. These results allow us to envision a new paradigm of quantum chemistry that shifts from the current transistor to a near-future trapped-ion-based technology.

Optical, analog and digital domain architectural considerations for visual communications

NASA Astrophysics Data System (ADS)

Metz, W. A.

2008-01-01

The end of the performance entitlement historically achieved by classic scaling of CMOS devices is within sight, driven ultimately by fundamental limits. Performance entitlements predicted by classic CMOS scaling have progressively failed to be realized in recent process generations due to excessive leakage, increasing interconnect delays and scaling of gate dielectrics. Prior to reaching fundamental limits, trends in technology, architecture and economics will pressure the industry to adopt new paradigms. A likely response is to repartition system functions away from digital implementations and into new architectures. Future architectures for visual communications will require extending the implementation into the optical and analog processing domains. The fundamental properties of these domains will in turn give rise to new architectural concepts. The limits of CMOS scaling and impact on architectures will be briefly reviewed. Alternative approaches in the optical, electronic and analog domains will then be examined for advantages, architectural impact and drawbacks.

From transistor to trapped-ion computers for quantum chemistry

PubMed Central

Yung, M.-H.; Casanova, J.; Mezzacapo, A.; McClean, J.; Lamata, L.; Aspuru-Guzik, A.; Solano, E.

2014-01-01

Over the last few decades, quantum chemistry has progressed through the development of computational methods based on modern digital computers. However, these methods can hardly fulfill the exponentially-growing resource requirements when applied to large quantum systems. As pointed out by Feynman, this restriction is intrinsic to all computational models based on classical physics. Recently, the rapid advancement of trapped-ion technologies has opened new possibilities for quantum control and quantum simulations. Here, we present an efficient toolkit that exploits both the internal and motional degrees of freedom of trapped ions for solving problems in quantum chemistry, including molecular electronic structure, molecular dynamics, and vibronic coupling. We focus on applications that go beyond the capacity of classical computers, but may be realizable on state-of-the-art trapped-ion systems. These results allow us to envision a new paradigm of quantum chemistry that shifts from the current transistor to a near-future trapped-ion-based technology. PMID:24395054

[Reconstituting evaluation methods based on both qualitative and quantitative paradigms].

PubMed

Miyata, Hiroaki; Okubo, Suguru; Yoshie, Satoru; Kai, Ichiro

2011-01-01

Debate about the relationship between quantitative and qualitative paradigms is often muddled and confusing and the clutter of terms and arguments has resulted in the concepts becoming obscure and unrecognizable. In this study we conducted content analysis regarding evaluation methods of qualitative healthcare research. We extracted descriptions on four types of evaluation paradigm (validity/credibility, reliability/credibility, objectivity/confirmability, and generalizability/transferability), and classified them into subcategories. In quantitative research, there has been many evaluation methods based on qualitative paradigms, and vice versa. Thus, it might not be useful to consider evaluation methods of qualitative paradigm are isolated from those of quantitative methods. Choosing practical evaluation methods based on the situation and prior conditions of each study is an important approach for researchers.

Amygdala's involvement in facilitating associative learning-induced plasticity: a promiscuous role for the amygdala in memory acquisition

PubMed Central

Chau, Lily S.; Galvez, Roberto

2012-01-01

It is widely accepted that the amygdala plays a critical role in acquisition and consolidation of fear-related memories. Some of the more widely employed behavioral paradigms that have assisted in solidifying the amygdala's role in fear-related memories are associative learning paradigms. With most associative learning tasks, a neutral conditioned stimulus (CS) is paired with a salient unconditioned stimulus (US) that elicits an unconditioned response (UR). After multiple CS-US pairings, the subject learns that the CS predicts the onset or delivery of the US, and thus elicits a learned conditioned response (CR). Most fear-related associative paradigms have suggested that an aspect of the fear association is stored in the amygdala; however, some fear-motivated associative paradigms suggest that the amygdala is not a site of storage, but rather facilitates consolidation in other brain regions. Based upon various learning theories, one of the most likely sites for storage of long-term memories is the neocortex. In support of these theories, findings from our laboratory, and others, have demonstrated that trace-conditioning, an associative paradigm where there is a separation in time between the CS and US, induces learning-specific neocortical plasticity. The following review will discuss the amygdala's involvement, either as a site of storage or facilitating storage in other brain regions such as the neocortex, in fear- and non-fear-motivated associative paradigms. In this review, we will discuss recent findings suggesting a broader role for the amygdala in increasing the saliency of behaviorally relevant information, thus facilitating acquisition for all forms of memory, both fear- and non-fear-related. This proposed promiscuous role of the amygdala in facilitating acquisition for all memories further suggests a potential role of the amygdala in general learning disabilities. PMID:23087626

Amygdala's involvement in facilitating associative learning-induced plasticity: a promiscuous role for the amygdala in memory acquisition.

PubMed

Chau, Lily S; Galvez, Roberto

2012-01-01

It is widely accepted that the amygdala plays a critical role in acquisition and consolidation of fear-related memories. Some of the more widely employed behavioral paradigms that have assisted in solidifying the amygdala's role in fear-related memories are associative learning paradigms. With most associative learning tasks, a neutral conditioned stimulus (CS) is paired with a salient unconditioned stimulus (US) that elicits an unconditioned response (UR). After multiple CS-US pairings, the subject learns that the CS predicts the onset or delivery of the US, and thus elicits a learned conditioned response (CR). Most fear-related associative paradigms have suggested that an aspect of the fear association is stored in the amygdala; however, some fear-motivated associative paradigms suggest that the amygdala is not a site of storage, but rather facilitates consolidation in other brain regions. Based upon various learning theories, one of the most likely sites for storage of long-term memories is the neocortex. In support of these theories, findings from our laboratory, and others, have demonstrated that trace-conditioning, an associative paradigm where there is a separation in time between the CS and US, induces learning-specific neocortical plasticity. The following review will discuss the amygdala's involvement, either as a site of storage or facilitating storage in other brain regions such as the neocortex, in fear- and non-fear-motivated associative paradigms. In this review, we will discuss recent findings suggesting a broader role for the amygdala in increasing the saliency of behaviorally relevant information, thus facilitating acquisition for all forms of memory, both fear- and non-fear-related. This proposed promiscuous role of the amygdala in facilitating acquisition for all memories further suggests a potential role of the amygdala in general learning disabilities.

A case report: a young waiter with Paget-Schroetter syndrome.

PubMed

Drakos, Nicholas; Gausche-Hill, Marianne

2013-03-01

Paget-Schroetter syndrome (PSS) is a rare presentation of primary axillary subclavian vein thrombosis that classically occurs in young men with a degree of underlying thoracic outlet syndrome after a period of upper extremity exertion. The primary complication of PSS is post-thrombotic syndrome, a result of chronic venous hypertension. To educate Emergency Physicians on this condition to potentiate timely diagnosis and appropriate disposition. A 29-year-old right-handed restaurant waiter presented with 3 days of non-painful, gradual-onset right upper extremity swelling with normal vital signs. The patient's history was otherwise notable for subjective fevers and a right forearm abrasion. Upon examination, the right upper extremity was neurovascularly intact and remarkable for uniform edema and erythema extending distally from the level of the mid-humerus. The primary differential diagnoses were deep venous thrombosis (DVT) vs. soft tissue infection. Venous phase contrast computed tomography did not reveal evidence of underlying soft tissue infection and was inconclusive regarding a DVT. Ultrasound demonstrated a right subclavian vein DVT. The patient was admitted and underwent thrombolysis, venolysis, and first rib resection and initiation of warfarin. PSS is a rare presentation of upper-extremity DVT occurring classically in patients without commonly recognized pro-thrombotic risk factors. PSS carries the potential of significant morbidity in the form of post-thrombotic syndrome and pulmonary embolism. Current literature suggests that optimal outcomes are achieved when treatment is initiated within 6 weeks of onset. The treatment paradigm calls for thrombolysis and, frequently, a first rib resection. Copyright © 2013 Elsevier Inc. All rights reserved.

Physical Models of Cognition

NASA Technical Reports Server (NTRS)

Zak, Michail

1994-01-01

This paper presents and discusses physical models for simulating some aspects of neural intelligence, and, in particular, the process of cognition. The main departure from the classical approach here is in utilization of a terminal version of classical dynamics introduced by the author earlier. Based upon violations of the Lipschitz condition at equilibrium points, terminal dynamics attains two new fundamental properties: it is spontaneous and nondeterministic. Special attention is focused on terminal neurodynamics as a particular architecture of terminal dynamics which is suitable for modeling of information flows. Terminal neurodynamics possesses a well-organized probabilistic structure which can be analytically predicted, prescribed, and controlled, and therefore which presents a powerful tool for modeling real-life uncertainties. Two basic phenomena associated with random behavior of neurodynamic solutions are exploited. The first one is a stochastic attractor ; a stable stationary stochastic process to which random solutions of a closed system converge. As a model of the cognition process, a stochastic attractor can be viewed as a universal tool for generalization and formation of classes of patterns. The concept of stochastic attractor is applied to model a collective brain paradigm explaining coordination between simple units of intelligence which perform a collective task without direct exchange of information. The second fundamental phenomenon discussed is terminal chaos which occurs in open systems. Applications of terminal chaos to information fusion as well as to explanation and modeling of coordination among neurons in biological systems are discussed. It should be emphasized that all the models of terminal neurodynamics are implementable in analog devices, which means that all the cognition processes discussed in the paper are reducible to the laws of Newtonian mechanics.

Association Between Initial Age of Exposure to Childhood Abuse and Cognitive Control: Preliminary Evidence.

PubMed

Mackiewicz Seghete, Kristen L; DePrince, Anne P; Banich, Marie T

2018-05-22

Cognitive control, which relies on the protracted development of frontal-parietal regions into adolescence, is a brain process that may be particularly vulnerable to the impact of childhood abuse. In this study, we used functional magnetic resonance imaging (fMRI) to examine associations between the age of onset of childhood abuse and alterations to the neural mechanisms supporting cognitive control in early adulthood, which have not been previously examined. During fMRI scanning, participants completed hybrid block/event-related versions of a classic color-word Stroop task as well as emotional Stroop tasks (threat and positive words). Participants were young adult women (N = 15; age range: 23-30 years) who had a history of childhood physical or sexual abuse that began prior to 13 years of age. Results indicated that earlier age of onset of childhood abuse was robustly associated with increased transient (i.e., event-related) recruitment of medial cognitive control regions in the classic color-word paradigm as well as with less suppression of medial frontal regions that are part of the default mode network, βs = -.16 to -.87. In comparison, increased activation in dorsolateral prefrontal regions was associated with earlier age of abuse onset under conditions of sustained (i.e., blocked) cognitive control in the emotional Stroop task for blocks of positive distracting words versus fixation, βs = -.50 to -.60. These results provide preliminary evidence that earlier age of exposure to childhood abuse impacts the functional activation of neural systems involved in cognitive control in adulthood. Copyright © 2018 International Society for Traumatic Stress Studies.

Sea Slugs, Subliminal Pictures, and Vegetative State Patients: Boundaries of Consciousness in Classical Conditioning

PubMed Central

Bekinschtein, Tristan A.; Peeters, Moos; Shalom, Diego; Sigman, Mariano

2011-01-01

Classical (trace) conditioning is a specific variant of associative learning in which a neutral stimulus leads to the subsequent prediction of an emotionally charged or noxious stimulus after a temporal gap. When conditioning is concurrent with a distraction task, only participants who can report the relationship (the contingency) between stimuli explicitly show associative learning. This suggests that consciousness is a prerequisite for trace conditioning. We review and question three main controversies concerning this view. Firstly, virtually all animals, even invertebrate sea slugs, show this type of learning; secondly, unconsciously perceived stimuli may elicit trace conditioning; and thirdly, some vegetative state patients show trace learning. We discuss and analyze these seemingly contradictory arguments to find the theoretical boundaries of consciousness in classical conditioning. We conclude that trace conditioning remains one of the best measures to test conscious processing in the absence of explicit reports. PMID:22164148

Training effectiveness assessment: Methodological problems and issues

NASA Technical Reports Server (NTRS)

Cross, Kenneth D.

1992-01-01

The U.S. military uses a large number of simulators to train and sustain the flying skills of helicopter pilots. Despite the enormous resources required to purchase, maintain, and use those simulators, little effort has been expended in assessing their training effectiveness. One reason for this is the lack of an evaluation methodology that yields comprehensive and valid data at a practical cost. Some of these methodological problems and issues that arise in assessing simulator training effectiveness, as well as problems with the classical transfer-of-learning paradigm were discussed.

Learning, epigenetics, and computation: An extension on Fitch's proposal. Comment on “Toward a computational framework for cognitive biology: Unifying approaches from cognitive neuroscience and comparative cognition” by W. Tecumseh Fitch

NASA Astrophysics Data System (ADS)

Okanoya, Kazuo

2014-09-01

The comparative computational approach of Fitch [1] attempts to renew the classical David Marr paradigm of computation, algorithm, and implementation, by introducing evolutionary view of the relationship between neural architecture and cognition. This comparative evolutionary view provides constraints useful in narrowing down the problem space for both cognition and neural mechanisms. I will provide two examples from our own studies that reinforce and extend Fitch's proposal.

Counterfactual Measurements and the Quantum Zeno Effect

NASA Astrophysics Data System (ADS)

Russo, Onofrio; Jiang, Liang

2014-03-01

The apparent paradoxical paradigm of an interaction free measurement (counterfactual measurement) of the presence of a classical or quantum object without any scattering or absorption of photons is considered in light of the quantum Zeno effect. From one perspective, the counterfactual measurement in principle is consistent with minimizing the interaction between the object and the photon. However, the quantum Zeno effect mandates that repeated interactions with photons (although weakly coupled) are required and necessary to inhibit the coherent evolution of the state of the system. We consider and appraise these seemingly conflicting concepts.

Two models for a maternal factor in the inheritance of Huntington disease.

PubMed Central

Boehnke, M; Conneally, P M; Lange, K

1983-01-01

Huntington disease is a classic example of an autosomal dominant trait. Over the years, however, a number of investigators have reported anomalies regarding the age of onset of the disease that are inconsistent with this paradigm. We propose two models in which a maternal factor--cytoplasmic in one case, autosomal or X-linked in the other--acts to delay onset in a manner consistent with the previously reported anomalies. Relevant data from the Huntington's Disease Research Roster are presented that reinforce and extend the previous observations. PMID:6225335

Cellular Automata with Anticipation: Examples and Presumable Applications

NASA Astrophysics Data System (ADS)

Krushinsky, Dmitry; Makarenko, Alexander

2010-11-01

One of the most prospective new methodologies for modelling is the so-called cellular automata (CA) approach. According to this paradigm, the models are built from simple elements connected into regular structures with local interaction between neighbours. The patterns of connections usually have a simple geometry (lattices). As one of the classical examples of CA we mention the game `Life' by J. Conway. This paper presents two examples of CA with anticipation property. These examples include a modification of the game `Life' and a cellular model of crowd movement.

An appraisal of the classic forest succession paradigm with the shade tolerance index.

PubMed

Lienard, Jean; Florescu, Ionut; Strigul, Nikolay

2015-01-01

In this paper we revisit the classic theory of forest succession that relates shade tolerance and species replacement and assess its validity to understand patch-mosaic patterns of forested ecosystems of the USA. We introduce a macroscopic parameter called the "shade tolerance index" and compare it to the classic continuum index in southern Wisconsin forests. We exemplify shade tolerance driven succession in White Pine-Eastern Hemlock forests using computer simulations and analyzing approximated chronosequence data from the USDA FIA forest inventory. We describe this parameter across the last 50 years in the ecoregions of mainland USA, and demonstrate that it does not correlate with the usual macroscopic characteristics of stand age, biomass, basal area, and biodiversity measures. We characterize the dynamics of shade tolerance index using transition matrices and delimit geographical areas based on the relevance of shade tolerance to explain forest succession. We conclude that shade tolerance driven succession is linked to climatic variables and can be considered as a primary driving factor of forest dynamics mostly in central-north and northeastern areas in the USA. Overall, the shade tolerance index constitutes a new quantitative approach that can be used to understand and predict succession of forested ecosystems and biogeographic patterns.

Social and structural housing conditions influence the development of a depressive-like phenotype in the learned helplessness paradigm in male mice.

PubMed

Chourbaji, Sabine; Zacher, Christiane; Sanchis-Segura, Carles; Spanagel, Rainer; Gass, Peter

2005-10-14

Structural and social factors are known to play a crucial role in the pathogenesis of depression. Since animal models of depression are a major tool to gain insights into the mechanisms involved in the pathophysiology of this disease it is important not only to exploit but also to be aware of factors that may affect these models. As housing represents a fundamental external factor, which is controversially debated to affect the animals' emotionality, this study aimed to investigate the impact of different social and structural housing conditions on the development of a depressive-like syndrome in the learned helplessness paradigm. Group housing in an impoverished environment led to an increased vulnerability in the learned helplessness paradigm. Groups that were housed enriched, however, were less helpless. Furthermore impoverished conditions did not increase the vulnerability in single housed animals. Regarding emotionality in the animals, basal anxiety was reduced and the exploration was enhanced by group housing and enriched environment. These results suggest that housing conditions significantly influence the outcome of learned helplessness studies.

Using the trauma film paradigm to explore interpersonal processes after trauma exposure.

PubMed

Woodward, Matthew J; Beck, J Gayle

2017-07-01

The present study sought to examine ways in which social support might influence trauma symptoms using a variation of the trauma film paradigm. Sixty-seven undergraduate female students in romantic relationships were randomized to watch a stressful film clip depicting a sexual assault, either in the presence (PP) or absence (PA) of their romantic partner. Analyses showed that the PP condition experienced more intrusive memories of the film than the PA condition. In addition, participants in the PP condition whose romantic partner reported low relationship trust had higher film-related distress than participants in the PP condition whose romantic partner reported high relationship trust. Observational coding of partner behaviors after viewing the film clip found that greater expression of negative emotion from partners predicted participants' negative affect and intrusive memories over time. Positive emotional support did not have any effect upon participants' distress. Findings identify possible ways in which interpersonal processes influence trauma adjustment and suggest that the trauma film paradigm can be adapted to examine the role of interpersonal processes in post-trauma adjustment. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Roles of octopaminergic and dopaminergic neurons in appetitive and aversive memory recall in an insect.

PubMed

Mizunami, Makoto; Unoki, Sae; Mori, Yasuhiro; Hirashima, Daisuke; Hatano, Ai; Matsumoto, Yukihisa

2009-08-04

In insect classical conditioning, octopamine (the invertebrate counterpart of noradrenaline) or dopamine has been suggested to mediate reinforcing properties of appetitive or aversive unconditioned stimulus, respectively. However, the roles of octopaminergic and dopaminergic neurons in memory recall have remained unclear. We studied the roles of octopaminergic and dopaminergic neurons in appetitive and aversive memory recall in olfactory and visual conditioning in crickets. We found that pharmacological blockade of octopamine and dopamine receptors impaired aversive memory recall and appetitive memory recall, respectively, thereby suggesting that activation of octopaminergic and dopaminergic neurons and the resulting release of octopamine and dopamine are needed for appetitive and aversive memory recall, respectively. On the basis of this finding, we propose a new model in which it is assumed that two types of synaptic connections are formed by conditioning and are activated during memory recall, one type being connections from neurons representing conditioned stimulus to neurons inducing conditioned response and the other being connections from neurons representing conditioned stimulus to octopaminergic or dopaminergic neurons representing appetitive or aversive unconditioned stimulus, respectively. The former is called 'stimulus-response connection' and the latter is called 'stimulus-stimulus connection' by theorists studying classical conditioning in higher vertebrates. Our model predicts that pharmacological blockade of octopamine or dopamine receptors during the first stage of second-order conditioning does not impair second-order conditioning, because it impairs the formation of the stimulus-response connection but not the stimulus-stimulus connection. The results of our study with a cross-modal second-order conditioning were in full accordance with this prediction. We suggest that insect classical conditioning involves the formation of two kinds of memory traces, which match to stimulus-stimulus connection and stimulus-response connection. This is the first study to suggest that classical conditioning in insects involves, as does classical conditioning in higher vertebrates, the formation of stimulus-stimulus connection and its activation for memory recall, which are often called cognitive processes.

