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Sample records for memory perceptual speed

  1. Perceptual Simulations and Linguistic Representations Have Differential Effects on Speeded Relatedness Judgments and Recognition Memory

    PubMed Central

    Tse, Chi-Shing; Kurby, Christopher A.; Du, Feng

    2010-01-01

    We examined the effect of spatial iconicity (a perceptual simulation of canonical locations of objects) and word-order frequency on language processing and episodic memory of orientation. Participants made speeded relatedness judgments to pairs of words presented in locations typical to their real world arrangements (e.g., ceiling on top and floor on bottom). They then engaged in a surprise orientation recognition task for the word pairs. We replicated Louwerse’s finding (2008) that word-order frequency has a stronger effect on semantic relatedness judgments than spatial iconicity. This is consistent with recent suggestions that linguistic representations have a stronger impact on immediate decisions about verbal materials than perceptual simulations. In contrast, spatial iconicity enhanced episodic memory of orientation to a greater extent than word-order frequency did. This new finding indicates that perceptual simulations have an important role in episodic memory. Results are discussed with respect to theories of perceptual representation and linguistic processing. PMID:19742388

  2. WAIS-III processing speed index scores after TBI: the influence of working memory, psychomotor speed and perceptual processing.

    PubMed

    Kennedy, Jan E; Clement, Pamelia F; Curtiss, Glenn

    2003-08-01

    This study investigates the extent to which working memory, motor speed and perceptual processing speed influence Wechsler Adult Intelligence Scale-III (WAIS-III) Processing Speed Index (PSI) scores. Sixty-eight adult outpatients with Traumatic Brain Injury (TBI) of varying severity and complete data on all outcome measures were identified. Two cases with outlying values on one outcome measure were omitted from the final sample. Working memory was measured by the Working Memory Index score from the WAIS-III. Motor speed was measured as score on the Halstead-Reitan Finger Oscillation Test (finger tapping) and perceptual processing as score on the Trail Making Test--Part B. In hierarchical multiple regression analyses, working memory accounted for 10% of the variance in PSI scores, whereas motor speed only accounted for 3%. An independent measure of perceptual processing, Trail Making Test--B, accounted for 26% of the variance in WAIS-III PSI scores. The total variance accounted for by the three factors was 56%. Findings confirm that the WAIS-III PSI scores of individuals who have received a TBI reflect perceptual processing speed, with an additional component attributable to working memory. Motor speed made only a small contribution to WAIS-III PSI scores in the present sample. PMID:14704894

  3. Nicotine facilitates memory consolidation in perceptual learning.

    PubMed

    Beer, Anton L; Vartak, Devavrat; Greenlee, Mark W

    2013-01-01

    Perceptual learning is a special type of non-declarative learning that involves experience-dependent plasticity in sensory cortices. The cholinergic system is known to modulate declarative learning. In particular, reduced levels or efficacy of the neurotransmitter acetylcholine were found to facilitate declarative memory consolidation. However, little is known about the role of the cholinergic system in memory consolidation of non-declarative learning. Here we compared two groups of non-smoking men who learned a visual texture discrimination task (TDT). One group received chewing tobacco containing nicotine for 1 h directly following the TDT training. The other group received a similar tasting control substance without nicotine. Electroencephalographic recordings during substance consumption showed reduced alpha activity and P300 latencies in the nicotine group compared to the control group. When re-tested on the TDT the following day, both groups responded more accurately and more rapidly than during training. These improvements were specific to the retinal location and orientation of the texture elements of the TDT suggesting that learning involved early visual cortex. A group comparison showed that learning effects were more pronounced in the nicotine group than in the control group. These findings suggest that oral consumption of nicotine enhances the efficacy of nicotinic acetylcholine receptors. Our findings further suggest that enhanced efficacy of the cholinergic system facilitates memory consolidation in perceptual learning (and possibly other types of non-declarative learning). In that regard acetylcholine seems to affect consolidation processes in perceptual learning in a different manner than in declarative learning. Alternatively, our findings might reflect dose-dependent cholinergic modulation of memory consolidation. This article is part of a Special Issue entitled 'Cognitive Enhancers'. PMID:22749926

  4. Generation and Perceptual Implicit Memory: Different Generation Tasks Produce Different Effects on Perceptual Priming

    ERIC Educational Resources Information Center

    Mulligan, Neil W.; Dew, Ilana T. Z.

    2009-01-01

    The generation manipulation has been critical in delineating differences between implicit and explicit memory. In contrast to past research, the present experiments indicate that generating from a rhyme cue produces as much perceptual priming as does reading. This is demonstrated for 3 visual priming tasks: perceptual identification, word-fragment…

  5. Great Expectations: Temporal Expectation Modulates Perceptual Processing Speed

    ERIC Educational Resources Information Center

    Vangkilde, Signe; Coull, Jennifer T.; Bundesen, Claus

    2012-01-01

    In a crowded dynamic world, temporal expectations guide our attention in time. Prior investigations have consistently demonstrated that temporal expectations speed motor behavior. We explore effects of temporal expectation on "perceptual" speed in three nonspeeded, cued recognition paradigms. Different hazard rate functions for the cue-stimulus…

  6. Lipreading, Processing Speed, and Working Memory in Younger and Older Adults

    ERIC Educational Resources Information Center

    Feld, Julia E.; Sommers, Mitchell S.

    2009-01-01

    Purpose: To examine several cognitive and perceptual abilities--including working memory (WM), information processing speed (PS), perceptual closure, and perceptual disembedding skill--as factors contributing to individual differences in lipreading performance and to examine how patterns in predictor variables change across age groups. Method:…

  7. Memory: Enduring Traces of Perceptual and Reflective Attention

    PubMed Central

    Chun, Marvin M.; Johnson, Marcia K.

    2011-01-01

    Attention and memory are typically studied as separate topics, but they are highly intertwined. Here we discuss the relation between memory and two fundamental types of attention: perceptual and reflective. Memory is the persisting consequence of cognitive activities initiated by and/or focused on external information from the environment (perceptual attention) and initiated by and/or focused on internal mental representations (reflective attention). We consider three key questions for advancing a cognitive neuroscience of attention and memory: To what extent do perception and reflection share representational areas? To what extent are the control processes that select, maintain, and manipulate perceptual and reflective information subserved by common areas and networks? During perception and reflection, to what extent are common areas responsible for binding features together to create complex, episodic memories and for reviving them later? Considering similarities and differences in perceptual and reflective attention helps integrate a broad range of findings and raises important unresolved issues. PMID:22099456

  8. False Memories Lack Perceptual Detail: Evidence from Implicit Word-Stem Completion and Perceptual Identification Tests

    ERIC Educational Resources Information Center

    Hicks, J.L.; Starns, J.J.

    2005-01-01

    We used implicit measures of memory to ascertain whether false memories for critical nonpresented items in the DRM paradigm (Deese, 1959; Roediger & McDermott, 1995) contain structural and perceptual detail. In Experiment 1, we manipulated presentation modality in a visual word-stem-completion task. Critical item priming was significant and…

  9. Perceptual memory drives learning of retinotopic biases for bistable stimuli

    PubMed Central

    Murphy, Aidan P.; Leopold, David A.; Welchman, Andrew E.

    2014-01-01

    The visual system exploits past experience at multiple timescales to resolve perceptual ambiguity in the retinal image. For example, perception of a bistable stimulus can be biased toward one interpretation over another when preceded by a brief presentation of a disambiguated version of the stimulus (positive priming) or through intermittent presentations of the ambiguous stimulus (stabilization). Similarly, prior presentations of unambiguous stimuli can be used to explicitly “train” a long-lasting association between a percept and a retinal location (perceptual association). These phenonema have typically been regarded as independent processes, with short-term biases attributed to perceptual memory and longer-term biases described as associative learning. Here we tested for interactions between these two forms of experience-dependent perceptual bias and demonstrate that short-term processes strongly influence long-term outcomes. We first demonstrate that the establishment of long-term perceptual contingencies does not require explicit training by unambiguous stimuli, but can arise spontaneously during the periodic presentation of brief, ambiguous stimuli. Using rotating Necker cube stimuli, we observed enduring, retinotopically specific perceptual biases that were expressed from the outset and remained stable for up to 40 min, consistent with the known phenomenon of perceptual stabilization. Further, bias was undiminished after a break period of 5 min, but was readily reset by interposed periods of continuous, as opposed to periodic, ambiguous presentation. Taken together, the results demonstrate that perceptual biases can arise naturally and may principally reflect the brain's tendency to favor recent perceptual interpretation at a given retinal location. Further, they suggest that an association between retinal location and perceptual state, rather than a physical stimulus, is sufficient to generate long-term biases in perceptual organization. PMID:24550874

  10. Speed of perceptual grouping in acquired brain injury.

    PubMed

    Kurylo, Daniel D; Larkin, Gabriella Brick; Waxman, Richard; Bukhari, Farhan

    2014-09-01

    Evidence exists that damage to white matter connections may contribute to reduced speed of information processing in traumatic brain injury and stroke. Damage to such axonal projections suggests a particular vulnerability to functions requiring integration across cortical sites. To test this prediction, measurements were made of perceptual grouping, which requires integration of stimulus components. A group of traumatic brain injury and cerebral vascular accident patients and a group of age-matched healthy control subjects viewed arrays of dots and indicated the pattern into which stimuli were perceptually grouped. Psychophysical measurements were made of perceptual grouping as well as processing speed. The patient group showed elevated grouping thresholds as well as extended processing time. In addition, most patients showed progressive slowing of processing speed across levels of difficulty, suggesting reduced resources to accommodate increased demands on grouping. These results support the prediction that brain injury results in a particular vulnerability to functions requiring integration of information across the cortex, which may result from dysfunction of long-range axonal connection. PMID:24820289

  11. Differential Effects of Intelligence, Perceptual Speed and Age on Growth in Attentional Speed and Accuracy

    ERIC Educational Resources Information Center

    Goldhammer, Frank; Rauch, Wolfgang A.; Schweizer, Karl; Moosbrugger, Helfried

    2010-01-01

    The study investigates the effects of intelligence, perceptual speed and age on intraindividual growth in attentional speed and attentional accuracy over the course of a 6-minute testing session. A sample of 193 subjects completed the Advanced Progressive Matrices and the Vienna Matrices Test representing intelligence, the tests Alertness and

  12. Infant Memory for Primitive Perceptual Features.

    ERIC Educational Resources Information Center

    Adler, Scott A.

    Textons are elongated blobs of specific color, angular orientation, ends of lines, and crossings of line segments that are proposed to be the perceptual building blocks of the visual system. A study was conducted to explore the relative memorability of different types and arrangements of textons, exploring the time course for the discrimination…

  13. Who can you trust? Behavioral and neural differences between perceptual and memory-based influences.

    PubMed

    Rudoy, John D; Paller, Ken A

    2009-01-01

    Decisions about whether to trust someone can be influenced by competing sources of information, such as analysis of facial features versus remembering specific information about the person. We hypothesized that such sources can differentially influence trustworthiness judgments depending on the circumstances in which judgments are made. In our experiments, subjects first learned face-word associations. Stimuli were trustworthy and untrustworthy faces, selected on the basis of consensus judgments, and personality attributes that carried either the same valence (consistent with face) or the opposite valence (inconsistent with face). Subsequently, subjects rated the trustworthiness of each face. Both learned and perceptual information influenced ratings, but learned information was less influential under speeded than under non-speeded conditions. EEG data further revealed neural evidence of the processing of these two competing sources. Perceptual influences were apparent earlier than memory influences, substantiating the conclusion that time pressure can selectively disrupt memory retrieval relevant to trustworthiness attributions. PMID:19738922

  14. Retrieval-Induced Forgetting in Perceptually Driven Memory Tests

    ERIC Educational Resources Information Center

    Bajo, M. Teresa; Gomez-Ariza, Carlos J.; Fernandez, Angel; Marful, Alejandra

    2006-01-01

    Recent data (T. J. Perfect, C. J. A. Moulin, M. A. Conway, & E. Perry, 2002) have suggested that retrieval-induced forgetting (RIF) depends on conceptual memory because the effect is not found in perceptually driven tasks. In 3 experiments, the authors aimed to show that the presence of RIF depends on whether the procedure induces appropriate…

  15. The objects of visuospatial short-term memory: Perceptual organization and change detection

    PubMed Central

    Nikolova, Atanaska; Macken, Bill

    2016-01-01

    We used a colour change-detection paradigm where participants were required to remember colours of six equally spaced circles. Items were superimposed on a background so as to perceptually group them within (a) an intact ring-shaped object, (b) a physically segmented but perceptually completed ring-shaped object, or (c) a corresponding background segmented into three arc-shaped objects. A nonpredictive cue at the location of one of the circles was followed by the memory items, which in turn were followed by a test display containing a probe indicating the circle to be judged same/different. Reaction times for correct responses revealed a same-object advantage; correct responses were faster to probes on the same object as the cue than to equidistant probes on a segmented object. This same-object advantage was identical for physically and perceptually completed objects, but was only evident in reaction times, and not in accuracy measures. Not only, therefore, is it important to consider object-level perceptual organization of stimulus elements when assessing the influence of a range of factors (e.g., number and complexity of elements) in visuospatial short-term memory, but a more detailed picture of the structure of information in memory may be revealed by measuring speed as well as accuracy. PMID:26286369

  16. The objects of visuospatial short-term memory: Perceptual organization and change detection.

    PubMed

    Nikolova, Atanaska; Macken, Bill

    2016-07-01

    We used a colour change-detection paradigm where participants were required to remember colours of six equally spaced circles. Items were superimposed on a background so as to perceptually group them within (a) an intact ring-shaped object, (b) a physically segmented but perceptually completed ring-shaped object, or (c) a corresponding background segmented into three arc-shaped objects. A nonpredictive cue at the location of one of the circles was followed by the memory items, which in turn were followed by a test display containing a probe indicating the circle to be judged same/different. Reaction times for correct responses revealed a same-object advantage; correct responses were faster to probes on the same object as the cue than to equidistant probes on a segmented object. This same-object advantage was identical for physically and perceptually completed objects, but was only evident in reaction times, and not in accuracy measures. Not only, therefore, is it important to consider object-level perceptual organization of stimulus elements when assessing the influence of a range of factors (e.g., number and complexity of elements) in visuospatial short-term memory, but a more detailed picture of the structure of information in memory may be revealed by measuring speed as well as accuracy. PMID:26286369

  17. Perceptual learning of acoustic noise generates memory-evoked potentials.

    PubMed

    Andrillon, Thomas; Kouider, Sid; Agus, Trevor; Pressnitzer, Daniel

    2015-11-01

    Experience continuously imprints on the brain at allstages of life. The traces it leaves behind can produce perceptual learning [1], which drives adaptive behavior to previously encountered stimuli. Recently, it has been shown that even random noise, a type of sound devoid of acoustic structure, can trigger fast and robust perceptual learning after repeated exposure [2]. Here, by combining psychophysics, electroencephalography (EEG), and modeling, we show thatthe perceptual learning of noise is associated with evoked potentials, without any salient physical discontinuity or obvious acoustic landmark in the sound. Rather, the potentials appeared whenever amemory trace was observed behaviorally. Such memory-evoked potentials were characterized by early latencies and auditory topographies, consistent with a sensory origin. Furthermore, they were generated even on conditions of diverted attention. The EEG waveforms could be modeled as standard evoked responses to auditory events (N1-P2) [3], triggered by idiosyncratic perceptual features acquired through learning. Thus, we argue that the learning of noise is accompanied by the rapid formation of sharp neural selectivity to arbitrary and complex acoustic patterns, within sensory regions. Such a mechanism bridges the gap between the short-term and longer-term plasticity observed in the learning of noise [2, 4-6]. It could also be key to the processing of natural sounds within auditory cortices [7], suggesting that the neural code for sound source identification will be shaped by experience as well as by acoustics. PMID:26455302

  18. Memory plays tricks on me: perceptual bias induced by memory reactivated size in Ebbinghaus illusion.

    PubMed

    Rey, Amandine E; Vallet, Guillaume T; Riou, Benoit; Lesourd, Mathieu; Versace, Rémy

    2015-10-01

    The relationship between perceptual and memory processing is at the core of cognition. Growing evidence suggests reciprocal influences between them so that memory features should lead to an actual perceptual bias. In the present study, we investigate the reciprocal influence of perceptual and memory processing by further adapting the Ebbinghaus illusion and tested it in a psychophysical design. In a 2AFC (two-alternative forced choice) paradigm, the perceptual bias in the Ebbinghaus illusion was induced by a physical size (Experiment 1) or a memory reactivated size of the inducers (Experiment 2, the size was reactivated thanks to a color-size association). One test disk was presented on the left of the screen and was surrounded by six inducers with a large or small (perceptual or reactivated) size. The test disk varied in size and participants were asked to indicate whether this test disk was smaller or larger than a reference disk presented on the right of the screen (the reference disk was invariant in size). Participants' responses were influenced by the size of the inducers for the perceptual and the reactivated size of the inducers. These results provide new evidence for the influence of memory on perception in a psychophysics paradigm. PMID:26372936

  19. Retrieval-induced forgetting in perceptually driven memory tests.

    PubMed

    Bajo, M Teresa; Gómez-Ariza, Carlos J; Fernandez, Angel; Marful, Alejandra

    2006-09-01

    Recent data (T. J. Perfect, C. J. A. Moulin, M. A. Conway, & E. Perry, 2002) have suggested that retrieval-induced forgetting (RIF) depends on conceptual memory because the effect is not found in perceptually driven tasks. In 3 experiments, the authors aimed to show that the presence of RIF depends on whether the procedure induces appropriate transfer between representations and competition rather than on the nature of the final test. The authors adapted the standard paradigm to introduce lexical categories (words that shared the first 2 letters) at study and practice. Direct and indirect fragment completion tests were used at retrieval. The results showed significant RIF effects in perceptually driven tasks. Furthermore, they indicated that the presence of RIF effects depended on using adequate cuing to induce competition during the retrieval practice and on the final memory test tapping the inhibited representation. PMID:16938055

  20. An investigation of false memory in perceptual implicit tasks.

    PubMed

    McBride, Dawn M; Coane, Jennifer H; Raulerson, Bascom A

    2006-11-01

    Reports of critical lure priming in perceptual implicit tasks [e.g., McKone, E., & Murphy, B. (2000). Implicit false memory: Effects of modality and multiple study presentations on long-lived semantic priming. Journal of Memory and Language, 43, 89-109] using the Deese-Roediger-McDermott [Roediger, H. L., III, & McDermott, K. B. (1995). Creating false memories: Remembering words not presented in lists. Journal of Experimental Psychology: Learning, Memory, and Cognition, 21, 803-814] procedure have suggested availability of the lexical form of lure items at study. Three experiments were conducted to further explore "false" implicit priming in perceptual tests. In Experiments 1 and 3, implicit and explicit stem completion tests were given in the DRM procedure with semantic lists; in Experiment 2, a graphemic response test was used in a similar design. For all experiments, explicit instructions resulted in reliable false memory, while implicit instructions resulted in priming for list items and no priming for lure items. Priming for lure items was evident for "test-aware" subjects only in Experiment 1 and in a combined analysis for all three experiments. These results establish boundary conditions for priming for critical lures and indicate that access to the lexical form of critical lures may not occur under incidental learning conditions when strong controls against explicit retrieval are implemented. PMID:16510106

  1. Accounting for speed-accuracy tradeoff in perceptual learning.

    PubMed

    Liu, Charles C; Watanabe, Takeo

    2012-05-15

    In the perceptual learning (PL) literature, researchers typically focus on improvements in accuracy, such as d'. In contrast, researchers who investigate the practice of cognitive skills focus on improvements in response times (RT). Here, we argue for the importance of accounting for both accuracy and RT in PL experiments, due to the phenomenon of speed-accuracy tradeoff (SAT): at a given level of discriminability, faster responses tend to produce more errors. A formal model of the decision process, such as the diffusion model, can explain the SAT. In this model, a parameter known as the drift rate represents the perceptual strength of the stimulus, where higher drift rates lead to more accurate and faster responses. We applied the diffusion model to analyze responses from a yes-no coherent motion detection task. The results indicate that observers do not use a fixed threshold for evidence accumulation, so changes in the observed accuracy may not provide the most appropriate estimate of learning. Instead, our results suggest that SAT can be accounted for by a modeling approach, and that drift rates offer a promising index of PL. PMID:21958757

  2. When Does Modality Matter? Perceptual versus Conceptual Fluency-Based Illusions in Recognition Memory

    ERIC Educational Resources Information Center

    Miller, Jeremy K.; Lloyd, Marianne E.; Westerman, Deanne L.

    2008-01-01

    Previous research has shown that illusions of recognition memory based on enhanced perceptual fluency are sensitive to the perceptual match between the study and test phases of an experiment. The results of the current study strengthen that conclusion, as they show that participants will not interpret enhanced perceptual fluency as a sign of

  3. When Does Modality Matter? Perceptual versus Conceptual Fluency-Based Illusions in Recognition Memory

    ERIC Educational Resources Information Center

    Miller, Jeremy K.; Lloyd, Marianne E.; Westerman, Deanne L.

    2008-01-01

    Previous research has shown that illusions of recognition memory based on enhanced perceptual fluency are sensitive to the perceptual match between the study and test phases of an experiment. The results of the current study strengthen that conclusion, as they show that participants will not interpret enhanced perceptual fluency as a sign of…

  4. Fluency Effects in Recognition Memory: Are Perceptual Fluency and Conceptual Fluency Interchangeable?

    ERIC Educational Resources Information Center

    Lanska, Meredith; Olds, Justin M.; Westerman, Deanne L.

    2014-01-01

    On a recognition memory test, both perceptual and conceptual fluency can engender a sense of familiarity and elicit recognition memory illusions. To date, perceptual and conceptual fluency have been studied separately but are they interchangeable in terms of their influence on recognition judgments? Five experiments compared the effect of

  5. Working memory effects in speeded RSVP tasks.

    PubMed

    Gil-Gómez de Liaño, Beatriz; Potter, Mary C; Rodríguez, Carmen

    2014-01-01

    The present paper examines the effects of memory contents and memory load in rapid serial visual presentation (RSVP) speeded tasks, trying to explain previous inconsistent results. We used a one target (Experiment 1) and a two-target (Experiment 2) RSVP task with a concurrent memory load of one or four items, in a dual-task paradigm. A relation between material in working memory and the target in the RSVP impaired the identification of the target. In Experiments 3 and 4, the single task was to determine whether any information in memory matched the target in the RSVP, while varying the memory load. A match was detected faster than a non-match, although only when there was some distance between targets in the RSVP (Experiment 4). The results suggest that memory contents automatically capture attention, slowing processing when the memory contents are irrelevant to the task, and speeding processing when they are relevant. PMID:23397260

  6. Effects of imagery on perceptual implicit memory tests.

    PubMed

    McDermott, K B; Roediger, H L

    1994-11-01

    Four experiments demonstrate that imagery can promote priming on perceptual implicit memory tests. When Ss were given words during a study phase and asked to form mental images of corresponding pictures, more priming was obtained on a picture fragment identification test than from a study condition in which Ss performed semantic analyses of words. Imaginal priming of picture fragment identification occurred for recoverable fragments, but not for nonrecoverable fragments. The imagery effect was restricted to the imaged type of material: Imagining pictures (when presented with words) enhanced priming on a picture fragment identification test but not on word fragment completion. Similarly, when pictures were presented, imagining the corresponding words increased priming on word fragment completion but not on picture fragment identification. Overall, results support the hypothesis that imagining engages some of the same mechanisms used in perception and thereby produces priming. PMID:7983469

  7. Distinct frontoparietal networks set the stage for later perceptual identification priming and episodic recognition memory.

    PubMed

    Wimber, Maria; Heinze, Hans-Jochen; Richardson-Klavehn, Alan

    2010-10-01

    Recent imaging evidence suggests that a network of brain regions including the medial temporal lobe, ventrolateral prefrontal cortex, and dorsal posterior parietal cortex supports the successful encoding of long-term memories. Other areas, like the ventral posterior parietal and dorsolateral prefrontal cortices, have been associated with encoding failure rather than success. In line with the transfer-appropriate processing view, we hypothesized that distinct neural networks predict successful encoding depending on whether the later memory test draws primarily on perceptual or conceptual memory representations. Following an encoding phase, memory was assessed in a combined incidental perceptual identification and intentional recognition memory test. We found that during encoding, activation in ventral posterior parietal and dorsolateral prefrontal cortex predicted successful perceptual identification priming, whereas activation in ventrolateral prefrontal and dorsal posterior parietal cortex predicted successful recognition memory. Extending recent theories of attention to memory, the results suggest that ventral parietal regions support stimulus-driven attention to perceptual item features, forming memories accessed by later perceptual memory tests, whereas dorsal parietal regions support attention to meaningful item features, forming memories accessed by later conceptual memory tests. PMID:20926653

  8. Kirshner Saroj Visual Perceptual Speed Test: A Test of Visual Readiness for Reading.

    ERIC Educational Resources Information Center

    Kirshner, A. J.; Saroj, Satish K.

    Described is the Kirshner Saroj Visual Perception Speed Test (KSVPST), a measure of perceptual speed using pictures to identify children whose reading difficulties are due to visual processing deficiencies. It is explained that 323 children 6-13 years old were given the Keystone Visual Skills Test, the KSVPST, and reading readiness tests. Data are…

  9. Further Explorations of Perceptual Speed Abilities in the Context of Assessment Methods, Cognitive Abilities, and Individual Differences during Skill Acquisition

    ERIC Educational Resources Information Center

    Ackerman, Phillip L.; Beier, Margaret E.

    2007-01-01

    Measures of perceptual speed ability have been shown to be an important part of assessment batteries for predicting performance on tasks and jobs that require a high level of speed and accuracy. However, traditional measures of perceptual speed ability sometimes have limited cost-effectiveness because of the requirements for administration and…

  10. Prior perceptual processing enhances the effect of emotional arousal on the neural correlates of memory retrieval

    PubMed Central

    Dew, Ilana T. Z.; Ritchey, Maureen; LaBar, Kevin S.; Cabeza, Roberto

    2014-01-01

    A fundamental idea in memory research is that items are more likely to be remembered if encoded with a semantic, rather than perceptual, processing strategy. Interestingly, this effect has been shown to reverse for emotionally arousing materials, such that perceptual processing enhances memory for emotional information or events. The current fMRI study investigated the neural mechanisms of this effect by testing how neural activations during emotional memory retrieval are influenced by the prior encoding strategy. Participants incidentally encoded emotional and neutral pictures under instructions to attend to either semantic or perceptual properties of each picture. Recognition memory was tested two days later. fMRI analyses yielded three main findings. First, right amygdalar activity associated with emotional memory strength was enhanced by prior perceptual processing. Second, prior perceptual processing of emotional pictures produced a stronger effect on recollection- than familiarity-related activations in the right amygdala and left hippocampus. Finally, prior perceptual processing enhanced amygdalar connectivity with regions strongly associated with retrieval success, including hippocampal/parahippocampal regions, visual cortex, and ventral parietal cortex. Taken together, the results specify how encoding orientations yield alterations in brain systems that retrieve emotional memories. PMID:24380867

  11. Prior perceptual processing enhances the effect of emotional arousal on the neural correlates of memory retrieval.

    PubMed

    Dew, Ilana T Z; Ritchey, Maureen; LaBar, Kevin S; Cabeza, Roberto

    2014-07-01

    A fundamental idea in memory research is that items are more likely to be remembered if encoded with a semantic, rather than perceptual, processing strategy. Interestingly, this effect has been shown to reverse for emotionally arousing materials, such that perceptual processing enhances memory for emotional information or events. The current fMRI study investigated the neural mechanisms of this effect by testing how neural activations during emotional memory retrieval are influenced by the prior encoding strategy. Participants incidentally encoded emotional and neutral pictures under instructions to attend to either semantic or perceptual properties of each picture. Recognition memory was tested 2 days later. fMRI analyses yielded three main findings. First, right amygdalar activity associated with emotional memory strength was enhanced by prior perceptual processing. Second, prior perceptual processing of emotional pictures produced a stronger effect on recollection- than familiarity-related activations in the right amygdala and left hippocampus. Finally, prior perceptual processing enhanced amygdalar connectivity with regions strongly associated with retrieval success, including hippocampal/parahippocampal regions, visual cortex, and ventral parietal cortex. Taken together, the results specify how encoding orientations yield alterations in brain systems that retrieve emotional memories. PMID:24380867

  12. The Competitive Influences of Perceptual Load and Working Memory Guidance on Selective Attention.

    PubMed

    Tan, Jinfeng; Zhao, Yuanfang; Wang, Lijun; Tian, Xia; Cui, Yan; Yang, Qian; Pan, Weigang; Zhao, Xiaoyue; Chen, Antao

    2015-01-01

    The perceptual load theory in selective attention literature proposes that the interference from task-irrelevant distractor is eliminated when perceptual capacity is fully consumed by task-relevant information. However, the biased competition model suggests that the contents of working memory (WM) can guide attentional selection automatically, even when this guidance is detrimental to visual search. An intriguing but unsolved question is what will happen when selective attention is influenced by both perceptual load and WM guidance. To study this issue, behavioral performances and event-related potentials (ERPs) were recorded when participants were presented with a cue to either identify or hold in memory and had to perform a visual search task subsequently, under conditions of low or high perceptual load. Behavioural data showed that high perceptual load eliminated the attentional capture by WM. The ERP results revealed an obvious WM guidance effect in P1 component with invalid trials eliciting larger P1 than neutral trials, regardless of the level of perceptual load. The interaction between perceptual load and WM guidance was significant for the posterior N1 component. The memory guidance effect on N1 was eliminated by high perceptual load. Standardized Low Resolution Electrical Tomography Analysis (sLORETA) showed that the WM guidance effect and the perceptual load effect on attention can be localized into the occipital area and parietal lobe, respectively. Merely identifying the cue produced no effect on the P1 or N1 component. These results suggest that in selective attention, the information held in WM could capture attention at the early stage of visual processing in the occipital cortex. Interestingly, this initial capture of attention by WM could be modulated by the level of perceptual load and the parietal lobe mediates target selection at the discrimination stage. PMID:26098079

  13. Perceptual and Cognitive Factors Imposing “Speed Limits” on Reading Rate: A Study with the Rapid Serial Visual Presentation

    PubMed Central

    Spinelli, Donatella; Zoccolotti, Pierluigi; De Luca, Maria; Martelli, Marialuisa

    2016-01-01

    Adults read at high speed, but estimates of their reading rate vary greatly, i.e., from 100 to 1500 words per minute (wpm). This discrepancy is likely due to different recording methods and to the different perceptual and cognitive processes involved in specific test conditions. The present study investigated the origins of these notable differences in RSVP reading rate (RR). In six experiments we investigated the role of many different perceptual and cognitive variables. The presence of a mask caused a steep decline in reading rate, with an estimated masking cost of about 200 wpm. When the decoding process was isolated, RR approached values of 1200 wpm. When the number of stimuli exceeded the short-term memory span, RR decreased to 800 wpm. The semantic context contributed to reading speed only by a factor of 1.4. Finally, eye movements imposed an upper limit on RR (around 300 wpm). Overall, data indicate a speed limit of 300 wpm, which corresponds to the time needed for eye movement execution, i.e., the most time consuming mechanism. Results reconcile differences in reading rates reported by different laboratories and thus provide suggestions for targeting different components of reading rate. PMID:27088226

  14. Perceptual and Cognitive Factors Imposing "Speed Limits" on Reading Rate: A Study with the Rapid Serial Visual Presentation.

    PubMed

    Primativo, Silvia; Spinelli, Donatella; Zoccolotti, Pierluigi; De Luca, Maria; Martelli, Marialuisa

    2016-01-01

    Adults read at high speed, but estimates of their reading rate vary greatly, i.e., from 100 to 1500 words per minute (wpm). This discrepancy is likely due to different recording methods and to the different perceptual and cognitive processes involved in specific test conditions. The present study investigated the origins of these notable differences in RSVP reading rate (RR). In six experiments we investigated the role of many different perceptual and cognitive variables. The presence of a mask caused a steep decline in reading rate, with an estimated masking cost of about 200 wpm. When the decoding process was isolated, RR approached values of 1200 wpm. When the number of stimuli exceeded the short-term memory span, RR decreased to 800 wpm. The semantic context contributed to reading speed only by a factor of 1.4. Finally, eye movements imposed an upper limit on RR (around 300 wpm). Overall, data indicate a speed limit of 300 wpm, which corresponds to the time needed for eye movement execution, i.e., the most time consuming mechanism. Results reconcile differences in reading rates reported by different laboratories and thus provide suggestions for targeting different components of reading rate. PMID:27088226

  15. Memory Predictions Are Influenced by Perceptual Information: Evidence for Metacognitive Illusions

    ERIC Educational Resources Information Center

    Rhodes, Matthew G.; Castel, Alan D.

    2008-01-01

    Although perceptual information is utilized to judge size or depth, little work has investigated whether such information is used to make memory predictions. The present study examined how the font size of to-be-remembered words influences predicted memory performance. Participants studied words for a free-recall test that varied in font size and…

  16. Memory Predictions Are Influenced by Perceptual Information: Evidence for Metacognitive Illusions

    ERIC Educational Resources Information Center

    Rhodes, Matthew G.; Castel, Alan D.

    2008-01-01

    Although perceptual information is utilized to judge size or depth, little work has investigated whether such information is used to make memory predictions. The present study examined how the font size of to-be-remembered words influences predicted memory performance. Participants studied words for a free-recall test that varied in font size and

  17. Perceptual chunking and its effect on memory in speech processing: ERP and behavioral evidence.

    PubMed

    Gilbert, Annie C; Boucher, Victor J; Jemel, Boutheina

    2014-01-01

    We examined how perceptual chunks of varying size in utterances can influence immediate memory of heard items (monosyllabic words). Using behavioral measures and event-related potentials (N400) we evaluated the quality of the memory trace for targets taken from perceived temporal groups (TGs) of three and four items. Variations in the amplitude of the N400 showed a better memory trace for items presented in TGs of three compared to those in groups of four. Analyses of behavioral responses along with P300 components also revealed effects of chunk position in the utterance. This is the first study to measure the online effects of perceptual chunks on the memory trace of spoken items. Taken together, the N400 and P300 responses demonstrate that the perceptual chunking of speech facilitates information buffering and a processing on a chunk-by-chunk basis. PMID:24678304

  18. Perceptual chunking and its effect on memory in speech processing: ERP and behavioral evidence

    PubMed Central

    Gilbert, Annie C.; Boucher, Victor J.; Jemel, Boutheina

    2014-01-01

    We examined how perceptual chunks of varying size in utterances can influence immediate memory of heard items (monosyllabic words). Using behavioral measures and event-related potentials (N400) we evaluated the quality of the memory trace for targets taken from perceived temporal groups (TGs) of three and four items. Variations in the amplitude of the N400 showed a better memory trace for items presented in TGs of three compared to those in groups of four. Analyses of behavioral responses along with P300 components also revealed effects of chunk position in the utterance. This is the first study to measure the online effects of perceptual chunks on the memory trace of spoken items. Taken together, the N400 and P300 responses demonstrate that the perceptual chunking of speech facilitates information buffering and a processing on a chunk-by-chunk basis. PMID:24678304

  19. Revisiting a Cognitive Framework for Test Design: Applications for a Computerized Perceptual Speed Test.

    ERIC Educational Resources Information Center

    Alderton, David L.

    This paper highlights the need for a systematic, content aware, and theoretically-based approach to test design. The cognitive components approach is endorsed, and is applied to the development of a computerized perceptual speed test. Psychometric literature is reviewed and shows that: every major multi-factor theory includes a clerical/perceptual…

  20. Processing Speed, Speech Rate, and Memory.

    ERIC Educational Resources Information Center

    Kail, Robert

    1992-01-01

    The memory, processing speed, and articulation rate of 24 9 year olds and 24 adults were measured. Results supported a model in which individuals execute cognitive processes more rapidly as they grow older. In addition, age contributes to more rapid rehearsal of words, which yields more accurate recall. (BG)

  1. Beyond perceptual load and dilution: a review of the role of working memory in selective attention

    PubMed Central

    de Fockert, Jan W.