Modulation of 7 T fMRI Signal in the Cerebellar Cortex and Nuclei During Acquisition, Extinction, and Reacquisition of Conditioned Eyeblink Responses.

PubMed

Ernst, Thomas M; Thürling, Markus; Müller, Sarah; Kahl, Fabian; Maderwald, Stefan; Schlamann, Marc; Boele, Henk-Jan; Koekkoek, Sebastiaan K E; Diedrichsen, Jörn; De Zeeuw, Chris I; Ladd, Mark E; Timmann, Dagmar

2017-08-01

Classical delay eyeblink conditioning is likely the most commonly used paradigm to study cerebellar learning. As yet, few studies have focused on extinction and savings of conditioned eyeblink responses (CRs). Saving effects, which are reflected in a reacquisition after extinction that is faster than the initial acquisition, suggest that learned associations are at least partly preserved during extinction. In this study, we tested the hypothesis that acquisition-related plasticity is nihilated during extinction in the cerebellar cortex, but retained in the cerebellar nuclei, allowing for faster reacquisition. Changes of 7 T functional magnetic resonance imaging (fMRI) signals were investigated in the cerebellar cortex and nuclei of young and healthy human subjects. Main effects of acquisition, extinction, and reacquisition against rest were calculated in conditioned stimulus-only trials. First-level β values were determined for a spherical region of interest (ROI) around the acquisition peak voxel in lobule VI, and dentate and interposed nuclei ipsilateral to the unconditioned stimulus. In the cerebellar cortex and nuclei, fMRI signals were significantly lower in extinction compared to acquisition and reacquisition, but not significantly different between acquisition and reacquisition. These findings are consistent with the theory of bidirectional learning in both the cerebellar cortex and nuclei. It cannot explain, however, why conditioned responses reappear almost immediately in reacquisition following extinction. Although the present data do not exclude that part of the initial memory remains in the cerebellum in extinction, future studies should also explore changes in extracerebellar regions as a potential substrate of saving effects. Hum Brain Mapp 38:3957-3974, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Sex-specific neuroanatomical correlates of fear expression in prefrontal-amygdala circuits.

PubMed

Gruene, Tina M; Roberts, Elian; Thomas, Virginia; Ronzio, Ashley; Shansky, Rebecca M

2015-08-01

The neural projections from the infralimbic region of the prefrontal cortex to the amygdala are important for the maintenance of conditioned fear extinction. Neurons in this pathway exhibit a unique pattern of structural plasticity that is sex-dependent, but the relationship between the morphologic characteristics of these neurons and successful extinction in male and female subjects is unknown. Using classic cued fear conditioning and an extinction paradigm in large cohorts of male and female rats, we identified subpopulations of both sexes that exhibited high (HF) or low (LF) levels of freezing on an extinction retrieval test, representing failed or successful extinction maintenance, respectively. We combined retrograde tracing with fluorescent intracellular microinjections to perform three-dimensional reconstructions of infralimbic neurons that project to the basolateral amygdala in these groups. The HF and LF male rats exhibited neuroanatomical distinctions that were not observed in HF or LF female rats. A retrospective analysis of behavior during fear conditioning and extinction revealed that despite no overall sex differences in freezing behavior, HF and LF phenotypes emerged in male rats during extinction and in female rats during fear conditioning, which does not involve infralimbic-basolateral amygdala neurons. Our results suggest that the neural processes underlying successful or failed extinction maintenance may be sex-specific. These findings are relevant not only to future basic research on sex differences in fear conditioning and extinction but also to exposure-based clinical therapies, which are similar in premise to fear extinction and which are primarily used to treat disorders that are more common in women than in men. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Teaching a changing paradigm in physiology: a historical perspective on gut interstitial cells.

PubMed

Drumm, Bernard T; Baker, Salah A

2017-03-01

The study and teaching of gastrointestinal (GI) physiology necessitates an understanding of the cellular basis of contractile and electrical coupling behaviors in the muscle layers that comprise the gut wall. Our knowledge of the cellular origin of GI motility has drastically changed over the last 100 yr. While the pacing and coordination of GI contraction was once thought to be solely attributable to smooth muscle cells, it is now widely accepted that the motility patterns observed in the GI tract exist as a result of a multicellular system, consisting of not only smooth muscle cells but also enteric neurons and distinct populations of specialized interstitial cells that all work in concert to ensure proper GI functions. In this historical perspective, we focus on the emerging role of interstitial cells in GI motility and examine the key discoveries and experiments that led to a major shift in a paradigm of GI physiology regarding the role of interstitial cells in modulating GI contractile patterns. A review of these now classic experiments and papers will enable students and educators to fully appreciate the complex, multicellular nature of GI muscles as well as impart lessons on how shifting paradigms in physiology are fueled by new technologies that lead to new emerging discoveries. Copyright © 2017 the American Physiological Society.

Does recall of a past music event invoke a reminiscence bump in young adults?

PubMed

Schubert, Emery

2016-08-01

Many studies of the reminiscence bump (RB) in music invoke memories from different autobiographical times by using stimulus specific prompts (SSPs). This study investigated the utility of a non-SSP paradigm to determine whether the RB would emerge when participants were asked to recall a single memorable musical event from "a time long ago". The presence of a RB in response to music has not been obtained in such a manner for younger participants. Eighty-eight 20-22 year olds reported music episodes that peaked when their autobiographical age was 13-14 years. Self-selected stimuli included a range of musical styles, including classical and non-Western pop forms, such as J-pop and K-pop, as well as generational pop music, such as the Beatles. However, most participants reported pop/rock music that was contemporaneous with encoding age, providing support for the utility of published SSP paradigms using pop music. Implications for and limitations of SSP paradigms are discussed. Participants were also asked to relate the selected musical piece to current musical tastes. Most participants liked the music that they selected, with many continuing to like the music, but most also reported a general broadening of their taste, consistent with developmental literature on open-earedness.

Structural biology of intrinsically disordered proteins: Revisiting unsolved mysteries.

PubMed

Sigalov, Alexander B

2016-06-01

The emergence of intrinsically disordered proteins (IDPs) has challenged the classical protein structure-function paradigm by introducing a new paradigm of "coupled binding and folding". This paradigm suggests that IDPs fold upon binding to their partners. Further studies, however, revealed a novel and previously unrecognized phenomenon of "uncoupled binding and folding" suggesting that IDPs do not necessarily fold upon interaction with their lipid and protein partners. The complex and often unusual biophysics of IDPs makes structural characterization of these proteins and their complexes not only challenging but often resulting in opposite conclusions. For this reason, some crucial questions in this field remain unsolved for well over a decade. Considering an important role of IDPs in cellular regulation, signaling and control in health and disease, more efforts are needed to solve these mysteries. Here, I focus on two long-standing contradictions in the literature concerning dimerization and membrane-binding activities of IDPs. Molecular explanation of these discrepancies is provided. I also demonstrate how resolution of these critical issues in the field of IDPs results in our expanded understanding of cell function and has multiple applications in biology and medicine. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Social conditioning and extinction paradigm: a translational study in virtual reality.

PubMed

Shiban, Youssef; Reichenberger, Jonas; Neumann, Inga D; Mühlberger, Andreas

2015-01-01

In human beings, experiments investigating fear conditioning with social stimuli are rare. The current study aims at translating an animal model for social fear conditioning (SFC) to a human sample using an operant SFC paradigm in virtual reality. Forty participants actively (using a joystick) approached virtual male agents that served as conditioned stimuli (CS). During the acquisition phase, unconditioned stimuli (US), a combination of an air blast (5 bar, 10 ms) and a female scream (95 dB, 40 ms), were presented when participants reached a defined proximity to the agent with a contingency of 75% for CS+ agents and never for CS- agents. During the extinction and the test phases, no US was delivered. Outcome variables were pleasantness ratings and physiological reactions in heart rate (HR) and fear-potentiated startle. Additionally, the influence of social anxiety, which was measured with the Social Phobia Inventory scale, was evaluated. As expected after the acquisition phase the CS+ was rated clearly less pleasant than the CS-. This difference vanished during extinction. Furthermore, the HR remained high for the CS+, while the HR for the CS- was clearly lower after than before the acquisition. Furthermore, a clear difference between CS+ and CS- after the acquisition indicated successful conditioning on this translational measure. Contrariwise no CS+/CS- differences were observed in the physiological variables during extinction. Importantly, at the generalization test, higher socially fearful participants rated pleasantness of all agents as low whereas the lower socially fearful participants rated pleasantness as low only for the CS+. SFC was successfully induced and extinguished confirming operant conditioning in this SFC paradigm. These findings suggest that the paradigm is suitable to expand the knowledge about the learning and unlearning of social fears. Further studies should investigate the operant mechanisms of development and treatment of social anxiety disorder.

Evidence of Pavlovian conditioned fear following electrical stimulation of the periaqueductal grey in the rat.

PubMed

Di Scala, G; Mana, M J; Jacobs, W J; Phillips, A G

1987-01-01

Stimulation of the periaqueductal grey (PAG) has been used to support aversive conditioning in a variety of species with several experimental paradigms. However, it has not been clearly demonstrated whether the behavioral changes produced by PAG stimulation in these paradigms are mediated by associative or nonassociative mechanisms. The present studies demonstrate that electrical stimulation of the PAG in the rat may be used to support associative learning in a Pavlovian paradigm. In each experiment, a fully controlled conditional emotional response (CER) procedure was used to examine the unconditional aversive properties of PAG stimulation. In Experiment 1a, weak associative conditioning was observed when a light CS was paired with PAG stimulation over 6 conditioning trials. In Experiment 1b, robust associative conditioning was obtained with a light CS when 18 conditioning trials were used. In Experiment 2, robust associative conditioning was demonstrated with a tone CS when 6 conditioning trials were used. The results parallel those found when other aversive stimuli are used as a UCS (e.g., footshock or intraorbital air puff), and because the present experiments included the proper control procedures the results clearly indicate that the behavioral changes produced by PAG stimulation are mediated by associative Pavlovian learning mechanisms rather than nonassociative mechanisms such as sensitization or pseudoconditioning. The present technique may be useful for assessing the neuroanatomical and neurochemical substrates underlying the aversive effects of brain-stimulation, and for screening the effects of drugs on the conditional and unconditional responses produced by such stimulation.

Stimulus Configuration, Classical Conditioning, and Hippocampal Function.

ERIC Educational Resources Information Center

Schmajuk, Nestor A.; DiCarlo, James J.

1991-01-01

The participation of the hippocampus in classical conditioning is described in terms of a multilayer network portraying stimulus configuration. A model of hippocampal function is presented, and computer simulations are used to study neural activity in the various brain areas mapped according to the model. (SLD)

Reinforcement in an in Vitro Analog of Appetitive Classical Conditioning of Feeding Behavior in "Aplysia": Blockade by a Dopamine Antagonist

ERIC Educational Resources Information Center

Reyes, Fredy D.; Mozzachiodi, Riccardo; Baxter, Douglas A.; Byrne, John H.

2005-01-01

In a recently developed in vitro analog of appetitive classical conditioning of feeding in "Aplysia," the unconditioned stimulus (US) was electrical stimulation of the esophageal nerve (En). This nerve is rich in dopamine (DA)-containing processes, which suggests that DA mediates reinforcement during appetitive conditioning. To test this…

Feeding behavior of Aplysia: a model system for comparing cellular mechanisms of classical and operant conditioning.

PubMed

Baxter, Douglas A; Byrne, John H

2006-01-01

Feeding behavior of Aplysia provides an excellent model system for analyzing and comparing mechanisms underlying appetitive classical conditioning and reward operant conditioning. Behavioral protocols have been developed for both forms of associative learning, both of which increase the occurrence of biting following training. Because the neural circuitry that mediates the behavior is well characterized and amenable to detailed cellular analyses, substantial progress has been made toward a comparative analysis of the cellular mechanisms underlying these two forms of associative learning. Both forms of associative learning use the same reinforcement pathway (the esophageal nerve, En) and the same reinforcement transmitter (dopamine, DA). In addition, at least one cellular locus of plasticity (cell B51) is modified by both forms of associative learning. However, the two forms of associative learning have opposite effects on B51. Classical conditioning decreases the excitability of B51, whereas operant conditioning increases the excitability of B51. Thus, the approach of using two forms of associative learning to modify a single behavior, which is mediated by an analytically tractable neural circuit, is revealing similarities and differences in the mechanisms that underlie classical and operant conditioning.

Effects of the swimming exercise on the consolidation and persistence of auditory and contextual fear memory.

PubMed

Faria, Rodolfo Souza; Gutierres, Luís Felipe Soares; Sobrinho, Fernando César Faria; Miranda, Iris do Vale; Reis, Júlia Dos; Dias, Elayne Vieira; Sartori, Cesar Renato; Moreira, Dalmo Antonio Ribeiro

2016-08-15

Exposure to negative environmental events triggers defensive behavior and leads to the formation of aversive associative memory. Cellular and molecular changes in the central nervous system underlie this memory formation, as well as the associated behavioral changes. In general, memory process is established in distinct phases such as acquisition, consolidation, evocation, persistence, and extinction of the acquired information. After exposure to a particular event, early changes in involved neural circuits support the memory consolidation, which corresponds to the short-term memory. Re-exposure to previously memorized events evokes the original memory, a process that is considered essential for the reactivation and consequent persistence of memory, ensuring that long-term memory is established. Different environmental stimuli may modulate the memory formation process, as well as their distinct phases. Among the different environmental stimuli able of modulating memory formation is the physical exercise which is a potent modulator of neuronal activity. There are many studies showing that physical exercise modulates learning and memory processes, mainly in the consolidation phase of the explicit memory. However, there are few reports in the literature regarding the role of physical exercise in implicit aversive associative memory, especially at the persistence phase. Thus, the present study aimed to investigate the relationship between swimming exercise and the consolidation and persistence of contextual and auditory-cued fear memory. Male Wistar rats were submitted to sessions of swimming exercise five times a week, over six weeks. After that, the rats were submitted to classical aversive conditioning training by a pairing tone/foot shock paradigm. Finally, rats were evaluated for consolidation and persistence of fear memory to both auditory and contextual cues. Our results demonstrate that classical aversive conditioning with tone/foot shock pairing induced consolidation as well as persistence of conditioned fear memory. In addition, rats submitted to swimming exercise over six weeks showed an improved performance in the test of auditory-cued fear memory persistence, but not in the test of contextual fear memory persistence. Moreover, no significant effect from swimming exercise was observed on consolidation of both contextual and auditory fear memory. So, our study, revealing the effect of the swimming exercise on different stages of implicit memory of tone/foot shock conditioning, contributes to and complements the current knowledge about the environmental modulation of memory process. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

A New Engine for Schools: The Flexible Scheduling Paradigm

ERIC Educational Resources Information Center

Snyder, Yaakov; Herer, Yale T.; Moore, Michael

2012-01-01

We present a new approach for the organization of schools, which we call the flexible scheduling paradigm (FSP). FSP improves student learning by dynamically redeploying teachers and other pedagogical resources to provide students with customized learning conditions over shorter time periods called "mini-terms" instead of semesters or years. By…

Role of classical conditioning in learning gastrointestinal symptoms

PubMed Central

Stockhorst, Ursula; Enck, Paul; Klosterhalfen, Sibylle

2007-01-01

Nausea and/or vomiting are aversive gastrointestinal (GI) symptoms. Nausea and vomiting manifest unconditionally after a nauseogenic experience. However, there is correlative, quasiexperimental and experimental evidence that nausea and vomiting can also be learned via classical (Pavlovian) conditioning and might occur in anticipation of the nauseogenic event. Classical conditioning of nausea can develop with chemotherapy in cancer patients. Initially, nausea and vomiting occur during and after the administration of cytotoxic drugs (post-treatment nausea and vomiting) as unconditioned responses (UR). In addition, 20%-30% of cancer patients receiving chemotherapy report these side effects, despite antiemetic medication, when being re-exposed to the stimuli that usually signal the chemotherapy session and its drug infusion. These symptoms are called anticipatory nausea (AN) and/or anticipatory vomiting (ANV) and are explained by classical conditioning. Moreover, there is recent evidence for the assumption that post-chemotherapy nausea is at least partly influenced by learning. After summarizing the relevant assumptions of the conditioning model, revealing that a context can become a conditioned stimulus (CS), the present paper summarizes data that nausea and/or vomiting is acquired by classical conditioning and, consequently, may be alleviated by conditioning techniques. Our own research has focussed on two aspects and is emphasized here. First, a conditioned nausea model was established in healthy humans using body rotation as the nausea-inducing treatment. The validity of this motion-sickness model to examine conditioning mechanisms in the acquisition and alleviation of conditioned nausea and associated endocrine and immunological responses is summarized. Results from the rotation-induced motion sickness model showed that gender is an important moderator variable to be considered in further studies. This paper concludes with a review of the application of the demonstrated conditioning principles as interventions to ameliorate distressing AN/ANV in cancer patients undergoing chemotherapy, which is the second focus of our work. PMID:17659689

Role of classical conditioning in learning gastrointestinal symptoms.

PubMed

Stockhorst, Ursula; Enck, Paul; Klosterhalfen, Sibylle

2007-07-07

Nausea and/or vomiting are aversive gastrointestinal (GI) symptoms. Nausea and vomiting manifest unconditionally after a nauseogenic experience. However, there is correlative, quasiexperimental and experimental evidence that nausea and vomiting can also be learned via classical (Pavlovian) conditioning and might occur in anticipation of the nauseogenic event. Classical conditioning of nausea can develop with chemotherapy in cancer patients. Initially, nausea and vomiting occur during and after the administration of cytotoxic drugs (post-treatment nausea and vomiting) as unconditioned responses (UR). In addition, 20%-30% of cancer patients receiving chemotherapy report these side effects, despite antiemetic medication, when being re-exposed to the stimuli that usually signal the chemotherapy session and its drug infusion. These symptoms are called anticipatory nausea (AN) and/or anticipatory vomiting (ANV) and are explained by classical conditioning. Moreover, there is recent evidence for the assumption that post-chemotherapy nausea is at least partly influenced by learning. After summarizing the relevant assumptions of the conditioning model, revealing that a context can become a conditioned stimulus (CS), the present paper summarizes data that nausea and/or vomiting is acquired by classical conditioning and, consequently, may be alleviated by conditioning techniques. Our own research has focussed on two aspects and is emphasized here. First, a conditioned nausea model was established in healthy humans using body rotation as the nausea-inducing treatment. The validity of this motion-sickness model to examine conditioning mechanisms in the acquisition and alleviation of conditioned nausea and associated endocrine and immunological responses is summarized. Results from the rotation-induced motion sickness model showed that gender is an important moderator variable to be considered in further studies. This paper concludes with a review of the application of the demonstrated conditioning principles as interventions to ameliorate distressing AN/ANV in cancer patients undergoing chemotherapy, which is the second focus of our work.

Neural Correlates of Central Inhibition during Physical Fatigue

PubMed Central

Tanaka, Masaaki; Ishii, Akira; Watanabe, Yasuyoshi

2013-01-01

Central inhibition plays a pivotal role in determining physical performance during physical fatigue. Classical conditioning of central inhibition is believed to be associated with the pathophysiology of chronic fatigue. We tried to determine whether classical conditioning of central inhibition can really occur and to clarify the neural mechanisms of central inhibition related to classical conditioning during physical fatigue using magnetoencephalography (MEG). Eight right-handed volunteers participated in this study. We used metronome sounds as conditioned stimuli and maximum handgrip trials as unconditioned stimuli to cause central inhibition. Participants underwent MEG recording during imagery of maximum grips of the right hand guided by metronome sounds for 10 min. Thereafter, fatigue-inducing maximum handgrip trials were performed for 10 min; the metronome sounds were started 5 min after the beginning of the handgrip trials. The next day, neural activities during imagery of maximum grips of the right hand guided by metronome sounds were measured for 10 min. Levels of fatigue sensation and sympathetic nerve activity on the second day were significantly higher relative to those of the first day. Equivalent current dipoles (ECDs) in the posterior cingulated cortex (PCC), with latencies of approximately 460 ms, were observed in all the participants on the second day, although ECDs were not identified in any of the participants on the first day. We demonstrated that classical conditioning of central inhibition can occur and that the PCC is involved in the neural substrates of central inhibition related to classical conditioning during physical fatigue. PMID:23923034

Listening Effort Through Depth of Processing in School-Age Children.

PubMed

Hsu, Benson Cheng-Lin; Vanpoucke, Filiep; van Wieringen, Astrid

A reliable and practical measure of listening effort is crucial in the aural rehabilitation of children with communication disorders. In this article, we propose a novel behavioral paradigm designed to measure listening effort in school-age children based on different depths and levels of verbal processing. The paradigm consists of a classic word recognition task performed in quiet and in noise coupled to one of three additional tasks asking the children to judge the color of simple pictures or a certain semantic category of the presented words. The response time (RT) from the categorization tasks is considered the primary indicator of listening effort. The listening effort paradigm was evaluated in a group of 31 normal-hearing, normal-developing children 7 to 12 years of age. A total of 146 Dutch nouns were selected for the experiment after surveying 14 local Dutch-speaking children. Windows-based custom software was developed to administer the behavioral paradigm from a conventional laptop computer. A separate touch screen was used as a response interface to gather the RT data from the participants. Verbal repetition of each presented word was scored by the tester and a percentage-correct word recognition score (WRS) was calculated for each condition. Randomized lists of target words were presented in one of three signal to noise ratios (SNR) to examine the effect of background noise on the two outcome measures of WRS and RT. Three novel categorization tasks, each corresponding to a different depth or elaboration level of semantic processing, were developed to examine the effect of processing level on either WRS or RT. It was hypothesized that, while listening effort as measured by RT would be affected by both noise and processing level, WRS performance would be affected by changes in noise level only. The RT measure was also hypothesized to increase more from an increase in noise level in categorization conditions demanding a deeper or more elaborate form of semantic processing. There was a significant effect of SNR level on school-age children's WRS: their word recognition performance tended to decrease with increasing background noise level. However, depth of processing did not seem to affect WRS. Moreover, a repeated-measure analysis of variance fitted to transformed RT data revealed that this measure of listening effort in normal-hearing school-age children was significantly affected by both SNR level and the depth of semantic processing. There was no significant interaction between noise level and the type of categorization task with regard to RT. The observed patterns of WRS and RT supported the hypotheses regarding the effects of background noise and depth of processing on word recognition performance and a behavioral measure of listening effort. The magnitude of noise-induced change in RT did not differ between categorization tasks, however. Our findings point to future research directions regarding the potential effects of age, working memory capacity, and cross-modality interaction when measuring listening effort in different levels of semantic processing.

Evolution of diffusion and dissemination theory.

PubMed

Dearing, James W

2008-01-01

The article provides a review and considers how the diffusion of innovations Research paradigm has changed, and offers suggestions for the further development of this theory of social change. Main emphases of diffusion Research studies are compared over time, with special attention to applications of diffusion theory-based concepts as types of dissemination science. A considerable degree of paradigmatic evolution is observed. The classical diffusion model focused on adopter innovativeness, individuals as the locus of decision, communication channels, and adoption as the primary outcome measures in post hoc observational study designs. The diffusion systems in question were centralized, with fidelity of implementation often assumed. Current dissemination Research and practice is better characterized by tests of interventions that operationalize one or more diffusion theory-based concepts and concepts from other change approaches, involve complex organizations as the units of adoption, and focus on implementation issues. Foment characterizes dissemination and implementation Research, Reflecting both its interdisciplinary Roots and the imperative of spreading evidence-based innovations as a basis for a new paradigm of translational studies of dissemination science.

One for all: social power increases self-anchoring of traits, attitudes, and emotions.

PubMed

Overbeck, Jennifer R; Droutman, Vitaliya

2013-08-01

We argue that powerful people tend to engage in social projection. Specifically, they self-anchor: They use the self as a reference point when judging others' internal states. In Study 1, which used a reaction-time paradigm, powerful people used their own traits as a reference when assessing the traits of group members, classifying group descriptors more quickly if they had previously reported that those terms described themselves. Study 2, which used a classic false-consensus paradigm, showed that powerful people believed that their group-related attitudes were shared by group members. Study 3 showed that more-powerful people relied more on their own state affect when judging other people's ambiguous emotional expressions. These results support our argument that power fosters self-anchoring, because powerful individuals are often called on to act as the representative face of their groups, and the association between power and representation prompts the heuristic use of the self to infer group properties.

Re-reading "Little Hans": Freud's case study and the question of competing paradigms in psychoanalysis.

PubMed

Midgley, Nicholas

2006-01-01

Psychoanalysts have long recognized the complex interaction between clinical data and formal psychoanalytic theories. While clinical data are often used to provide "evidence" for psychoanalytic paradigms, the theoretical model used by the analyst also structures what can and cannot be seen in the data. This delicate interaction between theory and clinical data can be seen in the history of interpretations of Freud's "Analysis of a Phobia in a Five-Year-Old Boy" ("Little Hans"). Freud's himself revised his reading of the case in 1926, after which a number of psychoanalysts--including Melanie Klein, Jacques Lacan, and John Bowlby--reinterpreted the case in the light of their particular models of the mind. These analysts each found "evidence" for their theoretical model within this classic case study, and in doing so they illuminated aspects of the case that had previously been obscured, while also revealing a great deal about the shifting preoccupations of psychoanalysis as a field.

gSRT-Soft: a generic software application and some methodological guidelines to investigate implicit learning through visual-motor sequential tasks.

PubMed

Chambaron, Stéphanie; Ginhac, Dominique; Perruchet, Pierre

2008-05-01

Serial reaction time tasks and, more generally, the visual-motor sequential paradigms are increasingly popular tools in a variety of research domains, from studies on implicit learning in laboratory contexts to the assessment of residual learning capabilities of patients in clinical settings. A consequence of this success, however, is the increased variability in paradigms and the difficulty inherent in respecting the methodological principles that two decades of experimental investigations have made more and more stringent. The purpose of the present article is to address those problems. We present a user-friendly application that simplifies running classical experiments, but is flexible enough to permit a broad range of nonstandard manipulations for more specific objectives. Basic methodological guidelines are also provided, as are suggestions for using the software to explore unconventional directions of research. The most recent version of gSRT-Soft may be obtained for free by contacting the authors.

Performance analysis of a Principal Component Analysis ensemble classifier for Emotiv headset P300 spellers.

PubMed

Elsawy, Amr S; Eldawlatly, Seif; Taher, Mohamed; Aly, Gamal M

2014-01-01

The current trend to use Brain-Computer Interfaces (BCIs) with mobile devices mandates the development of efficient EEG data processing methods. In this paper, we demonstrate the performance of a Principal Component Analysis (PCA) ensemble classifier for P300-based spellers. We recorded EEG data from multiple subjects using the Emotiv neuroheadset in the context of a classical oddball P300 speller paradigm. We compare the performance of the proposed ensemble classifier to the performance of traditional feature extraction and classifier methods. Our results demonstrate the capability of the PCA ensemble classifier to classify P300 data recorded using the Emotiv neuroheadset with an average accuracy of 86.29% on cross-validation data. In addition, offline testing of the recorded data reveals an average classification accuracy of 73.3% that is significantly higher than that achieved using traditional methods. Finally, we demonstrate the effect of the parameters of the P300 speller paradigm on the performance of the method.

Insects modify their behaviour depending on the feedback sensor used when walking on a trackball in virtual reality.

PubMed

Taylor, Gavin J; Paulk, Angelique C; Pearson, Thomas W J; Moore, Richard J D; Stacey, Jacqui A; Ball, David; van Swinderen, Bruno; Srinivasan, Mandyam V

2015-10-01

When using virtual-reality paradigms to study animal behaviour, careful attention must be paid to how the animal's actions are detected. This is particularly relevant in closed-loop experiments where the animal interacts with a stimulus. Many different sensor types have been used to measure aspects of behaviour, and although some sensors may be more accurate than others, few studies have examined whether, and how, such differences affect an animal's behaviour in a closed-loop experiment. To investigate this issue, we conducted experiments with tethered honeybees walking on an air-supported trackball and fixating a visual object in closed-loop. Bees walked faster and along straighter paths when the motion of the trackball was measured in the classical fashion - using optical motion sensors repurposed from computer mice - than when measured more accurately using a computer vision algorithm called 'FicTrac'. When computer mouse sensors were used to measure bees' behaviour, the bees modified their behaviour and achieved improved control of the stimulus. This behavioural change appears to be a response to a systematic error in the computer mouse sensor that reduces the sensitivity of this sensor system under certain conditions. Although the large perceived inertia and mass of the trackball relative to the honeybee is a limitation of tethered walking paradigms, observing differences depending on the sensor system used to measure bee behaviour was not expected. This study suggests that bees are capable of fine-tuning their motor control to improve the outcome of the task they are performing. Further, our findings show that caution is required when designing virtual-reality experiments, as animals can potentially respond to the artificial scenario in unexpected and unintended ways. © 2015. Published by The Company of Biologists Ltd.

Contrast Enhancement without Transient Map Expansion for Species-Specific Vocalizations in Core Auditory Cortex during Learning

PubMed Central

Shepard, Kathryn N.; Chong, Kelly K.

2016-01-01

Tonotopic map plasticity in the adult auditory cortex (AC) is a well established and oft-cited measure of auditory associative learning in classical conditioning paradigms. However, its necessity as an enduring memory trace has been debated, especially given a recent finding that the areal expansion of core AC tuned to a newly relevant frequency range may arise only transiently to support auditory learning. This has been reinforced by an ethological paradigm showing that map expansion is not observed for ultrasonic vocalizations (USVs) or for ultrasound frequencies in postweaning dams for whom USVs emitted by pups acquire behavioral relevance. However, whether transient expansion occurs during maternal experience is not known, and could help to reveal the generality of cortical map expansion as a correlate for auditory learning. We thus mapped the auditory cortices of maternal mice at postnatal time points surrounding the peak in pup USV emission, but found no evidence of frequency map expansion for the behaviorally relevant high ultrasound range in AC. Instead, regions tuned to low frequencies outside of the ultrasound range show progressively greater suppression of activity in response to the playback of ultrasounds or pup USVs for maternally experienced animals assessed at their pups’ postnatal day 9 (P9) to P10, or postweaning. This provides new evidence for a lateral-band suppression mechanism elicited by behaviorally meaningful USVs, likely enhancing their population-level signal-to-noise ratio. These results demonstrate that tonotopic map enlargement has limits as a construct for conceptualizing how experience leaves neural memory traces within sensory cortex in the context of ethological auditory learning. PMID:27957529

Effects of early life abuse differ across development: Infant social behavior deficits are followed by adolescent depressive-like behaviors mediated by the amygdala

PubMed Central

Raineki, Charlis; Cortés, Millie Rincón; Belnoue, Laure; Sullivan, Regina M.

2012-01-01

Abuse during early life, especially from the caregiver, increases vulnerability to develop later life psychopathologies such as depression. Although signs of depression are typically not expressed until later life, signs of dysfunctional social behavior have been found earlier. How infant abuse alters the trajectory of brain development to produce pathways to pathology is not completely understood. Here we address this question using two different but complementary rat models of early-life abuse from postnatal days (PN) 8–12: a naturalistic paradigm, where the mother is provided with insufficient bedding for nest building and a more controlled paradigm, where infants undergo olfactory classical conditioning. Amygdala neural assessment (c-Fos), as well as social behavior and forced swim tests were performed at preweaning (PN20) and adolescence (PN45). Our results show that both models of early life abuse induce deficits in social behavior, even during the preweaning period; however, depressive-like behaviors were observed only during adolescence. Adolescent depressive-like behavior corresponds with an increase in amygdala neural activity in response to forced swim test. A causal relationship between the amygdala and depressive-like behavior was suggested through amygdala temporary deactivation (muscimol infusions), which rescued the depressive-like behavior in the forced swim test. Our results indicate that social behavior deficits in infancy could serve as an early marker for later psychopathology. Moreover, the implication of the amygdala in the ontogeny of depressive-like behaviors in infant abused animals is an important step toward understanding the underlying mechanisms of later life mental disease associated with early-life abuse. PMID:22649253

Pavlovian conditioning of psychomotor stimulant-induced behaviours: has convenience led us astray?

PubMed

Martin-Iverson, M.T.; Fawcett, S.L.

1996-01-01

In order to classically condition the behavioural effects of psychomotor stimulants within a test context, rats were treated for 10 days with (+)-amphetamine (1.5mg/kg), (+)-4-propyl-9-hydroxynaphthoxazine (PHNO, 30µg/kg) or vehicle prior to a 1h placement into a test box. Conditioned behavioural effects were then measured in the previously drug-paired context after a vehicle injection (drug-free test day). Each rat was videotaped for the 1h test box exposure on days 1, 4, 7 and 10 of the drug conditioning trials, and on the drug-free test day. Eleven of 28 behaviours that were scored for frequency, duration and mean bout duration (bout length) were significantly influenced by at least one of the two drugs. Amphetamine predominantly increased bout lengths while PHNO predominantly increased bout frequency. Only two measures that were influenced by the drugs exhibited clear increases over controls in a manner consistent with a classical conditioning interpretation. Behavioural sensitization clearly occurred to some of the effects of amphetamine and PHNO, but these were not the same effects as those increased on the non-drug day testing for classical conditioning. Most behavioural effects of amphetamine and PHNO are not classically conditioned, and behavioural sensitization to these drugs, while perhaps context-specific, is not due to classical conditioning. Automated measures of behaviours have provided misleading evidence concerning the similarity among behavioural effects of stimulants, sensitization and effects of exposure to an environment previously paired with stimulants. Analysis of transitions between behaviours does not support the view that stimulants increase switching or response competition, or that behavioural reorganization is responsible for sensitization. Rather, it is suggested that stimulants selectively facilitate current stimulus-guided behaviours.

Treatment of raw and ozonated oil sands process-affected water under decoupled denitrifying anoxic and nitrifying aerobic conditions: a comparative study.

PubMed

Xue, Jinkai; Zhang, Yanyan; Liu, Yang; Gamal El-Din, Mohamed

2016-11-01

Batch experiments were performed to evaluate biodegradation of raw and ozonated oil sands process-affected water (OSPW) under denitrifying anoxic and nitrifying aerobic conditions for 33 days. The results showed both the anoxic and aerobic conditions are effective in degrading OSPW classical and oxidized naphthenic acids (NAs) with the aerobic conditions demonstrating higher removal efficiency. The reactors under nitrifying aerobic condition reduced the total classical NAs of raw OSPW by 69.1 %, with better efficiency for species of higher hydrophobicity. Compared with conventional aerobic reactor, nitrifying aerobic condition substantially shortened the NA degradation half-life to 16 days. The mild-dose ozonation remarkably accelerated the subsequent aerobic biodegradation of classical NAs within the first 14 days, especially for those with long carbon chains. Moreover, the ozone pretreatment enhanced the biological removal of OSPW classical NAs by leaving a considerably lower final residual concentration of 10.4 mg/L under anoxic conditions, and 5.7 mg/L under aerobic conditions. The combination of ozonation and nitrifying aerobic biodegradation removed total classical NAs by 76.5 % and total oxy-NAs (O3-O6) by 23.6 %. 454 Pyrosequencing revealed that microbial species capable of degrading recalcitrant hydrocarbons were dominant in all reactors. The most abundant genus in the raw and ozonated anoxic reactors was Thauera (~56 % in the raw OSPW anoxic reactor, and ~65 % in the ozonated OSPW anoxic reactor); whereas Rhodanobacter (~40 %) and Pseudomonas (~40 %) dominated the raw and ozonated aerobic reactors, respectively. Therefore, the combination of mild-dose ozone pretreatment and subsequent biological process could be a competent choice for OSPW treatment.

Realizing IoT service's policy privacy over publish/subscribe-based middleware.

PubMed

Duan, Li; Zhang, Yang; Chen, Shiping; Wang, Shiyao; Cheng, Bo; Chen, Junliang

2016-01-01

The publish/subscribe paradigm makes IoT service collaborations more scalable and flexible, due to the space, time and control decoupling of event producers and consumers. Thus, the paradigm can be used to establish large-scale IoT service communication infrastructures such as Supervisory Control and Data Acquisition systems. However, preserving IoT service's policy privacy is difficult in this paradigm, because a classical publisher has little control of its own event after being published; and a subscriber has to accept all the events from the subscribed event type with no choice. Few existing publish/subscribe middleware have built-in mechanisms to address the above issues. In this paper, we present a novel access control framework, which is capable of preserving IoT service's policy privacy. In particular, we adopt the publish/subscribe paradigm as the IoT service communication infrastructure to facilitate the protection of IoT services policy privacy. The key idea in our policy-privacy solution is using a two-layer cooperating method to match bi-directional privacy control requirements: (a) data layer for protecting IoT events; and (b) application layer for preserving the privacy of service policy. Furthermore, the anonymous-set-based principle is adopted to realize the functionalities of the framework, including policy embedding and policy encoding as well as policy matching. Our security analysis shows that the policy privacy framework is Chosen-Plaintext Attack secure. We extend the open source Apache ActiveMQ broker by building into a policy-based authorization mechanism to enforce the privacy policy. The performance evaluation results indicate that our approach is scalable with reasonable overheads.

Using a Paradigm Shift to Teach Neurobiology and the Nature of Science-a C.R.E.A.T.E.-based Approach.

PubMed

Hoskins, Sally G

2008-01-01

Decades ago, classic experiments established the phenomenon of "neural induction" (Spemann and Mangold, 1924; Holtfreter, 1933). It appeared clear that amphibian ectoderm was pre-programmed to form epidermis, and that the neural phenotype was induced by a chemical signal from mesoderm. The "ectoderm makes skin, unless induced to make nervous system" model appeared in many textbooks. This interpretation, however, was not simply incorrect but 180 degrees out of alignment with the actual situation. As subsequently demonstrated, the default state of amphibian ectoderm is neuronal, and the expression of the epidermal phenotype requires cell signaling (Hemmati-Brivanlou and Melton, 1992; 1994; 1997). In this activity, students are presented with key experiments in a stepwise fashion. At several points, they work in groups to devise models that explain particular experimental results. The stepwise presentation of results mirrors the history of discoveries in this experimental system. Eventually, faced with seemingly contradictory data, students must revise their models substantially and in doing so, experience the paradigm shift. The lesson also examines the history of this paradigm shift. Data inconsistent with the "epidermal default" model were published years before the "neural default" model was proposed, but the significance of the surprising new data was underemphasized by the scientists who made the discovery. Discussing this situation provides insight into how science works and highlights the possibility that working scientists may become entrenched in prevailing paradigms. Such "nature of science" discussions emphasize research as a human activity, and help to dispel student misconceptions about science and scientists.