    2013-01-01

    The perceptual load and dilution models differ fundamentally in terms of the proposed mechanism underlying variation in distractibility during different perceptual conditions. However, both models predict that distracting information can be processed beyond perceptual processing under certain conditions, a prediction that is well-supported by the literature. Load theory proposes that in such cases, where perceptual task aspects do not allow for sufficient attentional selectivity, the maintenance of task-relevant processing depends on cognitive control mechanisms, including working memory. The key prediction is that working memory plays a role in keeping clear processing priorities in the face of potential distraction, and the evidence reviewed and evaluated in a meta-analysis here supports this claim, by showing that the processing of distracting information tends to be enhanced when load on a concurrent task of working memory is high. Low working memory capacity is similarly associated with greater distractor processing in selective attention, again suggesting that the unavailability of working memory during selective attention leads to an increase in distractibility. Together, these findings suggest that selective attention against distractors that are processed beyond perception depends on the availability of working memory. Possible mechanisms for the effects of working memory on selective attention are discussed. PMID:23734139

  2. Quantitative values for perceptual notion of speech speed.

    PubMed

    Wainschenker, R; Doorn, J; Castro, M

    2002-01-01

    Although it is widely used in everyday activities and in several professions such as locution, shorthand and stenography among others, the magnitude speed of speech does not have a precise meaning in everyday use. Such precision is fundamental in the context of the study of the typical behaviour of a large set of language allophones as the basic components for robust speech synthesis. No information was found for Spanish and less for the variant spoken in Uruguay and the center and south of Argentina, usually called Riverplatean Spanish. This article presents a quantitative characterization of the intuitive notions of fast, slow and normal speech speed. The article reports research with strong experimental foundation since its conclusions were obtained from 120 texts uttered by different speakers at different speeds in a context free of any sort of conditioning. More than a half of the texts were collected from public sources and from people who never knew they were being recorded for this purpose. PMID:12237043

  3. Dissociation between Conceptual and Perceptual Implicit Memory: Evidence from Patients with Frontal and Occipital Lobe Lesions

    PubMed Central

    Gong, Liang; Wang, JiHua; Yang, XuDong; Feng, Lei; Li, Xiu; Gu, Cui; Wang, MeiHong; Hu, JiaYun; Cheng, Huaidong

    2016-01-01

    The latest neuroimaging studies about implicit memory (IM) have revealed that different IM types may be processed by different parts of the brain. However, studies have rarely examined what subtypes of IM processes are affected in patients with various brain injuries. Twenty patients with frontal lobe injury, 25 patients with occipital lobe injury, and 29 healthy controls (HC) were recruited for the study. Two subtypes of IM were investigated by using structurally parallel perceptual (picture identification task) and conceptual (category exemplar generation task) IM tests in the three groups, as well as explicit memory (EM) tests. The results indicated that the priming of conceptual IM and EM tasks in patients with frontal lobe injury was poorer than that observed in HC, while perceptual IM was identical between the two groups. By contrast, the priming of perceptual IM in patients with occipital lobe injury was poorer than that in HC, whereas the priming of conceptual IM and EM was similar to that in HC. This double dissociation between perceptual and conceptual IM across the brain areas implies that occipital lobes may participate in perceptual IM, while frontal lobes may be involved in processing conceptual memory. PMID:26793093

  4. Perceptual blurring and recognition memory: A desirable difficulty effect revealed.

    PubMed

    Rosner, Tamara M; Davis, Hanae; Milliken, Bruce

    2015-09-01

    Recent research in the area of desirable difficulty--defined as processing difficulty at either encoding or retrieval that improves long-term retention--has demonstrated that perceptually blurring an item makes processing less fluent, but does not improve remembering (Yue et al., 2013). This result led us to examine more closely perceptual blurring as a potential desirable difficulty. In Experiment 1, better recognition of blurry than clear words was observed, a result that contrasts with those reported by Yue et al. This result was replicated in Experiment 2, in which both mixed-list and pure-list designs were used. The following experiments were conducted to determine when blurring does and does not result in enhanced remembering. The desirable difficulty effect observed in Experiments 1 and 2 was replicated in Experiments 3A, 3B, and 3C, despite varying encoding intent during study, context reinstatement at the time of test, study list length, and the nature of the distractor task between study and test phases. It was only in Experiments 4A and 4B that a null effect of perceptual blurring on remembering was found. These experiments demonstrated that (1) the level of blurring used is critical, with a lower blurring level producing results similar to Yue et al. (2013), and (2) the introduction of judgments of learning at the time of study eliminated the benefit of blurring on remembering. These results extend the desirable difficulty principle to encoding manipulations involving perceptual blurring, and identify judgments of learning at encoding as a powerful moderator of this particular desirable difficulty effect. PMID:26134415

  5. Action Video Games Do Not Improve the Speed of Information Processing in Simple Perceptual Tasks

    PubMed Central

    van Ravenzwaaij, Don; Boekel, Wouter; Forstmann, Birte U.; Ratcliff, Roger; Wagenmakers, Eric-Jan

    2015-01-01

    Previous research suggests that playing action video games improves performance on sensory, perceptual, and attentional tasks. For instance, Green, Pouget, and Bavelier (2010) used the diffusion model to decompose data from a motion detection task and estimate the contribution of several underlying psychological processes. Their analysis indicated that playing action video games leads to faster information processing, reduced response caution, and no difference in motor responding. Because perceptual learning is generally thought to be highly context-specific, this transfer from gaming is surprising and warrants corroborative evidence from a large-scale training study. We conducted 2 experiments in which participants practiced either an action video game or a cognitive game in 5 separate, supervised sessions. Prior to each session and following the last session, participants performed a perceptual discrimination task. In the second experiment, we included a third condition in which no video games were played at all. Behavioral data and diffusion model parameters showed similar practice effects for the action gamers, the cognitive gamers, and the nongamers and suggest that, in contrast to earlier reports, playing action video games does not improve the speed of information processing in simple perceptual tasks. PMID:24933517

  6. Action video games do not improve the speed of information processing in simple perceptual tasks.

    PubMed

    van Ravenzwaaij, Don; Boekel, Wouter; Forstmann, Birte U; Ratcliff, Roger; Wagenmakers, Eric-Jan

    2014-10-01

    Previous research suggests that playing action video games improves performance on sensory, perceptual, and attentional tasks. For instance, Green, Pouget, and Bavelier (2010) used the diffusion model to decompose data from a motion detection task and estimate the contribution of several underlying psychological processes. Their analysis indicated that playing action video games leads to faster information processing, reduced response caution, and no difference in motor responding. Because perceptual learning is generally thought to be highly context-specific, this transfer from gaming is surprising and warrants corroborative evidence from a large-scale training study. We conducted 2 experiments in which participants practiced either an action video game or a cognitive game in 5 separate, supervised sessions. Prior to each session and following the last session, participants performed a perceptual discrimination task. In the second experiment, we included a third condition in which no video games were played at all. Behavioral data and diffusion model parameters showed similar practice effects for the action gamers, the cognitive gamers, and the nongamers and suggest that, in contrast to earlier reports, playing action video games does not improve the speed of information processing in simple perceptual tasks. PMID:24933517

  7. The speed and accuracy of perceptual decisions in a random-tone pitch task.

    PubMed

    Mulder, Martijn J; Keuken, Max C; van Maanen, Leendert; Boekel, Wouter; Forstmann, Birte U; Wagenmakers, Eric-Jan

    2013-07-01

    Research in perceptual decision making is dominated by paradigms that tap the visual system, such as the random-dot motion (RDM) paradigm. In this study, we investigated whether the behavioral signature of perceptual decisions in the auditory domain is similar to those observed in the visual domain. We developed an auditory version of the RDM task, in which tones correspond to dots and pitch corresponds to motion (the random-tone pitch task, RTP). In this task, participants have to decide quickly whether the pitch of a "sound cloud" of tones is moving up or down. Stimulus strength and speed-accuracy trade-off were manipulated. To describe the relationship between stimulus strength and performance, we fitted the proportional-rate diffusion model to the data. The results showed a close coupling between stimulus strength and the speed and accuracy of perceptual decisions in both tasks. Additionally, we fitted the full drift diffusion model (DDM) to the data and showed that three of the four participants had similar speed-accuracy trade-offs in both tasks. However, for the RTP task, drift rates were larger and nondecision times slower, suggesting that some DDM parameters might be dependent on stimulus modality (drift rate and nondecision time), whereas others might not be (decision bound). The results illustrate that the RTP task is suitable for investigating the dynamics of auditory perceptual choices. Future studies using the task might help to investigate modality-specific effects on decision making at both the behavioral and neuronal levels. PMID:23572205

  8. Time-resolved neuroimaging of visual short term memory consolidation by post-perceptual attention shifts.

    PubMed

    Hecht, Marcus; Thiemann, Ulf; Freitag, Christine M; Bender, Stephan

    2016-01-15

    Post-perceptual cues can enhance visual short term memory encoding even after the offset of the visual stimulus. However, both the mechanisms by which the sensory stimulus characteristics are buffered as well as the mechanisms by which post-perceptual selective attention enhances short term memory encoding remain unclear. We analyzed late post-perceptual event-related potentials (ERPs) in visual change detection tasks (100ms stimulus duration) by high-resolution ERP analysis to elucidate these mechanisms. The effects of early and late auditory post-cues (300ms or 850ms after visual stimulus onset) as well as the effects of a visual interference stimulus were examined in 27 healthy right-handed adults. Focusing attention with post-perceptual cues at both latencies significantly improved memory performance, i.e. sensory stimulus characteristics were available for up to 850ms after stimulus presentation. Passive watching of the visual stimuli without auditory cue presentation evoked a slow negative wave (N700) over occipito-temporal visual areas. N700 was strongly reduced by a visual interference stimulus which impeded memory maintenance. In contrast, contralateral delay activity (CDA) still developed in this condition after the application of auditory post-cues and was thereby dissociated from N700. CDA and N700 seem to represent two different processes involved in short term memory encoding. While N700 could reflect visual post processing by automatic attention attraction, CDA may reflect the top-down process of searching selectively for the required information through post-perceptual attention. PMID:26571051

  9. Differentiation of perceptual and semantic subsequent memory effects using an orthographic paradigm.

    PubMed

    Kuo, Michael C C; Liu, Karen P Y; Ting, Kin Hung; Chan, Chetwyn C H

    2012-11-27

    This study aimed to differentiate perceptual and semantic encoding processes using subsequent memory effects (SMEs) elicited by the recognition of orthographs of single Chinese characters. Participants studied a series of Chinese characters perceptually (by inspecting orthographic components) or semantically (by determining the object making sounds), and then made studied or unstudied judgments during the recognition phase. Recognition performance in terms of d-prime measure in the semantic condition was higher, though not significant, than that of the perceptual condition. The between perceptual-semantic condition differences in SMEs at P550 and late positive component latencies (700-1000ms) were not significant in the frontal area. An additional analysis identified larger SME in the semantic condition during 600-1000ms in the frontal pole regions. These results indicate that coordination and incorporation of orthographic information into mental representation is essential to both task conditions. The differentiation was also revealed in earlier SMEs (perceptual>semantic) at N3 (240-360ms) latency, which is a novel finding. The left-distributed N3 was interpreted as more efficient processing of meaning with semantically learned characters. Frontal pole SMEs indicated strategic processing by executive functions, which would further enhance memory. PMID:23063888

  10. The Comparison of Visual Working Memory Representations with Perceptual Inputs

    ERIC Educational Resources Information Center

    Hyun, Joo-seok; Woodman, Geoffrey F.; Vogel, Edward K.; Hollingworth, Andrew; Luck, Steven J.

    2009-01-01

    The human visual system can notice differences between memories of previous visual inputs and perceptions of new visual inputs, but the comparison process that detects these differences has not been well characterized. In this study, the authors tested the hypothesis that differences between the memory of a stimulus array and the perception of a…

  11. FPGA Flash Memory High Speed Data Acquisition

    NASA Technical Reports Server (NTRS)

    Gonzalez, April

    2013-01-01

    The purpose of this research is to design and implement a VHDL ONFI Controller module for a Modular Instrumentation System. The goal of the Modular Instrumentation System will be to have a low power device that will store data and send the data at a low speed to a processor. The benefit of such a system will give an advantage over other purchased binary IP due to the capability of allowing NASA to re-use and modify the memory controller module. To accomplish the performance criteria of a low power system, an in house auxiliary board (Flash/ADC board), FPGA development kit, debug board, and modular instrumentation board will be jointly used for the data acquisition. The Flash/ADC board contains four, 1 MSPS, input channel signals and an Open NAND Flash memory module with an analog to digital converter. The ADC, data bits, and control line signals from the board are sent to an Microsemi/Actel FPGA development kit for VHDL programming of the flash memory WRITE, READ, READ STATUS, ERASE, and RESET operation waveforms using Libero software. The debug board will be used for verification of the analog input signal and be able to communicate via serial interface with the module instrumentation. The scope of the new controller module was to find and develop an ONFI controller with the debug board layout designed and completed for manufacture. Successful flash memory operation waveform test routines were completed, simulated, and tested to work on the FPGA board. Through connection of the Flash/ADC board with the FPGA, it was found that the device specifications were not being meet with Vdd reaching half of its voltage. Further testing showed that it was the manufactured Flash/ADC board that contained a misalignment with the ONFI memory module traces. The errors proved to be too great to fix in the time limit set for the project.

  12. Perceptual difficulty in source memory encoding and retrieval: Prefrontal versus parietal electrical brain activity

    PubMed Central

    Kuo, Trudy Y.; Van Petten, Cyma

    2008-01-01

    It is well established that source memory retrieval – remembering relationships between a core item and some additional attribute of an event – engages prefrontal cortex (PFC) more than simple item memory. In event-related potentials (ERPs), this is manifest in a late-onset difference over PFC between studied items which mandate retrieval of a second attribute, and unstudied items which can be immediately rejected. Although some sorts of attribute conjunctions are easier to remember than others, the role of source retrieval difficulty on prefrontal activity has received little attention. We examined memory for conjunctions of object shape and color when color was an integral part of the depicted object, and when monochrome objects were surrounded by colored frames. Source accuracy was reliably worse when shape and color were spatially separated, but prefrontal activity did not vary across the object–color and frame-color conditions. The insensitivity of prefrontal ERPs to this perceptual manipulation of difficulty stands in contrast to their sensitivity to encoding task: deliberate voluntary effort to integrate objects and colors during encoding reduced prefrontal activity during retrieval, but perceptual organization of stimuli did not. The amplitudes of ERPs over parietal cortex were larger for frame-color than object–color stimuli during both study and test phases of the memory task. Individual variability in parietal ERPs was strongly correlated with memory accuracy, which we suggest reflects a contribution of visual working memory to long-term memory. We discuss multiple bottlenecks for source memory performance. PMID:18402989

  13. The time course of protecting a visual memory representation from perceptual interference

    PubMed Central

    van Moorselaar, Dirk; Gunseli, Eren; Theeuwes, Jan; N. L. Olivers, Christian

    2015-01-01

    Cueing a remembered item during the delay of a visual memory task leads to enhanced recall of the cued item compared to when an item is not cued. This cueing benefit has been proposed to reflect attention within visual memory being shifted from a distributed mode to a focused mode, thus protecting the cued item against perceptual interference. Here we investigated the dynamics of building up this mnemonic protection against visual interference by systematically varying the stimulus onset asynchrony (SOA) between cue onset and a subsequent visual mask in an orientation memory task. Experiment 1 showed that a cue counteracted the deteriorating effect of pattern masks. Experiment 2 demonstrated that building up this protection is a continuous process that is completed in approximately half a second after cue onset. The similarities between shifting attention in perceptual and remembered space are discussed. PMID:25628555

  14. Memory's aging echo: age-related decline in neural reactivation of perceptual details during recollection.

    PubMed

    McDonough, Ian M; Cervantes, Sasha N; Gray, Stephen J; Gallo, David A

    2014-09-01

    Episodic memory decline is a hallmark of normal cognitive aging. Here, we report the first event-related fMRI study to directly investigate age differences in the neural reactivation of qualitatively rich perceptual details during recollection. Younger and older adults studied pictures of complex scenes at different presentation durations along with descriptive verbal labels, and these labels subsequently were used during fMRI scanning to cue picture recollections of varying perceptual detail. As expected from prior behavioral work, the two age groups subjectively rated their recollections as containing similar amounts of perceptual detail, despite objectively measured recollection impairment in older adults. In both age groups, comparisons of retrieval trials that varied in recollected detail revealed robust activity in brain regions previously linked to recollection, including hippocampus and both medial and lateral regions of the prefrontal and posterior parietal cortex. Critically, this analysis also revealed recollection-related activity in visual processing regions that were active in an independent picture-perception task, and these regions showed age-related reductions in activity during recollection that cannot be attributed to age differences in response criteria. These fMRI findings provide new evidence that aging reduces the absolute quantity of perceptual details that are reactivated from memory, and they help to explain why aging reduces the reliability of subjective memory judgments. PMID:24828546

  15. Perceptual Organization as a Determinant of Visual Recognition Memory

    ERIC Educational Resources Information Center

    Wiseman, Sandor; Neisser, Ulric

    1974-01-01

    Ambiguous pictures that could be seen as faces or as meaningless patterns were the stimuli in two recognition-memory experiments. Recognition was far more accurate when the stimuli were seen as faces. (Editor)

  16. A visually impaired savant artist: interacting perceptual and memory representations.

    PubMed

    Hermelin, B; Pring, L; Buhler, M; Wolff, S; Heaton, P

    1999-10-01

    In this single case study, paintings by a visually impaired and cognitively handicapped savant artist are evaluated. He paints his pictures exclusively from memory, either after having looked at a natural scene through binoculars, or after studying landscape photographs in brochures, catalogues, and books. The paintings are compared with the models from which they were derived, and the resulting generative changes are accounted for by an interaction between impaired visual input and memory transformations. PMID:10576541

  17. Effects of cross-modal and intramodal division of attention on perceptual implicit memory.

    PubMed

    Mulligan, Neil W

    2003-03-01

    Extant results motivate 3 hypotheses on the role of attention in perceptual implicit memory. The first proposes that only intramodal manipulations of attention reduce perceptual priming. The second attributes reduced priming to the effects of distractor selection operating in a central bottleneck process. The third proposes that manipulations of attention only affect priming via disrupted stimulus identification. In Experiment 1, a standard cross-modal manipulation did not disrupt priming in perceptual identification. However, when study words and distractors were presented synchronously, cross-modal and intramodal distraction reduced priming. Increasing response frequency in the distractor task produced effects of attention regardless of target-distractor synchrony. These effects generalized to a different category of distractors arguing against domain-specific interference. The results support the distractor-selection hypothesis. PMID:12696814

  18. A Role for the Perceptual Representation Memory System in Category Learning

    PubMed Central

    Casale, Michael B.; Ashby, F. Gregory

    2008-01-01

    There is growing evidence that working memory, episodic/semantic memory, and procedural memory all play important roles in at least some types of category learning. Little is known however, about the role of the perceptual representation memory system (PRS). Two experiments are reported that provide evidence that under certain conditions, the PRS, by itself, is sufficient to mediate category learning. Both experiments compared performance in (A, not A) and (A, B) prototype distortion category-learning tasks, in which category exemplars are created by randomly distorting one category prototype in the (A, not A) conditions or two prototypes in the (A, B) conditions. Results showed that (A, not A) performance was more sensitive to prototype similarity and less affected by the removal of feedback than (A, B) performance. These results support the hypothesis that (A, not A) performance was mediated by the PRS, but that (A, B) performance recruited other memory systems. PMID:18717385

  19. Comparing the benefits of caffeine, naps and placebo on verbal, motor and perceptual memory.

    PubMed

    Mednick, Sara C; Cai, Denise J; Kanady, Jennifer; Drummond, Sean P A

    2008-11-01

    Caffeine, the world's most common psychoactive substance, is used by approximately 90% of North Americans everyday. Little is known, however, about its benefits for memory. Napping has been shown to increase alertness and promote learning on some memory tasks. We directly compared caffeine (200mg) with napping (60-90min) and placebo on three distinct memory processes: declarative verbal memory, procedural motor skills, and perceptual learning. In the verbal task, recall and recognition for unassociated words were tested after a 7h retention period (with a between-session nap or drug intervention). A second, different, word list was administered post-intervention and memory was tested after a 20min retention period. The non-declarative tasks (finger tapping task (FTT) and texture discrimination task (TDT)) were trained before the intervention and then retested afterwards. Naps enhanced recall of words after a 7h and 20min retention interval relative to both caffeine and placebo. Caffeine significantly impaired motor learning compared to placebo and naps. Napping produced robust perceptual learning compared with placebo; however, naps and caffeine were not significantly different. These findings provide evidence of the limited benefits of caffeine for memory improvement compared with napping. We hypothesize that impairment from caffeine may be restricted to tasks that contain explicit information; whereas strictly implicit learning is less compromised. PMID:18554731

  20. Comparing the benefits of Caffeine, Naps and Placebo on Verbal, Motor and Perceptual Memory

    PubMed Central

    Mednick, Sara C.; Cai, Denise J.; Kanady, Jennifer; Drummond, Sean P.A.

    2008-01-01

    Caffeine, the world’s most common psychoactive substance, is used by approximately 90% of North Americans everyday. Little is known, however, about its benefits for memory. Napping has been shown to increase alertness and promote learning on some memory tasks. We directly compared caffeine (200mg) with napping (60–90 minutes) and placebo on three distinct memory processes: declarative verbal memory, procedural motor skills, and perceptual learning. In the verbal task, recall and recognition for unassociated words were tested after a 7hr retention period (with a between-session nap or drug intervention). A second, different, word list was administered post-intervention and memory was tested after a 20min retention period. The non-declarative tasks (finger tapping task and texture discrimination task) were trained before the intervention and then retested afterwards. Naps enhanced recall of words after a 7hr and 20min retention interval relative to both caffeine and placebo. Caffeine significantly impaired motor learning compared to placebo and naps. Napping produced robust perceptual learning compared with placebo; however, naps and caffeine were not significantly different. These findings provide evidence of the limited benefits of caffeine for memory improvement compared with napping. We hypothesize that impairment from caffeine may be restricted to tasks that contain explicit information; whereas strictly implicit learning is less compromised. PMID:18554731

  1. The Comparison of Visual Working Memory Representations with Perceptual Inputs

    PubMed Central

    Hyun, Joo-seok; Woodman, Geoffrey F.; Vogel, Edward K.; Hollingworth, Andrew

    2008-01-01

    The human visual system can notice differences between memories of previous visual inputs and perceptions of new visual inputs, but the comparison process that detects these differences has not been well characterized. This study tests the hypothesis that differences between the memory of a stimulus array and the perception of a new array are detected in a manner that is analogous to the detection of simple features in visual search tasks. That is, just as the presence of a task-relevant feature in visual search can be detected in parallel, triggering a rapid shift of attention to the object containing the feature, the presence of a memory-percept difference along a task-relevant dimension can be detected in parallel, triggering a rapid shift of attention to the changed object. Supporting evidence was obtained in a series of experiments that examined manual reaction times, saccadic reaction times, and event-related potential latencies. However, these experiments also demonstrated that a slow, limited-capacity process must occur before the observer can make a manual change-detection response. PMID:19653755

  2. I "hear" what you're "saying": Auditory perceptual simulation, reading speed, and reading comprehension.

    PubMed

    Zhou, Peiyun; Christianson, Kiel

    2016-05-01

    Auditory perceptual simulation (APS) during silent reading refers to situations in which the reader actively simulates the voice of a character or other person depicted in a text. In three eye-tracking experiments, APS effects were investigated as people read utterances attributed to a native English speaker, a non-native English speaker, or no speaker at all. APS effects were measured via online eye movements and offline comprehension probes. Results demonstrated that inducing APS during silent reading resulted in observable differences in reading speed when readers simulated the speech of faster compared to slower speakers and compared to silent reading without APS. Social attitude survey results indicated that readers' attitudes towards the native and non-native speech did not consistently influence APS-related effects. APS of both native speech and non-native speech increased reading speed, facilitated deeper, less good-enough sentence processing, and improved comprehension compared to normal silent reading. PMID:25679796

  3. Age-related effects on perceptual and semantic encoding in memory.

    PubMed

    Kuo, M C C; Liu, K P Y; Ting, K H; Chan, C C H

    2014-03-01

    This study examined the age-related subsequent memory effect (SME) in perceptual and semantic encoding using event-related potentials (ERPs). Seventeen younger adults and 17 older adults studied a series of Chinese characters either perceptually (by inspecting orthographic components) or semantically (by determining whether the depicted object makes sounds). The two tasks had similar levels of difficulty. The participants made studied or unstudied judgments during the recognition phase. Younger adults performed better in both conditions, with significant SMEs detected in the time windows of P2, N3, P550, and late positive component (LPC). In the older group, SMEs were observed in the P2 and N3 latencies in both conditions but were only detected in the P550 in the semantic condition. Between-group analyses showed larger frontal and central SMEs in the younger sample in the LPC latency regardless of encoding type. Aging effect appears to be stronger on influencing perceptual than semantic encoding processes. The effects seem to be associated with a decline in updating and maintaining representations during perceptual encoding. The age-related decline in the encoding function may be due in part to changes in frontal lobe function. PMID:24374080

  4. Differently confident: Susceptibility to bias in perceptual judgments of size interacts with working memory capacity.

    PubMed

    A Sanchez, Christopher

    2016-05-01

    Much prior research has shown that retrieval of information from long-term memory (LTM) can influence many aspects of complex cognition in situ. However, research also has shown that not all individuals manage information retrieved from LTM in equivalent fashions. Specifically, high working memory capacity (WMC) individuals have been shown to be better able to manage not only what information is retrieved from LTM, but also whether it is applied to the task-at-hand. As such, it is likely that WMC will interact with the biasing influences of prior knowledge on current task performance. In this series of studies, high and low WMC individuals were asked to make perceptual judgments of size that either did or did not activate biasing prior knowledge. Results indicate that when retrieving information from LTM, high WMC individuals are actually more susceptible to perceptual bias and also are erroneously more confident in the accuracy of their response. However, when no retrieval from LTM is necessary, this effect reverses. This suggests that high WMC individuals are indeed able to inhibit such biasing information; however, their overconfidence in the quality of information retrieved from their own LTM can make them susceptible to making errors in perceptual judgments. PMID:26902248

  5. Bias in self-motion perceived speed can enhance episodic memory.

    PubMed

    Cerles, Mélanie; Rousset, Stéphane

    2012-08-01

    Prior experiences of a stimulus facilitate reprocessing of that stimulus on a subsequent occasion. This relative ease and speed with which information is processed is defined as fluency and can constitute a basis for memory judgment. Fluency can also be manipulated on line by perceptual bias (e.g., levels of noise), leading to an increase in recognition for items processed more fluently (e.g., items with less noise). Previous experiments using Remember-Know paradigm have shown an impact of perceptual fluency only on familiarity and not on recollection. Recent episodic memory models have postulated a strong link between episodic memory and spatial processes, especially with egocentric updating (Gomez et al. in Acta Psychol 132(3):221-227, 2009). The present experiment was conducted to determine whether self-motion fluency affects recognition performance and particularly has an impact on "Remember" responses. Thirty participants learned a 4-min path movie and then had to recognize among short paths if they were part of the learned path, followed by a Remember-Know procedure for recognized items. Self-motion fluency was manipulated with the presence of nimble acceleration applied on a small part of the recognition paths. Results show that the presence of a self-motion fluency increases significantly the proportion of remember responses solely on learned paths. This study spotlights for the first time a specific fluency effect on recollection and indicates an implication of egocentric-updating processing in episodic memory retrieval. PMID:22806647

  6. The ineluctable modality of the audible: perceptual determinants of auditory verbal short-term memory.

    PubMed

    Maidment, David W; Macken, William J

    2012-08-01

    Classical cognitive accounts of verbal short-term memory (STM) invoke an abstract, phonological level of representation which, although it may be derived differently via different modalities, is itself amodal. Key evidence for this view is that serial recall of phonologically similar verbal items (e.g., the letter sounds b, c, g, and d) is worse than that of dissimilar items, regardless of modality of presentation. Here we show that the effect of such phonological similarity in STM can be fully accounted for by the joint action of articulatory similarity, leading to errors in speech planning processes, and acoustic similarity within auditorily presented lists, which modulates their perceptual organization. The results indicate that key evidence used to argue for the existence of abstract phonological representation can in fact be fully accounted for by reference to modality-specific perceptual and motor planning mechanisms. PMID:22468724

  7. Memory predictions are influenced by perceptual information: evidence for metacognitive illusions.

    PubMed

    Rhodes, Matthew G; Castel, Alan D

    2008-11-01

    Although perceptual information is utilized to judge size or depth, little work has investigated whether such information is used to make memory predictions. The present study examined how the font size of to-be-remembered words influences predicted memory performance. Participants studied words for a free-recall test that varied in font size and made judgments of learning (JOLs) for each item. JOLs were influenced by font size, as larger font sizes were given higher JOLs, whereas little relationship was evident between font size and recall. The effect was modified when other, more valid, sources of information (e.g., associative strength) were available when JOLs were made and persisted despite experience with multiple study-test sessions, use of a forgetting scale to assess predictions, and explicit warning of participants that font size has little effect on memory performance. When ease of reading was manipulated, such that large font size words were made less fluent, the effect was eliminated. Thus, highly accessible perceptual cues can strongly influence JOLs, likely via encoding fluency, and this effect can lead to metacognitive illusions PMID:18999356

  8. Well-Being Affects Changes in Perceptual Speed in Advanced Old Age: Longitudinal Evidence for a Dynamic Link

    ERIC Educational Resources Information Center

    Gerstorf, Denis; Lovden, Martin; Rocke, Christina; Smith, Jacqui; Lindenberger, Ulman

    2007-01-01

    This study examined competing hypotheses about dynamic cross-domain associations between perceptual speed and well-being in advanced old age. We applied the bivariate dual change score model (J. J. McArdle & F. Hamagami, 2001) to 13-year incomplete longitudinal data from the Berlin Aging Study (P. B. Baltes & K. U. Mayer, 1999; N = 516, 70-103…

  9. Working Memory Influences Processing Speed and Reading Fluency in ADHD

    PubMed Central

    Jacobson, Lisa A.; Ryan, Matthew; Martin, Rebecca B.; Ewen, Joshua; Mostofsky, Stewart H.; Denckla, Martha B.; Mahone, E. Mark

    2012-01-01

    Processing speed deficits affect reading efficiency, even among individuals who recognize and decode words accurately. Children with ADHD who decode words accurately can still have inefficient reading fluency, leading to a bottleneck in other cognitive processes. This “slowing” in ADHD is associated with deficits in fundamental components of executive function underlying processing speed, including response selection. The purpose of the present study was to deconstruct processing speed in order to determine which components of executive control best explain the “processing” speed deficits related to reading fluency in ADHD. Participants (41 ADHD, 21 controls), ages 9-14, screened for language disorders, word reading deficits, and psychiatric disorders, were administered measures of copying speed, processing speed, reading fluency, working memory, reaction time, inhibition, and auditory attention span. Compared to controls, children with ADHD showed reduced oral and silent reading fluency, and reduced processing speed—driven primarily by deficits on WISC-IV Coding. In contrast, groups did not differ on copying speed. After controlling for copying speed, sex, severity of ADHD-related symptomatology, and GAI, slowed “processing” speed (i.e., Coding) was significantly associated with verbal span and measures of working memory, but not with measures of response control/inhibition, lexical retrieval speed, reaction time, or intra-subject variability. Further, “processing” speed (i.e., Coding, residualized for copying speed) and working memory were significant predictors of oral reading fluency. Abnormalities in working memory and response selection (which are frontally-mediated and enter into the output side of processing speed) may play an important role in deficits in reading fluency in ADHD, potentially more than posteriorally-mediated problems with orienting of attention or perceiving the stimulus. PMID:21287422

  10. Contextual consistency facilitates long-term memory of perceptual detail in barely seen images.

    PubMed

    Gronau, Nurit; Shachar, Meytal

    2015-08-01

    It is long known that contextual information affects memory for an object's identity (e.g., its basic level category), yet it is unclear whether schematic knowledge additionally enhances memory for the precise visual appearance of an item. Here we investigated memory for visual detail of merely glimpsed objects. Participants viewed pairs of contextually related and unrelated stimuli, presented for an extremely brief duration (24 ms, masked). They then performed a forced-choice memory-recognition test for the precise perceptual appearance of 1 of 2 objects within each pair (i.e., the "memory-target" item). In 3 experiments, we show that memory-target stimuli originally appearing within contextually related pairs are remembered better than targets appearing within unrelated pairs. These effects are obtained whether the target is presented at test with its counterpart pair object (i.e., when reiterating the original context at encoding) or whether the target is presented alone, implying that the contextual consistency effects are mediated predominantly by processes occurring during stimulus encoding, rather than during stimulus retrieval. Furthermore, visual detail encoding is improved whether object relations involve implied action or not, suggesting that, contrary to some prior suggestions, action is not a necessary component for object-to-object associative "grouping" processes. Our findings suggest that during a brief glimpse, but not under long viewing conditions, contextual associations may play a critical role in reducing stimulus competition for attention selection and in facilitating rapid encoding of sensory details. Theoretical implications with respect to classic frame theories are discussed. (PsycINFO Database Record PMID:26010591

  11. The Perceptual Root of Object-Based Storage: An Interactive Model of Perception and Visual Working Memory

    ERIC Educational Resources Information Center

    Gao, Tao; Gao, Zaifeng; Li, Jie; Sun, Zhongqiang; Shen, Mowei

    2011-01-01

    Mainstream theories of visual perception assume that visual working memory (VWM) is critical for integrating online perceptual information and constructing coherent visual experiences in changing environments. Given the dynamic interaction between online perception and VWM, we propose that how visual information is processed during visual…

  12. Breaking the Speed Limits of Phase-Change Memory

    NASA Astrophysics Data System (ADS)

    Loke, D.; Lee, T. H.; Wang, W. J.; Shi, L. P.; Zhao, R.; Yeo, Y. C.; Chong, T. C.; Elliott, S. R.

    2012-06-01

    Phase-change random-access memory (PCRAM) is one of the leading candidates for next-generation data-storage devices, but the trade-off between crystallization (writing) speed and amorphous-phase stability (data retention) presents a key challenge. We control the crystallization kinetics of a phase-change material by applying a constant low voltage via prestructural ordering (incubation) effects. A crystallization speed of 500 picoseconds was achieved, as well as high-speed reversible switching using 500-picosecond pulses. Ab initio molecular dynamics simulations reveal the phase-change kinetics in PCRAM devices and the structural origin of the incubation-assisted increase in crystallization speed. This paves the way for achieving a broadly applicable memory device, capable of nonvolatile operations beyond gigahertz data-transfer rates.

  13. Breaking the speed limits of phase-change memory.

    PubMed

    Loke, D; Lee, T H; Wang, W J; Shi, L P; Zhao, R; Yeo, Y C; Chong, T C; Elliott, S R

    2012-06-22

    Phase-change random-access memory (PCRAM) is one of the leading candidates for next-generation data-storage devices, but the trade-off between crystallization (writing) speed and amorphous-phase stability (data retention) presents a key challenge. We control the crystallization kinetics of a phase-change material by applying a constant low voltage via prestructural ordering (incubation) effects. A crystallization speed of 500 picoseconds was achieved, as well as high-speed reversible switching using 500-picosecond pulses. Ab initio molecular dynamics simulations reveal the phase-change kinetics in PCRAM devices and the structural origin of the incubation-assisted increase in crystallization speed. This paves the way for achieving a broadly applicable memory device, capable of nonvolatile operations beyond gigahertz data-transfer rates. PMID:22723419

  14. Speed of Processing, Working Memory, and Language Impairment in Children

    ERIC Educational Resources Information Center

    Leonard, Laurence B.; Weismer, Susan Ellis; Miller, Carol A.; Francis, David J.; Tomblin, J. Bruce; Kail, Robert V.

    2007-01-01

    Purpose: Children with language impairment (LI) often perform below the level of typically developing peers on measures of both processing speed and working memory. This study examined the relationship between these 2 types of measures and attempted to determine whether such measures can account for the LI itself. Method: Fourteen-year-old…

  15. High speed magneto-resistive random access memory

    NASA Technical Reports Server (NTRS)

    Wu, Jiin-Chuan (Inventor); Stadler, Henry L. (Inventor); Katti, Romney R. (Inventor)

    1992-01-01

    A high speed read MRAM memory element is configured from a sandwich of magnetizable, ferromagnetic film surrounding a magneto-resistive film which may be ferromagnetic or not. One outer ferromagnetic film has a higher coercive force than the other and therefore remains magnetized in one sense while the other may be switched in sense by a switching magnetic field. The magneto-resistive film is therefore sensitive to the amplitude of the resultant field between the outer ferromagnetic films and may be constructed of a high resistivity, high magneto-resistive material capable of higher sensing currents. This permits higher read voltages and therefore faster read operations. Alternate embodiments with perpendicular anisotropy, and in-plane anisotropy are shown, including an embodiment which uses high permeability guides to direct the closing flux path through the magneto-resistive material. High density, high speed, radiation hard, memory matrices may be constructed from these memory elements.