Stress as a one-armed bandit: Differential effects of stress paradigms on the morphology, neurochemistry and behavior in the rodent amygdala

PubMed Central

Wilson, Marlene A.; Grillo, Claudia A.; Fadel, Jim R.; Reagan, Lawrence P.

2015-01-01

Neuroplasticity may be defined as the ability of the central nervous system (CNS) to respond to changes in the internal and external environment and it is well established that some stimuli have the ability to facilitate or impair neuroplasticity depending on the pre-existing milieu. A classic example of a stimulus that can both facilitate and impair neuroplasticity is stress. Indeed, the ability of CNS to respond to acute stress is often dependent upon the prior stress history of the individual. While responses to acute stress are often viewed as adaptive in nature, stress reactivity in subjects with prior chronic stress experiences are often linked to neuropsychiatric disorders, including major depressive disorder, post-traumatic stress disorder (PTSD) and anxiety. In rodent studies, chronic stress exposure produces structural and functional alterations in the hippocampus and medial prefrontal cortex that are consistent across different types of stress paradigms. Conversely, the amygdala appears to exhibit differential structural and functional responses to stress that are dependent on a variety of factors, including the type of stressor performed and the duration of the stress paradigm. This is most evident in output measures including morphological analysis of amygdala neurons, measurement of glutamatergic tone in amygdalar subdivisions and the analysis of amygdala-centric behaviors. Accordingly, this review will provide an overview of the effects of stress on the structural and functional plasticity of the rodent amygdala, especially in relation to the differential effects of repeated or chronic stress paradigms on dendritic architecture, neurochemistry of the glutamatergic system and behavior. PMID:26844236

Classical conditioning in the treatment of psoriasis.

PubMed

Ader, R

2000-11-01

It has been argued that the placebo effect represents a learned response. Research is suggested to address the utility of applying principles derived from classical (Pavlovian) conditioning to the design of drug treatment protocols. In the present instance, it is hypothesized that, by capitalizing on conditioned pharmacotherapeutic responses, it may be possible to reduce the cumulative amount of corticosteroid medication used in the treatment of psoriasis.

Adult-Onset Hypothyroidism Enhances Fear Memory and Upregulates Mineralocorticoid and Glucocorticoid Receptors in the Amygdala

PubMed Central

Montero-Pedrazuela, Ana; Fernández-Lamo, Iván; Alieva, María; Pereda-Pérez, Inmaculada; Venero, César; Guadaño-Ferraz, Ana

2011-01-01

Hypothyroidism is the most common hormonal disease in adults, which is frequently accompanied by learning and memory impairments and emotional disorders. However, the deleterious effects of thyroid hormones deficiency on emotional memory are poorly understood and often underestimated. To evaluate the consequences of hypothyroidism on emotional learning and memory, we have performed a classical Pavlovian fear conditioning paradigm in euthyroid and adult-thyroidectomized Wistar rats. In this experimental model, learning acquisition was not impaired, fear memory was enhanced, memory extinction was delayed and spontaneous recovery of fear memory was exacerbated in hypothyroid rats. The potentiation of emotional memory under hypothyroidism was associated with an increase of corticosterone release after fear conditioning and with higher expression of glucocorticoid and mineralocorticoid receptors in the lateral and basolateral nuclei of the amygdala, nuclei that are critically involved in the circuitry of fear memory. Our results demonstrate for the first time that adult-onset hypothyroidism potentiates fear memory and also increases vulnerability to develop emotional memories. Furthermore, our findings suggest that enhanced corticosterone signaling in the amygdala is involved in the pathophysiological mechanisms of fear memory potentiation. Therefore, we recommend evaluating whether inappropriate regulation of fear in patients with post-traumatic stress and other mental disorders is associated with abnormal levels of thyroid hormones, especially those patients refractory to treatment. PMID:22039511

Pontine and Thalamic Influences on Fluid Rewards: III. Anticipatory Contrast for Sucrose and Corn Oil

PubMed Central

Liang, Nu-Chu; Norgren, Ralph; Grigson, Patricia S

2011-01-01

An anticipatory contrast effect (ACE) occurs when, across daily trials, an animal comes to respond less than normally to a first stimulus when it is followed shortly by a second, more preferred solution. Classically, ACE is studied using a low (L) concentration of saccharin or sucrose, followed by access to a higher (H) concentration of sucrose. Subjects in the control condition have two bouts of access to the weaker solution presented on the same schedule. The ACE is measured by the difference in intake of the first bout low solution between subjects in the low-low (L-L) vs. the low-high (L-H) conditions. Here we used this paradigm with sham feeding rats and determined that nutritional feedback was unnecessary for the development of ACE with two concentrations of sucrose or with two concentrations of corn oil. Next we showed that ibotenic acid lesions centered in the orosensory thalamus spared ACEs for both sucrose and corn oil. In contrast, lesions of the pontine parabrachial nuclei (PBN), the second central relay for taste in the rat, disrupted ACEs for both sucrose and corn oil. Although the sensory modalities needed for the oral detection of fats remain controversial, it appears that the PBN is involved in processing the comparison of disparate concentrations of sucrose and oil reward. PMID:21703289

Eyeblink conditioning in unmedicated schizophrenia patients: A positron emission tomography study

PubMed Central

Parker, Krystal L.; Andreasen, Nancy C.; Liu, Dawei; Freeman, John H.; O’Leary, Daniel S.

2014-01-01

Previous studies suggest that patients with schizophrenia exhibit dysfunctions in a widely distributed circuit—the cortico-cerebellar-thalamic-cortical circuit, or CCTCC—and that this may explain the multiple cognitive deficits observed in the disorder. This study uses positron emission tomography (PET) with O15 H2O to measure regional cerebral blood flow (rCBF) in response to a classic test of cerebellar function, the associative learning that occurs during eyeblink conditioning, in a sample of 20 unmedicated schizophrenia patients and 20 closely matched healthy controls. The PET paradigm examined three phases of acquisition and extinction (early, middle and late). The patients displayed impaired behavioral performance during both acquisition and extinction. The imaging data indicate that, compared to the control subjects, the patients displayed decreases in rCBF in all three components of the CCTCC during both acquisition and extinction. Specifically, patients had less rCBF in the middle and medial frontal lobes, anterior cerebellar lobules I/V and VI, as well as the thalamus during acquisition and although similar areas were found in the frontal lobe, ipsilateral cerebellar lobule IX showed consistently less activity in patients during extinction. Thus this study provides additional support for the hypothesis that patients with schizophrenia have a cognitive dysmetria—an inability to smoothly coordinate many different types of mental activity—that affects even a very basic cognitive task that taps into associative learning. PMID:24090512

Repeated Acquisitions and Extinctions in Classical Conditioning of the Rabbit Nictitating Membrane Response

ERIC Educational Resources Information Center

Kehoe, E. James

2006-01-01

The rabbit nictitating membrane (NM) response underwent successive stages of acquisition and extinction training in both delay (Experiment 1) and trace (Experiment 2) classical conditioning. In both cases, successive acquisitions became progressively faster, although the largest, most reliable acceleration occurred between the first and second…

Free Fermions and the Classical Compact Groups

NASA Astrophysics Data System (ADS)

Cunden, Fabio Deelan; Mezzadri, Francesco; O'Connell, Neil

2018-06-01

There is a close connection between the ground state of non-interacting fermions in a box with classical (absorbing, reflecting, and periodic) boundary conditions and the eigenvalue statistics of the classical compact groups. The associated determinantal point processes can be extended in two natural directions: (i) we consider the full family of admissible quantum boundary conditions (i.e., self-adjoint extensions) for the Laplacian on a bounded interval, and the corresponding projection correlation kernels; (ii) we construct the grand canonical extensions at finite temperature of the projection kernels, interpolating from Poisson to random matrix eigenvalue statistics. The scaling limits in the bulk and at the edges are studied in a unified framework, and the question of universality is addressed. Whether the finite temperature determinantal processes correspond to the eigenvalue statistics of some matrix models is, a priori, not obvious. We complete the picture by constructing a finite temperature extension of the Haar measure on the classical compact groups. The eigenvalue statistics of the resulting grand canonical matrix models (of random size) corresponds exactly to the grand canonical measure of free fermions with classical boundary conditions.

3-D Interpolation in Object Perception: Evidence from an Objective Performance Paradigm

ERIC Educational Resources Information Center

Kellman, Philip J.; Garrigan, Patrick; Shipley, Thomas F.; Yin, Carol; Machado, Liana

2005-01-01

Object perception requires interpolation processes that connect visible regions despite spatial gaps. Some research has suggested that interpolation may be a 3-D process, but objective performance data and evidence about the conditions leading to interpolation are needed. The authors developed an objective performance paradigm for testing 3-D…

77 FR 12059 - Using Innovative Technologies and Other Conditions of Safe Use To Expand Which Drug Products Can...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-28

... public on the feasibility of this paradigm and its potential benefits and costs. DATES: Public Hearing... costs decrease if this paradigm were instituted? IV. Attendance and/or Participation in the Public... Considered Nonprescription; Public Hearing AGENCY: Food and Drug Administration, HHS. ACTION: Notice of...

Assessment of aversion to different concentrations of CO2 gas by weaned pigs using an approach-avoidance paradigm

USDA-ARS?s Scientific Manuscript database

The objective of this study was to examine the aversiveness of carbon dioxide (CO2) to weaned pigs using approach-avoidance and condition place avoidance paradigms. A preference-testing device was custom designed with two connected chambers maintained at static gas concentrations. The control chambe...

School on Cloud: Towards a Paradigm Shift

ERIC Educational Resources Information Center

Koutsopoulos, Kostis C.; Kotsanis, Yannis C.

2014-01-01

This paper presents the basic concept of the EU Network School on Cloud: Namely, that present conditions require a new teaching and learning paradigm based on the integrated dimension of education, when considering the use of cloud computing. In other words, it is suggested that there is a need for an integrated approach which is simultaneously…

Links between causal effects and causal association for surrogacy evaluation in a gaussian setting.

PubMed

Conlon, Anna; Taylor, Jeremy; Li, Yun; Diaz-Ordaz, Karla; Elliott, Michael

2017-11-30

Two paradigms for the evaluation of surrogate markers in randomized clinical trials have been proposed: the causal effects paradigm and the causal association paradigm. Each of these paradigms rely on assumptions that must be made to proceed with estimation and to validate a candidate surrogate marker (S) for the true outcome of interest (T). We consider the setting in which S and T are Gaussian and are generated from structural models that include an unobserved confounder. Under the assumed structural models, we relate the quantities used to evaluate surrogacy within both the causal effects and causal association frameworks. We review some of the common assumptions made to aid in estimating these quantities and show that assumptions made within one framework can imply strong assumptions within the alternative framework. We demonstrate that there is a similarity, but not exact correspondence between the quantities used to evaluate surrogacy within each framework, and show that the conditions for identifiability of the surrogacy parameters are different from the conditions, which lead to a correspondence of these quantities. Copyright © 2017 John Wiley & Sons, Ltd.

Appetitive Pavlovian-instrumental Transfer: A review.

PubMed

Cartoni, Emilio; Balleine, Bernard; Baldassarre, Gianluca

2016-12-01

Reward-related cues are an important part of our daily life as they often influence and guide our actions. This paper reviews one of the experimental paradigms used to study the effects of cues, the Pavlovian to Instrumental Transfer paradigm. In this paradigm, cues associated with rewards through Pavlovian conditioning alter motivation and choice of instrumental actions. The first transfer experiments date back to the 1940s, but only in the last decade has it been fully recognised that there are two types of transfer, specific and general. This paper presents a systematic review of both the neural substrates and the behavioral factors affecting both types of transfer. It also examines the recent application of the paradigm to study the effect of cues on human participants, both in normal and pathological conditions, and the interactions of transfer with drugs of abuse. Finally, the paper analyses the theoretical aspects of transfer to build an overall picture of the phenomenon, from early theories to recent hierarchical accounts. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

The Digital Twin Paradigm for Future NASA and U.S. Air Force Vehicles

NASA Technical Reports Server (NTRS)

Glaessgen, Edward H.; Stargel, D. S.

2012-01-01

Future generations of NASA and U.S. Air Force vehicles will require lighter mass while being subjected to higher loads and more extreme service conditions over longer time periods than the present generation. Current approaches for certification, fleet management and sustainment are largely based on statistical distributions of material properties, heuristic design philosophies, physical testing and assumed similitude between testing and operational conditions and will likely be unable to address these extreme requirements. To address the shortcomings of conventional approaches, a fundamental paradigm shift is needed. This paradigm shift, the Digital Twin, integrates ultra-high fidelity simulation with the vehicle s on-board integrated vehicle health management system, maintenance history and all available historical and fleet data to mirror the life of its flying twin and enable unprecedented levels of safety and reliability.

Relationship between Fear Conditionability and Aversive Memories: Evidence from a Novel Conditioned-Intrusion Paradigm

PubMed Central

Wegerer, Melanie; Blechert, Jens; Kerschbaum, Hubert; Wilhelm, Frank H.

2013-01-01

Intrusive memories – a hallmark symptom of posttraumatic stress disorder (PTSD) – are often triggered by stimuli possessing similarity with cues that predicted or accompanied the traumatic event. According to learning theories, intrusive memories can be seen as a conditioned response to trauma reminders. However, direct laboratory evidence for the link between fear conditionability and intrusive memories is missing. Furthermore, fear conditioning studies have predominantly relied on standardized aversive stimuli (e.g. electric stimulation) that bear little resemblance to typical traumatic events. To investigate the general relationship between fear conditionability and aversive memories, we tested 66 mentally healthy females in a novel conditioned-intrusion paradigm designed to model real-life traumatic experiences. The paradigm included a differential fear conditioning procedure with neutral sounds as conditioned stimuli and short violent film clips as unconditioned stimuli. Subsequent aversive memories were assessed through a memory triggering task (within 30 minutes, in the laboratory) and ambulatory assessment (involuntary aversive memories in the 2 days following the experiment). Skin conductance responses and subjective ratings demonstrated successful differential conditioning indicating that naturalistic aversive film stimuli can be used in a fear conditioning experiment. Furthermore, aversive memories were elicited in response to the conditioned stimuli during the memory triggering task and also occurred in the 2 days following the experiment. Importantly, participants who displayed higher conditionability showed more aversive memories during the memory triggering task and during ambulatory assessment. This suggests that fear conditioning constitutes an important source of persistent aversive memories. Implications for PTSD and its treatment are discussed. PMID:24244407

The disengagement of visual attention in the gap paradigm across adolescence.

PubMed

Van der Stigchel, S; Hessels, R S; van Elst, J C; Kemner, C

2017-12-01

Attentional disengagement is important for successful interaction with our environment. The efficiency of attentional disengagement is commonly assessed using the gap paradigm. There is, however, a sharp contrast between the number of studies applying the gap paradigm to clinical populations and the knowledge about the underlying developmental trajectory of the gap effect. The aim of the present study was, therefore, to investigate attentional disengagement in a group of children aged 9-15. Besides the typically deployed gap and the overlap conditions, we also added a baseline condition in which the fixation point was removed at the moment that the target appeared. This allowed us to reveal the appropriate experimental conditions to unravel possible developmental differences. Correlational analyses showed that the size of the gap effect became smaller with increasing age, but only for the difference between the gap and the overlap conditions. This shows that there is a gradual increase in the capacity to disengage visual attention with increasing age, but that this effect only becomes apparent when the gap and the overlap conditions are compared. The gradual decrease of the gap effect with increasing age provides additional evidence that the attentional system becomes more efficient with increasing age and that this is a gradual process.

A demonstration of the application of the new paradigm for the evaluation of forensic evidence under conditions reflecting those of a real forensic-voice-comparison case.

PubMed

Enzinger, Ewald; Morrison, Geoffrey Stewart; Ochoa, Felipe

2016-01-01

The new paradigm for the evaluation of the strength of forensic evidence includes: The use of the likelihood-ratio framework. The use of relevant data, quantitative measurements, and statistical models. Empirical testing of validity and reliability under conditions reflecting those of the case under investigation. Transparency as to decisions made and procedures employed. The present paper illustrates the use of the new paradigm to evaluate strength of evidence under conditions reflecting those of a real forensic-voice-comparison case. The offender recording was from a landline telephone system, had background office noise, and was saved in a compressed format. The suspect recording included substantial reverberation and ventilation system noise, and was saved in a different compressed format. The present paper includes descriptions of the selection of the relevant hypotheses, sampling of data from the relevant population, simulation of suspect and offender recording conditions, and acoustic measurement and statistical modelling procedures. The present paper also explores the use of different techniques to compensate for the mismatch in recording conditions. It also examines how system performance would have differed had the suspect recording been of better quality. Copyright © 2015 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.

Stimulus uncertainty enhances long-term potentiation-like plasticity in human motor cortex.

PubMed

Sale, Martin V; Nydam, Abbey S; Mattingley, Jason B

2017-03-01

Plasticity can be induced in human cortex using paired associative stimulation (PAS), which repeatedly and predictably pairs a peripheral electrical stimulus with transcranial magnetic stimulation (TMS) to the contralateral motor region. Many studies have reported small or inconsistent effects of PAS. Given that uncertain stimuli can promote learning, the predictable nature of the stimulation in conventional PAS paradigms might serve to attenuate plasticity induction. Here, we introduced stimulus uncertainty into the PAS paradigm to investigate if it can boost plasticity induction. Across two experimental sessions, participants (n = 28) received a modified PAS paradigm consisting of a random combination of 90 paired stimuli and 90 unpaired (TMS-only) stimuli. Prior to each of these stimuli, participants also received an auditory cue which either reliably predicted whether the upcoming stimulus was paired or unpaired (no uncertainty condition) or did not predict the upcoming stimulus (maximum uncertainty condition). Motor evoked potentials (MEPs) evoked from abductor pollicis brevis (APB) muscle quantified cortical excitability before and after PAS. MEP amplitude increased significantly 15 min following PAS in the maximum uncertainty condition. There was no reliable change in MEP amplitude in the no uncertainty condition, nor between post-PAS MEP amplitudes across the two conditions. These results suggest that stimulus uncertainty may provide a novel means to enhance plasticity induction with the PAS paradigm in human motor cortex. To provide further support to the notion that stimulus uncertainty and prediction error promote plasticity, future studies should further explore the time course of these changes, and investigate what aspects of stimulus uncertainty are critical in boosting plasticity. Copyright © 2016 Elsevier Ltd. All rights reserved.

AD/HD and the capture of attention by briefly exposed delay-related cues: evidence from a conditioning paradigm.

PubMed

Sonuga-Barke, Edmund J S; De Houwer, Jan; De Ruiter, Karen; Ajzenstzen, Michal; Holland, Sarah

2004-02-01

The selective attention of children with attention deficit/hyperactivity disorder (AD/HD) to briefly exposed delay-related cues was examined in two experiments using a dot-probe conditioning paradigm. Colour cues were paired with negatively (i.e., imposition of delay) and positively valenced cues (i.e., escape from or avoidance of delay) during a conditioning phase. These cues were presented alongside neutral cues in a subsequent dot-probe detection phase. In experiment 1 teacher-identified children with AD/HD (N = 12), but not controls (N = 12), displayed an attentional bias towards both positively and negatively valenced cues. In experiment 2 children with a diagnosis of hyperkinetic disorder (N = 15), but not controls (N = 15), displayed a bias towards delay-related cues. However, this effect was largely carried by the response to positively valenced cues. These results confirm the dot-probe conditioning paradigm as a useful test of motivational influence on attention. They provide the first evidence of qualitative differences in the attentional style of children with AD/HD and give further support to those theories that highlight the motivational significance of delay in AD/HD.

Limited evidence of individual differences in holistic processing in different versions of the part-whole paradigm.

PubMed

Sunday, Mackenzie A; Richler, Jennifer J; Gauthier, Isabel

2017-07-01

The part-whole paradigm was one of the first measures of holistic processing and it has been used to address several topics in face recognition, including its development, other-race effects, and more recently, whether holistic processing is correlated with face recognition ability. However the task was not designed to measure individual differences and it has produced measurements with low reliability. We created a new holistic processing test designed to measure individual differences based on the part-whole paradigm, the Vanderbilt Part Whole Test (VPWT). Measurements in the part and whole conditions were reliable, but, surprisingly, there was no evidence for reliable individual differences in the part-whole index (how well a person can take advantage of a face part presented within a whole face context compared to the part presented without a whole face) because part and whole conditions were strongly correlated. The same result was obtained in a version of the original part-whole task that was modified to increase its reliability. Controlling for object recognition ability, we found that variance in the whole condition does not predict any additional variance in face recognition over what is already predicted by performance in the part condition.

Conditioning to colors: a population assay for visual learning in Drosophila.

PubMed

van Swinderen, Bruno

2011-11-01

Vision is a major sensory modality in Drosophila behavior, with more than one-half of the Drosophila brain devoted to visual processing. The mechanisms of vision in Drosophila can be studied in individuals and in populations of flies by using various paradigms. Although there has never been a widely used population assay for visual learning in Drosophila, some population paradigms have shown significant visual learning. These studies use colors as conditioned stimuli (CS) and shaking as the unconditioned stimulus (US). A simple version of the paradigm, conditioning to colors using a shaking device, is described here. A conditioning chamber, called a crab, is designed to center the flies after shaking by having them tumble down to the lowest point between joined glass tubes forming a V. Thus, vibration should be just strong enough to center most flies. After shaking, flies display a geotactic response and climb up either side of the V, and their choice of which side to climb is influenced by color displays on either side. The proportion of flies on either side determines the flies' natural preference or their learned avoidance of a color associated with shaking.

A Framework for Understanding the Patterns of Student Difficulties in Quantum Mechanics

NASA Astrophysics Data System (ADS)

Singh, Chandralekha

2015-04-01

Compared with introductory physics, relatively little is known about the development of expertise in advanced physics courses, especially in the case of quantum mechanics. We describe a theoretical framework for understanding the patterns of student reasoning difficulties and how students develop expertise in quantum mechanics. The framework posits that the challenges many students face in developing expertise in quantum mechanics are analogous to the challenges introductory students face in developing expertise in introductory classical mechanics. This framework incorporates the effects of diversity in students' prior preparation, goals and motivation for taking upper-level physics courses in general as well as the ``paradigm shift'' from classical mechanics to quantum mechanics. The framework is based on empirical investigations demonstrating that the patterns of reasoning, problem-solving, and self-monitoring difficulties in quantum mechanics bear a striking resemblance to those found in introductory classical mechanics. Examples from research in quantum mechanics and introductory classical mechanics will be discussed to illustrate how the patterns of difficulties are analogous as students learn to unpack the respective principles and grasp the formalism in each knowledge domain during the development of expertise. Embracing such a theoretical framework and contemplating the parallels between the difficulties in these two knowledge domains can enable researchers to leverage the extensive literature for introductory physics education research to guide the design of teaching and learning tools for helping students develop expertise in quantum mechanics. Support from the National Science Foundation is gratefully acknowledged.

Maladaptive behavioral consequences of conditioned fear-generalization: a pronounced, yet sparsely studied, feature of anxiety pathology.

PubMed

van Meurs, Brian; Wiggert, Nicole; Wicker, Isaac; Lissek, Shmuel

2014-06-01

Fear-conditioning experiments in the anxiety disorders focus almost exclusively on passive-emotional, Pavlovian conditioning, rather than active-behavioral, instrumental conditioning. Paradigms eliciting both types of conditioning are needed to study maladaptive, instrumental behaviors resulting from Pavlovian abnormalities found in clinical anxiety. One such Pavlovian abnormality is generalization of fear from a conditioned danger-cue (CS+) to resembling stimuli. Though lab-based findings repeatedly link overgeneralized Pavlovian-fear to clinical anxiety, no study assesses the degree to which Pavlovian overgeneralization corresponds with maladaptive, overgeneralized instrumental-avoidance. The current effort fills this gap by validating a novel fear-potentiated startle paradigm including Pavlovian and instrumental components. The paradigm is embedded in a computer game during which shapes appear on the screen. One shape paired with electric-shock serves as CS+, and other resembling shapes, presented in the absence of shock, serve as generalization stimuli (GSs). During the game, participants choose whether to behaviorally avoid shock at the cost of poorer performance. Avoidance during CS+ is considered adaptive because shock is a real possibility. By contrast, avoidance during GSs is considered maladaptive because shock is not a realistic prospect and thus unnecessarily compromises performance. Results indicate significant Pavlovian-instrumental relations, with greater generalization of Pavlovian fear associated with overgeneralization of maladaptive instrumental-avoidance. Copyright © 2014 Elsevier Ltd. All rights reserved.

Implicit and explicit learning in schizophrenics treated with olanzapine and with classic neuroleptics.

PubMed

Stevens, Andreas; Schwarz, Jürgen; Schwarz, Benedikt; Ruf, Ilona; Kolter, Thomas; Czekalla, Joerg

2002-03-01

Novel and classic neuroleptics differ in their effects on limbic striatal/nucleus accumbens (NA) and prefrontal cortex (PFC) dopamine turnover, suggesting differential effects on implicit and explicit learning as well as on anhedonia. The present study investigates whether such differences can be demonstrated in a naturalistic sample of schizophrenic patients. Twenty-five inpatients diagnosed with DSM-IV schizophrenic psychosis and treated for at least 14 days with the novel neuroleptic olanzapine were compared with 25 schizophrenics taking classic neuroleptics and with 25 healthy controls, matched by age and education level. PFC/NA-dependent implicit learning was assessed by a serial reaction time task (SRTT) and compared with cerebellum-mediated classical eye-blink conditioning and explicit visuospatial memory. Anhedonia was measured with the Snaith-Hamilton-Pleasure Scale (SHAPS). Implicit (SRTT) and psychomotor speed, but not explicit (visuospatial) learning were superior in the olanzapine-treated group as compared to the patients on classic neuroleptics. Compared to healthy controls, olanzapine-treated schizophrenics showed similar implicit learning, but reduced explicit (visuospatial) memory performance. Acquisition of eyeblink conditioning was not different between the three groups. There was no difference with regard to anhedonia and SANS scores between the patients. Olanzapine seems to interfere less with unattended learning and motor speed than classical neuroleptics. In daily life, this may translate into better adaptation to a rapidly changing environment. The effects seem specific, as in explicit learning and eyeblink conditioning no difference to classic NL was found.

The Role of Physical Fitness in the Neurocognitive Performance of Task Switching in Older Persons with Mild Cognitive Impairment.

PubMed

Tsai, Chia-Liang; Pai, Ming-Chyi; Ukropec, Jozef; Ukropcová, Barbara

2016-04-23

Although elderly people with amnestic mild cognitive impairment (aMCI) have been found to show impaired behavioral performance in task switching, no research has yet explored the electrophysiological mechanisms and the potential correlation between physical fitness and neurocognitive (i.e., behavioral and electrophysiological) performance in aMCI. The present study was thus aimed to examine whether there are differences in electrophysiological (i.e., event-related potential) performance between aMCI participants and controls when performing a task-switching paradigm, and to investigate the role of physical fitness in the relationship between neurocognitive performance and aMCI. Sixty participants were classified into aMCI (n = 30) and control (n = 30) groups, and performed a task-switching paradigm with concomitant electrophysiological recording, as well as underwent senior functional physical fitness tests. The aMCI group showed comparable scores on most parts of the physical fitness tests, but reduced lower body flexibility and VO2max as compared to the control group. When performing the task-switching paradigm, the aMCI group showed slower reaction times in the heterogeneous condition and larger global switching costs, although no significant difference was observed in accuracy rates between the two groups. In addition, the aMCI group showed significantly prolonged P3 latencies in the homogeneous and heterogeneous conditions, and a smaller P3 amplitude only in the heterogeneous condition. The level of cardiorespiratory fitness was significantly correlated with P3 amplitude in the aMCI group, particularly in the heterogeneous condition of the task-switching paradigm. These results show that the aMCI group exhibited abnormalities in their neurocognitive performance when performing the task-switching paradigm and such a deficit was likely associated with reduced cardiorespiratory fitness, which was shown to be the important predictor of neurocognitive performance.

A functional analysis of social reinforcement in vicarious verbal conditioning.

PubMed

Donohue, G B; Tryon, W W

1985-01-01

This article reports the results of 629 subjects in three experiments designed to replicate and extend the phenomenon of vicarious verbal conditioning. Experiment I replicated the finding that subjects who responded most to vicarious verbal conditioning were aware of the contingency involved. Experiment II attempted to examine the effects of prior history with the verbal reinforcer on vicarious verbal conditioning by providing seven groups of subjects with varying classic conditioning histories prior to vicarious verbal conditioning. The null results associated with this experiment were hypothesized to be due to the fact that the vicarious verbal conditioning took place in a language laboratory where the subjects could hear but not see the model. Experiment III replicated Experiment II in a live group context as was done in Experiment I. The results showed that vicarious verbal conditioning was again found to take place, that associating the verbal reinforcer with a tone or tone plus money via forward classic conditioning potentiated the effects of the verbal reinforcer, that backward classic conditioning did not potentiate the reinforcer, d) nor did either of two sensitization procedures potentiate the effects of the verbal reinforcer. Both aware and unaware subjects evidenced vicarious verbal conditioning.

Classic hippocampal sclerosis and hippocampal-onset epilepsy produced by a single “cryptic” episode of focal hippocampal excitation in awake rats

PubMed Central

Norwood, Braxton A.; Bumanglag, Argyle V.; Osculati, Francesco; Sbarbati, Andrea; Marzola, Pasquina; Nicolato, Elena; Fabene, Paolo F.; Sloviter, Robert S.

2010-01-01

In refractory temporal lobe epilepsy, seizures often arise from a shrunken hippocampus exhibiting a pattern of selective neuron loss called “classic hippocampal sclerosis.” No single experimental injury has reproduced this specific pathology, suggesting that hippocampal atrophy might be a progressive “endstage” pathology resulting from years of spontaneous seizures. We posed the alternate hypothesis that classic hippocampal sclerosis results from a single excitatory event that has never been successfully modeled experimentally because convulsive status epilepticus, the insult most commonly used to produce epileptogenic brain injury, is too severe and necessarily terminated before the hippocampus receives the needed duration of excitation. We tested this hypothesis by producing prolonged hippocampal excitation in awake rats without causing convulsive status epilepticus. Two daily 30-minute episodes of perforant pathway stimulation in Sprague-Dawley rats increased granule cell paired-pulse inhibition, decreased epileptiform afterdischarge durations during 8 hours of subsequent stimulation, and prevented convulsive status epilepticus. Similarly, one 8-hour episode of reduced-intensity stimulation in Long-Evans rats, which are relatively resistant to developing status epilepticus, produced hippocampal discharges without causing status epilepticus. Both paradigms immediately produced the extensive neuronal injury that defines classic hippocampal sclerosis, without giving any clinical indication during the insult that an injury was being inflicted. Spontaneous hippocampal-onset seizures began 16–25 days post-injury, before hippocampal atrophy developed, as demonstrated by sequential magnetic resonance imaging. These results indicate that classic hippocampal sclerosis is uniquely produced by a single episode of clinically “cryptic” excitation. Epileptogenic insults may often involve prolonged excitation that goes undetected at the time of injury. PMID:20575073

Harnessing the power of theta: natural manipulations of cognitive performance during hippocampal theta-contingent eyeblink conditioning

PubMed Central

Hoffmann, Loren C.; Cicchese, Joseph J.; Berry, Stephen D.

2015-01-01

Neurobiological oscillations are regarded as essential to normal information processing, including coordination and timing of cells and assemblies within structures as well as in long feedback loops of distributed neural systems. The hippocampal theta rhythm is a 3–12 Hz oscillatory potential observed during cognitive processes ranging from spatial navigation to associative learning. The lower range, 3–7 Hz, can occur during immobility and depends upon the integrity of cholinergic forebrain systems. Several studies have shown that the amount of pre-training theta in the rabbit strongly predicts the acquisition rate of classical eyeblink conditioning and that impairment of this system substantially slows the rate of learning. Our lab has used a brain-computer interface (BCI) that delivers eyeblink conditioning trials contingent upon the explicit presence or absence of hippocampal theta. A behavioral benefit of theta-contingent training has been demonstrated in both delay and trace forms of the paradigm with a two- to four-fold increase in learning speed. This behavioral effect is accompanied by enhanced amplitude and synchrony of hippocampal local field potential (LFP)s, multi-unit excitation, and single-unit response patterns that depend on theta state. Additionally, training in the presence of hippocampal theta has led to increases in the salience of tone-induced unit firing patterns in the medial prefrontal cortex, followed by persistent multi-unit activity during the trace interval. In cerebellum, rhythmicity and precise synchrony of stimulus time-locked LFPs with those of hippocampus occur preferentially under the theta condition. Here we review these findings, integrate them into current models of hippocampal-dependent learning and suggest how improvement in our understanding of neurobiological oscillations is critical for theories of medial temporal lobe processes underlying intact and pathological learning. PMID:25918501

Orexin receptor-1 in the locus coeruleus plays an important role in cue-dependent fear memory consolidation.

PubMed

Soya, Shingo; Shoji, Hirotaka; Hasegawa, Emi; Hondo, Mari; Miyakawa, Tsuyoshi; Yanagisawa, Masashi; Mieda, Michihiro; Sakurai, Takeshi

2013-09-04

The noradrenergic (NA) projections arising from the locus ceruleus (LC) to the amygdala and bed nucleus of the stria terminalis have been implicated in the formation of emotional memory. Since NA neurons in the LC (LC-NA neurons) abundantly express orexin receptor-1 (OX1R) and receive prominent innervation by orexin-producing neurons, we hypothesized that an OX1R-mediated pathway is involved in the physiological fear learning process via regulation of LC-NA neurons. To evaluate this hypothesis, we examined the phenotype of Ox1r(-/-) mice in the classic cued and contextual fear-conditioning test. We found that Ox1r(-/-) mice showed impaired freezing responses in both cued and contextual fear-conditioning paradigms. In contrast, Ox2r(-/-) mice showed normal freezing behavior in the cued fear-conditioning test, while they exhibited shorter freezing time in the contextual fear-conditioning test. Double immunolabeling of Fos and tyrosine hydroxylase showed that double-positive LC-NA neurons after test sessions of both cued and contextual stimuli were significantly fewer in Ox1r(-/-) mice. AAV-mediated expression of OX1R in LC-NA neurons in Ox1r(-/-) mice restored the freezing behavior to the auditory cue to a comparable level to that in wild-type mice in the test session. Decreased freezing time during the contextual fear test was not affected by restoring OX1R expression in LC-NA neurons. These observations support the hypothesis that the orexin system modulates the formation and expression of fear memory via OX1R in multiple pathways. Especially, OX1R in LC-NA neurons plays an important role in cue-dependent fear memory formation and/or retrieval.

Harnessing the power of theta: natural manipulations of cognitive performance during hippocampal theta-contingent eyeblink conditioning.

PubMed

Hoffmann, Loren C; Cicchese, Joseph J; Berry, Stephen D

2015-01-01

Neurobiological oscillations are regarded as essential to normal information processing, including coordination and timing of cells and assemblies within structures as well as in long feedback loops of distributed neural systems. The hippocampal theta rhythm is a 3-12 Hz oscillatory potential observed during cognitive processes ranging from spatial navigation to associative learning. The lower range, 3-7 Hz, can occur during immobility and depends upon the integrity of cholinergic forebrain systems. Several studies have shown that the amount of pre-training theta in the rabbit strongly predicts the acquisition rate of classical eyeblink conditioning and that impairment of this system substantially slows the rate of learning. Our lab has used a brain-computer interface (BCI) that delivers eyeblink conditioning trials contingent upon the explicit presence or absence of hippocampal theta. A behavioral benefit of theta-contingent training has been demonstrated in both delay and trace forms of the paradigm with a two- to four-fold increase in learning speed. This behavioral effect is accompanied by enhanced amplitude and synchrony of hippocampal local field potential (LFP)s, multi-unit excitation, and single-unit response patterns that depend on theta state. Additionally, training in the presence of hippocampal theta has led to increases in the salience of tone-induced unit firing patterns in the medial prefrontal cortex, followed by persistent multi-unit activity during the trace interval. In cerebellum, rhythmicity and precise synchrony of stimulus time-locked LFPs with those of hippocampus occur preferentially under the theta condition. Here we review these findings, integrate them into current models of hippocampal-dependent learning and suggest how improvement in our understanding of neurobiological oscillations is critical for theories of medial temporal lobe processes underlying intact and pathological learning.

Semi-classical analysis and pseudo-spectra

NASA Astrophysics Data System (ADS)

Davies, E. B.

We prove an approximate spectral theorem for non-self-adjoint operators and investigate its applications to second-order differential operators in the semi-classical limit. This leads to the construction of a twisted FBI transform. We also investigate the connections between pseudo-spectra and boundary conditions in the semi-classical limit.

Overview of Classical Swine Fever (Hog Cholera, Classical Swine fever)

USDA-ARS?s Scientific Manuscript database

Classical swine fever is a contagious often fatal disease of pigs clinically characterized by high body temperature, lethargy, yellowish diarrhea, vomits and purple skin discoloration of ears, lower abdomen and legs. It was first described in the early 19th century in the USA. Later, a condition i...

Development of the science of mass casualty incident management: reflection on the medical response to the Wenchuan earthquake and Hangzhou bus fire*

PubMed Central

Shen, Wei-feng; Jiang, Li-bing; Jiang, Guan-yu; Zhang, Mao; Ma, Yue-feng; He, Xiao-jun

2014-01-01

Objective: In this paper, we review the previous classic research paradigms of a mass casualty incident (MCI) systematically and reflect the medical response to the Wenchuan earthquake and Hangzhou bus fire, in order to outline and develop an improved research paradigm for MCI management. Methods: We searched PubMed, EMBASE, China Wanfang, and China Biology Medicine (CBM) databases for relevant studies. The following key words and medical subject headings were used: ‘mass casualty incident’, ‘MCI’, ‘research method’, ‘Wenchuan’, ‘earthquake’, ‘research paradigm’, ‘science of surge’, ‘surge’, ‘surge capacity’, and ‘vulnerability’. Searches were performed without year or language restriction. After searching the four literature databases using the above listed key words and medical subject headings, related articles containing research paradigms of MCI, 2008 Wenchuan earthquake, July 5 bus fire, and science of surge and vulnerability were independently included by two authors. Results: The current progresses on MCI management include new golden hour, damage control philosophy, chain of survival, and three links theory. In addition, there are three evaluation methods (medical severity index (MSI), potential injury creating event (PICE) classification, and disaster severity scale (DSS)), which can dynamically assess the MCI situations and decisions for MCI responses and can be made based on the results of such evaluations. However, the three methods only offer a retrospective evaluation of MCI and thus fail to develop a real-time assessment of MCI responses. Therefore, they cannot be used as practical guidance for decision-making during MCI. Although the theory of surge science has made great improvements, we found that a very important factor has been ignored—vulnerability, based on reflecting on the MCI response to the 2008 Wenchuan earthquake and July 5 bus fire in Hangzhou. Conclusions: This new paradigm breaks through the limitation of traditional research paradigms and will contribute to the development of a methodology for disaster research. PMID:25471837

Updating appetitive memory during reconsolidation window: critical role of cue-directed behavior and amygdala central nucleus.