  16. Language and Short-Term Memory: The Role of Perceptual-Motor Affordance

    PubMed Central

    2014-01-01

    The advantage for real words over nonwords in serial recall—the lexicality effect—is typically attributed to support for item-level phonology, either via redintegration, whereby partially degraded short-term traces are “cleaned up” via support from long-term representations of the phonological material or via the more robust temporary activation of long-term lexical phonological knowledge that derives from its combination with established lexical and semantic levels of representation. The much smaller effect of lexicality in serial recognition, where the items are re-presented in the recognition cue, is attributed either to the minimal role for redintegration from long-term memory or to the minimal role for item memory itself in such retrieval conditions. We show that the reduced lexicality effect in serial recognition is not a function of the retrieval conditions, but rather because previous demonstrations have used auditory presentation, and we demonstrate a robust lexicality effect for visual serial recognition in a setting where auditory presentation produces no such effect. Furthermore, this effect is abolished under conditions of articulatory suppression. We argue that linguistic knowledge affects the readiness with which verbal material is segmentally recoded via speech motor processes that support rehearsal and therefore affects tasks that involve recoding. On the other hand, auditory perceptual organization affords sequence matching in the absence of such a requirement for segmental recoding and therefore does not show such effects of linguistic knowledge. PMID:24797440

  17. Language and short-term memory: the role of perceptual-motor affordance.

    PubMed

    Macken, Bill; Taylor, John C; Jones, Dylan M

    2014-09-01

    The advantage for real words over nonwords in serial recall--the lexicality effect--is typically attributed to support for item-level phonology, either via redintegration, whereby partially degraded short-term traces are "cleaned up" via support from long-term representations of the phonological material or via the more robust temporary activation of long-term lexical phonological knowledge that derives from its combination with established lexical and semantic levels of representation. The much smaller effect of lexicality in serial recognition, where the items are re-presented in the recognition cue, is attributed either to the minimal role for redintegration from long-term memory or to the minimal role for item memory itself in such retrieval conditions. We show that the reduced lexicality effect in serial recognition is not a function of the retrieval conditions, but rather because previous demonstrations have used auditory presentation, and we demonstrate a robust lexicality effect for visual serial recognition in a setting where auditory presentation produces no such effect. Furthermore, this effect is abolished under conditions of articulatory suppression. We argue that linguistic knowledge affects the readiness with which verbal material is segmentally recoded via speech motor processes that support rehearsal and therefore affects tasks that involve recoding. On the other hand, auditory perceptual organization affords sequence matching in the absence of such a requirement for segmental recoding and therefore does not show such effects of linguistic knowledge. PMID:24797440

  18. Galvanic vestibular stimulation speeds visual memory recall.

    PubMed

    Wilkinson, David; Nicholls, Sophie; Pattenden, Charlotte; Kilduff, Patrick; Milberg, William

    2008-08-01

    The experiments of Alessandro Volta were amongst the first to indicate that visuo-spatial function can be altered by stimulating the vestibular nerves with galvanic current. Until recently, the beneficial effects of the procedure were masked by the high levels of electrical current applied, which induced nystagmus-related gaze deviation and spatial disorientation. However, several neuropsychological studies have shown that much weaker, imperceptible currents that do not elicit unpleasant side-effects can help overcome visual loss after stroke. Here, we show that visual processing in neurologically healthy individuals can also benefit from galvanic vestibular stimulation. Participants first learnt the names of eight unfamiliar faces and then after a short delay, answered questions from memory about how pairs of these faces differed. Mean correct reaction times were significantly shorter when sub-sensory, noise-enhanced anodal stimulation was administered to the left mastoid, compared to when no stimulation was administered at all. This advantage occurred with no loss in response accuracy, and raises the possibility that the procedure may constitute a more general form of cognitive enhancement. PMID:18584162

  19. Entrained rhythmic activities of neuronal ensembles as perceptual memory of time interval.

    PubMed

    Sumbre, Germán; Muto, Akira; Baier, Herwig; Poo, Mu-ming

    2008-11-01

    The ability to process temporal information is fundamental to sensory perception, cognitive processing and motor behaviour of all living organisms, from amoebae to humans. Neural circuit mechanisms based on neuronal and synaptic properties have been shown to process temporal information over the range of tens of microseconds to hundreds of milliseconds. How neural circuits process temporal information in the range of seconds to minutes is much less understood. Studies of working memory in monkeys and rats have shown that neurons in the prefrontal cortex, the parietal cortex and the thalamus exhibit ramping activities that linearly correlate with the lapse of time until the end of a specific time interval of several seconds that the animal is trained to memorize. Many organisms can also memorize the time interval of rhythmic sensory stimuli in the timescale of seconds and can coordinate motor behaviour accordingly, for example, by keeping the rhythm after exposure to the beat of music. Here we report a form of rhythmic activity among specific neuronal ensembles in the zebrafish optic tectum, which retains the memory of the time interval (in the order of seconds) of repetitive sensory stimuli for a duration of up to approximately 20 s. After repetitive visual conditioning stimulation (CS) of zebrafish larvae, we observed rhythmic post-CS activities among specific tectal neuronal ensembles, with a regular interval that closely matched the CS. Visuomotor behaviour of the zebrafish larvae also showed regular post-CS repetitions at the entrained time interval that correlated with rhythmic neuronal ensemble activities in the tectum. Thus, rhythmic activities among specific neuronal ensembles may act as an adjustable 'metronome' for time intervals in the order of seconds, and serve as a mechanism for the short-term perceptual memory of rhythmic sensory experience. PMID:18923391

  20. Integrated, nonvolatile, high-speed analog random access memory

    NASA Technical Reports Server (NTRS)

    Katti, Romney R. (Inventor); Wu, Jiin-Chuan (Inventor); Stadler, Henry L. (Inventor)

    1994-01-01

    This invention provides an integrated, non-volatile, high-speed random access memory. A magnetically switchable ferromagnetic or ferrimagnetic layer is sandwiched between an electrical conductor which provides the ability to magnetize the magnetically switchable layer and a magneto resistive or Hall effect material which allows sensing the magnetic field which emanates from the magnetization of the magnetically switchable layer. By using this integrated three-layer form, the writing process, which is controlled by the conductor, is separated from the storage medium in the magnetic layer and from the readback process which is controlled by the magnetoresistive layer. A circuit for implementing the memory in CMOS or the like is disclosed.

  1. Clocking perceptual processing speed: From chance to 75% correct in less than 30 milliseconds.

    PubMed

    Stanford, Terrence R; Salinas, Emilio

    2010-05-01

    THE NEURAL BASIS OF CHOICE BEHAVIOR HAS BEEN INTENSELY STUDIED WITH LABORATORY TASKS IN WHICH A SUBJECT SEES A STIMULUS AND MAKES A CORRESPONDING MOTOR RESPONSE, BUT THE ISSUE OF TIMING HAS BEEN HARD TO TACKLE: How much time is necessary to make the perceptual judgment versus executing the motor report? When and how does a subject commit to a particular choice, and what neural mechanisms determine that? A major limitation has been that reaction times (RTs) are affected by sensory and motor factors (e.g., task difficulty, urgency, expectation) that can be covertly traded. Recently, we designed a task that overcomes these problems and allows us to construct a new curve that unambiguously reveals how a subject's perceptual judgment unfolds in time. Specifically, the slope of this "tachometric" curve depends on the perceptual difficulty of the task and the perceptual capacity of the subject, but not on motor execution. This technique shows that monkeys can make accurate color discriminations in less than 30 ms. More importantly, it provides a novel metric for correlating the time courses of pyschophysical and neuronal responses, opening up a new avenue for investigating choice behaviors in a wide variety of experimental conditions. PMID:20714416

  2. Optic fiber clock distribution in high-speed video memory

    NASA Astrophysics Data System (ADS)

    Kosel, Peter B.; Hanjani, Amir A.

    2002-05-01

    An electronic system based on a novel high-speed massive video memory array using an optical fiber clock distribution network has been investigated for the generation of random patterns for testing high-resolution color video monitors with screen sizes in the realm of 4096 by 4096 pixels. For frame rates in the range of 30 to 100 per second with 256 (28) to 4096 (212) intensity levels for each primary color the speed requirement amounts to 1.21x1010 to 6.04x1010 bits per second. The massive memory makes use of high-speed MSM photodetectors, optical receiver amplifiers and gallium arsenide charged coupled devices which are integrated on GaAs chips. These chips are assembled into 16 planes of multi-chip modules with 32 GaAs chips per plane. Only GaAs CCDs have been found to provide the short access times required to achieve the above data rates that exceed the capabilities of current silicon-based DRAMs. For proper operation clock skew must be eliminated, therefore, a 2-phase laser driven optical fiber distribution network has been considered. In addition, the photodetectors and amplifiers driving the CCDs must have speeds that do not compromise the access times of the CCD registers. To meet all requirements the design was implemented with optical fiber v-groove coupling to the MSM monolithic detectors and high-speed preamplifiers that are fabricated with the same technology as used for the fabrication of the CCDs.

  3. Sparse distributed memory: understanding the speed and robustness of expert memory

    PubMed Central

    Brogliato, Marcelo S.; Chada, Daniel M.; Linhares, Alexandre

    2014-01-01

    How can experts, sometimes in exacting detail, almost immediately and very precisely recall memory items from a vast repertoire? The problem in which we will be interested concerns models of theoretical neuroscience that could explain the speed and robustness of an expert's recollection. The approach is based on Sparse Distributed Memory, which has been shown to be plausible, both in a neuroscientific and in a psychological manner, in a number of ways. A crucial characteristic concerns the limits of human recollection, the “tip-of-tongue” memory event—which is found at a non-linearity in the model. We expand the theoretical framework, deriving an optimization formula to solve this non-linearity. Numerical results demonstrate how the higher frequency of rehearsal, through work or study, immediately increases the robustness and speed associated with expert memory. PMID:24808842

  4. Granger causality analysis reveals distinct spatio-temporal connectivity patterns in motor and perceptual visuo-spatial working memory

    PubMed Central

    Protopapa, Foteini; Siettos, Constantinos I.; Evdokimidis, Ioannis; Smyrnis, Nikolaos

    2014-01-01

    We employed spectral Granger causality analysis on a full set of 56 electroencephalographic recordings acquired during the execution of either a 2D movement pointing or a perceptual (yes/no) change detection task with memory and non-memory conditions. On the basis of network characteristics across frequency bands, we provide evidence for the full dissociation of the corresponding cognitive processes. Movement-memory trial types exhibited higher degree nodes during the first 2 s of the delay period, mainly at central, left frontal and right-parietal areas. Change detection-memory trial types resulted in a three-peak temporal pattern of the total degree with higher degree nodes emerging mainly at central, right frontal, and occipital areas. Functional connectivity networks resulting from non-memory trial types were characterized by more sparse structures for both tasks. The movement-memory trial types encompassed an apparent coarse flow from frontal to parietal areas while the opposite flow from occipital, parietal to central and frontal areas was evident for the change detection-memory trial types. The differences among tasks and conditions were more profound in α (8–12 Hz) and β (12–30 Hz) and less in γ (30–45 Hz) band. Our results favor the hypothesis which considers spatial working memory as a by-product of specific mental processes that engages common brain areas under different network organizations. PMID:25431557

  5. Selection in spatial working memory is independent of perceptual selective attention, but they interact in a shared spatial priority map.

    PubMed

    Hedge, Craig; Oberauer, Klaus; Leonards, Ute

    2015-11-01

    We examined the relationship between the attentional selection of perceptual information and of information in working memory (WM) through four experiments, using a spatial WM-updating task. Participants remembered the locations of two objects in a matrix and worked through a sequence of updating operations, each mentally shifting one dot to a new location according to an arrow cue. Repeatedly updating the same object in two successive steps is typically faster than switching to the other object; this object switch cost reflects the shifting of attention in WM. In Experiment 1, the arrows were presented in random peripheral locations, drawing perceptual attention away from the selected object in WM. This manipulation did not eliminate the object switch cost, indicating that the mechanisms of perceptual selection do not underlie selection in WM. Experiments 2a and 2b corroborated the independence of selection observed in Experiment 1, but showed a benefit to reaction times when the placement of the arrow cue was aligned with the locations of relevant objects in WM. Experiment 2c showed that the same benefit also occurs when participants are not able to mark an updating location through eye fixations. Together, these data can be accounted for by a framework in which perceptual selection and selection in WM are separate mechanisms that interact through a shared spatial priority map. PMID:26341873

  6. Prediction, Postdiction, and Perceptual Length Contraction: A Bayesian Low-Speed Prior Captures the Cutaneous Rabbit and Related Illusions

    PubMed Central

    Goldreich, Daniel; Tong, Jonathan

    2013-01-01

    Illusions provide a window into the brain’s perceptual strategies. In certain illusions, an ostensibly task-irrelevant variable influences perception. For example, in touch as in audition and vision, the perceived distance between successive punctate stimuli reflects not only the actual distance but curiously the inter-stimulus time. Stimuli presented at different positions in rapid succession are drawn perceptually toward one another. This effect manifests in several illusions, among them the startling cutaneous rabbit, in which taps delivered to as few as two skin positions appear to hop progressively from one position to the next, landing in the process on intervening areas that were never stimulated. Here we provide an accessible step-by-step exposition of a Bayesian perceptual model that replicates the rabbit and related illusions. The Bayesian observer optimally joins uncertain estimates of spatial location with the expectation that stimuli tend to move slowly. We speculate that this expectation – a Bayesian prior – represents the statistics of naturally occurring stimuli, learned by humans through sensory experience. In its simplest form, the model contains a single free parameter, tau: a time constant for space perception. We show that the Bayesian observer incorporates both pre- and post-dictive inference. Directed spatial attention affects the prediction-postdiction balance, shifting the model’s percept toward the attended location, as observed experimentally in humans. Applying the model to the perception of multi-tap sequences, we show that the low-speed prior fits perception better than an alternative, low-acceleration prior. We discuss the applicability of our model to related tactile, visual, and auditory illusions. To facilitate future model-driven experimental studies, we present a convenient freeware computer program that implements the Bayesian observer; we invite investigators to use this program to create their own testable predictions. PMID:23675360

  7. The global slowdown effect: why does perceptual grouping reduce perceived speed?

    PubMed

    Kohler, Peter Jes; Caplovitz, Gideon Paul; Tse, Peter Ulric

    2014-04-01

    The percept of four rotating dot pairs is bistable. The "local percept" is of four pairs of dots rotating independently. The "global percept" is of two large squares translating over one another (Anstis & Kim 2011). We have previously demonstrated (Kohler, Caplovitz, & Tse 2009) that the global percept appears to move more slowly than the local percept. Here, we investigate and rule out several hypotheses for why this may be the case. First, we demonstrate that the global slowdown effect does not occur because the global percept is of larger objects than the local percept. Second, we show that the global slowdown effect is not related to rotation-specific detectors that may be more active in the local than in the global percept. Third, we find that the effect is also not due to a reduction of image elements during grouping and can occur with a stimulus very different from the one used previously. This suggests that the effect may reflect a general property of perceptual grouping. Having ruled out these possibilities, we suggest that the global slowdown effect may arise from emergent motion signals that are generated by the moving dots, which are interpreted as the ends of "barbell bars" in the local percept or the corners of the illusory squares in the global percept. Alternatively, the effect could be the result of noisy sources of motion information that arise from perceptual grouping that, in turn, increase the influence of Bayesian priors toward slow motion (Weiss, Simoncelli, & Adelson 2002). PMID:24448695

  8. The effect of electroconvulsive therapy (ECT) on implicit memory: skill learning and perceptual priming in patients with major depression.

    PubMed

    Vakil, E; Grunhaus, L; Nagar, I; Ben-Chaim, E; Dolberg, O T; Dannon, P N; Schreiber, S

    2000-01-01

    While explicit memory in amnesics is impaired, their implicit memory remains preserved. Memory impairment is one of the side effects of electroconvulsive therapy (ECT). ECT patients are expected to show impairment on explicit but not implicit tasks. The present study examined 17 normal controls and 17 patients with severe major depressive disorder who underwent right unilateral ECT. Patients were tested in three sessions: 24-48 hours prior to, 24-48 hours following the first ECT, and 24-48 hours following the eighth ECT. The controls were tested in three sessions, at time intervals that paralleled those of the patients. Implicit memory was tested by the perceptual priming task - Partial Picture-Identification (PPI). The skill learning task used entailed solving the Tower of Hanoi puzzle (TOHP). Explicit memory was tested by picture recall from the PPI task, verbal recall of information regarding the TOHP, and by the Visual Paired Association (VPA) test. Results showed that explicit questions about the implicit tasks were impaired following ECT treatment. Patients' learning ability, as measured by the VPA task, was only impaired in the first testing session, prior to ECT treatment, reflecting the effect of depression. In addition, groups only differed in the first session on the learning rate of the skill learning task. Perceptual priming was preserved in the patients' group in all sessions, indicating that it is resilient to the effect of depression and ECT. The results are interpreted in terms of the differential effect of depression and ECT on explicit and implicit memory. PMID:10869584

  9. Effects of Animation's Speed of Presentation on Perceptual Processing and Learning

    ERIC Educational Resources Information Center

    Meyer, Katja; Rasch, Thorsten; Schnotz, Wolfgang

    2010-01-01

    Animations presented at different speed are assumed to differentially interact with learners' perception and cognition due to the constraints imposed by learners' limited sensitivity to incoming dynamic information. To investigate the effects of high and low presentation speed of animation, two studies were conducted. In Study 1, participants were…

  10. Effects of Animation's Speed of Presentation on Perceptual Processing and Learning

    ERIC Educational Resources Information Center

    Meyer, Katja; Rasch, Thorsten; Schnotz, Wolfgang

    2010-01-01

    Animations presented at different speed are assumed to differentially interact with learners' perception and cognition due to the constraints imposed by learners' limited sensitivity to incoming dynamic information. To investigate the effects of high and low presentation speed of animation, two studies were conducted. In Study 1, participants were

  11. Short-term memory and perceptual decision for three-dimensional visual features in the caudal intraparietal sulcus (Area CIP).

    PubMed

    Tsutsui, Ken-Ichiro; Jiang, Min; Sakata, Hideo; Taira, Masato

    2003-07-01

    The purpose of the present study was to examine whether neurons in the caudolateral part of the intraparietal sulcus (area CIP), a part of the posterior parietal cortex, contribute to short-term memory and perceptual decision of three-dimensional (3D) surface orientation, in addition to its purely visual nature of responding selectively to 3D surface orientation. Activities of CIP neurons were recorded while monkeys performed a modified delayed matching-to-sample (DMTS) task using stereoscopic stimuli. Seventy-seven neurons were examined with a routine of the DMTS task, and 94% (72 of 77) of them showed selectivity to surface orientation. Furthermore, 82% (63 of 77) of the examined neurons showed sustained activity during delay, and 60% (38 of 63) of them showed selective delay activity depending on the sample stimulus, suggesting that they contribute to short-term memory of 3D visual features. On the other hand, 53% (41 of 77) of the examined neurons showed modulation of visual response depending on whether a stimulus appeared as a sample, match, or nonmatch stimulus (contextual modulation). The majority (73%, 30 of 41) of these neurons with contextual modulation showed activity change depending on whether the test stimuli did or did not match the sample stimuli (match-nonmatch modulation), suggesting their involvement in matching, or perceptual decision, concerning 3D visual features. These findings suggest that CIP neurons play important roles not only in the perception of 3D visual features but also in cognitive functions such as short-term memory and perceptual decision of 3D visual information. PMID:12843248

  12. FoxP influences the speed and accuracy of a perceptual decision in Drosophila.

    PubMed

    DasGupta, Shamik; Ferreira, Clara Howcroft; Miesenböck, Gero

    2014-05-23

    Decisions take time if information gradually accumulates to a response threshold, but the neural mechanisms of integration and thresholding are unknown. We characterized a decision process in Drosophila that bears the behavioral signature of evidence accumulation. As stimulus contrast in trained odor discriminations decreased, reaction times increased and perceptual accuracy declined, in quantitative agreement with a drift-diffusion model. FoxP mutants took longer than wild-type flies to form decisions of similar or reduced accuracy, especially in difficult, low-contrast tasks. RNA interference with FoxP expression in αβ core Kenyon cells, or the overexpression of a potassium conductance in these neurons, recapitulated the FoxP mutant phenotype. A mushroom body subdomain whose development or function require the transcription factor FoxP thus supports the progression of a decision toward commitment. PMID:24855268

  13. Memory and Processing Speed in Preterm Children at Eleven Years: A Comparison with Full-Terms.

    ERIC Educational Resources Information Center

    Rose, Susan A.; Feldman, Judith F.

    1996-01-01

    Examined the effects of premature birth on ninety 11-year-olds' memory and processing speed, using the new Cognitive Abilities Test (CAT). Found that preterm subjects performed more poorly than their full-term counterparts on all CAT memory tasks, and that preterms were also slower on selected aspects of processing speed but not on motor speed.…

  14. Working memory capacity is associated with optimal adaptation of response bias to perceptual sensitivity in emotion perception.

    PubMed

    Lynn, Spencer K; Ibagon, Camila; Bui, Eric; Palitz, Sophie A; Simon, Naomi M; Barrett, Lisa Feldman

    2016-03-01

    Emotion perception, inferring the emotional state of another person, is a frequent judgment made under perceptual uncertainty (e.g., a scowling facial expression can indicate anger or concentration) and behavioral risk (e.g., incorrect judgment can be costly to the perceiver). Working memory capacity (WMC), the ability to maintain controlled processing in the face of competing demands, is an important component of many decisions. We investigated the association of WMC and anger perception in a task in which "angry" and "not angry" categories comprised overlapping ranges of scowl intensity, and correct and incorrect responses earned and lost points, respectively. Participants attempted to earn as many points as they could; adopting an optimal response bias would maximize decision utility. Participants with higher WMC more optimally tuned their anger perception response bias to accommodate their perceptual sensitivity (their ability to discriminate the categories) than did participants with lower WMC. Other factors that influence response bias (i.e., the relative base rate of angry vs. not angry faces and the decision costs and benefits) were ruled out as contributors to the WMC-bias relationship. Our results suggest that WMC optimizes emotion perception by contributing to perceivers' ability to adjust their response bias to account for their level of perceptual sensitivity, likely an important component of adapting emotion perception to dynamic social interactions and changing circumstances. (PsycINFO Database Record PMID:26461251

  15. Speed Matters: Relationship between Speed of Eye Movements and Modification of Aversive Autobiographical Memories.

    PubMed

    van Veen, Suzanne Chantal; van Schie, Kevin; Wijngaards-de Meij, Leoniek D N V; Littel, Marianne; Engelhard, Iris M; van den Hout, Marcel A

    2015-01-01

    Eye movement desensitization and reprocessing (EMDR) is an efficacious treatment for post-traumatic stress disorder. In EMDR, patients recall a distressing memory and simultaneously make eye movements (EM). Both tasks are considered to require limited working memory (WM) resources. Because this leaves fewer resources available for memory retrieval, the memory should become less vivid and less emotional during future recall. In EMDR analogue studies, a standardized procedure has been used, in which participants receive the same dual task manipulation of 1 EM cycle per second (1 Hz). From a WM perspective, the WM taxation of the dual task might be titrated to the WM taxation of the memory image. We hypothesized that highly vivid images are more affected by high WM taxation and less vivid images are more affected by low WM taxation. In study 1, 34 participants performed a reaction time task, and rated image vividness, and difficulty of retrieving an image, during five speeds of EM and no EM. Both a high WM taxing frequency (fast EM; 1.2 Hz) and a low WM taxing frequency (slow EM; 0.8 Hz) were selected. In study 2, 72 participants recalled three highly vivid aversive autobiographical memory images (n = 36) or three less vivid images (n = 36) under each of three conditions: recall + fast EM, recall + slow EM, or recall only. Multi-level modeling revealed a consistent pattern for all outcome measures: recall + fast EM led to less emotional, less vivid and more difficult to retrieve images than recall + slow EM and recall only, and the effects of recall + slow EM felt consistently in between the effects of recall + fast EM and recall only, but only differed significantly from recall + fast EM. Crucially, image vividness did not interact with condition on the decrease of emotionality over time, which was inconsistent with the prediction. Implications for understanding the mechanisms of action in memory modification and directions for future research are discussed. PMID:25904871

  16. Speed Matters: Relationship between Speed of Eye Movements and Modification of Aversive Autobiographical Memories

    PubMed Central

    van Veen, Suzanne Chantal; van Schie, Kevin; Wijngaards-de Meij, Leoniek D. N. V.; Littel, Marianne; Engelhard, Iris M.; van den Hout, Marcel A.

    2015-01-01

    Eye movement desensitization and reprocessing (EMDR) is an efficacious treatment for post-traumatic stress disorder. In EMDR, patients recall a distressing memory and simultaneously make eye movements (EM). Both tasks are considered to require limited working memory (WM) resources. Because this leaves fewer resources available for memory retrieval, the memory should become less vivid and less emotional during future recall. In EMDR analogue studies, a standardized procedure has been used, in which participants receive the same dual task manipulation of 1 EM cycle per second (1 Hz). From a WM perspective, the WM taxation of the dual task might be titrated to the WM taxation of the memory image. We hypothesized that highly vivid images are more affected by high WM taxation and less vivid images are more affected by low WM taxation. In study 1, 34 participants performed a reaction time task, and rated image vividness, and difficulty of retrieving an image, during five speeds of EM and no EM. Both a high WM taxing frequency (fast EM; 1.2 Hz) and a low WM taxing frequency (slow EM; 0.8 Hz) were selected. In study 2, 72 participants recalled three highly vivid aversive autobiographical memory images (n = 36) or three less vivid images (n = 36) under each of three conditions: recall + fast EM, recall + slow EM, or recall only. Multi-level modeling revealed a consistent pattern for all outcome measures: recall + fast EM led to less emotional, less vivid and more difficult to retrieve images than recall + slow EM and recall only, and the effects of recall + slow EM felt consistently in between the effects of recall + fast EM and recall only, but only differed significantly from recall + fast EM. Crucially, image vividness did not interact with condition on the decrease of emotionality over time, which was inconsistent with the prediction. Implications for understanding the mechanisms of action in memory modification and directions for future research are discussed. PMID:25904871

  17. Monetary Incentives in Speeded Perceptual Decision: Effects of Penalizing Errors Versus Slow Responses

    PubMed Central

    Dambacher, Michael; Hbner, Ronald; Schlsser, Jan

    2011-01-01

    The influence of monetary incentives on performance has been widely investigated among various disciplines. While the results reveal positive incentive effects only under specific conditions, the exact nature, and the contribution of mediating factors are largely unexplored. The present study examined influences of payoff schemes as one of these factors. In particular, we manipulated penalties for errors and slow responses in a speeded categorization task. The data show improved performance for monetary over symbolic incentives when (a) penalties are higher for slow responses than for errors, and (b) neither slow responses nor errors are punished. Conversely, payoff schemes with stronger punishment for errors than for slow responses resulted in worse performance under monetary incentives. The findings suggest that an emphasis of speed is favorable for positive influences of monetary incentives, whereas an emphasis of accuracy under time pressure has the opposite effect. PMID:21980316

  18. A Latent Variables Examination of Processing Speed, Response Inhibition, and Working Memory during Typical Development

    ERIC Educational Resources Information Center

    McAuley, Tara; White, Desiree A.

    2011-01-01

    This study addressed three related aims: (a) to replicate and extend previous work regarding the nonunitary nature of processing speed, response inhibition, and working memory during development; (b) to quantify the rate at which processing speed, response inhibition, and working memory develop and the extent to which the development of these

  19. Memory-based methodology for wind speed prediction

    SciTech Connect

    Song, Y.D.; Deng, X.H.

    1998-12-31

    A new approach for wind speed forecast is presented in this paper. This method makes use of memorized wind speed to predict the next step speed. It is shown that as long as the wind speed variation is not extremely brisk, the proposed algorithm is able to forecast the wind speed with a fairly good precision. The result is verified via computer simulation.

  20. Perceptual inference.

    PubMed

    Aggelopoulos, Nikolaos C

    2015-08-01

    Perceptual inference refers to the ability to infer sensory stimuli from predictions that result from internal neural representations built through prior experience. Methods of Bayesian statistical inference and decision theory model cognition adequately by using error sensing either in guiding action or in "generative" models that predict the sensory information. In this framework, perception can be seen as a process qualitatively distinct from sensation, a process of information evaluation using previously acquired and stored representations (memories) that is guided by sensory feedback. The stored representations can be utilised as internal models of sensory stimuli enabling long term associations, for example in operant conditioning. Evidence for perceptual inference is contributed by such phenomena as the cortical co-localisation of object perception with object memory, the response invariance in the responses of some neurons to variations in the stimulus, as well as from situations in which perception can be dissociated from sensation. In the context of perceptual inference, sensory areas of the cerebral cortex that have been facilitated by a priming signal may be regarded as comparators in a closed feedback loop, similar to the better known motor reflexes in the sensorimotor system. The adult cerebral cortex can be regarded as similar to a servomechanism, in using sensory feedback to correct internal models, producing predictions of the outside world on the basis of past experience. PMID:25976632

  1. Perceptual Filtering in L2 Lexical Memory: A Neural Network Approach to Second Language Acquisition

    ERIC Educational Resources Information Center

    Nelson, Robert

    2012-01-01

    A number of asymmetries in lexical memory emerge when monolinguals and early bilinguals are compared to (relatively) late second language (L2) learners. Their study promises to provide insight into the internal processes that both support and ultimately limit L2 learner achievement. Generally, theory building in L2 and bilingual lexical memory has…

  2. Three-year changes in leisure activities are associated with concurrent changes in white matter microstructure and perceptual speed in individuals aged 80 years and older.

    PubMed

    Köhncke, Ylva; Laukka, Erika J; Brehmer, Yvonne; Kalpouzos, Grégoria; Li, Tie-Qiang; Fratiglioni, Laura; Bäckman, Lars; Lövdén, Martin

    2016-05-01

    Accumulating evidence suggests that engagement in leisure activities is associated with favorable trajectories of cognitive aging, but little is known about brain changes related to both activities and cognition. White matter microstructure shows experience-dependent plasticity and declines in aging. Therefore, we investigated the role of change in white matter microstructure in the activities-cognition link. We used repeated assessments of engagement, perceptual speed, and white matter microstructure (probed with diffusion tensor imaging) in a population-based sample of individuals over 80 years without dementia (n = 442, Mage = 85.1; n = 70 for diffusion tensor imaging; 2 occasions 3 years apart). Using multivariate latent change modeling, we observed positive correlations among changes in predominantly social activities, white matter microstructure, and perceptual speed. Interindividual differences in change in white matter microstructure statistically accounted for the association between change in leisure activities and change in perceptual speed. However, as analyses are based on observational data from 2 measurement occasions, causality remains unclear. PMID:27103530

  3. Untangling Perceptual Memory: Hysteresis and Adaptation Map into Separate Cortical Networks

    PubMed Central

    Schwiedrzik, Caspar M.; Ruff, Christian C.; Lazar, Andreea; Leitner, Frauke C.; Singer, Wolf; Melloni, Lucia

    2014-01-01

    Perception is an active inferential process in which prior knowledge is combined with sensory input, the result of which determines the contents of awareness. Accordingly, previous experience is known to help the brain “decide” what to perceive. However, a critical aspect that has not been addressed is that previous experience can exert 2 opposing effects on perception: An attractive effect, sensitizing the brain to perceive the same again (hysteresis), or a repulsive effect, making it more likely to perceive something else (adaptation). We used functional magnetic resonance imaging and modeling to elucidate how the brain entertains these 2 opposing processes, and what determines the direction of such experience-dependent perceptual effects. We found that although affecting our perception concurrently, hysteresis and adaptation map into distinct cortical networks: a widespread network of higher-order visual and fronto-parietal areas was involved in perceptual stabilization, while adaptation was confined to early visual areas. This areal and hierarchical segregation may explain how the brain maintains the balance between exploiting redundancies and staying sensitive to new information. We provide a Bayesian model that accounts for the coexistence of hysteresis and adaptation by separating their causes into 2 distinct terms: Hysteresis alters the prior, whereas adaptation changes the sensory evidence (the likelihood function). PMID:23236204

  4. Microstructural White Matter Properties Mediate the Association between APOE and Perceptual Speed in Very Old Persons without Dementia

    PubMed Central

    Laukka, Erika J.; Lövdén, Martin; Kalpouzos, Grégoria; Papenberg, Goran; Keller, Lina; Graff, Caroline; Li, Tie-Qiang; Fratiglioni, Laura; Bäckman, Lars

    2015-01-01

    Background Reduced white matter integrity, as indicated by lower fractional anisotropy (FA) and higher mean diffusivity (MD), has been related to poorer perceptual speed (PS) performance. As the ε4 allele has been associated with lower white matter integrity in old age, this represents a potential mechanism through which APOE may affect PS. Objective To examine whether the association between APOE and PS is mediated by white matter microstructure in very old persons without dementia. Method Participants were selected from the population-based SNAC-K study. After excluding persons with dementia, preclinical dementia, and other neurological disorders, 652 persons (age range 78–90) were included in the study, of which 89 had data on diffusion tensor imaging (DTI). We used structural equation modeling to form seven latent white matter factors (FA and MD) and one latent PS factor. Separate analyses were performed for FA and MD and mediational analyses were carried out for tracts where significant associations were observed to both APOE and PS. Results APOE was associated with white matter microstructure in 2 out of 14 tracts; ε4 carriers had significantly lower FA in forceps major and higher MD in the cortico-spinal tract. Allowing the white matter microstructure indicators in these tracts to mediate the association between APOE and PS resulted in a markedly attenuated association between these variables. Bootstrapping statistics in the subsample with DTI data (n = 89) indicated that FA in forceps major significantly mediated the association between APOE and PS (indirect effect: -0.070, 95% bias corrected CIs -0.197 to -0.004). Conclusion Lower white matter integrity may represent one of several mechanisms through which APOE affects PS performance in elderly persons free of dementia and preclinical dementia. PMID:26252210

  5. Transfer-Appropriate Processing in Recognition Memory: Perceptual and Conceptual Effects on Recognition Memory Depend on Task Demands

    ERIC Educational Resources Information Center

    Parks, Colleen M.

    2013-01-01

    Research examining the importance of surface-level information to familiarity in recognition memory tasks is mixed: Sometimes it affects recognition and sometimes it does not. One potential explanation of the inconsistent findings comes from the ideas of dual process theory of recognition and the transfer-appropriate processing framework, which…

  6. Working Memory Is Related to Perceptual Processing: A Case from Color Perception

    ERIC Educational Resources Information Center

    Allen, Elizabeth C.; Beilock, Sian L.; Shevell, Steven K.

    2011-01-01

    We explored the relation between individual differences in working memory (WM) and color constancy, the phenomenon of color perception that allows us to perceive the color of an object as relatively stable under changes in illumination. Successive color constancy (measured by first viewing a colored surface under a particular illumination and

  7. The Ineluctable Modality of the Audible: Perceptual Determinants of Auditory Verbal Short-Term Memory

    ERIC Educational Resources Information Center

    Maidment, David W.; Macken, William J.

    2012-01-01

    Classical cognitive accounts of verbal short-term memory (STM) invoke an abstract, phonological level of representation which, although it may be derived differently via different modalities, is itself amodal. Key evidence for this view is that serial recall of phonologically similar verbal items (e.g., the letter sounds "b", "c", "g", and "d") is…

  8. Working Memory Is Related to Perceptual Processing: A Case from Color Perception

    ERIC Educational Resources Information Center

    Allen, Elizabeth C.; Beilock, Sian L.; Shevell, Steven K.

    2011-01-01

    We explored the relation between individual differences in working memory (WM) and color constancy, the phenomenon of color perception that allows us to perceive the color of an object as relatively stable under changes in illumination. Successive color constancy (measured by first viewing a colored surface under a particular illumination and…

  9. The Effects of Alcohol on the Speed of Memory Retrieval.

    ERIC Educational Resources Information Center

    Stempel, Jennifer J.; And Others

    Recent research has clearly indicated that intoxication with alcohol impairs memory. The present study investigated the effects of alcohol on retrieval from long-term memory by using a set of cognitive decision tasks. Subjects (N=24) were female college students in good health not taking oral contraceptives. Subjects were administered 0 or 1.0…

  10. Endurance-write-speed tradeoffs in nonvolatile memories

    NASA Astrophysics Data System (ADS)

    Strukov, Dmitri B.

    2016-04-01

    We derive phenomenological model for endurance-write time switching tradeoff for nonvolatile memories with thermally activated switching mechanisms. The model predicts linear to cubic dependence of endurance on write time for metal oxide memristors and flash memories, which is partially supported by experimental data for the breakdown of metal oxide thin films.

  11. The Effects of Alcohol on the Speed of Memory Retrieval.

    ERIC Educational Resources Information Center

    Stempel, Jennifer J.; And Others

    Recent research has clearly indicated that intoxication with alcohol impairs memory. The present study investigated the effects of alcohol on retrieval from long-term memory by using a set of cognitive decision tasks. Subjects (N=24) were female college students in good health not taking oral contraceptives. Subjects were administered 0 or 1.0

  12. Enabling Universal Memory by Overcoming the Contradictory Speed and Stability Nature of Phase-Change Materials

    PubMed Central

    Wang, Weijie; Loke, Desmond; Shi, Luping; Zhao, Rong; Yang, Hongxin; Law, Leong-Tat; Ng, Lung-Tat; Lim, Kian-Guan; Yeo, Yee-Chia; Chong, Tow-Chong; Lacaita, Andrea L.

    2012-01-01

    The quest for universal memory is driving the rapid development of memories with superior all-round capabilities in non-volatility, high speed, high endurance and low power. Phase-change materials are highly promising in this respect. However, their contradictory speed and stability properties present a key challenge towards this ambition. We reveal that as the device size decreases, the phase-change mechanism changes from the material inherent crystallization mechanism (either nucleation- or growth-dominated), to the hetero-crystallization mechanism, which resulted in a significant increase in PCRAM speeds. Reducing the grain size can further increase the speed of phase-change. Such grain size effect on speed becomes increasingly significant at smaller device sizes. Together with the nano-thermal and electrical effects, fast phase-change, good stability and high endurance can be achieved. These findings lead to a feasible solution to achieve a universal memory. PMID:22496956

  13. Enabling Universal Memory by Overcoming the Contradictory Speed and Stability Nature of Phase-Change Materials

    NASA Astrophysics Data System (ADS)

    Wang, Weijie; Loke, Desmond; Shi, Luping; Zhao, Rong; Yang, Hongxin; Law, Leong-Tat; Ng, Lung-Tat; Lim, Kian-Guan; Yeo, Yee-Chia; Chong, Tow-Chong; Lacaita, Andrea L.

    2012-04-01

    The quest for universal memory is driving the rapid development of memories with superior all-round capabilities in non-volatility, high speed, high endurance and low power. Phase-change materials are highly promising in this respect. However, their contradictory speed and stability properties present a key challenge towards this ambition. We reveal that as the device size decreases, the phase-change mechanism changes from the material inherent crystallization mechanism (either nucleation- or growth-dominated), to the hetero-crystallization mechanism, which resulted in a significant increase in PCRAM speeds. Reducing the grain size can further increase the speed of phase-change. Such grain size effect on speed becomes increasingly significant at smaller device sizes. Together with the nano-thermal and electrical effects, fast phase-change, good stability and high endurance can be achieved. These findings lead to a feasible solution to achieve a universal memory.

  14. Enabling universal memory by overcoming the contradictory speed and stability nature of phase-change materials.

    PubMed

    Wang, Weijie; Loke, Desmond; Shi, Luping; Zhao, Rong; Yang, Hongxin; Law, Leong-Tat; Ng, Lung-Tat; Lim, Kian-Guan; Yeo, Yee-Chia; Chong, Tow-Chong; Lacaita, Andrea L

    2012-01-01

    The quest for universal memory is driving the rapid development of memories with superior all-round capabilities in non-volatility, high speed, high endurance and low power. Phase-change materials are highly promising in this respect. However, their contradictory speed and stability properties present a key challenge towards this ambition. We reveal that as the device size decreases, the phase-change mechanism changes from the material inherent crystallization mechanism (either nucleation- or growth-dominated), to the hetero-crystallization mechanism, which resulted in a significant increase in PCRAM speeds. Reducing the grain size can further increase the speed of phase-change. Such grain size effect on speed becomes increasingly significant at smaller device sizes. Together with the nano-thermal and electrical effects, fast phase-change, good stability and high endurance can be achieved. These findings lead to a feasible solution to achieve a universal memory. PMID:22496956

  15. Letter Processing and the Formation of Memory Representations in Children with Naming Speed Deficits

    ERIC Educational Resources Information Center

    Conrad, Nicole J.; Levy, Betty Ann

    2007-01-01

    The ability to recognize letter patterns within words as a single unit is important for fluent reading. This skill is based on previously established memory representations of common letter patterns. The ability to form these memory representations may be impaired in some poor readers, particularly readers with naming speed deficits (NSD). This

  16. Letter Processing and the Formation of Memory Representations in Children with Naming Speed Deficits

    ERIC Educational Resources Information Center

    Conrad, Nicole J.; Levy, Betty Ann

    2007-01-01

    The ability to recognize letter patterns within words as a single unit is important for fluent reading. This skill is based on previously established memory representations of common letter patterns. The ability to form these memory representations may be impaired in some poor readers, particularly readers with naming speed deficits (NSD). This…

  17. Speeding in school zones: violation or lapse in prospective memory?

    PubMed

    Gregory, Bree; Irwin, Julia D; Faulks, Ian J; Chekaluk, Eugene

    2014-09-01

    Inappropriate speed is a causal factor in around one third of fatal accidents (OECD/ECMT, 2006). But are drivers always consciously responsible for their speeding behavior? Two studies are reported which show that an interruption to a journey, caused by stopping at a red traffic light, can result in failure to resume the speed of travel prior to the interruption (Study 1). In Study 2 we showed that the addition of a reminder cue could offset this interruption. These studies were conducted in a number of Australian school zone sites subject to a 40 km/h speed limit, requiring a reduction of between 20 km/h and 40 km/h. Motorists who had stopped at a red traffic signal sped on average, 8.27 km/h over the speed limit compared with only 1.76 km/h over the limit for those who had not been required to stop. In the second study a flashing "check speed" reminder cue, placed 70 m after the traffic lights, in the same school zones as those in Study 1 eliminated the interruptive effect of stopping with drivers resuming their journey at the legal speed. These findings have practical implications for the design of road environments, enforcement of speed limits, and the safety of pedestrians. PMID:24884545

  18. Design of a GHz high-speed memory system

    NASA Astrophysics Data System (ADS)

    Lim, Teck Y.; Foo, Say W.; Chan, Kheng Kang

    1999-12-01

    Digital application has moved towards operating speed of hundreds of Mega Hertz, with the sampling speed of ADC moving into Giga Hertz range. There is an increasing need for the design and development of a high-speed data acquisition system that is capable of capturing and processing digitized analogue signal at high speed. Due to the tight timing budget, high operating speed components, Emitter-Coupled-Logic families components with rise time of typically less than 300 ps were used in the design. With this operating speed and short rise time, signal integrity issues like reflections due to impedance mismatches and crosstalk among the traces of the printed circuit board can no longer be neglected. A quick and reliable approach was taken in the design and implementation of a 1 GHz high-speed data acquisition system using commercial-off-the-shelf discrete components. High-speed digital design issues and methodology were explored in this project and verified with the implemented hardware. This paper gives an overview of the system and focuses on the use of functional and signal- integrity computer simulation software to confirm system performance at the early design stage before actual hardware implementation. Simulation results were further confirmed with the actual hardware implemented, and was found to be close. This has helped to reduce the design cycle time and development cost of the project.

  19. THE EFFECTS OF SYSTEMATIC VARIATION OF SPEED AND DIRECTION OF OBJECT FLIGHT AND OF SKILL AND AGE CLASSIFICATIONS UPON VISUO-PERCEPTUAL JUDGMENTS OF MOVING OBJECTS IN THREE-DIMENSIONAL SPACE. FINAL REPORT.

    ERIC Educational Resources Information Center

    WILLIAMS, HARRIET G.

    THIS STUDY WAS CONDUCTED TO INVESTIGATE THE EFFECTS OF VARIATIONS IN THE SPEED AND DIRECTION OF A FLYING OBJECT ON VISUO-PERCEPTUAL JUDGMENTS MADE, DIFFERENCES IN THE ABILITY OF SKILLED AND UNSKILLED SUBJECTS IN MAKING SUCH JUDGMENTS, AND THE EFFECTS OF AGE OR MATURITY LEVEL ON THE SPEED AND ACCURACY OF SUCH JUDGMENTS. THE SUBJECTS WERE 54 MALE…

  20. Atomic thermal motion effect on efficiency of a high-speed quantum memory

    NASA Astrophysics Data System (ADS)

    Tikhonov, Kirill; Golubeva, Tania; Golubev, Yuri

    2015-11-01

    We discuss the influence of atomic thermal motion on the efficiency of multimode quantum memory in two configurations: over the free expand of atoms cooled beforehand in a magneto-optical trap, and over complete mixing of atoms in a closed cell at room temperature. We consider the high-speed quantum memory, and assume that writing and retrieval are short enough, and the displacements of atoms during these stages are negligibly small. At the same time we take in account thermal motion during the storage time, which, as well known, must be much longer than durations of all the other memory processes for successful application of memory cell in communication and computation. We will analyze this influence in terms of eigenmodes of the full memory cycle and show that distortion of the eigenmodes, caused by thermal motion, leads to the efficiency reduction. We will demonstrate, that in the multimode memory this interconnection has complicated character.

  1. Local bias in autistic subjects as evidenced by graphic tasks: perceptual hierarchization or working memory deficit?

    PubMed

    Mottron, L; Belleville, S; Ménard, E

    1999-07-01

    In the present study, copying tasks were used to assess hierarchical aspects of visual perception in a group of 10 nonsavant autistic individuals with normal intelligence. In Experiment 1, the hierarchical order of graphic construction and the constancy of this order were measured for the copying of objects and nonobjects. In comparison to control participants, autistic individuals produced more local features at the start of the copying. However, they did not differ from controls with respect to graphic constancy. Experiment 2 measured the effect of geometrical impossibility on the copying of figures. Results revealed that autistic individuals were less affected by figure impossibility than were controls. Therefore, these experiments seem to support the notion of a local bias for visual information processing in individuals with autism. Two interpretations are proposed to account for this effect. According to the hierarchical deficit hypothesis, individuals with autism do not manifest the normal global bias in perceiving scenes and objects. Alternatively, the executive function hypothesis suggests that autism brings about limitations in the complexity of information that can be manipulated in short-term visual memory during graphic planning. PMID:10433408

  2. High-Speed Behavior of Some Shape Memory Alloys

    SciTech Connect

    Bragov, Anatoly M.; Lomunov, Andrey K.; Sergeichev, Ivan V.

    2006-07-28

    The results of dynamic tests of shape memory alloys Ti-Ni and Cu-Al-Ni are given. Compressive tests of Ti-Ni alloy were carried out at temperatures 293-573K. Considerable influence of temperature on module of elasticity prior to the dislocation plastic flow and dislocation yield limit has been mentioned in temperature interval of reverse martensitic transformation. For Cu-Al-Ni alloy a strain rate influence on phase yield limit, module of elasticity prior to the phase unelastic flow, module of elasticity prior to the dislocation plastic flow was negligible. The method of determination of duration of reverse martensitic transformation has been realized by the example of Cu-Al-Ni alloy.

  3. Convergent validity of the Integrated Visual and Auditory Continuous Performance Test (IVA+Plus): associations with working memory, processing speed, and behavioral ratings.

    PubMed

    Arble, Eamonn; Kuentzel, Jeffrey; Barnett, Douglas

    2014-05-01

    Though the Integrated Visual and Auditory Continuous Performance Test (IVA + Plus) is commonly used by researchers and clinicians, few investigations have assessed its convergent and discriminant validity, especially with regard to its use with children. The present study details correlates of the IVA + Plus using measures of cognitive ability and ratings of child behavior (parent and teacher), drawing upon a sample of 90 psychoeducational evaluations. Scores from the IVA + Plus correlated significantly with the Working Memory and Processing Speed Indexes from the Fourth Edition of the Wechsler Intelligence Scales for Children (WISC-IV), though fewer and weaker significant correlations were seen with behavior ratings scales, and significant associations also occurred with WISC-IV Verbal Comprehension and Perceptual Reasoning. The overall pattern of relations is supportive of the validity of the IVA + Plus; however, general cognitive ability was associated with better performance on most of the primary scores of the IVA + Plus, suggesting that interpretation should take intelligence into account. PMID:24687587

  4. Non-volatile high-speed resistance switching nanogap junction memory

    NASA Astrophysics Data System (ADS)

    Kumaragurubaran, Somu; Takahashi, Tsuyoshi; Masuda, Yuichiro; Furuta, Shegio; Sumiya, Torou; Ono, Masatoshi; Shimizu, Tetsuo; Suga, Hiroshi; Horikawa, Masayo; Naitoh, Yasuhisa

    2011-12-01

    Different voltage pulses were applied to Au nanogap junction to study the resistance switching characteristics. Consistent switching from a low to high resistance state was accomplished even at 20 ns pulse. Instead of setting current compliance for the reverse switching, we introduced a series resistance to the nanogap junction to limit the tunneling current and effectively performed the switching. The parasitic capacitance is shown to affect the programming speed. Upon reducing the capacitance, ns regime switching speed is achieved which indicates the potentiality of nanogap junction for high-speed random access memory.

  5. Cognitive Risk Factors for Specific Learning Disorder: Processing Speed, Temporal Processing, and Working Memory.

    PubMed

    Moll, Kristina; Göbel, Silke M; Gooch, Debbie; Landerl, Karin; Snowling, Margaret J

    2016-05-01

    High comorbidity rates between reading disorder (RD) and mathematics disorder (MD) indicate that, although the cognitive core deficits underlying these disorders are distinct, additional domain-general risk factors might be shared between the disorders. Three domain-general cognitive abilities were investigated in children with RD and MD: processing speed, temporal processing, and working memory. Since attention problems frequently co-occur with learning disorders, the study examined whether these three factors, which are known to be associated with attention problems, account for the comorbidity between these disorders. The sample comprised 99 primary school children in four groups: children with RD, children with MD, children with both disorders (RD+MD), and typically developing children (TD controls). Measures of processing speed, temporal processing, and memory were analyzed in a series of ANCOVAs including attention ratings as covariate. All three risk factors were associated with poor attention. After controlling for attention, associations with RD and MD differed: Although deficits in verbal memory were associated with both RD and MD, reduced processing speed was related to RD, but not MD; and the association with RD was restricted to processing speed for familiar nameable symbols. In contrast, impairments in temporal processing and visuospatial memory were associated with MD, but not RD. PMID:25124507

  6. Associative Learning Predicts Intelligence above and beyond Working Memory and Processing Speed

    ERIC Educational Resources Information Center

    Kaufman, Scott Barry; DeYoung, Colin G; Gray, Jeremy R.; Brown, Jamie; Mackintosh, Nicholas

    2009-01-01

    Recent evidence suggests the existence of multiple cognitive mechanisms that support the general cognitive ability factor (g). Working memory and processing speed are the two best established candidate mechanisms. Relatively little attention has been given to the possibility that associative learning is an additional mechanism contributing to g.…

  7. A novel claw pole memory machine for wide-speed-range applications

    NASA Astrophysics Data System (ADS)

    Jian, Linni; Gong, Yu; Wei, Jin; Shi, Yujun; Shao, Ziyun; Ching, T. W.

    2015-05-01

    Memory machines with both high-power-density and wide-speed-range are becoming very attractive most recently. The purpose of this paper is to propose a novel type of memory machine, namely, claw pole memory machine. It engages an axially magnetized AlNiCo PM ring on the claw pole rotor to build the main magnetic flux in air-gap which is responsible for the electromechanical energy conversion. A magnetizing coil is equipped to online regulate the magnetization level of the permanent magnet ring, so as to achieve wide-speed-range operation. The operating principle is analyzed. The Preisach hysteresis model is combined with 3D finite element method to conduct performance assessment of the proposed claw pole memory machine. Calculation results demonstrate that the air-gap flux density can be readily adjusted by injecting DC pulse into the magnetizing coil, and the speed-range of the proposed machine can be extended as wide as six times of its base speed.

  8. Associative Learning Predicts Intelligence above and beyond Working Memory and Processing Speed

    ERIC Educational Resources Information Center

    Kaufman, Scott Barry; DeYoung, Colin G; Gray, Jeremy R.; Brown, Jamie; Mackintosh, Nicholas

    2009-01-01

    Recent evidence suggests the existence of multiple cognitive mechanisms that support the general cognitive ability factor (g). Working memory and processing speed are the two best established candidate mechanisms. Relatively little attention has been given to the possibility that associative learning is an additional mechanism contributing to g.

  9. Verbal Processing Speed and Executive Functioning in Long-Term Cochlear Implant Users

    ERIC Educational Resources Information Center

    AuBuchon, Angela M.; Pisoni, David B.; Kronenberger, William G.

    2015-01-01

    Purpose: The purpose of this study was to report how "verbal rehearsal speed" (VRS), a form of covert speech used to maintain verbal information in working memory, and another verbal processing speed measure, perceptual encoding speed, are related to 3 domains of executive function (EF) at risk in cochlear implant (CI) users: verbal

  10. Verbal Processing Speed and Executive Functioning in Long-Term Cochlear Implant Users

    ERIC Educational Resources Information Center

    AuBuchon, Angela M.; Pisoni, David B.; Kronenberger, William G.

    2015-01-01

    Purpose: The purpose of this study was to report how "verbal rehearsal speed" (VRS), a form of covert speech used to maintain verbal information in working memory, and another verbal processing speed measure, perceptual encoding speed, are related to 3 domains of executive function (EF) at risk in cochlear implant (CI) users: verbal…

  11. High speed vision processor with reconfigurable processing element array based on full-custom distributed memory

    NASA Astrophysics Data System (ADS)

    Chen, Zhe; Yang, Jie; Shi, Cong; Qin, Qi; Liu, Liyuan; Wu, Nanjian

    2016-04-01

    In this paper, a hybrid vision processor based on a compact full-custom distributed memory for near-sensor high-speed image processing is proposed. The proposed processor consists of a reconfigurable processing element (PE) array, a row processor (RP) array, and a dual-core microprocessor. The PE array includes two-dimensional processing elements with a compact full-custom distributed memory. It supports real-time reconfiguration between the PE array and the self-organized map (SOM) neural network. The vision processor is fabricated using a 0.18 µm CMOS technology. The circuit area of the distributed memory is reduced markedly into 1/3 of that of the conventional memory so that the circuit area of the vision processor is reduced by 44.2%. Experimental results demonstrate that the proposed design achieves correct functions.

  12. A Perceptual Repetition Blindness Effect

    NASA Technical Reports Server (NTRS)

    Hochhaus, Larry; Johnston, James C.; Null, Cynthia H. (Technical Monitor)

    1994-01-01

    Before concluding Repetition Blindness is a perceptual phenomenon, alternative explanations based on memory retrieval problems and report bias must be rejected. Memory problems were minimized by requiring a judgment about only a single briefly displayed field. Bias and sensitivity effects were empirically measured with an ROC-curve analysis method based on confidence ratings. Results from five experiments support the hypothesis that Repetition Blindness can be a perceptual phenomenon.

  13. Dissociable mechanisms of speed-accuracy tradeoff during visual perceptual learning are revealed by a hierarchical drift-diffusion model

    PubMed Central

    Zhang, Jiaxiang; Rowe, James B.

    2014-01-01

    Two phenomena are commonly observed in decision-making. First, there is a speed-accuracy tradeoff (SAT) such that decisions are slower and more accurate when instructions emphasize accuracy over speed, and vice versa. Second, decision performance improves with practice, as a task is learnt. The SAT and learning effects have been explained under a well-established evidence-accumulation framework for decision-making, which suggests that evidence supporting each choice is accumulated over time, and a decision is committed to when the accumulated evidence reaches a decision boundary. This framework suggests that changing the decision boundary creates the tradeoff between decision speed and accuracy, while increasing the rate of accumulation leads to more accurate and faster decisions after learning. However, recent studies challenged the view that SAT and learning are associated with changes in distinct, single decision parameters. Further, the influence of speed-accuracy instructions over the course of learning remains largely unknown. Here, we used a hierarchical drift-diffusion model to examine the SAT during learning of a coherent motion discrimination task across multiple training sessions, and a transfer test session. The influence of speed-accuracy instructions was robust over training and generalized across untrained stimulus features. Emphasizing decision accuracy rather than speed was associated with increased boundary separation, drift rate and non-decision time at the beginning of training. However, after training, an emphasis on decision accuracy was only associated with increased boundary separation. In addition, faster and more accurate decisions after learning were due to a gradual decrease in boundary separation and an increase in drift rate. The results suggest that speed-accuracy instructions and learning differentially shape decision-making processes at different time scales. PMID:24782701

  14. A two-factor theory for concussion assessment using ImPACT: memory and speed.

    PubMed

    Schatz, Philip; Maerlender, Arthur

    2013-12-01

    We present the initial validation of a two-factor structure of Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) using ImPACT composite scores and document the reliability and validity of this factor structure. Factor analyses were conducted for baseline (N = 21,537) and post-concussion (N = 560) data, yielding "Memory" (Verbal and Visual) and "Speed" (Visual Motor Speed and Reaction Time) Factors; inclusion of Total Symptom Scores resulted in a third discrete factor. Speed and Memory z-scores were calculated, and test-retest reliability (using intra-class correlation coefficients) at 1 month (0.88/0.81), 1 year (0.85/0.75), and 2 years (0.76/0.74) were higher than published data using Composite scores. Speed and Memory scores yielded 89% sensitivity and 70% specificity, which was higher than composites (80%/62%) and comparable with subscales (91%/69%). This emergent two-factor structure has improved test-retest reliability with no loss of sensitivity/specificity and may improve understanding and interpretability of ImPACT test results. PMID:24123401

  15. Delayed Perceptual Awareness in Rapid Perceptual Decisions

    PubMed Central

    Gregori-Grgič, Regina; Balderi, Monica; de'Sperati, Claudio

    2011-01-01

    The flourishing of studies on the neural correlates of decision-making calls for an appraisal of the relation between perceptual decisions and conscious perception. By exploiting the long integration time of noisy motion stimuli, and by forcing human observers to make difficult speeded decisions – sometimes a blind guess – about stimulus direction, we traced the temporal buildup of motion discrimination capability and perceptual awareness, as assessed trial by trial through direct rating. We found that both increased gradually with motion coherence and viewing time, but discrimination was systematically leading awareness, reaching a plateau much earlier. Sensitivity and criterion changes contributed jointly to the slow buildup of perceptual awareness. It made no difference whether motion discrimination was accomplished by saccades or verbal responses. These findings suggest that perceptual awareness emerges on the top of a developing or even mature perceptual decision. We argue that the middle temporal (MT) cortical region does not confer us the full phenomenic depth of motion perception, although it may represent a precursor stage in building our subjective sense of visual motion. PMID:21379582

  16. Perceptual-Gestural (Mis)Mapping in Serial Short-Term Memory: The Impact of Talker Variability

    ERIC Educational Resources Information Center

    Hughes, Robert W.; Marsh, John E.; Jones, Dylan M.

    2009-01-01

    The mechanisms underlying the poorer serial recall of talker-variable lists (e.g., alternating female-male voices) as compared with single-voice lists were examined. We tested the novel hypothesis that this "talker variability effect" arises from the tendency for perceptual organization to partition the list into streams based on voice such that

  17. Perceptual-Gestural (Mis)Mapping in Serial Short-Term Memory: The Impact of Talker Variability

    ERIC Educational Resources Information Center

    Hughes, Robert W.; Marsh, John E.; Jones, Dylan M.

    2009-01-01

    The mechanisms underlying the poorer serial recall of talker-variable lists (e.g., alternating female-male voices) as compared with single-voice lists were examined. We tested the novel hypothesis that this "talker variability effect" arises from the tendency for perceptual organization to partition the list into streams based on voice such that…

  18. Perceptual Repetition Blindness Effects

    NASA Technical Reports Server (NTRS)

    Hochhaus, Larry; Johnston, James C.; Null, Cynthia H. (Technical Monitor)

    1994-01-01

    The phenomenon of repetition blindness (RB) may reveal a new limitation on human perceptual processing. Recently, however, researchers have attributed RB to post-perceptual processes such as memory retrieval and/or reporting biases. The standard rapid serial visual presentation (RSVP) paradigm used in most RB studies is, indeed, open to such objections. Here we investigate RB using a "single-frame" paradigm introduced by Johnston and Hale (1984) in which memory demands are minimal. Subjects made only a single judgement about whether one masked target word was the same or different than a post-target probe. Confidence ratings permitted use of signal detection methods to assess sensitivity and bias effects. In the critical condition for RB a precue of the post-target word was provided prior to the target stimulus (identity precue), so that the required judgement amounted to whether the target did or did not repeat the precue word. In control treatments, the precue was either an unrelated word or a dummy (XXXX). Results of five experiments show that perceptual sensitivity is strikingly and significantly reduced in the RB condition relative to both baseline control conditions. The data show RB can be obtained under conditions in which memory problems are minimal and where perceptual sensitivity is assessed independently of biases.

  19. Relationships Among Linguistic Processing Speed, Phonological Working Memory, and Attention in Children Who Stutter

    PubMed Central

    Anderson, Julie D.; Wagovich, Stacy A.

    2010-01-01

    Relatively recently, experimental studies of linguistic processing speed in children who stutter (CWS) have emerged, some of which suggest differences in performance among CWS compared to children who do not stutter (CWNS). What is not yet well understood is the extent to which underlying cognitive skills may impact performance on timed tasks of linguistic performance. The purpose of this study was to explore possible relationships between measures of linguistic processing speed and two aspects of cognition: phonological working memory and attention. Participants were 9 CWS and 14 CWNS between the ages of 3;6 and 5;2. Children participated in a computerized picture naming task (an index of linguistic processing speed) and a nonword repetition task (an index of phonological working memory). Parents completed a temperament behavior questionnaire, from which information about the children’s attentional skills was collected. Findings revealed that the groups did not differ from each other on speed of picture naming or attention; however, the CWS performed significantly worse in nonword repetition. In addition, after partialling out the effects of age, (a) for CWS only, there was a significant negative relationship between picture naming speed and nonword repetition; (b) there were no significant relationships for either group between aspects of attention and picture naming speed; and (c) only the CWNS showed a significant relationship between nonword repetition and focused attentional skills. These results underscore the need to consider the underlying skills associated with lexically-related aspects of language production when examining the task performances of CWS and CWNS. PMID:20831969

  20. High speed switching in quantum Dot/Ti-TiOx nonvolatile memory device

    NASA Astrophysics Data System (ADS)

    Kannan, V.; Kim, Hyun-Seok; Park, Hyun-Chang

    2016-03-01

    We report a Ti-TiOx/CdSe-ZnS core-shell quantum dot based bipolar nonvolatile resistive memory device. The device exhibits an ON/OFF ratio of 100 and is reproducible. The memory device showed good retention characteristics under stress and excellent stability even after 100,000 cycles of switching operation. The switching speed measured was around 15 ns. The devices are solution processed at room temperature in ambient atmosphere. The operating mechanism is discussed based on charge trapping in quantum dots resulting in the Coulomb blockade effect with a ZnS shell layer and metal-oxide layer acting as the barrier to confine the trapped charges. The proposed mechanism is validated by a three terminal device designed exclusively for this purpose. [Figure not available: see fulltext.

  1. Microwave synthesis and actuation of shape memory polycaprolactone foams with high speed

    PubMed Central

    Zhang, Fenghua; Zhou, Tianyang; Liu, Yanju; Leng, Jinsong

    2015-01-01

    Microwave technology is a highly effective approach to fast and uniform heating. This article investigates that the microwave heating as a novel method is used to rapidly foam and actuate biocompatible and biodegradable shape memory crosslinked-polycaprolactone (c-PCL) foams. The optical microscope proves that the resulting c-PCL foams have homogenous pore structure. Mechanical behavior and shape memory performance of c-PCL foams are investigated by static materials testing. Shape recovery ratio is approximately 100% and the whole recovery process takes only 98 s when trigged by microwave. Due to the unique principle of microwave heating, the recovery speed of c-PCL foams in microwave oven is several times faster than that in hot water and electric oven. Hence compared to the traditional heating methods, microwave is expected to bring more advantages to modern industry and scientific research in the field of smart materials and structures. PMID:26053586

  2. Microwave synthesis and actuation of shape memory polycaprolactone foams with high speed.

    PubMed

    Zhang, Fenghua; Zhou, Tianyang; Liu, Yanju; Leng, Jinsong

    2015-01-01

    Microwave technology is a highly effective approach to fast and uniform heating. This article investigates that the microwave heating as a novel method is used to rapidly foam and actuate biocompatible and biodegradable shape memory crosslinked-polycaprolactone (c-PCL) foams. The optical microscope proves that the resulting c-PCL foams have homogenous pore structure. Mechanical behavior and shape memory performance of c-PCL foams are investigated by static materials testing. Shape recovery ratio is approximately 100% and the whole recovery process takes only 98 s when trigged by microwave. Due to the unique principle of microwave heating, the recovery speed of c-PCL foams in microwave oven is several times faster than that in hot water and electric oven. Hence compared to the traditional heating methods, microwave is expected to bring more advantages to modern industry and scientific research in the field of smart materials and structures. PMID:26053586

  3. Microwave synthesis and actuation of shape memory polycaprolactone foams with high speed

    NASA Astrophysics Data System (ADS)

    Zhang, Fenghua; Zhou, Tianyang; Liu, Yanju; Leng, Jinsong

    2015-06-01

    Microwave technology is a highly effective approach to fast and uniform heating. This article investigates that the microwave heating as a novel method is used to rapidly foam and actuate biocompatible and biodegradable shape memory crosslinked-polycaprolactone (c-PCL) foams. The optical microscope proves that the resulting c-PCL foams have homogenous pore structure. Mechanical behavior and shape memory performance of c-PCL foams are investigated by static materials testing. Shape recovery ratio is approximately 100% and the whole recovery process takes only 98 s when trigged by microwave. Due to the unique principle of microwave heating, the recovery speed of c-PCL foams in microwave oven is several times faster than that in hot water and electric oven. Hence compared to the traditional heating methods, microwave is expected to bring more advantages to modern industry and scientific research in the field of smart materials and structures.

  4. Cycles in Speed-Working Memory-G Relations: Towards a Developmental-Differential Theory of the Mind

    ERIC Educational Resources Information Center

    Demetriou, Andreas; Spanoudis, George; Shayer, Michael; Mouyi, Antigoni; Kazi, Smaragda; Platsidou, Maria

    2013-01-01

    This article presents three studies, two of them longitudinal, which investigated the relations between age, processing speed, working memory (WM), and fluid intelligence ("g[subscript f]") from 4 to 16 years of age. Structural equation modeling showed that speed was a powerful covariate of age ([approximately] - 0.6 to - 0.7) from 4 to 13 years,…

  5. Cycles in Speed-Working Memory-G Relations: Towards a Developmental-Differential Theory of the Mind

    ERIC Educational Resources Information Center

    Demetriou, Andreas; Spanoudis, George; Shayer, Michael; Mouyi, Antigoni; Kazi, Smaragda; Platsidou, Maria

    2013-01-01

    This article presents three studies, two of them longitudinal, which investigated the relations between age, processing speed, working memory (WM), and fluid intelligence ("g[subscript f]") from 4 to 16 years of age. Structural equation modeling showed that speed was a powerful covariate of age ([approximately] - 0.6 to - 0.7) from 4 to 13 years,

  6. An ASIC memory buffer controller for a high speed disk system

    NASA Technical Reports Server (NTRS)

    Hodson, Robert F.; Campbell, Steve

    1993-01-01

    The need for large capacity, high speed mass memory storage devices has become increasingly evident at NASA during the past decade. High performance mass storage systems are crucial to present and future NASA systems. Spaceborne data storage system requirements have grown in response to the increasing amounts of data generated and processed by orbiting scientific experiments. Predictions indicate increases in the volume of data by orders of magnitude during the next decade. Current predictions are for storage capacities on the order of terabits (Tb), with data rates exceeding one gigabit per second (Gbps). As part of the design effort for a state of the art mass storage system, NASA Langley has designed a 144 CMOS ASIC to support high speed data transfers. This paper discusses the system architecture, ASIC design and some of the lessons learned in the development process.

  7. Dual N-Back Working Memory Training in Healthy Adults: A Randomized Comparison to Processing Speed Training

    PubMed Central

    Lawlor-Savage, Linette; Goghari, Vina M.

    2016-01-01

    Enhancing cognitive ability is an attractive concept, particularly for middle-aged adults interested in maintaining cognitive functioning and preventing age-related declines. Computerized working memory training has been investigated as a safe method of cognitive enhancement in younger and older adults, although few studies have considered the potential impact of working memory training on middle-aged adults. This study investigated dual n-back working memory training in healthy adults aged 30–60. Fifty-seven adults completed measures of working memory, processing speed, and fluid intelligence before and after a 5-week web-based dual n-back or active control (processing speed) training program. Results: Repeated measures multivariate analysis of variance failed to identify improvements across the three cognitive composites, working memory, processing speed, and fluid intelligence, after training. Follow-up Bayesian analyses supported null findings for training effects for each individual composite. Findings suggest that dual n-back working memory training may not benefit working memory or fluid intelligence in healthy adults. Further investigation is necessary to clarify if other forms of working memory training may be beneficial, and what factors impact training-related benefits, should they occur, in this population. PMID:27043141

  8. Menstrual Cycle Effects on Perceptual Closure Mediate Changes in Performance on a Fragmented Objects Test of Implicit Memory

    ERIC Educational Resources Information Center

    Hampson, E.; Finestone, J.M.; Levy, N.

    2005-01-01

    Healthy premenopausal women with regular menstrual cycles were assessed on a fragmented objects test of implicit memory. Testing took place at either the low estrogen (n=17) or the high estrogen (n=16) stages of the menstrual cycle. Concentrations of ovarian hormones were confirmed by saliva assays. Both groups of women exhibited a priming effect,

  9. Menstrual Cycle Effects on Perceptual Closure Mediate Changes in Performance on a Fragmented Objects Test of Implicit Memory

    ERIC Educational Resources Information Center

    Hampson, E.; Finestone, J.M.; Levy, N.

    2005-01-01

    Healthy premenopausal women with regular menstrual cycles were assessed on a fragmented objects test of implicit memory. Testing took place at either the low estrogen (n=17) or the high estrogen (n=16) stages of the menstrual cycle. Concentrations of ovarian hormones were confirmed by saliva assays. Both groups of women exhibited a priming effect,…

  10. Self-Construal Priming Affects Speed of Retrieval from Short-Term Memory

    PubMed Central

    MacDonald, Justin A.; Sandry, Joshua; Rice, Stephen

    2012-01-01

    We investigated the effects of collective or individual self-construal priming on recall in a short-term memory (STM) task. We primed participants to either their individual or their collective self-construals or a neutral control condition. Participants then completed a STM retrieval task using either random or patterned digit strings. Findings revealed that priming an individual self-construal resulted in faster retrieval of information from STM for both stimulus types. These results indicate that individual self-accessibility improves retrieval speed of digits from STM, regardless of set configuration. More broadly, the present findings extend prior research by adding further evidence of the effects of self-construal priming on cognitive information processing. PMID:23209632

  11. Pitch discrimination as a function of the inter-stimulus interval: Evidence against a simple model of perceptual memory

    NASA Astrophysics Data System (ADS)

    Demany, Laurent; Montandon, Gaspard; Semal, Catherine

    2003-04-01

    A listener's ability to compare two sounds separated by a silent time interval T is limited by a sum of ``sensory noise'' and ``memory noise.'' The present work was intended to test a model according to which these two components of internal noise are independent and, for a given sensory continuum, the memory noise depends only on T. In three experiments using brief sounds (<80 ms), pitch discrimination performances were measured in terms of d' as a function of T (0.1-4 s) and a physical parameter affecting the amount of sensory noise (pitch salience). As T increased, d' first increased rapidly and then declined more slowly. According to the tested model, the relative decline of d' beyond the optimal value of T should have been slower when pitch salience was low (large amount of sensory noise) than when pitch salience was high (small amount of sensory noise). However, this prediction was disproved in each of the three experiments. It was also found, when a ``roving'' procedure was used, that the optimal value of T was markedly shorter for very brief tone bursts (6 sine cycles) than for longer tone bursts (30 sine cycles).

  12. Enhancing Cognitive Function Using Perceptual-Cognitive Training.

    PubMed

    Parsons, Brendan; Magill, Tara; Boucher, Alexandra; Zhang, Monica; Zogbo, Katrine; Bérubé, Sarah; Scheffer, Olivier; Beauregard, Mario; Faubert, Jocelyn

    2016-01-01

    Three-dimensional multiple object tracking (3D-MOT) is a perceptual-cognitive training system based on a 3D virtual environment. This is the first study to examine the effects of 3D-MOT training on attention, working memory, and visual information processing speed as well as using functional brain imaging on a normative population. Twenty university-aged students were recruited and divided into a training (NT) and nonactive control (CON) group. Cognitive functions were assessed using neuropsychological tests, and correlates of brain functions were assessed using quantitative electroencephalography (qEEG). Results indicate that 10 sessions of 3D-MOT training can enhance attention, visual information processing speed, and working memory, and also leads to quantifiable changes in resting-state neuroelectric brain function. PMID:25550444

  13. Perceptual-Cognitive Expertise in Elite Volleyball Players

    PubMed Central

    Alves, Heloisa; Voss, Michelle W.; Boot, Walter R.; Deslandes, Andrea; Cossich, Victor; Salles, Jose Inacio; Kramer, Arthur F.

    2013-01-01

    The goal of the current study was to investigate the relationship between sport expertise and perceptual and cognitive skills, as measured by the component skills approach. We hypothesized that athletes would outperform non-athlete controls in a number of perceptual and cognitive domains and that sport expertise would minimize gender differences. A total of 154 individuals (87 professional volleyball players and 67 non-athlete controls) participated in the study. Participants performed a cognitive battery, which included tests of executive control, memory, and visuo-spatial attention. Athletes showed superior performance speed on three tasks (two executive control tasks and one visuo-spatial attentional processing task). In a subset of tasks, gender effects were observed mainly in the control group, supporting the notion that athletic experience can reduce traditional gender effects. The expertise effects obtained substantiate the view that laboratory tests of cognition may indeed enlighten the sport-cognition relationship. PMID:23471100

  14. Processing Speed, Inhibitory Control, and Working Memory: Three Important Factors to Account for Age-Related Cognitive Decline

    ERIC Educational Resources Information Center

    Pereiro Rozas, Arturo X.; Juncos-Rabadan, Onesimo; Gonzalez, Maria Soledad Rodriguez

    2008-01-01

    Processing speed, inhibitory control and working memory have been identified as the main possible culprits of age-related cognitive decline. This article describes a study of their interrelationships and dependence on age, including exploration of whether any of them mediates between age and the others. We carried out a LISREL analysis of the…

  15. Increased single-photon emission computed tomography image processing speed achieved in personal computers with memory-intensive algorithms.

    PubMed

    Pratt, J P; Lear, J L

    1993-11-01

    Recent dramatic reductions in the cost of computer random access memory (RAM) and the ability of newer microprocessors and associated personal computer operating systems to address large amounts of memory make novel strategies for high-speed image processing possible. We developed image processing algorithms that use this newly available memory to achieve increases in effective processing speed. These algorithms rely on the use of precomputed lookup tables to avoid repeated use of relatively expensive machine instructions, such as multiplications and divisions. Programs using this strategy to perform single photon emission computer tomography (SPECT) analysis were written in C and assembly language and tested on a Macintosh Quadra 950 (Apple Computer, Cupertino, CA) having 64 megabytes of RAM. The measured processing times are competitive with most dedicated nuclear medicine computers. A general implementation of such programs will allow personal computers to compete with dedicated imaging systems, at a substantial reduction in cost. PMID:8292644

  16. Perceptual telerobotics

    NASA Technical Reports Server (NTRS)

    Ligomenides, Panos A.

    1989-01-01

    A sensory world modeling system, congruent with a human expert's perception, is proposed. The Experiential Knowledge Base (EKB) system can provide a highly intelligible communication interface for telemonitoring and telecontrol of a real time robotic system operating in space. Paradigmatic acquisition of empirical perceptual knowledge, and real time experiential pattern recognition and knowledge integration are reviewed. The cellular architecture and operation of the EKB system are also examined.

  17. Active microring optical integrator associated with electroabsorption modulators for high speed low light power loadable and erasable optical memory unit.

    PubMed

    Ding, Yunhong; Zhang, Xiaobei; Zhang, Xinliang; Huang, Dexiu

    2009-07-20

    We propose and analyze a novel loadable and erasable optical memory unit based on an active microring optical integrator associated with electroabsorption modulators (EAM) on III-V material system. The gain of the active microring is characterized by the two energy band model with amplified spontaneous emission noises taken into account. Based on the light field propagation equation in the active microring waveguide and the transfer function of the EAM-MZI switch, the step function performances of the optical memory under the gain matching condition are discussed for different injection light powers. After that, the memory operation of the novel optical memory unit is analyzed in detail. Simulations show that, the step function response and memory performances are affected by the carrier consumption. However, such influence will be released, and the memory operates well for the low light power injection case. The novel optical memory unit is promising to be cascaded connected and densely integrated for high speed low power optical data stream storage and buffer. PMID:19654690

  18. GaAs analog to digital converter and memory IC's for ultra high speed transient recording

    SciTech Connect

    Eden, R.C.