PubMed

Olshavsky, Megan E; Song, Bryan J; Powell, Daniel J; Jones, Carolyn E; Monfils, Marie-H; Lee, Hongjoo J

2013-01-01

When presented with a light cue followed by food, some rats simply approach the foodcup (Nonorienters), while others first orient to the light in addition to displaying the food-cup approach behavior (Orienters). Cue-directed orienting may reflect enhanced attentional and/or emotional processing of the cue, suggesting divergent natures of cue-information processing in Orienters and Nonorienters. The current studies investigate how differences in cue processing might manifest in appetitive memory retrieval and updating using a paradigm developed to persistently attenuate fear responses (Retrieval-extinction paradigm; Monfils et al., 2009). First, we examined whether the retrieval-extinction paradigm could attenuate appetitive responses in Orienters and Nonorienters. Next, we investigated if the appetitive memory could be updated using reversal learning (fear conditioning) during the reconsolidation window (as opposed to repeated unreinforced trials, i.e., extinction). Both extinction and new fear learning given within the reconsolidation window were effective at persistently updating the initial appetitive memory in the Orienters, but not the Nonorienters. Since conditioned orienting is mediated by the amygdala central nucleus (CeA), our final experiment examined the CeA's role in the retrieval-extinction process. Bilateral CeA lesions interfered with the retrieval-extinction paradigm-did not prevent spontaneous recovery of food-cup approach. Together, our studies demonstrate the critical role of conditioned orienting behavior and the CeA in updating appetitive memory during the reconsolidation window.

Effective monopoles within thick branes

NASA Astrophysics Data System (ADS)

Hoff da Silva, J. M.; da Rocha, Roldão

2012-10-01

The monopole mass is revealed to be considerably modified in the thick braneworld paradigm, and depends on the position of the monopole in the brane as well. Accordingly, the monopole radius continuously increases, leading to an unacceptable setting that can be circumvented when the brane thickness has an upper limit. Despite such peculiar behavior, the accrued quantum corrections —involving the classical monopole solution— are shown to be still under control. We analyze the monopole's peculiarities also taking into account the localization of the gauge fields. Furthermore, some additional analysis in the thick braneworld context and the similar behavior evinced by the topological string are investigated.

Dynamic programming and graph algorithms in computer vision.

PubMed

Felzenszwalb, Pedro F; Zabih, Ramin

2011-04-01

Optimization is a powerful paradigm for expressing and solving problems in a wide range of areas, and has been successfully applied to many vision problems. Discrete optimization techniques are especially interesting since, by carefully exploiting problem structure, they often provide nontrivial guarantees concerning solution quality. In this paper, we review dynamic programming and graph algorithms, and discuss representative examples of how these discrete optimization techniques have been applied to some classical vision problems. We focus on the low-level vision problem of stereo, the mid-level problem of interactive object segmentation, and the high-level problem of model-based recognition.

High flexible Hydropower Generation concepts for future grids

NASA Astrophysics Data System (ADS)

Hell, Johann

2017-04-01

The ongoing changes in electric power generation are resulting in new requirements for the classical generating units. In consequence a paradigm change in operation of power systems is necessary and a new approach in finding solutions is needed. The presented paper is dealing with the new requirements on current and future energy systems with the focus on hydro power generation. A power generation landscape for some European regions is shown and generation and operational flexibility is explained. Based on the requirements from the Transmission System Operator in UK, the transient performance of a Pumped Storage installation is discussed.

The effect of product characteristic familiarity on product recognition

NASA Astrophysics Data System (ADS)

Yang, Cheng; An, Fang; Chen, Chen; Zhu, Bin

2017-09-01

In order to explore the effect of product appearance characteristic familiarity on product recognition, both EEG experiment and questionnaire evaluation are used in this research. The objective feedback of user is obtained through the EEG experiment and the subjective opinions are collected through the questionnaires. The EEG experiment is combined with the classical learning-recognition paradigm, and the old-new effect of recognition experiment is used as a metric of recognition degree. Experimental results show that the difference of characteristic familiarity does have a significant effect on product recognition. The conclusion can be used in innovation design.

Absolute pitch in children prior to the beginning of musical training.

PubMed

Ross, David A; Marks, Lawrence E

2009-07-01

Absolute pitch (AP) is a rare skill, historically defined as the ability to name notes. Until now, methodologic limitations made it impossible to directly test the extent to which the development of AP depends on musical training. Using a new paradigm, we tested children with minimal musical experience. Although most children performed poorly, two performed comparably to adult possessors of AP. Follow-up testing showed that the performance of both children progressed to that of "classic" AP. These data support the theory that AP can result from differences in the encoding of stimulus frequency that are independent of musical experience.

Geoid, topography, and convection-driven crustal deformation on Venus

NASA Technical Reports Server (NTRS)

Simons, Mark; Hager, Bradford H.; Solomon, Sean C.

1992-01-01

High-resolution Magellan images and altimetry of Venus reveal a wide range of styles and scales of surface deformation that cannot readily be explained within the classical terrestrial plate tectonic paradigm. The high correlation of long-wavelength topography and gravity and the large apparent depths of compensation suggest that Venus lacks an upper-mantle low-viscosity zone. A key difference between Earth and Venus may be the degree of coupling between the convecting mantle and the overlying lithosphere. Mantle flow should then have recognizable signatures in the relationships between surface topography, crustal deformation, and the observed gravity field.

An object-oriented framework for medical image registration, fusion, and visualization.

PubMed

Zhu, Yang-Ming; Cochoff, Steven M

2006-06-01

An object-oriented framework for image registration, fusion, and visualization was developed based on the classic model-view-controller paradigm. The framework employs many design patterns to facilitate legacy code reuse, manage software complexity, and enhance the maintainability and portability of the framework. Three sample applications built a-top of this framework are illustrated to show the effectiveness of this framework: the first one is for volume image grouping and re-sampling, the second one is for 2D registration and fusion, and the last one is for visualization of single images as well as registered volume images.

Generalized Rainich conditions, generalized stress-energy conditions, and the Hawking-Ellis classification

NASA Astrophysics Data System (ADS)

Martín–Moruno, Prado; Visser, Matt

2017-11-01

The (generalized) Rainich conditions are algebraic conditions which are polynomial in the (mixed-component) stress-energy tensor. As such they are logically distinct from the usual classical energy conditions (NEC, WEC, SEC, DEC), and logically distinct from the usual Hawking-Ellis (Segré-Plebański) classification of stress-energy tensors (type I, type II, type III, type IV). There will of course be significant inter-connections between these classification schemes, which we explore in the current article. Overall, we shall argue that it is best to view the (generalized) Rainich conditions as a refinement of the classical energy conditions and the usual Hawking-Ellis classification.

Clean Quantum and Classical Communication Protocols.

PubMed

Buhrman, Harry; Christandl, Matthias; Perry, Christopher; Zuiddam, Jeroen

2016-12-02

By how much must the communication complexity of a function increase if we demand that the parties not only correctly compute the function but also return all registers (other than the one containing the answer) to their initial states at the end of the communication protocol? Protocols that achieve this are referred to as clean and the associated cost as the clean communication complexity. Here we present clean protocols for calculating the inner product of two n-bit strings, showing that (in the absence of preshared entanglement) at most n+3 qubits or n+O(sqrt[n]) bits of communication are required. The quantum protocol provides inspiration for obtaining the optimal method to implement distributed cnot gates in parallel while minimizing the amount of quantum communication. For more general functions, we show that nearly all Boolean functions require close to 2n bits of classical communication to compute and close to n qubits if the parties have access to preshared entanglement. Both of these values are maximal for their respective paradigms.

Assessing the Liquidity of Firms: Robust Neural Network Regression as an Alternative to the Current Ratio

NASA Astrophysics Data System (ADS)

de Andrés, Javier; Landajo, Manuel; Lorca, Pedro; Labra, Jose; Ordóñez, Patricia

Artificial neural networks have proven to be useful tools for solving financial analysis problems such as financial distress prediction and audit risk assessment. In this paper we focus on the performance of robust (least absolute deviation-based) neural networks on measuring liquidity of firms. The problem of learning the bivariate relationship between the components (namely, current liabilities and current assets) of the so-called current ratio is analyzed, and the predictive performance of several modelling paradigms (namely, linear and log-linear regressions, classical ratios and neural networks) is compared. An empirical analysis is conducted on a representative data base from the Spanish economy. Results indicate that classical ratio models are largely inadequate as a realistic description of the studied relationship, especially when used for predictive purposes. In a number of cases, especially when the analyzed firms are microenterprises, the linear specification is improved by considering the flexible non-linear structures provided by neural networks.

Validating Self-Paced Sentence-by-Sentence Reading: Story Comprehension, Recall, and Narrative Transportation

ERIC Educational Resources Information Center

Chung-Fat-Yim, Ashley; Peterson, Jordan B.; Mar, Raymond A.

2017-01-01

Previous studies on discourse have employed a self-paced sentence-by-sentence paradigm to present text and record reading times. However, presenting discourse this way does not mirror real-world reading conditions; for example, this paradigm prevents regressions to earlier portions of the text. The purpose of the present study is to investigate…

Extending the Simultaneous-Sequential Paradigm to Measure Perceptual Capacity for Features and Words

ERIC Educational Resources Information Center

Scharff, Alec; Palmer, John; Moore, Cathleen M.

2011-01-01

In perception, divided attention refers to conditions in which multiple stimuli are relevant to an observer. To measure the effect of divided attention in terms of perceptual capacity, we introduce an extension of the simultaneous-sequential paradigm. The extension makes predictions for fixed-capacity models as well as for unlimited-capacity…

Neural cascade of conflict processing: Not just time-on-task.

PubMed

McKay, Cameron C; van den Berg, Berry; Woldorff, Marty G

2017-02-01

In visual conflict tasks (e.g., Stroop or flanker), response times (RTs) are generally longer on incongruent trials relative to congruent ones. Two event-related-potential (ERP) components classically associated with the processing of stimulus conflict are the fronto-central, incongruency-related negativity (N inc ) and the posterior late-positive complex (LPC), which are derived from the ERP difference waves for incongruent minus congruent trials. It has been questioned, however, whether these effects, or other neural measures of incongruency (e.g., fMRI responses in the anterior cingulate), reflect true conflict processing, or whether such effects derive mainly from differential time-on-task. To address this question, we leveraged high-temporal-resolution ERP measures of brain activity during two behavioral tasks. The first task, a modified Erikson flanker paradigm (with congruent and incongruent trials), was used to evoke the classic RT and ERP effects associated with conflict. The second was a non-conflict control task in which, participants visually discriminated a single stimulus (with easy and hard discrimination conditions). Behaviorally, the parameters were titrated to yield similar RT effects of conflict and difficulty (27ms). Neurally, both within-task contrasts showed an initial fronto-central negative-polarity wave (N2-latency effect), but they then diverged. In the difficulty difference wave, the initial negativity led directly into the posterior LPC, whereas in the incongruency contrast the initial negativity was followed a by a second fronto-central negative peak (N inc ), which was then followed by a considerably longer-latency LPC. These results provide clear evidence that the longer processing for incongruent stimulus inputs do not just reflect time-on-task or difficulty, but include a true conflict-processing component. Copyright © 2017 Elsevier Ltd. All rights reserved.

Interest Inventory Items as Attitude Eliciting Stimuli in Classical Conditioning: A Test of the A-R-D Theory. Language, Personality, and Cross-Cultural Study and Measurement of the Human A-R-D (Motivational) System.

ERIC Educational Resources Information Center

Gross, Michael C.; Staats, Arthur W.

An experiment was conducted to test the hypothesis that interest inventory items elicit classically conditionable attitudinal responses. A higher-order conditioning procedure was used in which items from the Strong Vocational Interest Blank were employed as unconditioned stimuli and nonsense syllables as conditioned stimuli. Items for which the…

Differential effects of MPEP and diazepam in tests of conditioned emotional response and Pavlovian-to-instrumental transfer suggests 'anxiolytic' effects are mediated by different mechanisms.

PubMed

George, S A; Hutson, P H; Stephens, D N

2009-06-01

The selective mGluR5 antagonist 2-methyl-6-(phenylethynyl)-pyridine (MPEP) is reported to be anxiolytic in several animal models of anxiety, including the conditioned emotional response (CER) paradigm. Suppression of responding during conditioned stimulus (CS) presentation in CER may reflect behavioural competition between lever pressing and adopting a shock-avoidance posture, or it may alternatively reflect altered value of the food reward following its association with a footshock, thus reducing its ability to motivate responding. If this is the case, then drugs that reduce the CER may interfere with the mechanism by which CSs are able to motivate responding, rather than by reducing anxiety. The standard test of the ability of Pavlovian cues to motivate responding is the Pavlovian-to-instrumental transfer (PIT) paradigm and it has recently been suggested that CER may be 'negative PIT'. We compared the effect of MPEP (0, 3, 10 and 30 mg/kg) and diazepam (0, 1, 3 and 10 mg/kg) in CER and PIT. Both MPEP and diazepam significantly reduced conditioned suppression in the CER paradigm. MPEP, but not diazepam, significantly reduced PIT. The findings support the hypothesis that MPEP may reduce expression of anxiety in the CER paradigm by interfering with the way in which emotionally salient cues are able to affect behaviour, but do not support such an analysis of the effect of diazepam. Diazepam and MPEP may therefore achieve their effects in CER by influencing different psychological processes.

Validation of Autonomic and Endocrine Reactivity to a Laboratory Stressor in Young Children

PubMed Central

Roos, Leslie E.; Giuliano, Ryan J.; Beauchamp, Kathryn G.; Gunnar, Megan; Amidon, Brigette; Fisher, Philip A.

2017-01-01

The validation of laboratory paradigms that reliably induce a stress response [including hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS) activation], is critical for understanding how children’s stress-response systems support emotional and cognitive function. Early childhood research to date is markedly limited, given the difficulty in establishing paradigms that reliably induce a cortisol response. Furthermore, research to date has not included a control condition or examined concurrent ANS reactivity. We addressed these limitations by characterizing the extent to which a modified matching task stressor paradigm induces HPA and ANS activation, beyond a closely matched control condition. Modifications include an unfamiliar and unfriendly assessor to increase the stressful nature of the task. Results validate the matching task as a laboratory stressor, with significant differences in HPA and ANS responsivity between conditions. The Stressor group exhibited a cortisol increase post-stressor, while the Control group was stable over time. Children in both conditions exhibited reduced parasympathetic activity to the first-half of the task, but in the second-half, only children in the Stressor condition, who were experiencing exaggerated signals of failure, exhibited further parasympathetic decline. The Stressor condition induced higher sympathetic activity (versus Control) throughout the task, with exaggerated second-half differences. Within the Stressor condition, responsivity was convergent across systems, with greater cortisol reactivity correlated with the magnitude of parasympathetic withdrawal and sympathetic engagement. Future research employing the matching task will facilitate understanding the role of HPA and ANS function in development. PMID:28024268

Location memory for dots in polygons versus cities in regions: evaluating the category adjustment model.

PubMed

Friedman, Alinda; Montello, Daniel R; Burte, Heather

2012-09-01

We conducted 3 experiments to examine the category adjustment model (Huttenlocher, Hedges, & Duncan, 1991) in circumstances in which the category boundaries were irregular schematized polygons made from outlines of maps. For the first time, accuracy was tested when only perceptual and/or existing long-term memory information about identical locations was cued. Participants from Alberta, Canada and California received 1 of 3 conditions: dots-only, in which a dot appeared within the polygon, and after a 4-s dynamic mask the empty polygon appeared and the participant indicated where the dot had been; dots-and-names, in which participants were told that the first polygon represented Alberta/California and that each dot was in the correct location for the city whose name appeared outside the polygon; and names-only, in which there was no first polygon, and participants clicked on the city locations from extant memory alone. Location recall in the dots-only and dots-and-names conditions did not differ from each other and had small but significant directional errors that pointed away from the centroids of the polygons. In contrast, the names-only condition had large and significant directional errors that pointed toward the centroids. Experiments 2 and 3 eliminated the distribution of stimuli and overall screen position as causal factors. The data suggest that in the "classic" category adjustment paradigm, it is difficult to determine a priori when Bayesian cue combination is applicable, making Bayesian analysis less useful as a theoretical approach to location estimation. PsycINFO Database Record (c) 2012 APA, all rights reserved.

Roles of heat shock factors in gametogenesis and development.

PubMed

Abane, Ryma; Mezger, Valérie

2010-10-01

Heat shock factors form a family of transcription factors (four in mammals), which were named according to the first discovery of their activation by heat shock. As a result of the universality and robustness of their response to heat shock, the stress-dependent activation of heat shock factor became a ‘paradigm’: by binding to conserved DNA sequences (heat shock elements), heat shock factors trigger the expression of genes encoding heat shock proteins that function as molecular chaperones, contributing to establish a cytoprotective state to various proteotoxic stress and in several pathological conditions. Besides their roles in the stress response, heat shock factors perform crucial roles during gametogenesis and development in physiological conditions. First, during these process, in stress conditions, they are either proactive for survival or, conversely, for apoptotic process, allowing elimination or, inversely, protection of certain cell populations in a way that prevents the formation of damaged gametes and secure future reproductive success. Second, heat shock factors display subtle interplay in a tissue- and stage-specific manner, in regulating very specific sets of heat shock genes, but also many other genes encoding growth factors or involved in cytoskeletal dynamics. Third, they act not only by their classical transcription factor activities, but are necessary for the establishment of chromatin structure and, likely, genome stability. Finally, in contrast to the heat shock gene paradigm, heat shock elements bound by heat shock factors in developmental process turn out to be extremely dispersed in the genome, which is susceptible to lead to the future definition of ‘developmental heat shock element’.

The effects of semantic congruency: a research of audiovisual P300-speller.

PubMed

Cao, Yong; An, Xingwei; Ke, Yufeng; Jiang, Jin; Yang, Hanjun; Chen, Yuqian; Jiao, Xuejun; Qi, Hongzhi; Ming, Dong

2017-07-25

Over the past few decades, there have been many studies of aspects of brain-computer interface (BCI). Of particular interests are event-related potential (ERP)-based BCI spellers that aim at helping mental typewriting. Nowadays, audiovisual unimodal stimuli based BCI systems have attracted much attention from researchers, and most of the existing studies of audiovisual BCIs were based on semantic incongruent stimuli paradigm. However, no related studies had reported that whether there is difference of system performance or participant comfort between BCI based on semantic congruent paradigm and that based on semantic incongruent paradigm. The goal of this study was to investigate the effects of semantic congruency in system performance and participant comfort in audiovisual BCI. Two audiovisual paradigms (semantic congruent and incongruent) were adopted, and 11 healthy subjects participated in the experiment. High-density electrical mapping of ERPs and behavioral data were measured for the two stimuli paradigms. The behavioral data indicated no significant difference between congruent and incongruent paradigms for offline classification accuracy. Nevertheless, eight of the 11 participants reported their priority to semantic congruent experiment, two reported no difference between the two conditions, and only one preferred the semantic incongruent paradigm. Besides, the result indicted that higher amplitude of ERP was found in incongruent stimuli based paradigm. In a word, semantic congruent paradigm had a better participant comfort, and maintained the same recognition rate as incongruent paradigm. Furthermore, our study suggested that the paradigm design of spellers must take both system performance and user experience into consideration rather than merely pursuing a larger ERP response.