    1983-02-01

    The excellent electron dynamical properties of gallium arsenide enable GaAs devices to achieve high speed performance levels many times those of corresponding silicon devices. These device performance advantages carry over into integrated circuit technologies as well, aided significantly by the fact that GaAs substrate material is available in semi-insulating (>10/sup 8/..cap omega..cm) form for very low parasitics in monolithic integrated circuits. This has led to the achievement of logic delays as low as 12.8ps at 77/sup 0/K or 16.8ps at 300/sup 0/K in the more exotic GaAs IC approaches. In the standard 1..mu..m gate length, planar MESFET GaAs circuits, ring oscillator delays of /tau/ /SUB d/ =52ps at P /SUB D/ =1mw/gate have been demonstrated, increasing to /tau/ /SUB d/ =70ps at P /SUB D/ =2mw/gate in MSI flip flop circuits (standard f /SUB toggle/ =1/5/tau/ /SUB d/ type-D flip flops toggle up to nearly 3 GHz). The planar ion implanted GaAs MESFET circuits have been fabricated in circuit complexities up to 1008 logic gates, with NOR gate delays as low as 150ps obtained in these LSI chips (e.g., a 35/tau/ /SUB d/ multiply time of 5.25ns in 8x8 bit latched parallel multiplier circuits). These 1..mu..m gate length MESFET circuits have been fabricated on up to 3'' diameter GaAs wafers using the same type of DSW optical lithography used for silicon VLSI, which is considered ample evidence that this GaAs IC technology can be cost-effective and is ready for commercialization. These paper focuses on the application of this MESFET GaAs IC technology for the types of digital memory and analog to digital converter circuits required to implement ultra high speed transient recorders.

  19. Working Memory and Arithmetic Calculation in Children: The Contributory Roles of Processing Speed, Short-Term Memory, and Reading

    ERIC Educational Resources Information Center

    Berg, Derek H.

    2008-01-01

    The cognitive underpinnings of arithmetic calculation in children are noted to involve working memory; however, cognitive processes related to arithmetic calculation and working memory suggest that this relationship is more complex than stated previously. The purpose of this investigation was to examine the relative contributions of processing…

  20. Processing Speed and Memory Mediate Age-Related Differences in Decision Making

    PubMed Central

    Henninger, Debra E.; Madden, David J.; Huettel, Scott A.

    2010-01-01

    Decision making under risk changes with age. Most commonly characterized have been increases in risk-aversion with age, although older adults may also be risk-seeking in some decision contexts. An important, and unanswered, question is whether these changes in decision making reflect a direct effect of aging or, alternatively, an indirect effect caused by age-related changes in specific cognitive processes. In the current study, older adults (mean = 71 years) and younger adults (mean = 24 years) completed a battery of tests of cognitive capacities and decision-making preferences. The results indicated systematic effects of age upon decision quality – with both increased risk-seeking and increased risk-aversion observed in different tasks – consistent with prior studies. Path analyses, however, revealed that age-related effects were mediated by individual differences in processing speed and memory. When those variables were included in the model, age was no longer a significant predictor of decision quality. The authors conclude that the reduction in decision quality (and associated changes in risk preferences) commonly ascribed to aging are instead mediated by age-related changes in underlying cognitive capacities. PMID:20545412

  1. Assessing the validity of computer-game-like tests of processing speed and working memory.

    PubMed

    McPherson, Jason; Burns, Nicholas R

    2008-11-01

    Processing speed (Gs) and working memory (WM) tasks have received considerable interest as correlates of more complex cognitive performance measures. Gs and WM tasks are often repetitive and are often rigidly presented, however. The effects of Gs and WM may, therefore, be confounded with those of motivation and anxiety. In an effort to address this problem, we assessed the concurrent and predictive validity of computer-game-like tests of Gs (Space Code) and WM (Space Matrix) across two experiments. In Experiment 1, within a university sample (N = 70), Space Matrix exhibited concurrent validity as a WM measure, whereas Space Code appeared to be a mixed-ability measure. In Experiment 2, Space Matrix exhibited concurrent validity as well as predictive validity (as a predictor of school grades) within a school-aged sample (N = 94), but the results for Space Code were less encouraging. Relationships between computer-game-like tests and gender, handedness, and computer-game experience are also discussed. PMID:19001388

  2. FRAS1-related extracellular matrix 3 (FREM3) single-nucleotide polymorphism effects on gene expression, amygdala reactivity and perceptual processing speed: An accelerated aging pathway of depression risk.

    PubMed

    Nikolova, Yuliya S; Iruku, Swetha P; Lin, Chien-Wei; Conley, Emily Drabant; Puralewski, Rachel; French, Beverly; Hariri, Ahmad R; Sibille, Etienne

    2015-01-01

    The A allele of the FRAS1-related extracellular matrix protein 3 (FREM3) rs7676614 single nucleotide polymorphism (SNP) was linked to major depressive disorder (MDD) in an early genome-wide association study (GWAS), and to symptoms of psychomotor retardation in a follow-up investigation. In line with significant overlap between age- and depression-related molecular pathways, parallel work has shown that FREM3 expression in postmortem human brain decreases with age. Here, we probe the effect of rs7676614 on amygdala reactivity and perceptual processing speed, both of which are altered in depression and aging. Amygdala reactivity was assessed using a face-matching BOLD fMRI paradigm in 365 Caucasian participants in the Duke Neurogenetics Study (DNS) (192 women, mean age 19.7 ± 1.2). Perceptual processing speed was indexed by reaction times in the same task and the Trail Making Test (TMT). The effect of rs7676614 on FREM3 mRNA brain expression levels was probed in a postmortem cohort of 169 Caucasian individuals (44 women, mean age 50.8 ± 14.9). The A allele of rs7676614 was associated with blunted amygdala reactivity to faces, slower reaction times in the face-matching condition (p < 0.04), as well as marginally slower performance on TMT Part B (p = 0.056). In the postmortem cohort, the T allele of rs6537170 (proxy for the rs7676614 A allele), was associated with trend-level reductions in gene expression in Brodmann areas 11 and 47 (p = 0.066), reminiscent of patterns characteristic of older age. The low-expressing allele of another FREM3 SNP (rs1391187) was similarly associated with reduced amygdala reactivity and slower TMT Part B speed, in addition to reduced BA47 activity and extraversion (p < 0.05). Together, these results suggest common genetic variation associated with reduced FREM3 expression may confer risk for a subtype of depression characterized by reduced reactivity to environmental stimuli and slower perceptual processing speed, possibly suggestive of accelerated aging. PMID:26441752

  3. FRAS1-related extracellular matrix 3 (FREM3) single-nucleotide polymorphism effects on gene expression, amygdala reactivity and perceptual processing speed: An accelerated aging pathway of depression risk

    PubMed Central

    Nikolova, Yuliya S.; Iruku, Swetha P.; Lin, Chien-Wei; Conley, Emily Drabant; Puralewski, Rachel; French, Beverly; Hariri, Ahmad R.; Sibille, Etienne

    2015-01-01

    The A allele of the FRAS1-related extracellular matrix protein 3 (FREM3) rs7676614 single nucleotide polymorphism (SNP) was linked to major depressive disorder (MDD) in an early genome-wide association study (GWAS), and to symptoms of psychomotor retardation in a follow-up investigation. In line with significant overlap between age- and depression-related molecular pathways, parallel work has shown that FREM3 expression in postmortem human brain decreases with age. Here, we probe the effect of rs7676614 on amygdala reactivity and perceptual processing speed, both of which are altered in depression and aging. Amygdala reactivity was assessed using a face-matching BOLD fMRI paradigm in 365 Caucasian participants in the Duke Neurogenetics Study (DNS) (192 women, mean age 19.7 ± 1.2). Perceptual processing speed was indexed by reaction times in the same task and the Trail Making Test (TMT). The effect of rs7676614 on FREM3 mRNA brain expression levels was probed in a postmortem cohort of 169 Caucasian individuals (44 women, mean age 50.8 ± 14.9). The A allele of rs7676614 was associated with blunted amygdala reactivity to faces, slower reaction times in the face-matching condition (p < 0.04), as well as marginally slower performance on TMT Part B (p = 0.056). In the postmortem cohort, the T allele of rs6537170 (proxy for the rs7676614 A allele), was associated with trend-level reductions in gene expression in Brodmann areas 11 and 47 (p = 0.066), reminiscent of patterns characteristic of older age. The low-expressing allele of another FREM3 SNP (rs1391187) was similarly associated with reduced amygdala reactivity and slower TMT Part B speed, in addition to reduced BA47 activity and extraversion (p < 0.05). Together, these results suggest common genetic variation associated with reduced FREM3 expression may confer risk for a subtype of depression characterized by reduced reactivity to environmental stimuli and slower perceptual processing speed, possibly suggestive of accelerated aging. PMID:26441752

  4. Polymorphisms in the Brain-Derived Neurotrophic Factor Gene Influence Memory and Processing Speed One Month after Brain Injury

    PubMed Central

    Tyler, Anna L.; Flashman, Laura A.; Rhodes, C. Harker; McDonald, Brenna C.; Saykin, Andrew J.; Tosteson, Tor D.; Tsongalis, Gregory J.; Moore, Jason H.

    2012-01-01

    Abstract Brain-derived neurotrophic factor (BDNF) plays a role in cognition, as well as neural survival and plasticity. There are several common polymorphisms in the BDNF gene, one of which (rs6265) is an extensively studied non-synonymous coding polymorphism (Val66Met) which has been linked to cognitive performance in healthy controls and some clinical populations. We hypothesized that the Met allele of rs6265 would be associated with poorer cognitive performance in individuals with mild-to-moderate traumatic brain injury, and that other polymorphisms in the BDNF gene would also affect cognition. Genotype at 9 single-nucleotide polymorphisms (SNPs) in the BDNF gene, and measures of speed of information processing, learning, and memory were assessed in 75 patients with mTBI and 38 healthy subjects. Consistent with previous reports, the Met allele of rs6265 was associated with cognition (slower processing speed) in the entire group. Two other SNPs were associated with processing speed in the mTBI group, but both are in linkage disequilibrium with rs6265, and neither remained significant after adjustment for rs6265 status. Within the mTBI group, but not the controls, 4 SNPs, but not rs6265, were associated with memory measures. These associations were not affected by adjustment for rs6265 status. Polymorphisms in BDNF influence cognitive performance shortly after mTBI. The results raise the possibility that a functional polymorphism other than rs6265 may contribute to memory function after mTBI. PMID:22188054

  5. Aging White Matter and Cognition: Differential Effects of Regional Variations in Diffusion Properties on Memory, Executive Functions, and Speed

    PubMed Central

    Kennedy, Kristen M.; Raz, Naftali

    2009-01-01

    Disruption of cerebral white matter has been proposed as an explanation for age-related cognitive declines. However, the role of specific regions in specific cognitive declines remains unclear. We used diffusion tensor imaging to examine the associations between regional microstructural integrity of the white matter and performance on age-sensitive cognitive tasks in a sample of healthy adults (N = 52, age 19–81 years). White matter integrity was assessed by fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in multiple regions of interest (genu and splenium of corpus callosum, internal capsule limbs, prefrontal, temporal, superior/posterior parietal, occipital white matter) and related to processing speed, working memory, inhibition, task switching, and episodic memory. We found that age and regional white matter integrity differentially influenced cognitive performance. Age-related degradation in anterior brain areas was associated with decreased processing speed and poorer working memory, whereas reduced inhibition and greater task switching costs were linked to decline in posterior areas. Poorer episodic memory was associated with age-related differences in central white matter regions. The observed multiple dissociations among specific age-sensitive cognitive skills and their putative neuroanatomical substrates support the view that age-related cognitive declines are unlikely to stem from a single cause. PMID:19166865

  6. Visual prediction and perceptual expertise

    PubMed Central

    Cheung, Olivia S.; Bar, Moshe

    2012-01-01

    Making accurate predictions about what may happen in the environment requires analogies between perceptual input and associations in memory. These elements of predictions are based on cortical representations, but little is known about how these processes can be enhanced by experience and training. On the other hand, studies on perceptual expertise have revealed that the acquisition of expertise leads to strengthened associative processing among features or objects, suggesting that predictions and expertise may be tightly connected. Here we review the behavioral and neural findings regarding the mechanisms involving prediction and expert processing, and highlight important possible overlaps between them. Future investigation should examine the relations among perception, memory and prediction skills as a function of expertise. The knowledge gained by this line of research will have implications for visual cognition research, and will advance our understanding of how the human brain can improve its ability to predict by learning from experience. PMID:22123523

  7. Verbal Processing Speed and Executive Functioning in Long-Term Cochlear Implant Users

    PubMed Central

    Pisoni, David B.; Kronenberger, William G.

    2015-01-01

    Purpose The purpose of this study was to report how verbal rehearsal speed (VRS), a form of covert speech used to maintain verbal information in working memory, and another verbal processing speed measure, perceptual encoding speed, are related to 3 domains of executive function (EF) at risk in cochlear implant (CI) users: verbal working memory, fluency-speed, and inhibition-concentration. Method EF, speech perception, and language outcome measures were obtained from 55 prelingually deaf, long-term CI users and matched controls with normal hearing (NH controls). Correlational analyses were used to assess relations between VRS (articulation rate), perceptual encoding speed (digit and color naming), and the outcomes in each sample. Results CI users displayed slower verbal processing speeds than NH controls. Verbal rehearsal speed was related to 2 EF domains in the NH sample but was unrelated to EF outcomes in CI users. Perceptual encoding speed was related to all EF domains in both groups. Conclusions Verbal rehearsal speed may be less influential for EF quality in CI users than for NH controls, whereas rapid automatized labeling skills and EF are closely related in both groups. CI users may develop processing strategies in EF tasks that differ from the covert speech strategies routinely employed by NH individuals. PMID:25320961

  8. Brain Training Game Boosts Executive Functions, Working Memory and Processing Speed in the Young Adults: A Randomized Controlled Trial

    PubMed Central

    Nouchi, Rui; Taki, Yasuyuki; Takeuchi, Hikaru; Hashizume, Hiroshi; Nozawa, Takayuki; Kambara, Toshimune; Sekiguchi, Atsushi; Miyauchi, Carlos Makoto; Kotozaki, Yuka; Nouchi, Haruka; Kawashima, Ryuta

    2013-01-01

    Background Do brain training games work? The beneficial effects of brain training games are expected to transfer to other cognitive functions. Yet in all honesty, beneficial transfer effects of the commercial brain training games in young adults have little scientific basis. Here we investigated the impact of the brain training game (Brain Age) on a wide range of cognitive functions in young adults. Methods We conducted a double-blind (de facto masking) randomized controlled trial using a popular brain training game (Brain Age) and a popular puzzle game (Tetris). Thirty-two volunteers were recruited through an advertisement in the local newspaper and randomly assigned to either of two game groups (Brain Age, Tetris). Participants in both the Brain Age and the Tetris groups played their game for about 15 minutes per day, at least 5 days per week, for 4 weeks. Measures of the cognitive functions were conducted before and after training. Measures of the cognitive functions fell into eight categories (fluid intelligence, executive function, working memory, short-term memory, attention, processing speed, visual ability, and reading ability). Results and Discussion Our results showed that commercial brain training game improves executive functions, working memory, and processing speed in young adults. Moreover, the popular puzzle game can engender improvement attention and visuo-spatial ability compared to playing the brain training game. The present study showed the scientific evidence which the brain training game had the beneficial effects on cognitive functions (executive functions, working memory and processing speed) in the healthy young adults. Conclusions Our results do not indicate that everyone should play brain training games. However, the commercial brain training game might be a simple and convenient means to improve some cognitive functions. We believe that our findings are highly relevant to applications in educational and clinical fields. Trial Registration UMIN Clinical Trial Registry 000005618. PMID:23405164

  9. Stochastic accumulation of feature information in perception and memory

    PubMed Central

    Kent, Christopher; Guest, Duncan; Adelman, James S.; Lamberts, Koen

    2014-01-01

    It is now well established that the time course of perceptual processing influences the first second or so of performance in a wide variety of cognitive tasks. Over the last 20 years, there has been a shift from modeling the speed at which a display is processed, to modeling the speed at which different features of the display are perceived and formalizing how this perceptual information is used in decision making. The first of these models (Lamberts, 1995) was implemented to fit the time course of performance in a speeded perceptual categorization task and assumed a simple stochastic accumulation of feature information. Subsequently, similar approaches have been used to model performance in a range of cognitive tasks including identification, absolute identification, perceptual matching, recognition, visual search, and word processing, again assuming a simple stochastic accumulation of feature information from both the stimulus and representations held in memory. These models are typically fit to data from signal-to-respond experiments whereby the effects of stimulus exposure duration on performance are examined, but response times (RTs) and RT distributions have also been modeled. In this article, we review this approach and explore the insights it has provided about the interplay between perceptual processing, memory retrieval, and decision making in a variety of tasks. In so doing, we highlight how such approaches can continue to usefully contribute to our understanding of cognition. PMID:24860530

  10. Speed and Accuracy of Accessing Information in Working Memory: An Individual Differences Investigation of Focus Switching

    ERIC Educational Resources Information Center

    Unsworth, Nash; Engle, Randall W.

    2008-01-01

    Three experiments examined the nature of individual differences in switching the focus of attention in working memory. Participants performed 3 versions of a continuous counting task that required successive updating and switching between counts. Across all 3 experiments, individual differences in working memory span and fluid intelligence were

  11. Speed and Accuracy of Accessing Information in Working Memory: An Individual Differences Investigation of Focus Switching

    ERIC Educational Resources Information Center

    Unsworth, Nash; Engle, Randall W.

    2008-01-01

    Three experiments examined the nature of individual differences in switching the focus of attention in working memory. Participants performed 3 versions of a continuous counting task that required successive updating and switching between counts. Across all 3 experiments, individual differences in working memory span and fluid intelligence were…

  12. Statistical Mechanics Model of the Speed - Accuracy Tradeoff in Spatial and Lexical Memory

    NASA Astrophysics Data System (ADS)

    Kaufman, Miron; Allen, Philip

    2000-03-01

    The molar neural network model of P. Allen, M. Kaufman, A. F. Smith, R. E. Popper, Psychology and Aging 13, 501 (1998) and Experimental Aging Research, 24, 307 (1998) is extended to incorporate reaction times. In our model the entropy associated with a particular task determines the reaction time. We use this molar neural model to directly analyze experimental data on episodic (spatial) memory and semantic (lexical) memory tasks. In particular we are interested in the effect of aging on the two types of memory. We find that there is no difference in performance levels for lexical memory tasks between younger and older adults. In the case spatial memory tasks we find that aging has a detrimental effect on the performance level. This work is supported by NIH/NIA grant AG09282-06.

  13. High speed, very large (8 megabyte) first in/first out buffer memory (FIFO)

    DOEpatents

    Baumbaugh, Alan E.; Knickerbocker, Kelly L.

    1989-01-01

    A fast FIFO (First In First Out) memory buffer capable of storing data at rates of 100 megabytes per second. The invention includes a data packer which concatenates small bit data words into large bit data words, a memory array having individual data storage addresses adapted to store the large bit data words, a data unpacker into which large bit data words from the array can be read and reconstructed into small bit data words, and a controller to control and keep track of the individual data storage addresses in the memory array into which data from the packer is being written and data to the unpacker is being read.

  14. Dissociation of rapid response learning and facilitation in perceptual and conceptual networks of person recognition.

    PubMed

    Valt, Christian; Klein, Christoph; Boehm, Stephan G

    2015-08-01

    Repetition priming is a prominent example of non-declarative memory, and it increases the accuracy and speed of responses to repeatedly processed stimuli. Major long-hold memory theories posit that repetition priming results from facilitation within perceptual and conceptual networks for stimulus recognition and categorization. Stimuli can also be bound to particular responses, and it has recently been suggested that this rapid response learning, not network facilitation, provides a sound theory of priming of object recognition. Here, we addressed the relevance of network facilitation and rapid response learning for priming of person recognition with a view to advance general theories of priming. In four experiments, participants performed conceptual decisions like occupation or nationality judgments for famous faces. The magnitude of rapid response learning varied across experiments, and rapid response learning co-occurred and interacted with facilitation in perceptual and conceptual networks. These findings indicate that rapid response learning and facilitation in perceptual and conceptual networks are complementary rather than competing theories of priming. Thus, future memory theories need to incorporate both rapid response learning and network facilitation as individual facets of priming. PMID:25291047

  15. Placing Inspection Time, Reaction Time, and Perceptual Speed in the Broader Context of Cognitive Ability: The VPR Model in the Lothian Birth Cohort 1936

    ERIC Educational Resources Information Center

    Johnson, Wendy; Deary, Ian J.

    2011-01-01

    The idea that information processing speed is related to cognitive ability has a long history. Much evidence has been amassed in its support, with respect to both individual differences in general intelligence and developmental trajectories. Two so-called elementary cognitive tasks, reaction time and inspection time, have been used to compile this

  16. Placing Inspection Time, Reaction Time, and Perceptual Speed in the Broader Context of Cognitive Ability: The VPR Model in the Lothian Birth Cohort 1936

    ERIC Educational Resources Information Center

    Johnson, Wendy; Deary, Ian J.

    2011-01-01

    The idea that information processing speed is related to cognitive ability has a long history. Much evidence has been amassed in its support, with respect to both individual differences in general intelligence and developmental trajectories. Two so-called elementary cognitive tasks, reaction time and inspection time, have been used to compile this…

  17. Recent research on the elastic unstableness of shape memory alloy in martensite transformation by micro-high-speed photography

    NASA Astrophysics Data System (ADS)

    Yang, Jie; Wu, Yuehua; Uyemura, Tsuneyoshi

    1993-01-01

    The paper reports the research results on the phenomenon of elastic unstableness in martensite transformation of Cu-Al-Ni shape memory alloy (SMA). We use the method of micro-high speed photography. The martensite of Cu-Al-Ni SMA presents thermoelastic strain in the heating and cooling process. While the sample is heated to As, the martensite begins to contract and the temperature reaches Af point, the martensite is gradually reducing. It is possible that the martensite suddenly disappears from certain visible size at the instant it is heated to Af temperature.

  18. Ge2Sb2Te5/Sb superlattice-like thin film for high speed phase change memory application

    NASA Astrophysics Data System (ADS)

    Hu, Yifeng; Zou, Hua; Zhang, Jianhao; Xue, Jianzhong; Sui, Yongxing; Wu, Weihua; Yuan, Li; Zhu, Xiaoqin; Song, Sannian; Song, Zhitang

    2015-12-01

    In order to improve the operation speed of phase change memory (PCM), superlattice-like Ge2Sb2Te5/Sb (SLL GST/Sb) thin films were prepared in a sputtering method to explore the suitability as an active material for PCM application. Compared with GST, SLL GST/Sb thin film has a lower crystallization temperature, crystallization activation energy, thermal conductivity, and smaller crystalline grain size. A faster SET/RESET switching speed (10 ns) and a lower operation power consumption (the energy for RESET operation 9.1 × 10-13 J) are obtained. In addition, GST/Sb shows a good endurance of 8.3 × 104 cycles.

  19. High speed spatially multimode Λ-type atomic memory with arbitrary frequency detuning

    NASA Astrophysics Data System (ADS)

    Golubeva, T.; Golubev, Y. M.; Mishina, O.; Bramati, A.; Laurat, J.; Giacobino, E.

    2012-10-01

    We present a general model for an atomic memory using ultra-short pulses of light, which allows both spatial and temporal multimode storage. The process involves the storage of a faint quantum light pulse into the spin coherence of the ground state of Λ-type 3-level atoms, in the presence of a strong driving pulse. Our model gives a full description of the evolution of the field and of the atomic coherence in space and time throughout the writing and the read-out processes. It is valid for any frequency detuning, from the resonant case to the Raman case, and allows a detailed optimization of the memory efficiency.

  20. INDIVIDUAL DIFFERENCES IN TASK-SPECIFIC PAIRED ASSOCIATES LEARNING IN OLDER ADULTS: THE ROLE OF PROCESSING SPEED AND WORKING MEMORY

    PubMed Central

    Kurtz, Tanja; Mogle, Jacqueline; Sliwinski, Martin J.; Hofer, Scott M.

    2013-01-01

    Background The role of processing speed and working memory was investigated in terms of individual differences in task-specific paired associates learning in a sample of older adults. Task-specific learning, as distinct from content-oriented item-specific learning, refers to gains in performance due to repeated practice on a learning task in which the to-be-learned material changes over trials. Methods Learning trajectories were modeled within an intensive repeated-measures design based on participants obtained from an opt-in internet-based sampling service (Mage = 65.3, SD = 4.81). Participants completed an eight-item paired associates task daily over a seven-day period. Results Results indicated that a three-parameter hyperbolic model (i.e., initial level, learning rate, and asymptotic performance) best described learning trajectory. After controlling for age-related effects, both higher working memory and higher processing speed had a positive effect on all three learning parameters. Conclusion These results emphasize the role of cognitive abilities for individual differences in task-specific learning of older adults. PMID:24151913

  1. Memory, processing, and routing applications of spatial-spectral holography in ultrahigh-speed computing systems

    NASA Astrophysics Data System (ADS)

    Babbitt, W. Randall

    1998-11-01

    Real-time, wide band information storage and signal processing devices are critical to many computing and communication systems. Optical spatial-spectral holography has the potential to perform real-time storage and continuous signal processing at data rates up to a terahertz, with storage/pattern densities on the order of a terabit per centimeter squared, and with data block sizes/time-bandwidth products well over 10000. These attributes, coupled with spatial selectivity and the ability to process amplitude, phase and frequency modulated signals makes spatial-spectral holography an extremely versatile technology. Applications include time-, frequency-, or code-division multiplexed routing, pattern recognition; multi-dimensional cache memory; high density, high bandwidth database memory, associative memory, and look- up tables; temporal encryption and decryption for secure communications; interior memory for optical networks; real- time address decoder; all optical passive routing of data; header and data stripper and isolator for network packets; true time delays for phase arrays with simultaneous tracking of multiple targets; and dynamic pulse shaping and distortion compensation.

  2. Selective attention and perceptual load in autism spectrum disorder.

    PubMed

    Remington, Anna; Swettenham, John; Campbell, Ruth; Coleman, Mike

    2009-11-01

    It has been suggested that the locus of selective attention (early vs. late in processing) is dependent on the perceptual load of the task. When perceptual load is low, irrelevant distractors are processed (late selection), whereas when perceptual load is high, distractor interference disappears (early selection). Attentional abnormalities have long been reported within autism spectrum disorder (ASD), and this study is the first to examine the effect of perceptual load on selective attention in this population. Fourteen adults with ASD and 23 adults without ASD performed a selective attention task with varying perceptual loads. Compared with the non-ASD group, the ASD group required higher levels of perceptual load to successfully ignore irrelevant distractors; moreover, the ASD group did not show any general reduction in performance speed or accuracy. These results suggest enhanced perceptual capacity in the ASD group and are consistent with previous observations regarding superior visual search abilities among individuals with ASD. PMID:19843262

  3. Perceptual learning in Vision Research.

    PubMed

    Sagi, Dov

    2011-07-01

    Reports published in Vision Research during the late years of the 20th century described surprising effects of long-term sensitivity improvement with some basic visual tasks as a result of training. These improvements, found in adult human observers, were highly specific to simple visual features, such as location in the visual field, spatial-frequency, local and global orientation, and in some cases even the eye of origin. The results were interpreted as arising from the plasticity of sensory brain regions that display those features of specificity within their constituting neuronal subpopulations. A new view of the visual cortex has emerged, according to which a degree of plasticity is retained at adult age, allowing flexibility in acquiring new visual skills when the need arises. Although this "sensory plasticity" interpretation is often questioned, it is commonly believed that learning has access to detailed low-level visual representations residing within the visual cortex. More recent studies during the last decade revealed the conditions needed for learning and the conditions under which learning can be generalized across stimuli and tasks. The results are consistent with an account of perceptual learning according to which visual processing is remodeled by the brain, utilizing sensory information acquired during task performance. The stability of the visual system is viewed as an adaptation to a stable environment and instances of perceptual learning as a reaction of the brain to abrupt changes in the environment. Training on a restricted stimulus set may lead to perceptual overfitting and over-specificity. The systemic methodology developed for perceptual learning, and the accumulated knowledge, allows us to explore issues related to learning and memory in general, such as learning rules, reinforcement, memory consolidation, and neural rehabilitation. A persistent open question is the neuro-anatomical substrate underlying these learning effects. PMID:20974167

  4. Memory.

    ERIC Educational Resources Information Center

    McKean, Kevin

    1983-01-01

    Discusses current research (including that involving amnesiacs and snails) into the nature of the memory process, differentiating between and providing examples of "fact" memory and "skill" memory. Suggests that three brain parts (thalamus, fornix, mammilary body) are involved in the memory process. (JN)

  5. Resistance to Interference of Olfactory Perceptual Learning

    ERIC Educational Resources Information Center

    Stevenson, Richard J.; Case, Trevor I.; Tomiczek, Caroline

    2007-01-01

    Olfactory memory is especially persistent. The current study explored whether this applies to a form of perceptual learning, in which experience of an odor mixture results in greater judged similarity between its elements. Experiment 1A contrasted 2 forms of interference procedure, "compound" (mixture AW, followed by presentation of new mixtures…

  6. Genetic Variance in Processing Speed Drives Variation in Aging of Spatial and Memory Abilities

    ERIC Educational Resources Information Center

    Finkel, Deborah; Reynolds, Chandra A.; McArdle, John J.; Hamagami, Fumiaki; Pedersen, Nancy L.

    2009-01-01

    Previous analyses have identified a genetic contribution to the correlation between declines with age in processing speed and higher cognitive abilities. The goal of the current analysis was to apply the biometric dual change score model to consider the possibility of temporal dynamics underlying the genetic covariance between aging trajectories…

  7. Verbal Knowledge, Working Memory, and Processing Speed as Predictors of Verbal Learning in Older Adults

    ERIC Educational Resources Information Center

    Rast, Philippe

    2011-01-01

    The present study aimed at modeling individual differences in a verbal learning task by means of a latent structured growth curve approach based on an exponential function that yielded 3 parameters: initial recall, learning rate, and asymptotic performance. Three cognitive variables--speed of information processing, verbal knowledge, working

  8. Genetic Variance in Processing Speed Drives Variation in Aging of Spatial and Memory Abilities

    ERIC Educational Resources Information Center

    Finkel, Deborah; Reynolds, Chandra A.; McArdle, John J.; Hamagami, Fumiaki; Pedersen, Nancy L.

    2009-01-01

    Previous analyses have identified a genetic contribution to the correlation between declines with age in processing speed and higher cognitive abilities. The goal of the current analysis was to apply the biometric dual change score model to consider the possibility of temporal dynamics underlying the genetic covariance between aging trajectories

  9. Verbal Knowledge, Working Memory, and Processing Speed as Predictors of Verbal Learning in Older Adults

    ERIC Educational Resources Information Center

    Rast, Philippe

    2011-01-01

    The present study aimed at modeling individual differences in a verbal learning task by means of a latent structured growth curve approach based on an exponential function that yielded 3 parameters: initial recall, learning rate, and asymptotic performance. Three cognitive variables--speed of information processing, verbal knowledge, working…

  10. A reward semi-Markov process with memory for wind speed modeling

    NASA Astrophysics Data System (ADS)

    Petroni, F.; D'Amico, G.; Prattico, F.

    2012-04-01

    The increasing interest in renewable energy leads scientific research to find a better way to recover most of the available energy. Particularly, the maximum energy recoverable from wind is equal to 59.3% of that available (Betz law) at a specific pitch angle and when the ratio between the wind speed in output and in input is equal to 1/3. The pitch angle is the angle formed between the airfoil of the blade of the wind turbine and the wind direction. Old turbine and a lot of that actually marketed, in fact, have always the same invariant geometry of the airfoil. This causes that wind turbines will work with an efficiency that is lower than 59.3%. New generation wind turbines, instead, have a system to variate the pitch angle by rotating the blades. This system able the wind turbines to recover, at different wind speed, always the maximum energy, working in Betz limit at different speed ratios. A powerful system control of the pitch angle allows the wind turbine to recover better the energy in transient regime. A good stochastic model for wind speed is then needed to help both the optimization of turbine design and to assist the system control to predict the value of the wind speed to positioning the blades quickly and correctly. The possibility to have synthetic data of wind speed is a powerful instrument to assist designer to verify the structures of the wind turbines or to estimate the energy recoverable from a specific site. To generate synthetic data, Markov chains of first or higher order are often used [1,2,3]. In particular in [1] is presented a comparison between a first-order Markov chain and a second-order Markov chain. A similar work, but only for the first-order Markov chain, is conduced by [2], presenting the probability transition matrix and comparing the energy spectral density and autocorrelation of real and synthetic wind speed data. A tentative to modeling and to join speed and direction of wind is presented in [3], by using two models, first-order Markov chain with different number of states, and Weibull distribution. All this model use Markov chains to generate synthetic wind speed time series but the search for a better model is still open. Approaching this issue, we applied new models which are generalization of Markov models. More precisely we applied semi-Markov models to generate synthetic wind speed time series. The primary goal of this analysis is the study of the time history of the wind in order to assess its reliability as a source of power and to determine the associated storage levels required. In order to assess this issue we use a probabilistic model based on indexed semi-Markov process [4] to which a reward structure is attached. Our model is used to calculate the expected energy produced by a given turbine and its variability expressed by the variance of the process. Our results can be used to compare different wind farms based on their reward and also on the risk of missed production due to the intrinsic variability of the wind speed process. The model is used to generate synthetic time series for wind speed by means of Monte Carlo simulations and backtesting procedure is used to compare results on first and second oder moments of rewards between real and synthetic data. [1] A. Shamshad, M.A. Bawadi, W.M.W. Wan Hussin, T.A. Majid, S.A.M. Sanusi, First and second order Markov chain models for synthetic gen- eration of wind speed time series, Energy 30 (2005) 693-708. [2] H. Nfaoui, H. Essiarab, A.A.M. Sayigh, A stochastic Markov chain model for simulating wind speed time series at Tangiers, Morocco, Re- newable Energy 29 (2004) 1407-1418. [3] F. Youcef Ettoumi, H. Sauvageot, A.-E.-H. Adane, Statistical bivariate modeling of wind using first-order Markov chain and Weibull distribu- tion, Renewable Energy 28 (2003) 1787-1802. [4]F. Petroni, G. D'Amico, F. Prattico, Indexed semi-Markov process for wind speed modeling. To be submitted.

  11. The Perceptual Abilities Project. Technical Report No. 1988-4.

    ERIC Educational Resources Information Center

    Bethscheider, Janine K.

    An experimental test battery designed to measure several perceptual abilities was administered to 1,368 (51.8% male) paying clients of the Johnson O'Connor Research Foundation (JOCRF) in an effort to identify and measure three perceptual abilities: (1) flexibility of closure; (2) speed of closure; and (3) spatial scanning. Subjects, who ranged in…

  12. Investigation of CuSb4Te2 alloy for high-speed phase change random access memory applications

    NASA Astrophysics Data System (ADS)

    Lu, Yegang; Song, Sannian; Song, Zhitang; Rao, Feng; Wu, Liangcai; Zhu, Min; Liu, Bo; Yao, Dongning

    2012-05-01

    The thermal stability of amorphous Sb2Te film can be significantly improved by the addition of Cu. CuSb4Te2 alloy is considered to be a potential candidate for phase change random access memory (PCRAM), as evidenced by a higher crystallization temperature, a better data retention ability, and a faster switching speed in comparison with those of Ge2Sb2Te5. A reversible switching between set and reset states can be realized by an electric pulse as short as 7 ns for CuSb4Te2-based PCRAM cell. In addition, CuSb4Te2 shows endurance up to 1.5 105 cycles with a resistance ratio of about two orders of magnitude.

  13. Longitudinal Mediation of Processing Speed on Age-Related Change in Memory and Fluid Intelligence

    PubMed Central

    Robitaille, Annie; Piccinin, Andrea M.; Muniz, Graciela; Hoffman, Lesa; Johansson, Boo; Deeg, Dorly J.H.; Aartsen, Marja J.; Comijs, Hannie C.; Hofer, Scott M.

    2014-01-01

    Age-related decline in processing speed has long been considered a key driver of cognitive aging. While the majority of empirical evidence for the processing speed hypothesis has been obtained from analyses of between-person age differences, longitudinal studies provide a direct test of within-person change. Using recent developments in longitudinal mediation analysis, we examine the speed–mediation hypothesis at both the within- and between-person levels in two longitudinal studies, LASA and OCTO-Twin. We found significant within-person indirect effects of change in age, such that increasing age was related to lower speed which, in turn, relates to lower performance across repeated measures on other cognitive outcomes. Although between-person indirect effects were also significant in LASA, they were not in OCTO-Twin. These differing magnitudes of direct and indirect effects across levels demonstrate the importance of separating between- and within-person effects in evaluating theoretical models of age-related change. PMID:23957224

  14. Novel High-Speed High Pressure Torsion Technology for Obtaining Fe-Mn-Si-Cr Shape Memory Alloy Active Elements

    NASA Astrophysics Data System (ADS)

    Gur?u, Gheorghe; Gur?u, Carmela; Poteca?u, Octavian; Alexandru, Petric?; Bujoreanu, Leandru-Gheorghe

    2014-07-01

    This paper introduces an adapted high-speed high pressure torsion (HS-HPT) method of severe plastic deformation applied for obtaining shape memory alloy (SMA) active elements with revolution symmetry, able to develop axial displacement/force. Billets with circular crown forms were cut from Fe-28Mn-6Si-5Cr (mass%) SMA ingots and, by means of HS-HPT technology, were directly turned into modules, with truncated cone shell configurations. This process was performed, during time intervals of seconds, under the effect of high pressure (up to 1 GPa) cumulated with high rotation speed (hundreds of rotations per minute) applied on the active surfaces of sintered-carbide anvils, specially designed for this purpose. Due to pressure and friction, generated by rotation, the entire sample volume is heated and simultaneously deformed to final shape. During the process, microstructure fragmentation occurred enabling to obtain (ultra)fine grains and nanocrystalline areas, in spite of the heat developed by friction, which was removed by conduction at the contact surface between sample and anvils, before the occurrence of any recrystallization phenomena. When compressed between flat surfaces, the truncated cone modules developed a superelastic-like response, unique among Fe -Mn-Si base SMAs and, when heated in compressed state, they were able to develop either axial strokes or recovery forces by either free or constrained recovery shape memory effect (SME), respectively. By means of optical (OM) and scanning electron microscopy (SEM) marked structural changes caused by HT-HPT were revealed, along with fine and ultrafine crystalline grains. The presence of stress-induced ?-hexagonal close-packed ( hcp) martensite, together with nanocrystalline areas were confirmed by x-ray diffraction.

  15. Preferred longitudes of sunspot groups and high-speed solar wind streams - Evidence for a 'solar memory'

    NASA Astrophysics Data System (ADS)

    Balthasar, H.; Schuessler, M.

    1983-08-01

    Correlation analysis of the mean longitude distribution of sunspot groups (taken from the Greenwich Photoheliographic Results) and high-speed solar wind streams (inferred from the C9 index for geomagnetic disturbances) with the Bartels rotation period P = 27.0 days shows anticorrelation for individual cycles. In particular, the longitudes of post-maximum stable streams of cycle 18 and 19 are well anticorrelated with the preferred longitudes of sunspot groups during the maximum activity periods of these cycles. This is further analyzed using the daily Zuerich sunspot number, R, between 1932 and 1980, which reveals a conspicuous similarity of cycle 18 and 19 as well as cycle 20 and 21. It is concluded that there is a 'solar memory' for preferred longitudes of activity extending at least over one, probably two cycles (i.e., one magnetic cycle of 22 years). It is conjectured that this memory extends over longer intervals of time as a long-term feature of solar activity.

  16. Cold pressor-induced pain does not impair WAIS-IV processing speed index or working memory index performance.

    PubMed

    Etherton, Joseph

    2014-01-01

    Chronic pain frequently involves cognitive complaints such as concentration and memory deficits, but studies of the effects of pain on cognition have not consistently demonstrated deficits and have not typically utilized standard neuropsychological instruments. Effects of cold pressor-induced pain on Wechsler Adult Intelligence Scale-Fourth Edition Processing Speed Index (PSI) and Working Memory Index (WMI) performance was examined in nonclinical volunteers (n = 40). All took one PSI subtest and one WMI subtest normally, and then took different PSI and WMI subtests during cold pressor-induced pain or painless warm-water immersion. Scaled scores for normal administration versus pain or painless water immersion did not differ and there was no interaction between group (control vs. pain) and manner of administration, despite moderately severe mean pain ratings (M = 6.8 on a 0-10 pain-rating scale). Results indicate that induced pain in nonclinical volunteers does not impair PSI or WMI performance, and they suggest that chronic pain per se should not be expected to substantially affect these cognitive functions. However, patients with chronic pain may differ from nonclinical volunteers in their experience of pain, potentially limiting generalizability. PMID:24826491

  17. Superlattice-like film for high data retention and high speed phase change random access memory

    NASA Astrophysics Data System (ADS)

    Li, Le; Song, Sannian; Zhang, Zhonghua; Chen, Liangliang; Song, Zhitang; Lv, Shilong; Liu, Bo; Guo, Tianqi

    2016-06-01

    Superlattice-like film (SLF) was formed alternately by Ti0.43Sb2Te3 (TST) and TiN, and TST is employed as phase change layers and TiN is employed as isolation layers of TST film. Comparing with single TST film with the same thickness, SLF owns higher data retention, higher phase change speed (5 ns) and endurance up to 1 × 105 cycles, and its power consumption of reset operation is significantly decreased by 65.2%. Two-dimensional thermal transient simulation of reset operation indicates that SLF-based device owns higher heating efficiency than 30-nm-thick TST-based device.

  18. Visual Working Memory and Perception Speed of 3- to 6-Year-Old Children Tested with a Matrix Film Battery Test

    ERIC Educational Resources Information Center

    Pittorf, Martin L.; Lehmann, Wolfgang; Huckauf, Anke

    2014-01-01

    In this study the visual working memory (VWM) and perception speed of 60 children between the ages of three and six years were tested with an age-based, easy-to-handle Matrix Film Battery Test (reliability R?=?0.71). It was thereby affirmed that the VWM is age dependent (correlation coefficient r?=?0.66***) as expected. Furthermore, a significant…

  19. ADHD Subtypes and Co-Occurring Anxiety, Depression, and Oppositional-Defiant Disorder: Differences in Gordon Diagnostic System and Wechsler Working Memory and Processing Speed Index Scores

    ERIC Educational Resources Information Center

    Mayes, Susan Dickerson; Calhoun, Susan L.; Chase, Gary A.; Mink, Danielle M.; Stagg, Ryan E.

    2009-01-01

    Objective: Wechsler Intelligence Scale for Children Freedom-from-Distractibility/Working Memory Index (FDI/WMI), Processing Speed Index (PSI), and Gordon Diagnostic System (GDS) scores in ADHD children were examined as a function of subtype and coexisting anxiety, depression, and oppositional-defiant disorder. Method: Participants were 587

  20. Visual Working Memory and Perception Speed of 3- to 6-Year-Old Children Tested with a Matrix Film Battery Test

    ERIC Educational Resources Information Center

    Pittorf, Martin L.; Lehmann, Wolfgang; Huckauf, Anke

    2014-01-01

    In this study the visual working memory (VWM) and perception speed of 60 children between the ages of three and six years were tested with an age-based, easy-to-handle Matrix Film Battery Test (reliability R?=?0.71). It was thereby affirmed that the VWM is age dependent (correlation coefficient r?=?0.66***) as expected. Furthermore, a significant

  1. ADHD Subtypes and Co-Occurring Anxiety, Depression, and Oppositional-Defiant Disorder: Differences in Gordon Diagnostic System and Wechsler Working Memory and Processing Speed Index Scores

    ERIC Educational Resources Information Center

    Mayes, Susan Dickerson; Calhoun, Susan L.; Chase, Gary A.; Mink, Danielle M.; Stagg, Ryan E.

    2009-01-01

    Objective: Wechsler Intelligence Scale for Children Freedom-from-Distractibility/Working Memory Index (FDI/WMI), Processing Speed Index (PSI), and Gordon Diagnostic System (GDS) scores in ADHD children were examined as a function of subtype and coexisting anxiety, depression, and oppositional-defiant disorder. Method: Participants were 587…

  2. Non-volatile, high density, high speed, Micromagnet-Hall effect Random Access Memory (MHRAM)

    NASA Technical Reports Server (NTRS)

    Wu, Jiin C.; Katti, Romney R.; Stadler, Henry L.

    1991-01-01

    The micromagnetic Hall effect random access memory (MHRAM) has the potential of replacing ROMs, EPROMs, EEPROMs, and SRAMs because of its ability to achieve non-volatility, radiation hardness, high density, and fast access times, simultaneously. Information is stored magnetically in small magnetic elements (micromagnets), allowing unlimited data retention time, unlimited numbers of rewrite cycles, and inherent radiation hardness and SEU immunity, making the MHRAM suitable for ground based as well as spaceflight applications. The MHRAM device design is not affected by areal property fluctuations in the micromagnet, so high operating margins and high yield can be achieved in large scale integrated circuit (IC) fabrication. The MHRAM has short access times (less than 100 nsec). Write access time is short because on-chip transistors are used to gate current quickly, and magnetization reversal in the micromagnet can occur in a matter of a few nanoseconds. Read access time is short because the high electron mobility sensor (InAs or InSb) produces a large signal voltage in response to the fringing magnetic field from the micromagnet. High storage density is achieved since a unit cell consists only of two transistors and one micromagnet Hall effect element. By comparison, a DRAM unit cell has one transistor and one capacitor, and a SRAM unit cell has six transistors.

  3. Mental imagery of speech implicates two mechanisms of perceptual reactivation.

    PubMed

    Tian, Xing; Zarate, Jean Mary; Poeppel, David

    2016-04-01

    Sensory cortices can be activated without any external stimuli. Yet, it is still unclear how this perceptual reactivation occurs and which neural structures mediate this reconstruction process. In this study, we employed fMRI with mental imagery paradigms to investigate the neural networks involved in perceptual reactivation. Subjects performed two speech imagery tasks: articulation imagery (AI) and hearing imagery (HI). We found that AI induced greater activity in frontal-parietal sensorimotor systems, including sensorimotor cortex, subcentral (BA 43), middle frontal cortex (BA 46) and parietal operculum (PO), whereas HI showed stronger activation in regions that have been implicated in memory retrieval: middle frontal (BA 8), inferior parietal cortex and intraparietal sulcus. Moreover, posterior superior temporal sulcus (pSTS) and anterior superior temporal gyrus (aSTG) was activated more in AI compared with HI, suggesting that covert motor processes induced stronger perceptual reactivation in the auditory cortices. These results suggest that motor-to-perceptual transformation and memory retrieval act as two complementary mechanisms to internally reconstruct corresponding perceptual outcomes. These two mechanisms can serve as a neurocomputational foundation for predicting perceptual changes, either via a previously learned relationship between actions and their perceptual consequences or via stored perceptual experiences of stimulus and episodic or contextual regularity. PMID:26889603

  4. Perceptual Fluency, Auditory Generation, and Metamemory: Analyzing the Perceptual Fluency Hypothesis in the Auditory Modality

    ERIC Educational Resources Information Center

    Besken, Miri; Mulligan, Neil W.

    2014-01-01

    Judgments of learning (JOLs) are sometimes influenced by factors that do not impact actual memory performance. One recent proposal is that perceptual fluency during encoding affects metamemory and is a basis of metacognitive illusions. In the present experiments, participants identified aurally presented words that contained inter-spliced silences

  5. Perceptual Fluency, Auditory Generation, and Metamemory: Analyzing the Perceptual Fluency Hypothesis in the Auditory Modality

    ERIC Educational Resources Information Center

    Besken, Miri; Mulligan, Neil W.

    2014-01-01

    Judgments of learning (JOLs) are sometimes influenced by factors that do not impact actual memory performance. One recent proposal is that perceptual fluency during encoding affects metamemory and is a basis of metacognitive illusions. In the present experiments, participants identified aurally presented words that contained inter-spliced silences…

  6. Relationship between perceptual learning in speech and statistical learning in younger and older adults.

    PubMed

    Neger, Thordis M; Rietveld, Toni; Janse, Esther

    2014-01-01

    Within a few sentences, listeners learn to understand severely degraded speech such as noise-vocoded speech. However, individuals vary in the amount of such perceptual learning and it is unclear what underlies these differences. The present study investigates whether perceptual learning in speech relates to statistical learning, as sensitivity to probabilistic information may aid identification of relevant cues in novel speech input. If statistical learning and perceptual learning (partly) draw on the same general mechanisms, then statistical learning in a non-auditory modality using non-linguistic sequences should predict adaptation to degraded speech. In the present study, 73 older adults (aged over 60 years) and 60 younger adults (aged between 18 and 30 years) performed a visual artificial grammar learning task and were presented with 60 meaningful noise-vocoded sentences in an auditory recall task. Within age groups, sentence recognition performance over exposure was analyzed as a function of statistical learning performance, and other variables that may predict learning (i.e., hearing, vocabulary, attention switching control, working memory, and processing speed). Younger and older adults showed similar amounts of perceptual learning, but only younger adults showed significant statistical learning. In older adults, improvement in understanding noise-vocoded speech was constrained by age. In younger adults, amount of adaptation was associated with lexical knowledge and with statistical learning ability. Thus, individual differences in general cognitive abilities explain listeners' variability in adapting to noise-vocoded speech. Results suggest that perceptual and statistical learning share mechanisms of implicit regularity detection, but that the ability to detect statistical regularities is impaired in older adults if visual sequences are presented quickly. PMID:25225475

  7. Two Thirds of the Age-Based Changes in Fluid and Crystallized Intelligence, Perceptual Speed, and Memory in Adulthood Are Shared

    ERIC Educational Resources Information Center

    Ghisletta, Paolo; Rabbitt, Patrick; Lunn, Mary; Lindenberger, Ulman

    2012-01-01

    Many aspects of cognition decline from middle to late adulthood, but the dimensionality and generality of this decline have rarely been examined. We analyzed 20-year longitudinal data of 6203 middle-aged to very old adults from Greater Manchester and Newcastle-upon-Tyne, UK. Participants were assessed up to eight times on 20 tasks of fluid…

  8. Processing speed enhances model-based over model-free reinforcement learning in the presence of high working memory functioning

    PubMed Central

    Schad, Daniel J.; Jünger, Elisabeth; Sebold, Miriam; Garbusow, Maria; Bernhardt, Nadine; Javadi, Amir-Homayoun; Zimmermann, Ulrich S.; Smolka, Michael N.; Heinz, Andreas; Rapp, Michael A.; Huys, Quentin J. M.

    2014-01-01

    Theories of decision-making and its neural substrates have long assumed the existence of two distinct and competing valuation systems, variously described as goal-directed vs. habitual, or, more recently and based on statistical arguments, as model-free vs. model-based reinforcement-learning. Though both have been shown to control choices, the cognitive abilities associated with these systems are under ongoing investigation. Here we examine the link to cognitive abilities, and find that individual differences in processing speed covary with a shift from model-free to model-based choice control in the presence of above-average working memory function. This suggests shared cognitive and neural processes; provides a bridge between literatures on intelligence and valuation; and may guide the development of process models of different valuation components. Furthermore, it provides a rationale for individual differences in the tendency to deploy valuation systems, which may be important for understanding the manifold neuropsychiatric diseases associated with malfunctions of valuation. PMID:25566131

  9. Why Chunking Should be Considered as an Explanation for Developmental Change before Short-Term Memory Capacity and Processing Speed.

    PubMed

    Jones, Gary

    2012-01-01

    The chunking hypothesis suggests that during the repeated exposure of stimulus material, information is organized into increasingly larger chunks. Many researchers have not considered the full power of the chunking hypothesis as both a learning mechanism and as an explanation of human behavior. Indeed, in developmental psychology there is relatively little mention of chunking and yet it can be the underlying cause of some of the mechanisms of development that have been proposed. This paper illustrates the chunking hypothesis in the domain of non-word repetition, a task that is a strong predictor of a child's language learning. A computer simulation of non-word repetition that instantiates the chunking mechanism shows that: (1) chunking causes task behavior to improve over time, consistent with children's performance; and (2) chunking causes perceived changes in areas such as short-term memory capacity and processing speed that are often cited as mechanisms of child development. Researchers should be cautious when considering explanations of developmental data, since chunking may be able to explain differences in performance without the need for additional mechanisms of development. PMID:22715331

  10. Generation and Context Memory

    ERIC Educational Resources Information Center

    Mulligan, Neil W.; Lozito, Jeffrey P.; Rosner, Zachary A.

    2006-01-01

    Generation enhances memory for occurrence but may not enhance other aspects of memory. The present study further delineates the negative generation effect in context memory reported in N. W. Mulligan (2004). First, the negative generation effect occurred for perceptual attributes of the target item (its color and font) but not for extratarget…

  11. Perceptual representations in false recognition and priming of pictures.

    PubMed

    Weinstein, Yana; Shanks, David R

    2008-12-01

    Using a new procedure, we investigate whether imagination can induce false memory by creating a perceptual representation. Participants studied pictures and words with and without an imagery task and at test performed both a direct recognition test and an indirect perceptual identification test on pictorial stimuli. Corrected false recognition rates were 7% for pictures studied in word form (Experiment 1), 26% for pictures imagined once (Experiment 2), and 48% for pictures imagined multiple times (Experiment 3), although on the indirect test, no priming was found for these items. Furthermore, a perceptual/conceptual imagery manipulation did not affect the tendency to claim that imagined items had been studied as pictures (Experiment 4). These results suggest that the false memories reported on direct tests are not driven by perceptual representations. PMID:19015501

  12. High-speed, high-density, coherent time-domain optical memory. Final report, 1 September 1990-31 August 1993

    SciTech Connect

    Kachru, R.; Shen, X.A.

    1993-11-01

    The objective of this research was to quantitatively evaluate the concept of time-domain optical memory (TDOM) using the hole-burning mechanism. The TDOM concept offers both high speed and high memory density. The advantage of TDOM over traditional semiconductor memory is its inherent parallelism, which allows data to be stored and retrieved from the memory at much higher speed. The practical success of the proposed memory, therefore, depends critically on-among other issues-the storage, retrieval, and processing of images. In addition, new data storage techniques are needed to implement a practical memory. The last three years of this research program have focused on (1) development of new phase modulation techniques to enhance the storage, retrieval, and integrity of the stored information; (2) experimental studies of image storage and phase conjugate retrieval; (3) Image processing; and (4) practical holographic storage of images by using the hybrid time-frequency approach. Specifically, SRI demonstrated data encryption by phase modulating the read and write pulses. Image correlation and convolution was demonstrated and its implication for pattern recognition examined. Finally, this laboratory demonstrated high-fidelity random access and retrieval using holographic storage in Pr3+: YA103 with a single-frequency ring laser. These experiments have clearly demonstrated the practical viability of TDOM with existing technology. In the next stage of the research, the performance Issues such as bit-error-rates, signal-to-noise ratios, and laser stability need to be addressed. Stimulated photon echoes, Optical memory, Image processing, Pattern recognition, Phase conjugation.

  13. Frequent Video Game Players Resist Perceptual Interference

    PubMed Central

    Berard, Aaron V.; Cain, Matthew S.; Watanabe, Takeo; Sasaki, Yuka

    2015-01-01

    Playing certain types of video games for a long time can improve a wide range of mental processes, from visual acuity to cognitive control. Frequent gamers have also displayed generalized improvements in perceptual learning. In the Texture Discrimination Task (TDT), a widely used perceptual learning paradigm, participants report the orientation of a target embedded in a field of lines and demonstrate robust over-night improvement. However, changing the orientation of the background lines midway through TDT training interferes with overnight improvements in overall performance on TDT. Interestingly, prior research has suggested that this effect will not occur if a one-hour break is allowed in between the changes. These results have suggested that after training is over, it may take some time for learning to become stabilized and resilient against interference. Here, we tested whether frequent gamers have faster stabilization of perceptual learning compared to non-gamers and examined the effect of daily video game playing on interference of training of TDT with one background orientation on perceptual learning of TDT with a different background orientation. As a result, we found that non-gamers showed overnight performance improvement only on one background orientation, replicating previous results with the interference in TDT. In contrast, frequent gamers demonstrated overnight improvements in performance with both background orientations, suggesting that they are better able to overcome interference in perceptual learning. This resistance to interference suggests that video game playing not only enhances the amplitude and speed of perceptual learning but also leads to faster and/or more robust stabilization of perceptual learning. PMID:25807394

  14. Common mechanisms of human perceptual and motor learning

    PubMed Central

    Censor, Nitzan; Sagi, Dov; Cohen, Leonardo G.

    2016-01-01

    The adult mammalian brain has a remarkable capacity to learn in both the perceptual and motor domains through the formation and consolidation of memories. Such practice-enabled procedural learning results in perceptual and motor skill improvements. Here, we examine evidence supporting the notion that perceptual and motor learning in humans exhibit analogous properties, including similarities in temporal dynamics and the interactions between primary cortical and higher-order brain areas. These similarities may point to the existence of a common general mechanism for learning in humans. PMID:22903222

  15. Memory

    MedlinePLUS

    ... a lot like a computer. Your brain puts information it judges to be important into "files." When you remember something, you pull up a file. Memory doesn't always work perfectly. As people grow ...

  16. Recovering and Preventing Loss of Detailed Memory: Differential Rates of Forgetting for Detail Types in Episodic Memory

    ERIC Educational Resources Information Center

    Sekeres, Melanie J.; Bonasia, Kyra; St-Laurent, Marie; Pishdadian, Sara; Winocur, Gordon; Grady, Cheryl; Moscovitch, Morris

    2016-01-01

    Episodic memories undergo qualitative changes with time, but little is known about how different aspects of memory are affected. Different types of information in a memory, such as perceptual detail, and central themes, may be lost at different rates. In patients with medial temporal lobe damage, memory for perceptual details is severely impaired,…

  17. Recovering and Preventing Loss of Detailed Memory: Differential Rates of Forgetting for Detail Types in Episodic Memory

    ERIC Educational Resources Information Center

    Sekeres, Melanie J.; Bonasia, Kyra; St-Laurent, Marie; Pishdadian, Sara; Winocur, Gordon; Grady, Cheryl; Moscovitch, Morris

    2016-01-01

    Episodic memories undergo qualitative changes with time, but little is known about how different aspects of memory are affected. Different types of information in a memory, such as perceptual detail, and central themes, may be lost at different rates. In patients with medial temporal lobe damage, memory for perceptual details is severely impaired,

  18. Pseudo Perceptual Differentiation

    ERIC Educational Resources Information Center

    Silverman, Julian; King, Catherine

    1970-01-01

    Two studies employing rod-and-frame test (RFT) and a size-estimation measure of "extensiveness of scanning reported. Results indicated perceptual differentiation interpretation of RFT performance erroneous for certain kinds of Ss. (Author)

  19. Implicit Memory in Monkeys: Development of a Delay Eyeblink Conditioning System with Parallel Electromyographic and High-Speed Video Measurements.

    PubMed

    Kishimoto, Yasushi; Yamamoto, Shigeyuki; Suzuki, Kazutaka; Toyoda, Haruyoshi; Kano, Masanobu; Tsukada, Hideo; Kirino, Yutaka

    2015-01-01

    Delay eyeblink conditioning, a cerebellum-dependent learning paradigm, has been applied to various mammalian species but not yet to monkeys. We therefore developed an accurate measuring system that we believe is the first system suitable for delay eyeblink conditioning in a monkey species (Macaca mulatta). Monkey eyeblinking was simultaneously monitored by orbicularis oculi electromyographic (OO-EMG) measurements and a high-speed camera-based tracking system built around a 1-kHz CMOS image sensor. A 1-kHz tone was the conditioned stimulus (CS), while an air puff (0.02 MPa) was the unconditioned stimulus. EMG analysis showed that the monkeys exhibited a conditioned response (CR) incidence of more than 60% of trials during the 5-day acquisition phase and an extinguished CR during the 2-day extinction phase. The camera system yielded similar results. Hence, we conclude that both methods are effective in evaluating monkey eyeblink conditioning. This system incorporating two different measuring principles enabled us to elucidate the relationship between the actual presence of eyelid closure and OO-EMG activity. An interesting finding permitted by the new system was that the monkeys frequently exhibited obvious CRs even when they produced visible facial signs of drowsiness or microsleep. Indeed, the probability of observing a CR in a given trial was not influenced by whether the monkeys closed their eyelids just before CS onset, suggesting that this memory could be expressed independently of wakefulness. This work presents a novel system for cognitive assessment in monkeys that will be useful for elucidating the neural mechanisms of implicit learning in nonhuman primates. PMID:26068663

  20. Implicit Memory in Monkeys: Development of a Delay Eyeblink Conditioning System with Parallel Electromyographic and High-Speed Video Measurements

    PubMed Central

    Suzuki, Kazutaka; Toyoda, Haruyoshi; Kano, Masanobu; Tsukada, Hideo; Kirino, Yutaka

    2015-01-01

    Delay eyeblink conditioning, a cerebellum-dependent learning paradigm, has been applied to various mammalian species but not yet to monkeys. We therefore developed an accurate measuring system that we believe is the first system suitable for delay eyeblink conditioning in a monkey species (Macaca mulatta). Monkey eyeblinking was simultaneously monitored by orbicularis oculi electromyographic (OO-EMG) measurements and a high-speed camera-based tracking system built around a 1-kHz CMOS image sensor. A 1-kHz tone was the conditioned stimulus (CS), while an air puff (0.02 MPa) was the unconditioned stimulus. EMG analysis showed that the monkeys exhibited a conditioned response (CR) incidence of more than 60% of trials during the 5-day acquisition phase and an extinguished CR during the 2-day extinction phase. The camera system yielded similar results. Hence, we conclude that both methods are effective in evaluating monkey eyeblink conditioning. This system incorporating two different measuring principles enabled us to elucidate the relationship between the actual presence of eyelid closure and OO-EMG activity. An interesting finding permitted by the new system was that the monkeys frequently exhibited obvious CRs even when they produced visible facial signs of drowsiness or microsleep. Indeed, the probability of observing a CR in a given trial was not influenced by whether the monkeys closed their eyelids just before CS onset, suggesting that this memory could be expressed independently of wakefulness. This work presents a novel system for cognitive assessment in monkeys that will be useful for elucidating the neural mechanisms of implicit learning in nonhuman primates. PMID:26068663

  1. "The Mask Who Wasn't There": Visual Masking Effect with the Perceptual Absence of the Mask

    ERIC Educational Resources Information Center

    Rey, Amandine Eve; Riou, Benoit; Muller, Dominique; Dabic, Stéphanie; Versace, Rémy

    2015-01-01

    Does a visual mask need to be perceptually present to disrupt processing? In the present research, we proposed to explore the link between perceptual and memory mechanisms by demonstrating that a typical sensory phenomenon (visual masking) can be replicated at a memory level. Experiment 1 highlighted an interference effect of a visual mask on the…

  2. "The Mask Who Wasn't There": Visual Masking Effect with the Perceptual Absence of the Mask

    ERIC Educational Resources Information Center

    Rey, Amandine Eve; Riou, Benoit; Muller, Dominique; Dabic, Stphanie; Versace, Rmy

    2015-01-01

    Does a visual mask need to be perceptually present to disrupt processing? In the present research, we proposed to explore the link between perceptual and memory mechanisms by demonstrating that a typical sensory phenomenon (visual masking) can be replicated at a memory level. Experiment 1 highlighted an interference effect of a visual mask on the

  3. Neural plasticity underlying visual perceptual learning in aging.

    PubMed

    Mishra, Jyoti; Rolle, Camarin; Gazzaley, Adam

    2015-07-01

    Healthy aging is associated with a decline in basic perceptual abilities, as well as higher-level cognitive functions such as working memory. In a recent perceptual training study using moving sweeps of Gabor stimuli, Berry et al. (2010) observed that older adults significantly improved discrimination abilities on the most challenging perceptual tasks that presented paired sweeps at rapid rates of 5 and 10 Hz. Berry et al. further showed that this perceptual training engendered transfer-of-benefit to an untrained working memory task. Here, we investigated the neural underpinnings of the improvements in these perceptual tasks, as assessed by event-related potential (ERP) recordings. Early visual ERP components time-locked to stimulus onset were compared pre- and post-training, as well as relative to a no-contact control group. The visual N1 and N2 components were significantly enhanced after training, and the N1 change correlated with improvements in perceptual discrimination on the task. Further, the change observed for the N1 and N2 was associated with the rapidity of the perceptual challenge; the visual N1 (120-150 ms) was enhanced post-training for 10 Hz sweep pairs, while the N2 (240-280 ms) was enhanced for the 5 Hz sweep pairs. We speculate that these observed post-training neural enhancements reflect improvements by older adults in the allocation of attention that is required to accurately dissociate perceptually overlapping stimuli when presented in rapid sequence. This article is part of a Special Issue entitled SI: Memory Å. PMID:25218557

  4. Memories.

    ERIC Educational Resources Information Center

    Brand, Judith, Ed.

    1998-01-01

    This theme issue of the journal "Exploring" covers the topic of "memories" and describes an exhibition at San Francisco's Exploratorium that ran from May 22, 1998 through January 1999 and that contained over 40 hands-on exhibits, demonstrations, artworks, images, sounds, smells, and tastes that demonstrated and depicted the biological,…

  5. Working Memory Capacity in a Go/No-Go Task: Age Differences in Interference, Processing Speed, and Attentional Control

    ERIC Educational Resources Information Center

    Rodríguez-Villagra, Odir Antonio; Göthe, Katrin; Oberauer, Klaus; Kliegl, Reinhold

    2013-01-01

    We tested the limits of working-memory capacity (WMC) of young adults, old adults, and children with a memory-updating task. The task consisted of mentally shifting spatial positions within a grid according to arrows, their color signaling either only go (control) or go/no-go conditions. The interference model (IM) of Oberauer and Kliegl (2006)…

  6. Working Memory Capacity in a Go/No-Go Task: Age Differences in Interference, Processing Speed, and Attentional Control

    ERIC Educational Resources Information Center

    Rodrguez-Villagra, Odir Antonio; Gthe, Katrin; Oberauer, Klaus; Kliegl, Reinhold

    2013-01-01

    We tested the limits of working-memory capacity (WMC) of young adults, old adults, and children with a memory-updating task. The task consisted of mentally shifting spatial positions within a grid according to arrows, their color signaling either only go (control) or go/no-go conditions. The interference model (IM) of Oberauer and Kliegl (2006)

  7. Subjective Confidence in Perceptual Judgments: A Test of the Self-Consistency Model

    ERIC Educational Resources Information Center

    Koriat, Asher

    2011-01-01

    Two questions about subjective confidence in perceptual judgments are examined: the bases for these judgments and the reasons for their accuracy. Confidence in perceptual judgments has been claimed to rest on qualitatively different processes than confidence in memory tasks. However, predictions from a self-consistency model (SCM), which had been…

  8. Brief Daily Exposures to Asian Females Reverses Perceptual Narrowing for Asian Faces in Caucasian Infants

    ERIC Educational Resources Information Center

    Anzures, Gizelle; Wheeler, Andrea; Quinn, Paul C.; Pascalis, Olivier; Slater, Alan M.; Heron-Delaney, Michelle; Tanaka, James W.; Lee, Kang

    2012-01-01

    Perceptual narrowing in the visual, auditory, and multisensory domains has its developmental origins during infancy. The current study shows that experimentally induced experience can reverse the effects of perceptual narrowing on infants' visual recognition memory of other-race faces. Caucasian 8- to 10-month-olds who could not discriminate…

  9. Normative perceptual estimates for 91 healthy subjects age 60–75: impact of age, education, employment, physical exercise, alcohol, and video gaming

    PubMed Central

    Wilms, Inge L.; Nielsen, Simon

    2014-01-01

    Visual perception serves as the basis for much of the higher level cognitive processing as well as human activity in general. Here we present normative estimates for the following components of visual perception: the visual perceptual threshold, the visual short-term memory (VSTM) capacity and the visual perceptual encoding/decoding speed (processing speed) of VSTM based on an assessment of 91 healthy subjects aged 60–75. The estimates were modeled from input from a whole-report assessment based on a theory of visual attention. In addition to the estimates themselves, we present correlational data, and multiple regression analyses between the estimates and self-reported demographic data and lifestyle variables. The regression statistics suggest that education level, video gaming activity, and employment status may significantly impact the encoding/decoding speed of VTSM but not the capacity of VSTM nor the visual perceptual threshold. The estimates will be useful for future studies into the effects of various types of intervention and training on cognition in general and visual attention in particular. PMID:25339932

  10. Perceptual presence without counterfactual richness.

    PubMed

    Madary, Michael

    2014-01-01

    In this commentary, I suggest that non-visual perceptual modalities provide counterexamples to Seth's claim that perceptual presence depends on counterfactual richness. Then I suggest a modification to Seth's view that is not vulnerable to these counterexamples. PMID:24739124

  11. Acetylcholine and Olfactory Perceptual Learning

    ERIC Educational Resources Information Center

    Wilson, Donald A.; Fletcher, Max L.; Sullivan, Regina M.

    2004-01-01

    Olfactory perceptual learning is a relatively long-term, learned increase in perceptual acuity, and has been described in both humans and animals. Data from recent electrophysiological studies have indicated that olfactory perceptual learning may be correlated with changes in odorant receptive fields of neurons in the olfactory bulb and piriform…

  12. Perceptual Processing Affects Conceptual Processing

    ERIC Educational Resources Information Center

    van Dantzig, Saskia; Pecher, Diane; Zeelenberg, Rene; Barsalou, Lawrence W.

    2008-01-01

    According to the Perceptual Symbols Theory of cognition (Barsalou, 1999), modality-specific simulations underlie the representation of concepts. A strong prediction of this view is that perceptual processing affects conceptual processing. In this study, participants performed a perceptual detection task and a conceptual property-verification task…

  13. Adaptation and perceptual norms

    NASA Astrophysics Data System (ADS)

    Webster, Michael A.; Yasuda, Maiko; Haber, Sara; Leonard, Deanne; Ballardini, Nicole

    2007-02-01

    We used adaptation to examine the relationship between perceptual norms--the stimuli observers describe as psychologically neutral, and response norms--the stimulus levels that leave visual sensitivity in a neutral or balanced state. Adapting to stimuli on opposite sides of a neutral point (e.g. redder or greener than white) biases appearance in opposite ways. Thus the adapting stimulus can be titrated to find the unique adapting level that does not bias appearance. We compared these response norms to subjectively defined neutral points both within the same observer (at different retinal eccentricities) and between observers. These comparisons were made for visual judgments of color, image focus, and human faces, stimuli that are very different and may depend on very different levels of processing, yet which share the property that for each there is a well defined and perceptually salient norm. In each case the adaptation aftereffects were consistent with an underlying sensitivity basis for the perceptual norm. Specifically, response norms were similar to and thus covaried with the perceptual norm, and under common adaptation differences between subjectively defined norms were reduced. These results are consistent with models of norm-based codes and suggest that these codes underlie an important link between visual coding and visual experience.

  14. Perceptual Tolerance Intersection

    NASA Astrophysics Data System (ADS)

    Wasilewski, Piotr; Peters, James F.; Ramanna, Sheela

    This paper elaborates on the introduction of perceptual tolerance intersection of sets as an example of a near set operation. Such operations are motivated by the need to consider similarities between digital images viewed as disjoint sets of points. The proposed approach is in keeping with work by E.C. Zeeman on tolerance spaces and visual perception and work by J.H. Poincar on sets of similar sensations used to define representative spaces (aka tolerance spaces) such as visual, tactile and motile spaces. Perceptual tolerance intersection of sets is a direct consequence of recent work on near sets. The theory of perceptual set intersection has many practical applications such as a solution to the problem of how one goes about measuring the closeness of digital images. The main contribution of this article is a description-based approach to formulating perceptual set intersections between disjoint sets that resemble each other. A practical application of the proposed approach is the discovery of resemblances between sets of points in digital image regions that represent tolerance rough sets.

  15. Perceptual-Motor Dysfunction.

    ERIC Educational Resources Information Center

    Pyfer, Jean L.

    Discussed are theoretical and treatment aspects of perceptual motor dysfunction and rehabilitation in 4- to 12-year-old academically failing children involved in a 3-year investigation at the University of Kansas. The program is said to stress increasing the amount of stimulation received by sensory receptors of the vestibular, reflex, and haptic…

  16. A Two-Stage Search of Visual Working Memory: Investigating Speed in the Change-Detection Paradigm

    PubMed Central

    Gilchrist, Amanda L.; Cowan, Nelson

    2014-01-01

    A popular procedure for investigating working memory processes has been the visual change-detection procedure. Models of performance in that procedure, however, tend to be based on performance accuracy and to treat working memory search as a one-step process, in which memory representations are compared to a test probe to determine if a match is present. To gain a clearer understanding of how search of these representations operate in the change-detection task, we examined reaction time in two experiments, with a single-item probe either located centrally or at the location of an array item. Contrary to current models of visual working memory capacity, our data point to a two-stage search process: a fast first step to check for the novelty of the probe and, in the absence of such novelty, a second, slower step to search exhaustively for a match between the test probe and a memory representation. In addition to these results, we found that participants tended not to use location information provided by the probe that theoretically could have abbreviated the search process. We suggest some basic revisions of current models of processing in this type of visual working memory task. PMID:25023891

  17. The cognitive effects of listening to background music on older adults: processing speed improves with upbeat music, while memory seems to benefit from both upbeat and downbeat music

    PubMed Central

    Bottiroli, Sara; Rosi, Alessia; Russo, Riccardo; Vecchi, Tomaso; Cavallini, Elena

    2014-01-01

    Background music refers to any music played while the listener is performing another activity. Most studies on this effect have been conducted on young adults, while little attention has been paid to the presence of this effect in older adults. Hence, this study aimed to address this imbalance by assessing the impact of different types of background music on cognitive tasks tapping declarative memory and processing speed in older adults. Overall, background music tended to improve performance over no music and white noise, but not always in the same manner. The theoretical and practical implications of the empirical findings are discussed. PMID:25360112

  18. The cognitive effects of listening to background music on older adults: processing speed improves with upbeat music, while memory seems to benefit from both upbeat and downbeat music.

    PubMed

    Bottiroli, Sara; Rosi, Alessia; Russo, Riccardo; Vecchi, Tomaso; Cavallini, Elena

    2014-01-01

    Background music refers to any music played while the listener is performing another activity. Most studies on this effect have been conducted on young adults, while little attention has been paid to the presence of this effect in older adults. Hence, this study aimed to address this imbalance by assessing the impact of different types of background music on cognitive tasks tapping declarative memory and processing speed in older adults. Overall, background music tended to improve performance over no music and white noise, but not always in the same manner. The theoretical and practical implications of the empirical findings are discussed. PMID:25360112

  19. "The mask who wasn't there": visual masking effect with the perceptual absence of the mask.