Behavioral Assessment of Listening Effort Using a Dual-Task Paradigm.

PubMed

Gagné, Jean-Pierre; Besser, Jana; Lemke, Ulrike

2017-01-01

Published investigations ( n = 29) in which a dual-task experimental paradigm was employed to measure listening effort during speech understanding in younger and older adults were reviewed. A summary of the main findings reported in the articles is provided with respect to the participants' age-group and hearing status. Effects of different signal characteristics, such as the test modality, on dual-task outcomes are evaluated, and associations with cognitive abilities and self-report measures of listening effort are described. Then, several procedural issues associated with the use of dual-task experiment paradigms are discussed. Finally, some issues that warrant future research are addressed. The review revealed large variability in the dual-task experimental paradigms that have been used to measure the listening effort expended during speech understanding. The differences in experimental procedures used across studies make it difficult to draw firm conclusions concerning the optimal choice of dual-task paradigm or the sensitivity of specific paradigms to different types of experimental manipulations. In general, the analysis confirmed that dual-task paradigms have been used successfully to measure differences in effort under different experimental conditions, in both younger and older adults. Several research questions that warrant further investigation in order to better understand and characterize the intricacies of dual-task paradigms were identified.

Behavioral Assessment of Listening Effort Using a Dual-Task Paradigm

PubMed Central

Besser, Jana; Lemke, Ulrike

2017-01-01

Published investigations (n = 29) in which a dual-task experimental paradigm was employed to measure listening effort during speech understanding in younger and older adults were reviewed. A summary of the main findings reported in the articles is provided with respect to the participants’ age-group and hearing status. Effects of different signal characteristics, such as the test modality, on dual-task outcomes are evaluated, and associations with cognitive abilities and self-report measures of listening effort are described. Then, several procedural issues associated with the use of dual-task experiment paradigms are discussed. Finally, some issues that warrant future research are addressed. The review revealed large variability in the dual-task experimental paradigms that have been used to measure the listening effort expended during speech understanding. The differences in experimental procedures used across studies make it difficult to draw firm conclusions concerning the optimal choice of dual-task paradigm or the sensitivity of specific paradigms to different types of experimental manipulations. In general, the analysis confirmed that dual-task paradigms have been used successfully to measure differences in effort under different experimental conditions, in both younger and older adults. Several research questions that warrant further investigation in order to better understand and characterize the intricacies of dual-task paradigms were identified. PMID:28091178

Is the phonological similarity effect in working memory due to proactive interference?

PubMed

Baddeley, Alan D; Hitch, Graham J; Quinlan, Philip T

2018-04-12

Immediate serial recall of verbal material is highly sensitive to impairment attributable to phonological similarity. Although this has traditionally been interpreted as a within-sequence similarity effect, Engle (2007) proposed an interpretation based on interference from prior sequences, a phenomenon analogous to that found in the Peterson short-term memory (STM) task. We use the method of serial reconstruction to test this in an experiment contrasting the standard paradigm in which successive sequences are drawn from the same set of phonologically similar or dissimilar words and one in which the vowel sound on which similarity is based is switched from trial to trial, a manipulation analogous to that producing release from PI in the Peterson task. A substantial similarity effect occurs under both conditions although there is a small advantage from switching across similar sequences. There is, however, no evidence for the suggestion that the similarity effect will be absent from the very first sequence tested. Our results support the within-sequence similarity rather than a between-list PI interpretation. Reasons for the contrast with the classic Peterson short-term forgetting task are briefly discussed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Probabilistic Inference: Task Dependency and Individual Differences of Probability Weighting Revealed by Hierarchical Bayesian Modeling

PubMed Central

Boos, Moritz; Seer, Caroline; Lange, Florian; Kopp, Bruno

2016-01-01

Cognitive determinants of probabilistic inference were examined using hierarchical Bayesian modeling techniques. A classic urn-ball paradigm served as experimental strategy, involving a factorial two (prior probabilities) by two (likelihoods) design. Five computational models of cognitive processes were compared with the observed behavior. Parameter-free Bayesian posterior probabilities and parameter-free base rate neglect provided inadequate models of probabilistic inference. The introduction of distorted subjective probabilities yielded more robust and generalizable results. A general class of (inverted) S-shaped probability weighting functions had been proposed; however, the possibility of large differences in probability distortions not only across experimental conditions, but also across individuals, seems critical for the model's success. It also seems advantageous to consider individual differences in parameters of probability weighting as being sampled from weakly informative prior distributions of individual parameter values. Thus, the results from hierarchical Bayesian modeling converge with previous results in revealing that probability weighting parameters show considerable task dependency and individual differences. Methodologically, this work exemplifies the usefulness of hierarchical Bayesian modeling techniques for cognitive psychology. Theoretically, human probabilistic inference might be best described as the application of individualized strategic policies for Bayesian belief revision. PMID:27303323

Sex Differences in Human and Animal Toxicology.

PubMed

Gochfeld, Michael

2017-01-01

Sex, the states of being female or male, potentially interacts with all xenobiotic exposures, both inadvertent and deliberate, and influences their toxicokinetics (TK), toxicodynamics, and outcomes. Sex differences occur in behavior, exposure, anatomy, physiology, biochemistry, and genetics, accounting for female-male differences in responses to environmental chemicals, diet, and pharmaceuticals, including adverse drug reactions (ADRs). Often viewed as an annoying confounder, researchers have studied only one sex, adjusted for sex, or ignored it. Occupational epidemiology, the basis for understanding many toxic effects in humans, usually excluded women. Likewise, Food and Drug Administration rules excluded women of childbearing age from drug studies for many years. Aside from sex-specific organs, sex differences and sex × age interactions occur for a wide range of disease states as well as hormone-influenced conditions and drug distribution. Women have more ADRs than men; the classic sex hormone paradigm (gonadectomy and replacement) reveals significant interaction of sex and TK including absorption, distribution, metabolisms, and elimination. Studies should be designed to detect sex differences, describe the mechanisms, and interpret these in a broad social, clinical, and evolutionary context with phenomena that do not differ. Sex matters, but how much of a difference is needed to matter remains challenging.

Dynamics of attentional selection under conflict: toward a rational Bayesian account.

PubMed

Yu, Angela J; Dayan, Peter; Cohen, Jonathan D

2009-06-01

The brain exhibits remarkable facility in exerting attentional control in most circumstances, but it also suffers apparent limitations in others. The authors' goal is to construct a rational account for why attentional control appears suboptimal under conditions of conflict and what this implies about the underlying computational principles. The formal framework used is based on Bayesian probability theory, which provides a convenient language for delineating the rationale and dynamics of attentional selection. The authors illustrate these issues with the Eriksen flanker task, a classical paradigm that explores the effects of competing sensory inputs on response tendencies. The authors show how 2 distinctly formulated models, based on compatibility bias and spatial uncertainty principles, can account for the behavioral data. They also suggest novel experiments that may differentiate these models. In addition, they elaborate a simplified model that approximates optimal computation and may map more directly onto the underlying neural machinery. This approximate model uses conflict monitoring, putatively mediated by the anterior cingulate cortex, as a proxy for compatibility representation. The authors also consider how this conflict information might be disseminated and used to control processing. (c) 2009 APA, all rights reserved.

Microscopic study reveals the singular origins of growth

NASA Astrophysics Data System (ADS)

Yaari, G.; Nowak, A.; Rakocy, K.; Solomon, S.

2008-04-01

Anderson [Science 177, 293 (1972)] proposed the concept of complexity in order to describe the emergence and growth of macroscopic collective patterns out of the simple interactions of many microscopic agents. In the physical sciences this paradigm was implemented systematically and confirmed repeatedly by successful confrontation with reality. In the social sciences however, the possibilities to stage experiments to validate it are limited. During the 90's a series of dramatic political and economic events have provided the opportunity to do so. We exploit the resulting empirical evidence to validate a simple agent based alternative to the classical logistic dynamics. The post-liberalization empirical data from Poland confirm the theoretical prediction that the dynamics is dominated by singular rare events which insure the resilience and adaptability of the system. We have shown that growth is led by few singular “growth centers" (Fig. 1), that initially developed at a tremendous rate (Fig. 3), followed by a diffusion process to the rest of the country and leading to a positive growth rate uniform across the counties. In addition to the interdisciplinary unifying potential of our generic formal approach, the present work reveals the strong causal ties between the “softer" social conditions and their “hard" economic consequences.

Sex Differences in Human and Animal Toxicology: Toxicokinetics

PubMed Central

Gochfeld, Michael

2016-01-01

Sex, the states of being female or male, potentially interacts with all xenobiotic exposures, both inadvertent and deliberate, and influences their toxicokinetics, toxicodynamics, and outcomes. Sex differences occur in behavior, exposure, anatomy, physiology, biochemistry, and genetics, accounting for female-male differences in responses to environmental chemicals, diet, and pharmaceuticals, including adverse drug reactions. Often viewed as an annoying confounder, researchers have studied only one sex, adjusted for sex, or ignored it. Occupational epidemiology, the basis for understanding many toxic effects in humans, usually excluded women. Likewise FDA rules excluded women of child-bearing age from drug studies for many years. Aside from sex-specific organs, sex differences and sex × age interactions occur for a wide range of disease states as well as hormone-influenced conditions and drug distribution. Women have more adverse drug reactions than men, The Classic Sex Hormone Paradigm (gonadectomy and replacement) reveals significant interaction of sex and toxicokinetics including absorption, distribution, metabolisms and elimination. Studies should be designed to detect sex differences, describe the mechanisms, and interpret these in a broad social, clinical and evolutionary context with phenomena that do not differ. Sex matters, but how much of a difference is needed to matter remains challenging. PMID:27895264

Lack of insula reactivity to aversive stimuli in schizophrenia.

PubMed

Linnman, Clas; Coombs, Garth; Goff, Donald C; Holt, Daphne J

2013-01-01

Patients with schizophrenia may have altered pain perception, as suggested by clinical reports of pain insensitivity, and recent neuroimaging findings. Here, we examined neural responses to an aversive electrical stimulus and the immediate anticipation of such a stimulus using fMRI and a classical conditioning paradigm, which involved pairing an electrical shock with a neutral photograph. Fifteen men with schizophrenia and 13 healthy men, matched for demographic characteristics, electrical stimulation level and scan movement, were studied. The shock induced robust responses in midbrain, thalamus, cingulate gyrus, insula and somatosensory cortex in both groups. However, compared to controls, the schizophrenic patients displayed significantly lower activation of the middle insula (p(FWE)=0.002, T=5.72, cluster size=24 voxels). Moreover, the lack of insula reactivity in the schizophrenia group was predicted by the magnitude of positive symptoms (r=-0.46, p=0.04). In contrast, there were no significant differences between the two groups in the magnitude of neural responses during anticipation of the shock. These findings provide support for the existence of a basic deficit in interoceptive perception in schizophrenia, which could play a role in the generation and/or maintenance of psychotic states. Copyright © 2012 Elsevier B.V. All rights reserved.

Systems analysis - a new paradigm and decision support tools for the water framework directive

NASA Astrophysics Data System (ADS)

Bruen, M.

2007-06-01

In the early days of Systems Analysis the focus was on providing tools for optimisation, modelling and simulation for use by experts. Now there is a recognition of the need to develop and disseminate tools to assist in making decisions, negotiating compromises and communicating preferences that can easily be used by stakeholders without the need for specialist training. The Water Framework Directive (WFD) requires public participation and thus provides a strong incentive for progress in this direction. This paper places the new paradigm in the context of the classical one and discusses some of the new approaches which can be used in the implementation of the WFD. These include multi-criteria decision support methods suitable for environmental problems, adaptive management, cognitive mapping, social learning and cooperative design and group decision-making. Concordance methods (such as ELECTRE) and the Analytical Hierarchy Process (AHP) are identified as multi-criteria methods that can be readily integrated into Decision Support Systems (DSS) that deal with complex environmental issues with very many criteria, some of which are qualitative. The expanding use of the new paradigm provides an opportunity to observe and learn from the interaction of stakeholders with the new technology and to assess its effectiveness. This is best done by trained sociologists fully integrated into the processes. The WINCOMS research project is an example applied to the implementation of the WFD in Ireland.

Delineation of a spatial working memory profile using a non-verbal eye-tracking paradigm in young children with autism and Williams syndrome.

PubMed

Fanning, Peter A J; Hocking, Darren R; Dissanayake, Cheryl; Vivanti, Giacomo

2018-05-01

Working memory deficits profoundly inhibit children's ability to learn. While deficits have been identified in disorders such as autism spectrum disorder (ASD) and Williams syndrome (WS), findings are equivocal, and very little is known about the nature of these deficits early in development. A major barrier to advances in this area is the availability of tasks suitable for young children with neurodevelopmental disorders who experience difficulties with following verbal instructions or who are distressed by formal testing demands. To address these issues, a novel eye-tracking paradigm was designed based on an adaptation of the classic A not B paradigm in order to examine the early foundations of spatial working memory capabilities in 26 developmentally delayed preschool children with ASD, 18 age- and IQ-matched children with WS, and 19 age-matched typically-developing (TD) children. The results revealed evidence that foundational spatial working memory performance in ASD and WS was comparable with that of TD children. Performance was associated with intellectual ability in the ASD and TD groups, but not in the WS group. Performance was not associated with adaptive behavior in any group. These findings are discussed in the context of previous research that has been largely limited to older and substantially less developmentally delayed children with these neurodevelopmental disorders.

An Appraisal of the Classic Forest Succession Paradigm with the Shade Tolerance Index

PubMed Central

Lienard, Jean; Florescu, Ionut; Strigul, Nikolay

2015-01-01

In this paper we revisit the classic theory of forest succession that relates shade tolerance and species replacement and assess its validity to understand patch-mosaic patterns of forested ecosystems of the USA. We introduce a macroscopic parameter called the “shade tolerance index” and compare it to the classic continuum index in southern Wisconsin forests. We exemplify shade tolerance driven succession in White Pine-Eastern Hemlock forests using computer simulations and analyzing approximated chronosequence data from the USDA FIA forest inventory. We describe this parameter across the last 50 years in the ecoregions of mainland USA, and demonstrate that it does not correlate with the usual macroscopic characteristics of stand age, biomass, basal area, and biodiversity measures. We characterize the dynamics of shade tolerance index using transition matrices and delimit geographical areas based on the relevance of shade tolerance to explain forest succession. We conclude that shade tolerance driven succession is linked to climatic variables and can be considered as a primary driving factor of forest dynamics mostly in central-north and northeastern areas in the USA. Overall, the shade tolerance index constitutes a new quantitative approach that can be used to understand and predict succession of forested ecosystems and biogeographic patterns. PMID:25658092

When congruence breeds preference: the influence of selective attention processes on evaluative conditioning.

PubMed

Blask, Katarina; Walther, Eva; Frings, Christian

2017-09-01

We investigated in two experiments whether selective attention processes modulate evaluative conditioning (EC). Based on the fact that the typical stimuli in an EC paradigm involve an affect-laden unconditioned stimulus (US) and a neutral conditioned stimulus (CS), we started from the assumption that learning might depend in part upon selective attention to the US. Attention to the US was manipulated by including a variant of the Eriksen flanker task in the EC paradigm. Similarly to the original Flanker paradigm, we implemented a target-distracter logic by introducing the CS as the task-relevant stimulus (i.e. the target) to which the participants had to respond and the US as a task-irrelevant distracter. Experiment 1 showed that CS-US congruence modulated EC if the CS had to be selected against the US. Specifically, EC was more pronounced for congruent CS-US pairs as compared to incongruent CS-US pairs. Experiment 2 disentangled CS-US congruence and CS-US compatibility and suggested that it is indeed CS-US stimulus congruence rather than CS-US response compatibility that modulates EC.

2010 Workplace and Gender Relations Survey of Active Duty Members. Tabulations of Responses

DTIC Science & Technology

2011-04-01

Sexual Coercion can be defined as classic quid pro quo , instances of special treatment or favoritism conditional...defined as classic quid pro quo , instances of special treatment or favoritism conditional on sexual cooperation. Percentages Percent Responding...marked as happening to you, do you consider to have been sexual harassment ? ........................................... 342 31. Sexual Harassment

Fertility in adult women with classic galactosemia and primary ovarian insufficiency.

PubMed

van Erven, Britt; Berry, Gerard T; Cassiman, David; Connolly, Geraldine; Forga, Maria; Gautschi, Matthias; Gubbels, Cynthia S; Hollak, Carla E M; Janssen, Mirian C; Knerr, Ina; Labrune, Philippe; Langendonk, Janneke G; Õunap, Katrin; Thijs, Abel; Vos, Rein; Wortmann, Saskia B; Rubio-Gozalbo, M Estela

2017-07-01

To study pregnancy chance in adult women with classic galactosemia and primary ovarian insufficiency. Despite dietary treatment, >90% of women with classic galactosemia develop primary ovarian insufficiency, resulting in impaired fertility. For many years, chance of spontaneous conception has not been considered, leading to counseling for infertility. But an increasing number of reports on pregnancies in this group questions whether current counseling approaches are correct. Multicenter retrospective observational study. Metabolic centers. Adult women (aged >18 y) with confirmed classic galactosemia and primary ovarian insufficiency were included. Participants and medical records were consulted to obtain study data in a standardized manner with the use of a questionnaire. Conception opportunities, time to pregnancy, pregnancy outcome, hormone replacement therapy use, fertility counseling, and the participants' vision of fertility were evaluated. Potential predictive factors for increased pregnancy chance were explored. Eighty-five women with classic galactosemia and primary ovarian insufficiency participated. Twenty-one women actively attempted to conceive or did not take adequate contraceptive precautions. Of these 21 women, nine became pregnant spontaneously (42.9%). This was higher than reported in primary ovarian insufficiency due to other causes (5%-10%). After a period of 12 months, a cumulative proportion of 27.8% of couples had conceived, which increased to 48.4% after 24 months and 61.3% after 27 months. Predictive factors could not be identified. A considerable miscarriage rate of 30% was observed (6 of 20 pregnancies). Although a substantial proportion of women expressed a child-wish (n = 28/53; 52.8%), the vast majority of participants (n = 43/57; 75.4%) considered conceiving to be highly unlikely, owing to negative counseling in the past. The pregnancy rate in women with classic galactosemia and primary ovarian insufficiency was higher than for women with primary ovarian insufficiency of any cause. This shifting paradigm carries significant implications for fertility counseling and potential application of fertility preservation techniques. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Quantum-classical correspondence in the vicinity of periodic orbits

NASA Astrophysics Data System (ADS)

Kumari, Meenu; Ghose, Shohini

2018-05-01

Quantum-classical correspondence in chaotic systems is a long-standing problem. We describe a method to quantify Bohr's correspondence principle and calculate the size of quantum numbers for which we can expect to observe quantum-classical correspondence near periodic orbits of Floquet systems. Our method shows how the stability of classical periodic orbits affects quantum dynamics. We demonstrate our method by analyzing quantum-classical correspondence in the quantum kicked top (QKT), which exhibits both regular and chaotic behavior. We use our correspondence conditions to identify signatures of classical bifurcations even in a deep quantum regime. Our method can be used to explain the breakdown of quantum-classical correspondence in chaotic systems.