    PubMed

    Rey, Amandine Eve; Riou, Benoit; Muller, Dominique; Dabic, Stéphanie; Versace, Rémy

    2015-03-01

    Does a visual mask need to be perceptually present to disrupt processing? In the present research, we proposed to explore the link between perceptual and memory mechanisms by demonstrating that a typical sensory phenomenon (visual masking) can be replicated at a memory level. Experiment 1 highlighted an interference effect of a visual mask on the categorization of auditory targets and confirmed the multimodal nature of knowledge. In Experiment 2, we proposed to reactivate this mask in a categorization task on visual targets. Results showed that the sensory mask has disrupted (slower reaction times) the processing of the targets whether the mask was perceptually present or reactivated in memory. These results support a sensory-based conception of memory processing and suggest that the difference between perceptual processes and memory processes is characterized by the presence (perception) or the absence (memory) of the sensory properties involved in the activity. PMID:25133514

  20. Perceptual merging contributes to cueing effects.

    PubMed

    Krüger, Hannah M; MacInnes, W Joseph; Hunt, Amelia R

    2014-01-01

    An uninformative exogenous cue speeds target detection if cue and target appear in the same location separated by a brief temporal interval. This finding is usually ascribed to the orienting of spatial attention to the cued location. Here we examine the role of perceptual merging of the two trial events in speeded target detection. That is, the cue and target may be perceived as a single event when they appear in the same location. If so, cueing effects could reflect, in part, the binding of the perceived target onset to the earlier cue onset. We observed the traditional facilitation of cued over uncued targets and asked the same observers to judge target onset time by noting the time on a clock when the target appeared. Observers consistently judged the onset time of the target as being earlier than it appeared with cued targets judged as earlier than uncued targets. When the event order is reversed so that the target precedes the cue, perceived onset is accurate in both cued and uncued locations. This pattern of results suggests that perceptual merging does occur in exogenous cueing. A modified attention account is discussed that proposes reentrant processing, evident through perceptual merging, as the underlying mechanism of reflexive orienting of attention. PMID:24961250

  1. Integrating Sensory and Perceptual Training in the Classroom.

    ERIC Educational Resources Information Center

    Worby, Carole

    1983-01-01

    Perceptual training activities are described for use in the regular primary or intermediate class that will not disrupt the academic program. Materials and procedures are considered for developing visual and haptic abilities, visual memory and figure-ground discrimination, and auditory, olfactory, taste, and motor skills. (CL)

  2. Perceptual Learning of Acoustic Noise by Individuals with Dyslexia

    ERIC Educational Resources Information Center

    Agus, Trevor R.; Carrin-Castillo, Amaia; Pressnitzer, Daniel; Ramus, Franck

    2014-01-01

    Purpose: A phonological deficit is thought to affect most individuals with developmental dyslexia. The present study addresses whether the phonological deficit is caused by difficulties with perceptual learning of fine acoustic details. Method: A demanding test of nonverbal auditory memory, "noise learning," was administered to both

  3. Prediction Error Associated with the Perceptual Segmentation of Naturalistic Events

    ERIC Educational Resources Information Center

    Zacks, Jeffrey M.; Kurby, Christopher A.; Eisenberg, Michelle L.; Haroutunian, Nayiri

    2011-01-01

    Predicting the near future is important for survival and plays a central role in theories of perception, language processing, and learning. Prediction failures may be particularly important for initiating the updating of perceptual and memory systems and, thus, for the subjective experience of events. Here, we asked observers to make predictions…

  4. Attentional Modulation of Perceptual Comparison for Feature Binding

    ERIC Educational Resources Information Center

    Kuo, Bo-Cheng; Rotshtein, Pia; Yeh, Yei-Yu

    2011-01-01

    We investigated the neural correlates of attentional modulation in the perceptual comparison process for detecting feature-binding changes in an event-related functional magnetic resonance imaging (fMRI) experiment. Participants performed a variant of a cued change detection task. They viewed a memory array, a spatial retro-cue, and later a probe…

  5. Perceptual Learning of Acoustic Noise by Individuals with Dyslexia

    ERIC Educational Resources Information Center

    Agus, Trevor R.; Carrión-Castillo, Amaia; Pressnitzer, Daniel; Ramus, Franck

    2014-01-01

    Purpose: A phonological deficit is thought to affect most individuals with developmental dyslexia. The present study addresses whether the phonological deficit is caused by difficulties with perceptual learning of fine acoustic details. Method: A demanding test of nonverbal auditory memory, "noise learning," was administered to both…

  6. Early Experience & Multisensory Perceptual Narrowing

    PubMed Central

    Lewkowicz, David J.

    2014-01-01

    Perceptual narrowing is a reflection of early experience and contributes in key ways to perceptual and cognitive development. In general, findings have shown that unisensory perceptual sensitivity in early infancy is broadly tuned such that young infants respond to, and discriminate, native as well as non-native sensory inputs, whereas older infants only respond to native inputs. Recently, my colleagues and I discovered that perceptual narrowing occurs at the multisensory processing level as well. The present article reviews this new evidence and puts it in the larger context of multisensory perceptual development and the role that perceptual experience plays in it. Together, the evidence on unisensory and multisensory narrowing shows that early experience shapes the emergence of perceptual specialization and expertise. PMID:24435505

  7. Perceptual learning and human expertise.

    PubMed

    Kellman, Philip J; Garrigan, Patrick

    2009-06-01

    We consider perceptual learning: experience-induced changes in the way perceivers extract information. Often neglected in scientific accounts of learning and in instruction, perceptual learning is a fundamental contributor to human expertise and is crucial in domains where humans show remarkable levels of attainment, such as language, chess, music, and mathematics. In Section 2, we give a brief history and discuss the relation of perceptual learning to other forms of learning. We consider in Section 3 several specific phenomena, illustrating the scope and characteristics of perceptual learning, including both discovery and fluency effects. We describe abstract perceptual learning, in which structural relationships are discovered and recognized in novel instances that do not share constituent elements or basic features. In Section 4, we consider primary concepts that have been used to explain and model perceptual learning, including receptive field change, selection, and relational recoding. In Section 5, we consider the scope of perceptual learning, contrasting recent research, focused on simple sensory discriminations, with earlier work that emphasized extraction of invariance from varied instances in more complex tasks. Contrary to some recent views, we argue that perceptual learning should not be confined to changes in early sensory analyzers. Phenomena at various levels, we suggest, can be unified by models that emphasize discovery and selection of relevant information. In a final section, we consider the potential role of perceptual learning in educational settings. Most instruction emphasizes facts and procedures that can be verbalized, whereas expertise depends heavily on implicit pattern recognition and selective extraction skills acquired through perceptual learning. We consider reasons why perceptual learning has not been systematically addressed in traditional instruction, and we describe recent successful efforts to create a technology of perceptual learning in areas such as aviation, mathematics, and medicine. Research in perceptual learning promises to advance scientific accounts of learning, and perceptual learning technology may offer similar promise in improving education. PMID:20416846

  8. Perceptual learning and human expertise

    NASA Astrophysics Data System (ADS)

    Kellman, Philip J.; Garrigan, Patrick

    2009-06-01

    We consider perceptual learning: experience-induced changes in the way perceivers extract information. Often neglected in scientific accounts of learning and in instruction, perceptual learning is a fundamental contributor to human expertise and is crucial in domains where humans show remarkable levels of attainment, such as language, chess, music, and mathematics. In Section 2, we give a brief history and discuss the relation of perceptual learning to other forms of learning. We consider in Section 3 several specific phenomena, illustrating the scope and characteristics of perceptual learning, including both discovery and fluency effects. We describe abstract perceptual learning, in which structural relationships are discovered and recognized in novel instances that do not share constituent elements or basic features. In Section 4, we consider primary concepts that have been used to explain and model perceptual learning, including receptive field change, selection, and relational recoding. In Section 5, we consider the scope of perceptual learning, contrasting recent research, focused on simple sensory discriminations, with earlier work that emphasized extraction of invariance from varied instances in more complex tasks. Contrary to some recent views, we argue that perceptual learning should not be confined to changes in early sensory analyzers. Phenomena at various levels, we suggest, can be unified by models that emphasize discovery and selection of relevant information. In a final section, we consider the potential role of perceptual learning in educational settings. Most instruction emphasizes facts and procedures that can be verbalized, whereas expertise depends heavily on implicit pattern recognition and selective extraction skills acquired through perceptual learning. We consider reasons why perceptual learning has not been systematically addressed in traditional instruction, and we describe recent successful efforts to create a technology of perceptual learning in areas such as aviation, mathematics, and medicine. Research in perceptual learning promises to advance scientific accounts of learning, and perceptual learning technology may offer similar promise in improving education.

  9. Abnormal categorization and perceptual learning in patients with hippocampal damage.

    PubMed

    Graham, Kim S; Scahill, Victoria L; Hornberger, Michael; Barense, Morgan D; Lee, Andy C H; Bussey, Timothy J; Saksida, Lisa M

    2006-07-19

    Prevailing theory holds that the medial temporal lobe (MTL) subserves declarative memory exclusively, whereas nondeclarative memory is independent of this brain region. Recent studies in patients with amnesia, however, have shown that performance on declarative memory tasks may not always be dependent on a single MTL memory system, instead highlighting the critical role of anatomically distinct structures in processing different stimulus types. In particular, the hippocampus has been implicated in spatial memory, whereas perirhinal cortex seems critical for object memory. To assess whether stimulus type would also be a key dimension in nondeclarative memory, patients with selective hippocampal lesions were tested on simple categorization and perceptual learning of faces and virtual reality scenes. The patients demonstrated preserved categorization and perceptual learning of faces but abnormal performance when the stimuli to be discriminated were virtual reality scenes. These findings imply that stimulus type may be a more critical predictor of performance on memory tasks (declarative and nondeclarative) than previously thought. They also suggest that reports of good nondeclarative memory after MTL damage may, in some cases, simply reflect the use of stimuli that fail to tap the processes dependent on structures in this region, such as spatial processing in the case of the hippocampus. PMID:16855082

  10. Perceptual processing affects the reactivation of a sensory dimension during a categorization task.

    PubMed

    Riou, Benoit; Rey, Amandine E; Vallet, Guillaume T; Cuny, Caroline; Versace, Rémy

    2015-01-01

    According to grounded theories of cognition, knowledge is grounded in its sensory-motor features. Therefore, perceptual and conceptual processing should be based on the same distributed system so that conceptual and perceptual processes should interact. The present study assesses whether gustatory stimulation (participants tasted a sweet or a nonsweet yoghurt) could influence performance on a categorization task that involves the reactivation of the same sensory dimension. The results indicate that participants were slower (Experiment 1) or faster (Experiment 2), respectively, at categorizing pictures as representing edible sweet stimuli when they either simultaneously or had previously tasted a sweet yoghurt as compared to a nonsweet yoghurt. These results confirm the significant overlap between perceptual and memory mechanisms and suggest the functional equivalence between perceptually present and perceptually absent (memory reactivated) dimensions. PMID:25409625

  11. Effects of Acute Cortisol Administration on Perceptual Priming of Trauma-Related Material

    PubMed Central

    Streb, Markus; Pfaltz, Monique; Michael, Tanja

    2014-01-01

    Intrusive memories are a hallmark symptom of posttraumatic stress disorder (PTSD). They reflect excessive and uncontrolled retrieval of the traumatic memory. Acute elevations of cortisol are known to impair the retrieval of already stored memory information. Thus, continuous cortisol administration might help in reducing intrusive memories in PTSD. Strong perceptual priming for neutral stimuli associated with a “traumatic” context has been shown to be one important learning mechanism that leads to intrusive memories. However, the memory modulating effects of cortisol have only been shown for explicit declarative memory processes. Thus, in our double blind, placebo controlled study we aimed to investigate whether cortisol influences perceptual priming of neutral stimuli that appeared in a “traumatic” context. Two groups of healthy volunteers (N = 160) watched either neutral or “traumatic” picture stories on a computer screen. Neutral objects were presented in between the pictures. Memory for these neutral objects was tested after 24 hours with a perceptual priming task and an explicit memory task. Prior to memory testing half of the participants in each group received 25 mg of cortisol, the other half received placebo. In the placebo group participants in the “traumatic” stories condition showed more perceptual priming for the neutral objects than participants in the neutral stories condition, indicating a strong perceptual priming effect for neutral stimuli presented in a “traumatic” context. In the cortisol group this effect was not present: Participants in the neutral stories and participants in the “traumatic” stories condition in the cortisol group showed comparable priming effects for the neutral objects. Our findings show that cortisol inhibits perceptual priming for neutral stimuli that appeared in a “traumatic” context. These findings indicate that cortisol influences PTSD-relevant memory processes and thus further support the idea that administration of cortisol might be an effective treatment strategy in reducing intrusive reexperiencing. PMID:25192334

  12. Exploring Possible Neural Mechanisms of Intelligence Differences Using Processing Speed and Working Memory Tasks: An fMRI Study

    ERIC Educational Resources Information Center

    Waiter, Gordon D.; Deary, Ian J.; Staff, Roger T.; Murray, Alison D.; Fox, Helen C.; Starr, John M.; Whalley, Lawrence J.

    2009-01-01

    To explore the possible neural foundations of individual differences in intelligence test scores, we examined the associations between Raven's Matrices scores and two tasks that were administered in a functional magnetic resonance imaging (fMRI) setting. The two tasks were an n-back working memory (N = 37) task and inspection time (N = 47). The…

  13. Exploring Possible Neural Mechanisms of Intelligence Differences Using Processing Speed and Working Memory Tasks: An fMRI Study

    ERIC Educational Resources Information Center

    Waiter, Gordon D.; Deary, Ian J.; Staff, Roger T.; Murray, Alison D.; Fox, Helen C.; Starr, John M.; Whalley, Lawrence J.

    2009-01-01

    To explore the possible neural foundations of individual differences in intelligence test scores, we examined the associations between Raven's Matrices scores and two tasks that were administered in a functional magnetic resonance imaging (fMRI) setting. The two tasks were an n-back working memory (N = 37) task and inspection time (N = 47). The

  14. Working Memory, Processing Speed, and Set-Shifting in Children with Developmental Coordination Disorder and Attention-Deficit-Hyperactivity Disorder

    ERIC Educational Resources Information Center

    Piek, Jan P.; Dyck, Murray J.; Francis, Mona; Conwell, Alistair

    2007-01-01

    It has been suggested that the high levels of comorbidity between attention-deficit-hyperactivity disorder (ADHD) and developmental coordination disorder (DCD) may be attributed to a common underlying neurocognitive mechanism. This study assessed whether children with DCD and ADHD share deficits on tasks measuring working memory, set-shifting, and…

  15. Perceptual grouping across eccentricity.

    PubMed

    Tannazzo, Teresa; Kurylo, Daniel D; Bukhari, Farhan

    2014-10-01

    Across the visual field, progressive differences exist in neural processing as well as perceptual abilities. Expansion of stimulus scale across eccentricity compensates for some basic visual capacities, but not for high-order functions. It was hypothesized that as with many higher-order functions, perceptual grouping ability should decline across eccentricity. To test this prediction, psychophysical measurements of grouping were made across eccentricity. Participants indicated the dominant grouping of dot grids in which grouping was based upon luminance, motion, orientation, or proximity. Across trials, the organization of stimuli was systematically decreased until perceived grouping became ambiguous. For all stimulus features, grouping ability remained relatively stable until 40°, beyond which thresholds significantly elevated. The pattern of change across eccentricity varied across stimulus feature, in which stimulus scale, dot size, or stimulus size interacted with eccentricity effects. These results demonstrate that perceptual grouping of such stimuli is not reliant upon foveal viewing, and suggest that selection of dominant grouping patterns from ambiguous displays operates similarly across much of the visual field. PMID:25175117

  16. Non-Attended Representations are Perceptual Rather than Unconscious in Nature

    PubMed Central

    Fahrenfort, Johannes J.; Ambroziak, Klaudia B.; Lamme, Victor A. F.

    2012-01-01

    Introspectively we experience a phenomenally rich world. In stark contrast, many studies show that we can only report on the few items that we happen to attend to. So what happens to the unattended objects? Are these consciously processed as our first person perspective would have us believe, or are they in fact entirely unconscious? Here, we attempt to resolve this question by investigating the perceptual characteristics of visual sensory memory. Sensory memory is a fleeting, high-capacity form of memory that precedes attentional selection and working memory. We found that memory capacity benefits from figural information induced by the Kanizsa illusion. Importantly, this benefit was larger for sensory memory than for working memory and depended critically on the illusion, not on the stimulus configuration. This shows that pre-attentive sensory memory contains representations that have a genuinely perceptual nature, suggesting that non-attended representations are phenomenally experienced rather than unconscious. PMID:23209639

  17. Abstraction in perceptual symbol systems.

    PubMed Central

    Barsalou, Lawrence W

    2003-01-01

    After reviewing six senses of abstraction, this article focuses on abstractions that take the form of summary representations. Three central properties of these abstractions are established: ( i ) type-token interpretation; (ii) structured representation; and (iii) dynamic realization. Traditional theories of representation handle interpretation and structure well but are not sufficiently dynamical. Conversely, connectionist theories are exquisitely dynamic but have problems with structure. Perceptual symbol systems offer an approach that implements all three properties naturally. Within this framework, a loose collection of property and relation simulators develops to represent abstractions. Type-token interpretation results from binding a property simulator to a region of a perceived or simulated category member. Structured representation results from binding a configuration of property and relation simulators to multiple regions in an integrated manner. Dynamic realization results from applying different subsets of property and relation simulators to category members on different occasions. From this standpoint, there are no permanent or complete abstractions of a category in memory. Instead, abstraction is the skill to construct temporary online interpretations of a category's members. Although an infinite number of abstractions are possible, attractors develop for habitual approaches to interpretation. This approach provides new ways of thinking about abstraction phenomena in categorization, inference, background knowledge and learning. PMID:12903648

  18. Post-traumatic stress is associated with verbal learning, memory, and psychomotor speed in HIV-infected and HIV-uninfected women

    PubMed Central

    Pyra, Maria; Cook, Judith A.; Weber, Kathleen M.; Cohen, Mardge H.; Martin, Eileen; Valcour, Victor; Milam, Joel; Anastos, Kathryn; Young, Mary A.; Alden, Christine; Gustafson, Deborah R.; Maki, Pauline M.

    2015-01-01

    The prevalence of post-traumatic stress disorder (PTSD) is higher among HIV-infected (HIV+) women compared with HIV-uninfected (HIV−) women, and deficits in episodic memory are a common feature of both PTSD and HIV infection. We investigated the association between a probable PTSD diagnosis using the PTSD Checklist-Civilian (PCL-C) version and verbal learning and memory using the Hopkins Verbal Learning Test in 1004 HIV+ and 496 at-risk HIV− women. HIV infection was not associated with a probable PTSD diagnosis (17 % HIV+, 16 % HIV−; p=0.49) but was associated with lower verbal learning (p<0.01) and memory scores (p<0.01). Irrespective of HIV status, a probable PTSD diagnosis was associated with poorer performance in verbal learning (p<0.01) and memory (p<0.01) and psychomotor speed (p<0.001). The particular pattern of cognitive correlates of probable PTSD varied depending on exposure to sexual abuse and/or violence, with exposure to either being associated with a greater number of cognitive domains and a worse cognitive profile. A statistical interaction between HIV serostatus and PTSD was observed on the fine motor skills domain (p= 0.03). Among women with probable PTSD, HIV− women performed worse than HIV+ women on fine motor skills (p=0.01), but among women without probable PTSD, there was no significant difference in performance between the groups (p= 0.59). These findings underscore the importance of considering mental health factors as correlates to cognitive deficits in women with HIV. PMID:26404435

  19. Post-traumatic stress is associated with verbal learning, memory, and psychomotor speed in HIV-infected and HIV-uninfected women.

    PubMed

    Rubin, Leah H; Pyra, Maria; Cook, Judith A; Weber, Kathleen M; Cohen, Mardge H; Martin, Eileen; Valcour, Victor; Milam, Joel; Anastos, Kathryn; Young, Mary A; Alden, Christine; Gustafson, Deborah R; Maki, Pauline M

    2016-04-01

    The prevalence of post-traumatic stress disorder (PTSD) is higher among HIV-infected (HIV+) women compared with HIV-uninfected (HIV-) women, and deficits in episodic memory are a common feature of both PTSD and HIV infection. We investigated the association between a probable PTSD diagnosis using the PTSD Checklist-Civilian (PCL-C) version and verbal learning and memory using the Hopkins Verbal Learning Test in 1004 HIV+ and 496 at-risk HIV- women. HIV infection was not associated with a probable PTSD diagnosis (17 % HIV+, 16 % HIV-; p = 0.49) but was associated with lower verbal learning (p < 0.01) and memory scores (p < 0.01). Irrespective of HIV status, a probable PTSD diagnosis was associated with poorer performance in verbal learning (p < 0.01) and memory (p < 0.01) and psychomotor speed (p < 0.001). The particular pattern of cognitive correlates of probable PTSD varied depending on exposure to sexual abuse and/or violence, with exposure to either being associated with a greater number of cognitive domains and a worse cognitive profile. A statistical interaction between HIV serostatus and PTSD was observed on the fine motor skills domain (p = 0.03). Among women with probable PTSD, HIV- women performed worse than HIV+ women on fine motor skills (p = 0.01), but among women without probable PTSD, there was no significant difference in performance between the groups (p = 0.59). These findings underscore the importance of considering mental health factors as correlates to cognitive deficits in women with HIV. PMID:26404435

  20. When High-Capacity Readers Slow Down and Low-Capacity Readers Speed Up: Working Memory and Locality Effects

    PubMed Central

    Nicenboim, Bruno; Logačev, Pavel; Gattei, Carolina; Vasishth, Shravan

    2016-01-01

    We examined the effects of argument-head distance in SVO and SOV languages (Spanish and German), while taking into account readers' working memory capacity and controlling for expectation (Levy, 2008) and other factors. We predicted only locality effects, that is, a slowdown produced by increased dependency distance (Gibson, 2000; Lewis and Vasishth, 2005). Furthermore, we expected stronger locality effects for readers with low working memory capacity. Contrary to our predictions, low-capacity readers showed faster reading with increased distance, while high-capacity readers showed locality effects. We suggest that while the locality effects are compatible with memory-based explanations, the speedup of low-capacity readers can be explained by an increased probability of retrieval failure. We present a computational model based on ACT-R built under the previous assumptions, which is able to give a qualitative account for the present data and can be tested in future research. Our results suggest that in some cases, interpreting longer RTs as indexing increased processing difficulty and shorter RTs as facilitation may be too simplistic: The same increase in processing difficulty may lead to slowdowns in high-capacity readers and speedups in low-capacity ones. Ignoring individual level capacity differences when investigating locality effects may lead to misleading conclusions. PMID:27014113

  1. When High-Capacity Readers Slow Down and Low-Capacity Readers Speed Up: Working Memory and Locality Effects.

    PubMed

    Nicenboim, Bruno; Logačev, Pavel; Gattei, Carolina; Vasishth, Shravan

    2016-01-01

    We examined the effects of argument-head distance in SVO and SOV languages (Spanish and German), while taking into account readers' working memory capacity and controlling for expectation (Levy, 2008) and other factors. We predicted only locality effects, that is, a slowdown produced by increased dependency distance (Gibson, 2000; Lewis and Vasishth, 2005). Furthermore, we expected stronger locality effects for readers with low working memory capacity. Contrary to our predictions, low-capacity readers showed faster reading with increased distance, while high-capacity readers showed locality effects. We suggest that while the locality effects are compatible with memory-based explanations, the speedup of low-capacity readers can be explained by an increased probability of retrieval failure. We present a computational model based on ACT-R built under the previous assumptions, which is able to give a qualitative account for the present data and can be tested in future research. Our results suggest that in some cases, interpreting longer RTs as indexing increased processing difficulty and shorter RTs as facilitation may be too simplistic: The same increase in processing difficulty may lead to slowdowns in high-capacity readers and speedups in low-capacity ones. Ignoring individual level capacity differences when investigating locality effects may lead to misleading conclusions. PMID:27014113

  2. Effect of (HfO2) X (Al2O3)1- X /SiO2 double-layered blocking oxide on program and erase speed in charge trapping memory devices

    NASA Astrophysics Data System (ADS)

    Oh, Jinho; Ko, Eun Jung; Na, Heedo; Ko, Dae-Hong; Sohn, Hyunchul

    2016-03-01

    In this work, the effect of hole injection into the charge trap layers from channel prior to program operation is investigated in charge trapping (CT) memory with stacked blocking oxide (BO). For efficient hole injection, a (HfO2) X (Al2O3)1 - X /SiO2 stacked BO structure is used. The CT memory device with stacked BO shows faster programming and erasing speed compared with single-layered SiO2 BO. The enhanced programming speed is attributed to the enhanced electric field introduced by excess holes injected into SiN charge trap layer. In addition, efficient hole injection from channel produced the widened memory window in CT memory.

  3. Perceptual Audio Hashing Functions

    NASA Astrophysics Data System (ADS)

    Özer, Hamza; Sankur, Bülent; Memon, Nasir; Anarım, Emin

    2005-12-01

    Perceptual hash functions provide a tool for fast and reliable identification of content. We present new audio hash functions based on summarization of the time-frequency spectral characteristics of an audio document. The proposed hash functions are based on the periodicity series of the fundamental frequency and on singular-value description of the cepstral frequencies. They are found, on one hand, to perform very satisfactorily in identification and verification tests, and on the other hand, to be very resilient to a large variety of attacks. Moreover, we address the issue of security of hashes and propose a keying technique, and thereby a key-dependent hash function.

  4. Modulation of cortical activity during comprehension of familiar and unfamiliar text topics in speed reading and speed listening

    PubMed Central

    Buchweitz, Augusto; Mason, Robert A.; Meschyan, Gayane; Keller, Timothy A.; Just, Marcel Adam

    2014-01-01

    Brain activation associated with normal and speeded comprehension of expository texts on familiar and unfamiliar topics was investigated in reading and listening. The goal was to determine how brain activation and the comprehension processes it reflects are modulated by comprehension speed and topic familiarity. Passages on more familiar topics differentially activated a set of areas in the anterior temporal lobe and medial frontal gyrus, areas often associated with text-level integration processes, which we interpret to reflect integration of previous knowledge with the passage content. Passages presented at the faster presentation resulted in more activation of a network of frontal areas associated with strategic and working-memory processes (as well as visual or auditory sensory-related regions), which we interpret to reflect maintenance of local coherence among briefly available passage segments. The implications of this research is to demonstrate how the brain system for text comprehension adapts to varying perceptual and knowledge conditions. PMID:25463816

  5. Modulation of cortical activity during comprehension of familiar and unfamiliar text topics in speed reading and speed listening.

    PubMed

    Buchweitz, Augusto; Mason, Robert A; Meschyan, Gayane; Keller, Timothy A; Just, Marcel Adam

    2014-12-01

    Brain activation associated with normal and speeded comprehension of expository texts on familiar and unfamiliar topics was investigated in reading and listening. The goal was to determine how brain activation and the comprehension processes it reflects are modulated by comprehension speed and topic familiarity. Passages on more familiar topics differentially activated a set of areas in the anterior temporal lobe and medial frontal gyrus, areas often associated with text-level integration processes, which we interpret to reflect integration of previous knowledge with the passage content. Passages presented at the faster presentation resulted in more activation of a network of frontal areas associated with strategic and working-memory processes (as well as visual or auditory sensory-related regions), which we interpret to reflect maintenance of local coherence among briefly available passage segments. The implications of this research is that the brain system for text comprehension adapts to varying perceptual and knowledge conditions. PMID:25463816

  6. The Auditory-Visual Speech Benefit on Working Memory in Older Adults with Hearing Impairment

    PubMed Central

    Frtusova, Jana B.; Phillips, Natalie A.

    2016-01-01

    This study examined the effect of auditory-visual (AV) speech stimuli on working memory in older adults with poorer-hearing (PH) in comparison to age- and education-matched older adults with better hearing (BH). Participants completed a working memory n-back task (0- to 2-back) in which sequences of digits were presented in visual-only (i.e., speech-reading), auditory-only (A-only), and AV conditions. Auditory event-related potentials (ERP) were collected to assess the relationship between perceptual and working memory processing. The behavioral results showed that both groups were faster in the AV condition in comparison to the unisensory conditions. The ERP data showed perceptual facilitation in the AV condition, in the form of reduced amplitudes and latencies of the auditory N1 and/or P1 components, in the PH group. Furthermore, a working memory ERP component, the P3, peaked earlier for both groups in the AV condition compared to the A-only condition. In general, the PH group showed a more robust AV benefit; however, the BH group showed a dose-response relationship between perceptual facilitation and working memory improvement, especially for facilitation of processing speed. Two measures, reaction time and P3 amplitude, suggested that the presence of visual speech cues may have helped the PH group to counteract the demanding auditory processing, to the level that no group differences were evident during the AV modality despite lower performance during the A-only condition. Overall, this study provides support for the theory of an integrated perceptual-cognitive system. The practical significance of these findings is also discussed. PMID:27148106

  7. The Auditory-Visual Speech Benefit on Working Memory in Older Adults with Hearing Impairment.

    PubMed

    Frtusova, Jana B; Phillips, Natalie A

    2016-01-01

    This study examined the effect of auditory-visual (AV) speech stimuli on working memory in older adults with poorer-hearing (PH) in comparison to age- and education-matched older adults with better hearing (BH). Participants completed a working memory n-back task (0- to 2-back) in which sequences of digits were presented in visual-only (i.e., speech-reading), auditory-only (A-only), and AV conditions. Auditory event-related potentials (ERP) were collected to assess the relationship between perceptual and working memory processing. The behavioral results showed that both groups were faster in the AV condition in comparison to the unisensory conditions. The ERP data showed perceptual facilitation in the AV condition, in the form of reduced amplitudes and latencies of the auditory N1 and/or P1 components, in the PH group. Furthermore, a working memory ERP component, the P3, peaked earlier for both groups in the AV condition compared to the A-only condition. In general, the PH group showed a more robust AV benefit; however, the BH group showed a dose-response relationship between perceptual facilitation and working memory improvement, especially for facilitation of processing speed. Two measures, reaction time and P3 amplitude, suggested that the presence of visual speech cues may have helped the PH group to counteract the demanding auditory processing, to the level that no group differences were evident during the AV modality despite lower performance during the A-only condition. Overall, this study provides support for the theory of an integrated perceptual-cognitive system. The practical significance of these findings is also discussed. PMID:27148106

  8. Perceptual Load Alters Visual Excitability

    ERIC Educational Resources Information Center

    Carmel, David; Thorne, Jeremy D.; Rees, Geraint; Lavie, Nilli

    2011-01-01

    Increasing perceptual load reduces the processing of visual stimuli outside the focus of attention, but the mechanism underlying these effects remains unclear. Here we tested an account attributing the effects of perceptual load to modulations of visual cortex excitability. In contrast to stimulus competition accounts, which propose that load…

  9. Top-down (Prior Knowledge) and Bottom-up (Perceptual Modality) Influences on Spontaneous Interpersonal Synchronization.

    PubMed

    Gipson, Christina L; Gorman, Jamie C; Hessler, Eric E

    2016-04-01

    Coordination with others is such a fundamental part of human activity that it can happen unintentionally. This unintentional coordination can manifest as synchronization and is observed in physical and human systems alike. We investigated the role of top-down influences (prior knowledge of the perceptual modality their partner is using) and bottom-up factors (perceptual modality combination) on spontaneous interpersonal synchronization. We examine this phenomena with respect to two different theoretical perspectives that differently emphasize top-down and bottom-up factors in interpersonal synchronization: joint-action/shared cognition theories and ecological-interactive theories. In an empirical study twelve dyads performed a finger oscillation task while attending to each other's movements through either visual, auditory, or visual and auditory perceptual modalities. Half of the participants were given prior knowledge of their partner's perceptual capabilities for coordinating across these different perceptual modality combinations. We found that the effect of top-down influence depends on the perceptual modality combination between two individuals. When people used the same perceptual modalities, top-down influence resulted in less synchronization and when people used different perceptual modalities, top-down influence resulted in more synchronization. Furthermore, persistence in the change in behavior as a result of having perceptual information about each other ('social memory') was stronger when this top-down influence was present. PMID:27033133

  10. Perceptual basis for reactive teleoperation

    NASA Astrophysics Data System (ADS)

    Park, Young S.; Ewing, Thomas F.; Boyle, James M.; Yule, Thomas J.

    2001-10-01

    To improve task performance in partially structured environments, enhancements to teleoperation have been proposed by introducing autonomous behaviors. Such autonomy is implemented based on a reactive robotic architecture, where reactive motor agents that directly couple sensory inputs and motor actions become the building blocks. To this end, a perceptual basis for the motor agents is presented in this paper. The perceptual basis consists of perceptual agents that extract environmental information from a structured light vision system and provide action-oriented perception for the corresponding motor agents. Rather than performing general scene reconstruction, a perceptual agent directly provides the motion reference for the motor behavior. Various sensory mechanisms - sensor fission, fusion, and fashion - become basic building blocks of the perception process. Since perception is a process deeply intertwined with the motor actions, active perception may also incorporate motor behaviors as an integral perceptual process.

  11. Perceptual basis for reactive teleoperation.

    SciTech Connect

    Park, Y. S.; Ewing, T. F.; Boyle, J. M.; Yule, T. J.

    2001-08-28

    To enhance task performance in partially structured environment, enhancement of teleoperation was proposed by introducing autonomous behaviors. Such autonomy is implemented based on reactive robotic architecture, where reactive motor agents that directly couples sensory inputs and motor actions become the building blocks. To this end, presented in this paper is a perceptual basis for the motor agents. The perceptual basis consists of perceptual agents that extracts environmental information from a structured light vision system and provide action oriented perception for the corresponding motor agents. Rather than performing general scene reconstruction, a perceptual agent directly provides the motion reference for the motor behavior. Various sensory mechanisms--sensor fission, fusion, and fashion--becomes basic building blocks of the perception process. Since perception is a process deeply intertwined with the motor actions, active perception may also incorporate motor behaviors as an integral perceptual process.

  12. Investigation of Cr0.06(Sb4Te)0.94 alloy for high-speed and high-data-retention phase change random access memory applications

    NASA Astrophysics Data System (ADS)

    Li, Le; Song, Sannian; Zhang, Zhonghua; Song, Zhitang; Cheng, Yan; Lv, Shilong; Wu, Liangcai; Liu, Bo; Feng, Songlin

    2015-08-01

    The effects of Cr doping on the structural and electrical properties of Cr x (Sb4Te)1- x materials have been investigated in order to solve the contradiction between thermal stability and fast crystallization speed of Sb4Te alloys. Cr0.06(Sb4Te)0.94 alloy is considered to be a potential candidate for phase change random access memory (PCM), as evidenced by a higher crystallization temperature (204 °C), a better data retention ability (137.6 °C for 10 years), a lower melting point (558 °C), a lower energy consumption, and a faster switching speed in comparison with those of Ge2Sb2Te5. A reversible switching between set and reset states can be realized by an electric pulse as short as 5 ns for Cr0.06(Sb4Te)0.94-based PCM cell. In addition, Cr0.06(Sb4Te)0.94 shows good endurance up to 1.1 × 104 cycles with a resistance ratio of about two orders of magnitude.

  13. Multi-timescale perceptual history resolves visual ambiguity.

    PubMed

    Brascamp, Jan W; Knapen, Tomas H J; Kanai, Ryota; Noest, André J; van Ee, Raymond; van den Berg, Albert V

    2008-01-01

    When visual input is inconclusive, does previous experience aid the visual system in attaining an accurate perceptual interpretation? Prolonged viewing of a visually ambiguous stimulus causes perception to alternate between conflicting interpretations. When viewed intermittently, however, ambiguous stimuli tend to evoke the same percept on many consecutive presentations. This perceptual stabilization has been suggested to reflect persistence of the most recent percept throughout the blank that separates two presentations. Here we show that the memory trace that causes stabilization reflects not just the latest percept, but perception during a much longer period. That is, the choice between competing percepts at stimulus reappearance is determined by an elaborate history of prior perception. Specifically, we demonstrate a seconds-long influence of the latest percept, as well as a more persistent influence based on the relative proportion of dominance during a preceding period of at least one minute. In case short-term perceptual history and long-term perceptual history are opposed (because perception has recently switched after prolonged stabilization), the long-term influence recovers after the effect of the latest percept has worn off, indicating independence between time scales. We accommodate these results by adding two positive adaptation terms, one with a short time constant and one with a long time constant, to a standard model of perceptual switching. PMID:18231584

  14. Perceptual issues in scientific visualization

    NASA Technical Reports Server (NTRS)

    Kaiser, Mary K.; Proffitt, Dennis R.

    1989-01-01

    In order to develop effective tools for scientific visulaization, consideration must be given to the perceptual competencies, limitations, and biases of the human operator. Perceptual psychology has amassed a rich body of research on these issues and can lend insight to the development of visualization tehcniques. Within a perceptual psychological framework, the computer display screen can best be thought of as a special kind of impoverished visual environemnt. Guidelines can be gleaned from the psychological literature to help visualization tool designers avoid ambiguities and/or illusions in the resulting data displays.