The gap-startle paradigm to assess auditory temporal processing: Bridging animal and human research.

PubMed

Fournier, Philippe; Hébert, Sylvie

2016-05-01

The gap-prepulse inhibition of the acoustic startle (GPIAS) paradigm is the primary test used in animal research to identify gap detection thresholds and impairment. When a silent gap is presented shortly before a loud startling stimulus, the startle reflex is inhibited and the extent of inhibition is assumed to reflect detection. Here, we applied the same paradigm in humans. One hundred and fifty-seven normal-hearing participants were tested using one of five gap durations (5, 25, 50, 100, 200 ms) in one of the following two paradigms-gap-embedded in or gap-following-the continuous background noise. The duration-inhibition relationship was observable for both conditions but followed different patterns. In the gap-embedded paradigm, GPIAS increased significantly with gap duration up to 50 ms and then more slowly up to 200 ms (trend only). In contrast, in the gap-following paradigm, significant inhibition-different from 0--was observable only at gap durations from 50 to 200 ms. The finding that different patterns are found depending on gap position within the background noise is compatible with distinct mechanisms underlying each of the two paradigms. © 2016 Society for Psychophysiological Research.

Social conditioning and extinction paradigm: a translational study in virtual reality

PubMed Central

Shiban, Youssef; Reichenberger, Jonas; Neumann, Inga D.; Mühlberger, Andreas

2015-01-01

In human beings, experiments investigating fear conditioning with social stimuli are rare. The current study aims at translating an animal model for social fear conditioning (SFC) to a human sample using an operant SFC paradigm in virtual reality. Forty participants actively (using a joystick) approached virtual male agents that served as conditioned stimuli (CS). During the acquisition phase, unconditioned stimuli (US), a combination of an air blast (5 bar, 10 ms) and a female scream (95 dB, 40 ms), were presented when participants reached a defined proximity to the agent with a contingency of 75% for CS+ agents and never for CS– agents. During the extinction and the test phases, no US was delivered. Outcome variables were pleasantness ratings and physiological reactions in heart rate (HR) and fear-potentiated startle. Additionally, the influence of social anxiety, which was measured with the Social Phobia Inventory scale, was evaluated. As expected after the acquisition phase the CS+ was rated clearly less pleasant than the CS–. This difference vanished during extinction. Furthermore, the HR remained high for the CS+, while the HR for the CS– was clearly lower after than before the acquisition. Furthermore, a clear difference between CS+ and CS– after the acquisition indicated successful conditioning on this translational measure. Contrariwise no CS+/CS– differences were observed in the physiological variables during extinction. Importantly, at the generalization test, higher socially fearful participants rated pleasantness of all agents as low whereas the lower socially fearful participants rated pleasantness as low only for the CS+. SFC was successfully induced and extinguished confirming operant conditioning in this SFC paradigm. These findings suggest that the paradigm is suitable to expand the knowledge about the learning and unlearning of social fears. Further studies should investigate the operant mechanisms of development and treatment of social anxiety disorder. PMID:25904889

The Language Research Center's Computerized Test System for environmental enrichment and psychological assessment

NASA Technical Reports Server (NTRS)

Washburn, D. A.; Rumbaugh, D. M.; Richardson, W. K.

1992-01-01

In the spring of 1987, we undertook to provide environmental enrichment to nonhuman primate subjects in ways that would complement and even contribute to the bio-behaviorial science that justified the monkeys' captivity. Of course, the psychological well-being of captive primates--and indeed all research species-- has been an area of intense research activity since the 1985 amendment of the Animal Welfare Act. This mandate for researchers to ensure the psychological, as well as physical, fitness of experimental animals catalyzed the humane and scientific interests of the research community. The contemporary literature is replete with proposed means both of assaying and of providing enrichment and well-being. Notwithstanding, consensus on either assessment or intervention has yet to be reached. The paradigm we employed was modelled after successful efforts with chimpanzees. An automated test system was constructed in which subjects responded to computer tasks by manipulating a joystick. The tasks, interactive game-like versions of many of the classic testing paradigms of cognitive and comparative psychology, permitted the controlled presentation of stimuli and demands without the required presence of a human experimenter. Despite significant barriers to the success, rhesus monkeys (Macaca mulatta) and a variety of other primate species (including, of course, humans) have mastered the skills necessary for testing in this paradigm. Previous experiments have illustrated the utility of the test system for addressing questions of learning, memory, attention, perception, and motivation. Additional data have been reported to support the contention that the Language Research Center's Computerized Test System (LRC-CTS) serves its other raison d'etre--providing environmental enrichment and assessing psychological well-being. This paper is designed to augment previous descriptions of the technology and the paradigm for scientists and caretakers interested in environmental enrichment and performance assessment with primates.

Predicting fear of heights, snakes, and public speaking from multimodal classical conditioning events.

PubMed

Wu, Ning Ying; Conger, Anthony J; Dygdon, Judith A

2006-04-01

Two hundred fifty one men and women participated in a study of the prediction of fear of heights, snakes, and public speaking by providing retrospective accounts of multimodal classical conditioning events involving those stimuli. The fears selected for study represent those believed by some to be innate (i.e., heights), prepared (i.e., snakes), and purely experientially learned (i.e., public speaking). This study evaluated the extent to which classical conditioning experiences in direct, observational, and verbal modes contributed to the prediction of the current level of fear severity. Subjects were asked to describe their current level of fear and to estimate their experience with fear response-augmenting events (first- and higher-order aversive pairings) and fear response-moderating events (first- and higher-order appetitive pairings, and pre- and post-conditioning neutral presentations) in direct, observational, and verbal modes. For each stimulus, fear was predictable from direct response-augmenting events and prediction was enhanced by the inclusion of response-moderating events. Furthermore, for each fear, maximum prediction was attained by the addition of variables tapping experiences in the observational and/or verbal modes. Conclusions are offered regarding the importance of including response-augmenting and response-moderating events in all three modes in both research and clinical applications of classical conditioning.

Win some, lose some: parental hypertension and heart rate change in an incentive versus response cost paradigm.

PubMed

Hastrup, J L; Johnson, C A; Hotchkiss, A P; Kraemer, D L

1986-11-01

Fowles (1983), citing evidence from separate studies, suggests that both incentive and response cost paradigms increase heart rate and should be subsumed under Gray's (1975) 'appetitive motivational system'. Shock avoidance and loss of reward (response cost) contingencies, while aversive, appear to evoke this motivational system; consequently both should elicit heart rate increases independent of anxiety. The present investigation compared magnitude of heart rate changes observed under conditions of winning and losing money. Results showed: no differences between incentive and response cost conditions; no effect of state anxiety on heart rate in these conditions, despite an elevation of state anxiety on the task day relative to a subsequent relaxation day assessment; and some evidence for the presence under both such appetitive conditions of cardiovascular hyperresponsivity among offspring of hypertensive parents. The results suggest a need for systematic parametric studies of experimental conditions.

The Roles of Spreading Activation and Retrieval Mode in Producing False Recognition in the DRM Paradigm

ERIC Educational Resources Information Center

Meade, Michelle L.; Watson, Jason M.; Balota, David A.; Roediger, Henry L., III

2007-01-01

The nature of persisting spreading activation from list presentation in eliciting false recognition in the Deese-Roediger-McDermott (DRM) paradigm was examined in two experiments. We compared the time course of semantic priming in the lexical decision task (LDT) and false alarms in speeded recognition under identical study and test conditions. The…

Combined eye tracking and fMRI reveals neural basis of linguistic predictions during sentence comprehension.

PubMed

Bonhage, Corinna E; Mueller, Jutta L; Friederici, Angela D; Fiebach, Christian J

2015-07-01

It is widely agreed upon that linguistic predictions are an integral part of language comprehension. Yet, experimental proof of their existence remains challenging. Here, we introduce a new predictive eye gaze reading task combining eye tracking and functional magnetic resonance imaging (fMRI) that allows us to infer the existence and timing of linguistic predictions via anticipatory eye-movements. Participants read different types of word sequences (i.e., regular sentences, meaningless jabberwocky sentences, non-word lists) up to the pre-final word. The final target word was displayed with a temporal delay and its screen position was dependent on the syntactic word category (nouns vs verbs). During the delay, anticipatory eye-movements into the correct target word area were indicative of linguistic predictions. For fMRI analysis, the predictive sentence conditions were contrasted to the non-word condition, with the anticipatory eye-movements specifying differences in timing across conditions. A conjunction analysis of both sentence conditions revealed the neural substrate of word category prediction, namely a distributed network of cortical and subcortical brain regions including language systems, basal ganglia, thalamus, and hippocampus. Direct contrasts between the regular sentence condition and the jabberwocky condition indicate that prediction of word category in meaningless jabberwocky sentences relies on classical left-hemispheric language systems involving Brodman's area 44/45 in the left inferior frontal gyrus, left superior temporal areas, and the dorsal caudate nucleus. Regular sentences, in contrast, allowed for the prediction of specific words. Word-specific predictions were specifically associated with more widely distributed temporal and parietal cortical systems, most prominently in the right hemisphere. Our results support the presence of linguistic predictions during sentence processing and demonstrate the validity of the predictive eye gaze paradigm for measuring syntactic and semantic aspects of linguistic predictions, as well as for investigating their neural substrates. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lead exposure and fear-potentiated startle in the VA Normative Aging Study: a pilot study of a novel physiological approach to investigating neurotoxicant effects.

PubMed

Grashow, Rachel; Miller, Mark W; McKinney, Ann; Nie, Linda H; Sparrow, David; Hu, Howard; Weisskopf, Marc G

2013-01-01

Physiologically-based indicators of neural plasticity in humans could provide mechanistic insights into toxicant actions on learning in the brain, and perhaps prove more objective and sensitive measures of such effects than other methods. We explored the association between lead exposure and classical conditioning of the acoustic startle reflex (ASR)-a simple form of associative learning in the brain-in a population of elderly men. Fifty-one men from the VA Normative Aging Study with cumulative bone lead exposure measurements made with K-X-Ray-Fluorescence participated in a fear-conditioning protocol. The mean age of the men was 75.5years (standard deviation [sd]=5.9) and mean patella lead concentration was 22.7μg/g bone (sd=15.9). Baseline ASR eyeblink response decreased with age, but was not associated with subsequent conditioning. Among 37 men with valid responses at the end of the protocol, higher patella lead was associated with decreased awareness of the conditioning contingency (declarative learning; adjusted odds ratio [OR] per 20μg/g patella lead=0.91, 95% confidence interval [CI]: 0.84, 0.99, p=0.03). Eyeblink conditioning (non-declarative learning) was 0.44sd less (95% CI: -0.91, 0.02; p=0.06) per 20μg/g patella lead after adjustment. Each result was stronger when correcting for the interval between lead measurement and startle testing (awareness: OR=0.88, 95% CI: 0.78, 0.99, p=0.04; conditioning: -0.79sd less, 95% CI: -1.56, 0.03, p=0.04). This initial exploration suggests that lead exposure interferes with specific neural mechanisms of learning and offers the possibility that the ASR may provide a new approach to physiologically explore the effects of neurotoxicant exposures on neural mechanisms of learning in humans with a paradigm that is directly comparable to animal models. Copyright © 2013 Elsevier Inc. All rights reserved.

ABC transporter content diversity in Streptococcus pneumoniae impacts competence regulation and bacteriocin production.

PubMed

Wang, Charles Y; Patel, Nisha; Wholey, Wei-Yun; Dawid, Suzanne

2018-06-19

The opportunistic pathogen Streptococcus pneumoniae (pneumococcus) uses natural genetic competence to increase its adaptability through horizontal gene transfer. One method of acquiring DNA is through predation of neighboring strains with antimicrobial peptides called "bacteriocins." Competence and production of the major family of pneumococcal bacteriocins, pneumocins, are regulated by the quorum-sensing systems com and blp , respectively. In the classical paradigm, the ABC transporters ComAB and BlpAB each secretes its own system's signaling pheromone and in the case of BlpAB also secretes the pneumocins. While ComAB is found in all pneumococci, only 25% of strains encode an intact version of BlpAB [BlpAB(+)] while the rest do not [BlpAB(-)]. Contrary to the classical paradigm, it was previously shown that BlpAB(-) strains can activate blp through ComAB-mediated secretion of the blp pheromone during brief periods of competence. To better understand the full extent of com - blp crosstalk, we examined the contribution of each transporter to competence development and pneumocin secretion. We found that BlpAB(+) strains have a greater capacity for competence activation through BlpAB-mediated secretion of the com pheromone. Similarly, we show that ComAB and BlpAB are promiscuous and both can secrete pneumocins. Consequently, differences in pneumocin secretion between BlpAB(+) and BlpAB(-) strains derive from the regulation and kinetics of transporter expression rather than substrate specificity. We speculate that BlpAB(-) strains (opportunists) use pneumocins mainly in a narrowly tailored role for DNA acquisition and defense during competence while BlpAB(+) strains (aggressors) expand their use for the general inhibition of rival strains. Copyright © 2018 the Author(s). Published by PNAS.

Convergent paradigms for visual neuroscience and dissociative identity disorder.

PubMed

Manning, Mark L; Manning, Rana L

2009-01-01

Although dissociative identity disorder, a condition in which multiple individuals appear to inhabit a single body, is a recognized psychiatric disorder, patients may yet encounter health professionals who declare that they simply "do not believe in multiple personalities." This article explores the proposal that resistance to the disorder represents a failure to apply an appropriate paradigm from which the disorder should be interpreted. Trauma and sociocognitive explanations of dissociative identity disorder are contrasted. The trauma hypothesis is further differentiated into paradigms in which trauma affects a defense mechanism, and one in which trauma serves to inhibit the normal integration sequence of parallel processes of the self in childhood. This latter paradigm is shown to be broadly consistent with current models of cortical processing in another system, the cortical visual system.

A Temporal-Specific and Transient cAMP Increase Characterizes Odorant Classical Conditioning

ERIC Educational Resources Information Center

Cui, Wen; Smith, Andrew; Darby-King, Andrea; Harley, Carolyn W.; McLean, John H.

2007-01-01

Increases in cyclic adenosine monophosphate (cAMP) are proposed to initiate learning in a wide variety of species. Here, we measure changes in cAMP in the olfactory bulb prior to, during, and following a classically conditioned odor preference trial in rat pups. Measurements were taken up to the point of maximal CREB phosphorylation in olfactory…

2008 Gender Relations Survey of Reserve Component Members

DTIC Science & Technology

2009-03-01

Sexual coercion is defined as classic quid pro quo instances of specific treatment or favoritism conditioned on...defined by both the U.S. legal system and DoD as behaviors that might lead to a hostile work environment, or represent quid pro quo harassment ...relationship; • Sexual coercion—classic quid pro quo instances of specific treatment or favoritism conditioned on sexual cooperation. For

Social learning of an associative foraging task in zebrafish

NASA Astrophysics Data System (ADS)

Zala, Sarah M.; Määttänen, Ilmari

2013-05-01

The zebrafish ( Danio rerio) is increasingly becoming an important model species for studies on the genetic and neural mechanisms controlling behaviour and cognition. Here, we utilized a conditioned place preference (CPP) paradigm to study social learning in zebrafish. We tested whether social interactions with conditioned demonstrators enhance the ability of focal naïve individuals to learn an associative foraging task. We found that the presence of conditioned demonstrators improved focal fish foraging behaviour through the process of social transmission, whereas the presence of inexperienced demonstrators interfered with the learning of the control focal fish. Our results indicate that zebrafish use social learning for finding food and that this CPP paradigm is an efficient assay to study social learning and memory in zebrafish.

Elucidating the role of D4 receptors in mediating attributions of salience to incentive stimuli on Pavlovian conditioned approach and conditioned reinforcement paradigms.

PubMed

Cocker, P J; Vonder Haar, C; Winstanley, C A

2016-10-01

The power of drug-associated cues to instigate drug 'wanting' and consequently promote drug seeking is a corner stone of contemporary theories of addiction. Gambling disorder has recently been added to the pantheon of addictive disorders due to the phenomenological similarities between the diseases. However, the neurobiological mechanism that may mediate increased sensitivity towards conditioned stimuli in addictive disorders is unclear. We have previously demonstrated using a rodent analogue of a simple slot machine that the dopamine D4 receptor is critically engaged in controlling animals' attribution of salience to stimuli associated with reward in this paradigm, and consequently may represent a target for the treatment of gambling disorder. Here, we investigated the role of acute administration of a D4 receptor agonist on animals' responsivity to conditioned stimuli on both a Pavlovian conditioned approach (autoshaping) and a conditioned reinforcement paradigm. Following training on one of the two tasks, separate cohorts of rats (male and female) were administered a dose of PD168077 shown to be maximally effective at precipitating errors in reward expectancy on the rat slot machine task (10mg/kg). However, augmenting the activity of the D4 receptors in this manner did not alter behaviour on either task. These data therefore provide novel evidence that the D4 receptor does not alter incentive motivation in response to cues on simple behavioural tasks. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of the efficacy of six supraglottic devices for airway management in dark conditions: a crossover randomized simulation trial.

PubMed

Ohchi, Fumihiro; Komasawa, Nobuyasu; Imagawa, Kentaro; Okamoto, Kaori; Minami, Toshiaki

2015-12-01

During out-of-hospital cardiopulmonary resuscitation, several factors can render tracheal intubation more difficult, such as when rescuers must secure the airway in complete darkness or with limited illumination. The purpose of this study was to evaluate the efficacy of six supraglottic devices (SGDs), ProSeal(®) (ProSeal), Classic(®) (Classic), Supreme(®) (Supreme), Laryngeal Tube(®) (LT), air-Q(®) (air-Q), and i-gel(®) (i-gel), for airway management under light and dark conditions using a manikin. Seventeen novice doctors and 15 experienced doctors performed insertion of six SGDs under light and dark conditions using an adult manikin. Insertion time, successful ventilation rate, and subjective insertion difficulty on a visual analogue scale (VAS) were measured. Both novice and experienced doctors had a significantly lower ventilation success rate in the dark than in the light when ProSeal and Classic were used, but not with the other four SGDs. Novice doctors required a significantly longer insertion time in the dark than in the light with all SGDs. Experienced doctors required a significantly longer insertion time in the dark than in the light with ProSeal or Classic, but not with the other four SGDs. VAS was significantly higher for both novice and experienced doctors when ProSeal and Classic were used, as compared with the other four SGDs in the dark. Compared to ProSeal and Classic, Supreme, i-gel, LT, and air-Q are more effective for airway management in the dark. Our findings suggest that anatomically shaped SGDs may help novice doctors secure the airway under dark conditions.

Autonomous control systems: applications to remote sensing and image processing

NASA Astrophysics Data System (ADS)

Jamshidi, Mohammad

2001-11-01

One of the main challenges of any control (or image processing) paradigm is being able to handle complex systems under unforeseen uncertainties. A system may be called complex here if its dimension (order) is too high and its model (if available) is nonlinear, interconnected, and information on the system is uncertain such that classical techniques cannot easily handle the problem. Examples of complex systems are power networks, space robotic colonies, national air traffic control system, and integrated manufacturing plant, the Hubble Telescope, the International Space Station, etc. Soft computing, a consortia of methodologies such as fuzzy logic, neuro-computing, genetic algorithms and genetic programming, has proven to be powerful tools for adding autonomy and semi-autonomy to many complex systems. For such systems the size of soft computing control architecture will be nearly infinite. In this paper new paradigms using soft computing approaches are utilized to design autonomous controllers and image enhancers for a number of application areas. These applications are satellite array formations for synthetic aperture radar interferometry (InSAR) and enhancement of analog and digital images.