  15. Understanding processing speed weaknesses among pedophilic child molesters: response style vs. neuropathology.

    PubMed

    Suchy, Yana; Eastvold, Angela D; Strassberg, Donald S; Franchow, Emilie I

    2014-02-01

    Research shows that pedophilic (PED) child molesters exhibit slower performance speed and greater performance accuracy when compared to nonpedophilic (N-PED) child molesters or other criminal and noncriminal controls. The purpose of the present study was to examine whether these differences reflect a slow/deliberate response style among PEDS (as we have previously hypothesized; Eastvold, Suchy, & Strassberg, 2011; Suchy, Whittaker, Strassberg, & Eastvold, 2009a, 2009b), or a fundamental neuropathological weakness in processing speed. Data came from a larger study examining neurocognition among sex offenders. Processing speed in three different domains (motor speed, visual-perceptual speed, and visual-motor integration) was examined in 20 phallometrically identified PEDs, 20 N-PEDs, and 20 nonsexual offenders, using both clinical (Finger Tapping, Symbol Search, Digit Symbol Coding) and experimental measures (Inspection Time Task [ITT]). The ITT assessed speed of visual-perceptual processing independent of response speed. On clinical measures, PEDs exhibited slower visual perception [F(2, 57) = 5.24, p = .008] and visual-motor integration [F(2, 57) = 5.02, p = .010] than the other groups, with no differences for simple motor speed. On the ITT, PEDs performed less accurately than the other groups [F(2, 57) = 3.95, p = .025], clearly indicating that slow processing speed cannot be explained by a deliberate response style. Group differences persisted after controlling for other potential confounds (age, estimate IQ, working memory, ethnicity, and substance use). PEDs' slower performance is due to a fundamental neurocognitive weakness, rather than a slow/deliberate response style. These results are consistent with Cantor et al.'s (2008) work identifying white matter abnormalities among PEDs and provide further support for a neurodevelopmental etiology of pedophilia. PMID:24661177

  16. Learning, Memory, and Synesthesia

    PubMed Central

    Witthoft, Nathan; Winawer, Jonathan

    2013-01-01

    People with color-grapheme synesthesia experience color when viewing written letters or numerals, usually with a particular color evoked by each grapheme. Here we report on 11 color-grapheme synesthetes with startlingly similar color-grapheme pairings traceable to childhood toys containing colored letters. These data are the first and only to show learned synesthesia of this kind in a group larger than a single case. While some researchers have focused on genetic and perceptual aspects of synesthesia, these results indicate that a complete explanation of synesthesia must also incorporate a central role for learning and memory. We argue that these two positions can be reconciled by thinking of synesthesia as the automatic retrieval of highly specific mnemonic associations, where perceptual contents are brought to mind, akin to mental imagery or the perceptual reinstatement effects found in the memory literature. PMID:23307940

  17. Writing to dictation and handwriting performance among Chinese children with dyslexia: relationships with orthographic knowledge and perceptual-motor skills.

    PubMed

    Cheng-Lai, Alice; Li-Tsang, Cecilia W P; Chan, Alan H L; Lo, Amy G W

    2013-10-01

    The purpose of this study was to investigate the relationships between writing to dictation, handwriting, orthographic, and perceptual-motor skills among Chinese children with dyslexia. A cross-sectional design was used. A total of 45 third graders with dyslexia were assessed. Results of stepwise multiple regression models showed that Chinese character naming was the only predictor associated with word dictation (β=.32); handwriting speed was related to deficits in rapid automatic naming (β=-.36) and saccadic efficiency (β=-.29), and visual-motor integration predicted both of the number of characters exceeded grid (β=-.41) and variability of character size (β=-.38). The findings provided support to a multi-stage working memory model of writing for explaining the possible underlying mechanism of writing to dictation and handwriting difficulties. PMID:23911643

  18. Improvement of reliability and speed of phase change memory devices with N7.9(Ge46.9Bi7.2Te45.9) films

    NASA Astrophysics Data System (ADS)

    Park, J. H.; Kim, S.-W.; Kim, J. H.; Ko, D.-H.; Wu, Z.; Cho, S. L.; Ahn, D.; Ahn, D. H.; Lee, J. M.; Nam, S. W.

    2015-08-01

    In this study, we propose a nitrogen-incorporated GeBiTe ternary phase of N7.9(Ge46.9Bi7.2Te45.9) as a phase change material for reliable PCM (Phase Change Memory) with high speed operation. We found that the N7.9(Ge46.9Bi7.2Te45.9) film shows the resistance value of 40 kΩ after annealing at 440oC for 10 minutes, which is much higher than the value of 3.4 kΩ in the case of conventional N7.0(Ge22.0Sb22.0Te56.0) films. A set operation time of 14 nsec was achieved in the devices due to the increased probability of the nucleation by the addition of the elemental Bi. The long data retention time of 10 years at 85oC on the base of 1% failure was obtained as the result of higher activation energy of 2.52 eV for the crystallization compared to the case of N7.0(Ge22.0Sb22.0Te56.0) film, in which the activation energy is 2.1 eV. In addition, a reset current reduction of 27% and longer cycles of endurance as much as 2 order of magnitude compared to the case of N7.0(Ge22.0Sb22.0Te56.0) were observed at a set operation time of 14 nsec. Our results show that N7.9(Ge46.9Bi7.2Te45.9) is highly promising for use as a phase change material in reliable PCMs with high performance and also in forthcoming storage class memory applications, too.

  19. Perceptual style and tracking performance

    NASA Technical Reports Server (NTRS)

    Atchley, Paul

    1991-01-01

    The relationship between perceptual style and tracking of a target was examined. Four pilots were given the Embedded Figures Test to assess their degrees of field dependence or independence. Then they flew in a helicopter simulator and attempted to track an airborne target. A high negative correlation was found between perceptual style and tracking performance. Field-independent subjects were able to track the target for longer periods than field-dependent subjects.

  20. What is the Bandwidth of Perceptual Experience?

    PubMed

    Cohen, Michael A; Dennett, Daniel C; Kanwisher, Nancy

    2016-05-01

    Although our subjective impression is of a richly detailed visual world, numerous empirical results suggest that the amount of visual information observers can perceive and remember at any given moment is limited. How can our subjective impressions be reconciled with these objective observations? Here, we answer this question by arguing that, although we see more than the handful of objects, claimed by prominent models of visual attention and working memory, we still see far less than we think we do. Taken together, we argue that these considerations resolve the apparent conflict between our subjective impressions and empirical data on visual capacity, while also illuminating the nature of the representations underlying perceptual experience. PMID:27105668

  1. Perceptual benefits of objecthood.

    PubMed

    Naber, Marnix; Carlson, Thomas A; Verstraten, Frans A J; Einhäuser, Wolfgang

    2011-01-01

    Object-based attention facilitates the processing of features that form the object. Two hypotheses are conceivable for how object-based attention is deployed to an object's features: first, the object is attended by selecting its features; alternatively, a configuration of features as such is attended by selecting the object representation they form. Only for the latter alternative, the perception of a feature configuration as entity ("objecthood") is a necessary condition for object-based attention. Disentangling the two alternatives requires the comparison of identical feature configurations that induce the perception of an object in one condition ("bound") and do not do so in another condition ("unbound"). We used an ambiguous stimulus, whose percept spontaneously switches between bound and unbound, while the stimulus itself remains unchanged. We tested discrimination on the boundary of the diamond as well as detection of probes inside and outside the diamond. We found discrimination performance to be increased if features were perceptually bound into an object. Furthermore, detection performance was higher within and lower outside the bound object as compared to the unbound configuration. Consequently, the facilitation of processing by object-based attention requires objecthood, that is, a unified internal representation of an "object"-not a mere collection of features. PMID:21493707

  2. Perceptually Lossless Wavelet Compression

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B.; Yang, Gloria Y.; Solomon, Joshua A.; Villasenor, John

    1996-01-01

    The Discrete Wavelet Transform (DWT) decomposes an image into bands that vary in spatial frequency and orientation. It is widely used for image compression. Measures of the visibility of DWT quantization errors are required to achieve optimal compression. Uniform quantization of a single band of coefficients results in an artifact that is the sum of a lattice of random amplitude basis functions of the corresponding DWT synthesis filter, which we call DWT uniform quantization noise. We measured visual detection thresholds for samples of DWT uniform quantization noise in Y, Cb, and Cr color channels. The spatial frequency of a wavelet is r 2(exp -1), where r is display visual resolution in pixels/degree, and L is the wavelet level. Amplitude thresholds increase rapidly with spatial frequency. Thresholds also increase from Y to Cr to Cb, and with orientation from low-pass to horizontal/vertical to diagonal. We propose a mathematical model for DWT noise detection thresholds that is a function of level, orientation, and display visual resolution. This allows calculation of a 'perceptually lossless' quantization matrix for which all errors are in theory below the visual threshold. The model may also be used as the basis for adaptive quantization schemes.

  3. Effects of the common cold on mood, psychomotor performance, the encoding of new information, speed of working memory and semantic processing.

    PubMed

    Smith, Andrew P

    2012-10-01

    Previous research has shown that people with the common cold report a more negative mood and psychomotor slowing. Recent research suggests that memory speed may also be impaired. This was examined in the study reported here. A prospective design was used and all participants (N=200; half male, half female; mean age 21 years, range 18-30 years) carried out a baseline session when healthy. The test battery involved mood rating, simple and choice reaction time, verbal reasoning and semantic processing. Volunteers returned when they developed an upper respiratory tract illness (URTI) and repeated the test battery. If they remained healthy they were recalled as a control. One hundred and eighty-nine participants completed the study and 48 developed URTIs and 141 were in the healthy control group. Symptoms and signs suggested that those who were ill had colds rather than influenza. The results showed that those with colds reported lower alertness, a more negative mood, and psychomotor slowing. They were also slower at encoding new information and slower on the verbal reasoning and semantic processing tasks. The magnitude of the mood changes associated with being ill were correlated with symptom severity. The performance changes were not correlated with symptom severity, sleep duration or mood changes. Further research is now needed to elucidate the underlying mechanisms of the behavioral malaise associated with URTIs. PMID:22749892

  4. Gains following perceptual learning are closely linked to the initial visual acuity

    PubMed Central

    Yehezkel, Oren; Sterkin, Anna; Lev, Maria; Levi, Dennis M.; Polat, Uri

    2016-01-01

    The goal of the present study was to evaluate the dependence of perceptual learning gains on initial visual acuity (VA), in a large sample of subjects with a wide range of VAs. A large sample of normally sighted and presbyopic subjects (N = 119; aged 40 to 63) with a wide range of uncorrected near visual acuities (VA, −0.12 to 0.8 LogMAR), underwent perceptual learning. Training consisted of detecting briefly presented Gabor stimuli under spatial and temporal masking conditions. Consistent with previous findings, perceptual learning induced a significant improvement in near VA and reading speed under conditions of limited exposure duration. Our results show that the improvements in VA and reading speed observed following perceptual learning are closely linked to the initial VA, with only a minor fraction of the observed improvement that may be attributed to the additional sessions performed by those with the worse VA. PMID:27122254

  5. Gains following perceptual learning are closely linked to the initial visual acuity.

    PubMed

    Yehezkel, Oren; Sterkin, Anna; Lev, Maria; Levi, Dennis M; Polat, Uri

    2016-01-01

    The goal of the present study was to evaluate the dependence of perceptual learning gains on initial visual acuity (VA), in a large sample of subjects with a wide range of VAs. A large sample of normally sighted and presbyopic subjects (N = 119; aged 40 to 63) with a wide range of uncorrected near visual acuities (VA, -0.12 to 0.8 LogMAR), underwent perceptual learning. Training consisted of detecting briefly presented Gabor stimuli under spatial and temporal masking conditions. Consistent with previous findings, perceptual learning induced a significant improvement in near VA and reading speed under conditions of limited exposure duration. Our results show that the improvements in VA and reading speed observed following perceptual learning are closely linked to the initial VA, with only a minor fraction of the observed improvement that may be attributed to the additional sessions performed by those with the worse VA. PMID:27122254

  6. Do people with schizophrenia have differential impairment in episodic memory and/or working memory relative to other cognitive abilities?

    PubMed

    Palmer, Barton W; Savla, Gauri N; Fellows, Ian E; Twamley, Elizabeth W; Jeste, Dilip V; Lacro, Jonathan P

    2010-02-01

    Efforts to identify differential or core cognitive deficits in schizophrenia have been made for several decades, with limited success. Part of the difficulty in establishing a cognitive profile in schizophrenia is the considerable inter-patient heterogeneity in the level of cognitive impairment. Thus, it may be useful to examine the presence of relative cognitive weaknesses on an intra-person level. In the present study we examined the rates of significant intra-person differences between crystallized verbal ability versus five other cognitive abilities among 127 persons with schizophrenia or schizoaffective disorder and 127 demographically matched normal comparison (NC) subjects. We found that the rates of significant discrepancies above the NC group base-rates was significantly greater in reference to those discrepancies involving visual memory relative to those associated with auditory memory, working memory, processing speed, and perceptual organization. The findings conflict with prior suggestions that working memory or auditory episodic memory are differential or core deficits in schizophrenia, and highlight the importance of considering visual memory in characterizing the cognitive effects of this condition. PMID:19945256

  7. Perceptual basis of bimanual coordination.

    PubMed

    Mechsner, F; Kerzel, D; Knoblich, G; Prinz, W

    2001-11-01

    Periodic bimanual movements are often the focus of studies of the basic organizational principles of human actions. In such movements there is a typical spontaneous tendency towards mirror symmetry. Even involuntary slips from asymmetrical movement patterns into symmetry occur, but not vice versa. Traditionally, this phenomenon has been interpreted as a tendency towards co-activation of homologous muscles, probably originating in motoric neuronal structures. Here we provide evidence contrary to this widespread assumption. We show for two prominent experimental models-bimanual finger oscillation and bimanual four-finger tapping-that the symmetry bias is actually towards spatial, perceptual symmetry, without regard to the muscles involved. We suggest that spontaneous coordination phenomena of this kind are purely perceptual in nature. In the case of a bimanual circling model, our findings reveal that highly complex, even 'impossible' movements can easily be performed with only simple visual feedback. A 'motoric' representation of the performed perceptual oscillation patterns is not necessary. Thus there is no need to translate such a 'motoric' into a 'perceptual' representation or vice versa, using 'internal models' (ref. 29). We suggest that voluntary movements are organized by way of a representation of the perceptual goals, whereas the corresponding motor activity, of sometimes high complexity, is spontaneously and flexibly tuned in. PMID:11689944

  8. Perceptual Anomalies in Schizophrenia: Integrating Phenomenology and Cognitive Neuroscience

    PubMed Central

    Uhlhaas, Peter J.; Mishara, Aaron L.

    2007-01-01

    From phenomenological and experimental perspectives, research in schizophrenia has emphasized deficits in “higher” cognitive functions, including attention, executive function, as well as memory. In contrast, general consensus has viewed dysfunctions in basic perceptual processes to be relatively unimportant in the explanation of more complex aspects of the disorder, including changes in self-experience and the development of symptoms such as delusions. We present evidence from phenomenology and cognitive neuroscience that changes in the perceptual field in schizophrenia may represent a core impairment. After introducing the phenomenological approach to perception (Husserl, the Gestalt School), we discuss the views of Paul Matussek, Klaus Conrad, Ludwig Binswanger, and Wolfgang Blankenburg on perception in schizophrenia. These 4 psychiatrists describe changes in perception and automatic processes that are related to the altered experience of self. The altered self-experience, in turn, may be responsible for the emergence of delusions. The phenomenological data are compatible with current research that conceptualizes dysfunctions in perceptual processing as a deficit in the ability to combine stimulus elements into coherent object representations. Relationships of deficits in perceptual organization to cognitive and social dysfunction as well as the possible neurobiological mechanisms are discussed. PMID:17118973

  9. Perceptual and Conceptual Distortions of Implicit Hand Maps

    PubMed Central

    Longo, Matthew R.; Mattioni, Stefania; Ganea, Nataşa

    2015-01-01

    Recent studies have revealed that human position sense relies on a massively distorted representation of hand size and shape. By comparing the judged location of landmarks on an occluded hand, Longo and Haggard (2010) constructed implicit perceptual maps of represented hand structure, showing large underestimation of finger length and overestimation of hand width. Here, we investigated the contribution of two potential sources of distortions to such effects: perceptual distortions reflecting spatial warping of the representation of bodily tissue itself, perhaps reflecting distortions of somatotopic cortical maps, and conceptual distortions reflecting mistaken beliefs about the locations of different landmarks within the body. In Experiment 1 we compared distorted hand maps to a task in which participants explicitly judged the location of their knuckles in a hand silhouette. The results revealed the conceptual distortions are responsible for at least part of the underestimation of finger length, but cannot explain overestimation of hand width. Experiment 2 compared distortions of the participant’s own hand based on position sense with a prosthetic hand based on visual memory. Underestimation of finger length was found for both hands, providing further evidence that it reflects a conceptual distortion. In contrast, overestimation of hand width was specific to representation of the participant’s own hand, confirming it reflects a perceptual distortion. Together, these results suggest that distorted body representations do not reflect a single underlying cause. Rather, both perceptual and conceptual distortions contribute to the overall configuration of the hand representation. PMID:26733842

  10. Mutual information, perceptual independence, and holistic face perception.

    PubMed

    Fitousi, Daniel

    2013-07-01

    The concept of perceptual independence is ubiquitous in psychology. It addresses the question of whether two (or more) dimensions are perceived independently. Several authors have proposed perceptual independence (or its lack thereof) as a viable measure of holistic face perception (Loftus, Oberg, & Dillon, Psychological Review 111:835-863, 2004; Wenger & Ingvalson, Learning, Memory, and Cognition 28:872-892, 2002). According to this notion, the processing of facial features occurs in an interactive manner. Here, I examine this idea from the perspective of two theories of perceptual independence: the multivariate uncertainty analysis (MUA; Garner & Morton, Definitions, models, and experimental paradigms. Psychological Bulletin 72:233-259, 1969), and the general recognition theory (GRT; Ashby & Townsend, Psychological Review 93:154-179, 1986). The goals of the study were to (1) introduce the MUA, (2) examine various possible relations between MUA and GRT using numerical simulations, and (3) apply the MUA to two consensual markers of holistic face perception(-)recognition of facial features (Farah, Wilson, Drain, & Tanaka, Psychological Review 105:482-498, 1998) and the composite face effect (Young, Hellawell, & Hay, Perception 16:747-759, 1987). The results suggest that facial holism is generated by violations of several types of perceptual independence. They highlight the important theoretical role played by converging operations in the study of holistic face perception. PMID:23661158

  11. Perceptual and behavioral adjustments after action inhibition.

    PubMed

    Kirsch, Wladimir; Kunde, Wilfried

    2015-10-01

    Inhibiting a motor action typically prompts a more cautious action mode, leaning toward accuracy rather than speed. In the present study, we explored whether action inhibition is also accompanied by changes of visual perception. Our participants performed goal-directed hand movements from a start to a target position and then judged the start-target distance. On a proportion of the trials, movement execution had to be stopped before the target position was reached. The results of two experiments revealed smaller start-target distance estimates after interrupted than after unrestricted movements. Moreover, movement amplitudes were decreased in movements that followed interrupted ones. In line with the predictions of action-specific accounts of perception, this outcome indicates that subjective perceptual changes might inform us how to plan future actions. PMID:25504460

  12. Schizotypy and false memory.

    PubMed

    Dagnall, Neil; Parker, Andrew

    2009-03-01

    Using the Deese-Roediger-McDermott (DRM) paradigm the present study examined the relationship between schizotypy and recognition memory. Participants scoring in the upper and lower quartile ranges for schizotypy (Schizotypal Personality Questionnaire brief version; SPQ-B) and on each of the SPQ-B subscales (cognitive-perceptual, interpersonal and disorganized) were compared on true and false memory performance. Participants scoring in the lower quartile range on the cognitive-perceptual subscale recognised a higher proportion of both true and false memories than those scoring in the higher quartile range. Participants scoring in the upper quartile on the interpersonal factor recognised fewer true items than those in the lower quartile range. No differences were found for overall schizotypy or on the disorganized subscale. PMID:18817907

  13. The perceptual chunking of speech: a demonstration using ERPs.

    PubMed

    Gilbert, Annie C; Boucher, Victor J; Jemel, Boutheina

    2015-04-01

    In tasks involving the learning of verbal or non-verbal sequences, groupings are spontaneously produced. These groupings are generally marked by a lengthening of final elements and have been attributed to a domain-general perceptual chunking linked to working memory. Yet, no study has shown how this domain-general chunking applies to speech processing, partly because of the traditional view that chunking involves a conceptual recoding of meaningful verbal items like words (Miller, 1956). The present study provides a demonstration of the perceptual chunking of speech by way of two experiments using evoked Positive Shifts (PSs), which capture on-line neural responses to marks of various groups. We observed listeners׳ response to utterances (Experiment 1) and meaningless series of syllables (Experiment 2) containing changing intonation and temporal marks, while also examining how these marks affect the recognition of heard items. The results show that, across conditions - and irrespective of the presence of meaningful items - PSs are specifically evoked by groups marked by lengthening. Moreover, this on-line detection of marks corresponds to characteristic grouping effects on listeners' immediate recognition of heard items, which suggests chunking effects linked to working memory. These findings bear out a perceptual chunking of speech input in terms of groups marked by lengthening, which constitute the defining marks of a domain-general chunking. PMID:25636270

  14. Is random access memory random?

    NASA Technical Reports Server (NTRS)

    Denning, P. J.

    1986-01-01

    Most software is contructed on the assumption that the programs and data are stored in random access memory (RAM). Physical limitations on the relative speeds of processor and memory elements lead to a variety of memory organizations that match processor addressing rate with memory service rate. These include interleaved and cached memory. A very high fraction of a processor's address requests can be satified from the cache without reference to the main memory. The cache requests information from main memory in blocks that can be transferred at the full memory speed. Programmers who organize algorithms for locality can realize the highest performance from these computers.

  15. Subcortical hyperintensity volumetrics in Alzheimer’s disease and normal elderly in the Sunnybrook Dementia Study: correlations with atrophy, executive function, mental processing speed, and verbal memory

    PubMed Central

    2014-01-01

    Introduction Subcortical hyperintensities (SHs) are radiological entities commonly observed on magnetic resonance imaging (MRI) of patients with Alzheimer’s disease (AD) and normal elderly controls. Although the presence of SH is believed to indicate some form of subcortical vasculopathy, pathological heterogeneity, methodological differences, and the contribution of brain atrophy associated with AD pathology have yielded inconsistent results in the literature. Methods Using the Lesion Explorer (LE) MRI processing pipeline for SH quantification and brain atrophy, this study examined SH volumes of interest and cognitive function in a sample of patients with AD (n = 265) and normal elderly controls (n = 100) from the Sunnybrook Dementia Study. Results Compared with healthy controls, patients with AD were found to have less gray matter, less white matter, and more sulcal and ventricular cerebrospinal fluid (all significant, P <0.0001). Additionally, patients with AD had greater volumes of whole-brain SH (P <0.01), periventricular SH (pvSH) (P <0.01), deep white SH (dwSH) (P <0.05), and lacunar lesions (P <0.0001). In patients with AD, regression analyses revealed a significant association between global atrophy and pvSH (P = 0.02) and ventricular atrophy with whole-brain SH (P <0.0001). Regional volumes of interest revealed significant correlations with medial middle frontal SH volume and executive function (P <0.001) in normal controls but not in patients with AD, global pvSH volume and mental processing speed (P <0.01) in patients with AD, and left temporal SH volume and memory (P <0.01) in patients with AD. Conclusions These brain-behavior relationships and correlations with brain atrophy suggest that subtle, yet measurable, signs of small vessel disease may have potential clinical relevance as targets for treatment in Alzheimer’s dementia. PMID:25478020

  16. Integrated perceptual information for designers

    NASA Astrophysics Data System (ADS)

    Boff, K. R.

    The Integrated Perceptual Information for Designers (IPID) program has been developed in order to optimize the operator's contribution to system effectiveness. Information management objectives of the IPID program are: the consolidation of relevant sensory and perceptual data, the effective presentation of data to the designer, and accessibility to the data. Data pertain particularly to aircrew simulator and operational control/display designer needs. IPID data can be useful in generating design options, specifications, and standards, and in evaluating standards and examining alternatives. Specific applications of IPID data include supervisory control, operator interface definition in automated systems, and visual standards definitions.

  17. Ferroelectric memories.

    PubMed

    Scott, J F; Paz de Araujo, C A

    1989-12-15

    In the past year it has become possible to fabricate ferroelectric thin-film memories onto standard silicon integrated circuits that combine very high speed (30-nanosecond read/erase/rewrite operation), 5-volt standard silicon logic levels, very high density (2 by 2 micrometer cell size), complete nonvolatility (no standby power required), and extreme radiation hardness. These ferroelectric random-access memories are expected to replace magnetic core memory, magnetic bubble memory systems, and electrically erasable read-only memory for many applications. The switching kinetics of these films, 100 to 300 nanometers thick, are now well understood, with switching times that fit an activation field dependence that scales applied field and temperature. Earlier problems of fatigue and retention failure are also now understood and have been improved to acceptable levels. PMID:17755995

  18. Perceptual approach for unsupervised digital color restoration of cinematographic archives

    NASA Astrophysics Data System (ADS)

    Chambah, Majed; Rizzi, Alessandro; Gatta, Carlo; Besserer, Bernard; Marini, Daniele

    2003-01-01

    The cinematographic archives represent an important part of our collective memory. We present in this paper some advances in automating the color fading restoration process, especially with regard to the automatic color correction technique. The proposed color correction method is based on the ACE model, an unsupervised color equalization algorithm based on a perceptual approach and inspired by some adaptation mechanisms of the human visual system, in particular lightness constancy and color constancy. There are some advantages in a perceptual approach: mainly its robustness and its local filtering properties, that lead to more effective results. The resulting technique, is not just an application of ACE on movie images, but an enhancement of ACE principles to meet the requirements in the digital film restoration field. The presented preliminary results are satisfying and promising.

  19. Proceedings Region East Perceptual Motor Conference.

    ERIC Educational Resources Information Center

    American Alliance for Health, Physical Education, and Recreation, Washington, DC.

    This book of conference proceeding presents speeches and panel discussions from the Region East Perceptual-Motor Conference. The purpose of the conference was to seek an understanding of children and their perceptual-motor development through (a) exchange of knowledge and practices in perceptual-motor development, (b) examination of program

  20. Characterizing Perceptual Learning with External Noise

    ERIC Educational Resources Information Center

    Gold, Jason M.; Sekuler, Allison B.; Bennett, Partrick J.

    2004-01-01

    Performance in perceptual tasks often improves with practice. This effect is known as "perceptual learning," and it has been the source of a great deal of interest and debate over the course of the last century. Here, we consider the effects of perceptual learning within the context of signal detection theory. According to signal detection theory,…

  1. Neurally Constrained Modeling of Perceptual Decision Making

    ERIC Educational Resources Information Center

    Purcell, Braden A.; Heitz, Richard P.; Cohen, Jeremiah Y.; Schall, Jeffrey D.; Logan, Gordon D.; Palmeri, Thomas J.

    2010-01-01

    Stochastic accumulator models account for response time in perceptual decision-making tasks by assuming that perceptual evidence accumulates to a threshold. The present investigation mapped the firing rate of frontal eye field (FEF) visual neurons onto perceptual evidence and the firing rate of FEF movement neurons onto evidence accumulation to

  2. Neurally Constrained Modeling of Perceptual Decision Making

    ERIC Educational Resources Information Center

    Purcell, Braden A.; Heitz, Richard P.; Cohen, Jeremiah Y.; Schall, Jeffrey D.; Logan, Gordon D.; Palmeri, Thomas J.

    2010-01-01

    Stochastic accumulator models account for response time in perceptual decision-making tasks by assuming that perceptual evidence accumulates to a threshold. The present investigation mapped the firing rate of frontal eye field (FEF) visual neurons onto perceptual evidence and the firing rate of FEF movement neurons onto evidence accumulation to…

  3. Perceptual Fading without Retinal Adaptation

    ERIC Educational Resources Information Center

    Hsieh, Po-Jang; Colas, Jaron T.

    2012-01-01

    A retinally stabilized object readily undergoes perceptual fading and disappears from consciousness. This startling phenomenon is commonly believed to arise from local bottom-up sensory adaptation to edge information that occurs early in the visual pathway, such as in the lateral geniculate nucleus of the thalamus or retinal ganglion cells. Here…

  4. Perceptual transparency from image deformation

    PubMed Central

    Kawabe, Takahiro; Maruya, Kazushi; Nishida, Shin’ya

    2015-01-01

    Human vision has a remarkable ability to perceive two layers at the same retinal locations, a transparent layer in front of a background surface. Critical image cues to perceptual transparency, studied extensively in the past, are changes in luminance or color that could be caused by light absorptions and reflections by the front layer, but such image changes may not be clearly visible when the front layer consists of a pure transparent material such as water. Our daily experiences with transparent materials of this kind suggest that an alternative potential cue of visual transparency is image deformations of a background pattern caused by light refraction. Although previous studies have indicated that these image deformations, at least static ones, play little role in perceptual transparency, here we show that dynamic image deformations of the background pattern, which could be produced by light refraction on a moving liquid’s surface, can produce a vivid impression of a transparent liquid layer without the aid of any other visual cues as to the presence of a transparent layer. Furthermore, a transparent liquid layer perceptually emerges even from a randomly generated dynamic image deformation as long as it is similar to real liquid deformations in its spatiotemporal frequency profile. Our findings indicate that the brain can perceptually infer the presence of “invisible” transparent liquids by analyzing the spatiotemporal structure of dynamic image deformation, for which it uses a relatively simple computation that does not require high-level knowledge about the detailed physics of liquid deformation. PMID:26240313

  5. Perceptual transparency from image deformation.

    PubMed

    Kawabe, Takahiro; Maruya, Kazushi; Nishida, Shin'ya

    2015-08-18

    Human vision has a remarkable ability to perceive two layers at the same retinal locations, a transparent layer in front of a background surface. Critical image cues to perceptual transparency, studied extensively in the past, are changes in luminance or color that could be caused by light absorptions and reflections by the front layer, but such image changes may not be clearly visible when the front layer consists of a pure transparent material such as water. Our daily experiences with transparent materials of this kind suggest that an alternative potential cue of visual transparency is image deformations of a background pattern caused by light refraction. Although previous studies have indicated that these image deformations, at least static ones, play little role in perceptual transparency, here we show that dynamic image deformations of the background pattern, which could be produced by light refraction on a moving liquid's surface, can produce a vivid impression of a transparent liquid layer without the aid of any other visual cues as to the presence of a transparent layer. Furthermore, a transparent liquid layer perceptually emerges even from a randomly generated dynamic image deformation as long as it is similar to real liquid deformations in its spatiotemporal frequency profile. Our findings indicate that the brain can perceptually infer the presence of "invisible" transparent liquids by analyzing the spatiotemporal structure of dynamic image deformation, for which it uses a relatively simple computation that does not require high-level knowledge about the detailed physics of liquid deformation. PMID:26240313

  6. Is Perceptual Narrowing Too Narrow?

    ERIC Educational Resources Information Center

    Cashon, Cara H.; Denicola, Christopher A.

    2011-01-01

    There is a growing list of examples illustrating that infants are transitioning from having earlier abilities that appear more "universal," "broadly tuned," or "unconstrained" to having later abilities that appear more "specialized," "narrowly tuned," or "constrained." Perceptual narrowing, a well-known phenomenon related to face, speech, and…

  7. Perceptual Bases of Visual Literacy.

    ERIC Educational Resources Information Center

    Messaris, Paul

    The perceptual bases of visual literacy are explored, drawing on research into the interpretation of pictures by viewers not familiar with pictorial representation. Research has indicated that inexperienced viewers do not find it difficult to recognize pictures that may be discrepant in color or shape from a familiar object, but may be troubled by…

  8. Perceptual Learning, Cognition, and Expertise

    ERIC Educational Resources Information Center

    Kellman, Philip J.; Massey, Christine M.

    2013-01-01

    Recent research indicates that perceptual learning (PL)--experience-induced changes in the way perceivers extract information--plays a larger role in complex cognitive tasks, including abstract and symbolic domains, than has been understood in theory or implemented in instruction. Here, we describe the involvement of PL in complex cognitive tasks…

  9. Some Perceptual Prerequisites for Reading.

    ERIC Educational Resources Information Center

    Frith, Uta; Vogel, Juliet M.

    The two chapters of this monograph deal with the issue of the existence of a perceptual grammar that influences reading proficiency, particularly initial reading proficiency. The first chapter indicates the importance of studying reading and writing in terms of readers' and writers' knowledge of visuo-spatial processing rules. It discusses…

  10. Perceptual Fading without Retinal Adaptation

    ERIC Educational Resources Information Center

    Hsieh, Po-Jang; Colas, Jaron T.

    2012-01-01

    A retinally stabilized object readily undergoes perceptual fading and disappears from consciousness. This startling phenomenon is commonly believed to arise from local bottom-up sensory adaptation to edge information that occurs early in the visual pathway, such as in the lateral geniculate nucleus of the thalamus or retinal ganglion cells. Here

  11. Sleep rescues perceptual learning from interference.

    PubMed

    McDevitt, Elizabeth; Niknazar, Mohammad; Mednick, Sara

    2015-01-01

    Daily living involves copious information processing that has the potential to "overload" the brain and result in memory loss (i.e., interference). Since we do not need to stabilize each waking experience with a nap before encountering the next, there must be a mechanism that allows the brain to rescue memories damaged by interference. Using a texture discrimination task with short training (120 trials/condition), we induced interference by testing back-to-back conditions in the same visual field before a consolidation period. Four consolidation groups were tested: active wake, quiet wake, non-rapid eye movement (NREM) naps, or NREM+REM naps. Wake produced perceptual learning (PL) in the no interference condition, likely due to the short training, and sleep was not correlated with performance. With interference, PL was abolished in all groups except REM naps. Sleep explained 22% of the variance in magnitude of PL, and minutes of slow wave sleep (SWS, p=.04) and REM (p=.009) were significant predictors of improvement. Performance was correlated with specific sleep features: a) the degree of temporal coupling between spindles and slow oscillations (0.5-1Hz) during Stage 2 (r=.30); b) SWS spindle density (#spindles/SWSmin) from the occipital site contralateral to the trained visual field (r=.54), but not spindle density from the ipsilateral site (r=.09); and c) REM density (#rapid eye movements/REMmin; r=.38). These results, for the first time, demonstrate a process by which the brain can rescue and consolidate memories damaged by interference, and that this process is mediated by specific brain states. Specifically, active wake is sufficient to support PL under conditions of no interference and short training, and REM sleep is critical for rescuing PL damaged by interference. When sleep is necessary for PL, retinotopically-specific sleep spindles, spindle-slow oscillation coupling, and REM density may play important roles. Meeting abstract presented at VSS 2015. PMID:26326826

  12. The effect of haptic cues on motor and perceptual based implicit sequence learning

    PubMed Central

    Kim, Dongwon; Johnson, Brandon J.; Gillespie, R. Brent; Seidler, Rachael D.

    2014-01-01

    We introduced haptic cues to the serial reaction time (SRT) sequence learning task alongside the standard visual cues to assess the relative contributions of visual and haptic stimuli to the formation of motor and perceptual memories. We used motorized keys to deliver brief pulse-like displacements to the resting fingers, expecting that the proximity and similarity of these cues to the subsequent response motor actions (finger-activated key-presses) would strengthen the motor memory trace in particular. We adopted the experimental protocol developed by Willingham (1999) to explore whether haptic cues contribute differently than visual cues to the balance of motor and perceptual learning. We found that sequence learning occurs with haptic stimuli as well as with visual stimuli and we found that irrespective of the stimuli (visual or haptic) the SRT task leads to a greater amount of motor learning than perceptual learning. PMID:24734013

  13. The effect of haptic cues on motor and perceptual based implicit sequence learning.

    PubMed

    Kim, Dongwon; Johnson, Brandon J; Gillespie, R Brent; Seidler, Rachael D

    2014-01-01

    We introduced haptic cues to the serial reaction time (SRT) sequence learning task alongside the standard visual cues to assess the relative contributions of visual and haptic stimuli to the formation of motor and perceptual memories. We used motorized keys to deliver brief pulse-like displacements to the resting fingers, expecting that the proximity and similarity of these cues to the subsequent response motor actions (finger-activated key-presses) would strengthen the motor memory trace in particular. We adopted the experimental protocol developed by Willingham (1999) to explore whether haptic cues contribute differently than visual cues to the balance of motor and perceptual learning. We found that sequence learning occurs with haptic stimuli as well as with visual stimuli and we found that irrespective of the stimuli (visual or haptic) the SRT task leads to a greater amount of motor learning than perceptual learning. PMID:24734013

  14. Recency Effects as a Window to Generalization: Separating Decisional and Perceptual Sequential Effects in Category Learning

    ERIC Educational Resources Information Center

    Jones, Matt; Love, Bradley C.; Maddox, W. Todd

    2006-01-01

    Accounts of learning and generalization typically focus on factors related to lasting changes in representation (i.e., long-term memory). The authors present evidence that shorter term effects also play a critical role in determining performance and that these recency effects can be subdivided into perceptual and decisional components.…

  15. Exploring the Perceptual Spaces of Faces, Cars and Birds in Children and Adults

    ERIC Educational Resources Information Center

    Tanaka, James W.; Meixner, Tamara L.; Kantner, Justin

    2011-01-01

    While much developmental research has focused on the strategies that children employ to recognize faces, less is known about the principles governing the organization of face exemplars in perceptual memory. In this study, we tested a novel, child-friendly paradigm for investigating the organization of face, bird and car exemplars. Children ages…

  16. Exploring the Perceptual Spaces of Faces, Cars and Birds in Children and Adults

    ERIC Educational Resources Information Center

    Tanaka, James W.; Meixner, Tamara L.; Kantner, Justin

    2011-01-01

    While much developmental research has focused on the strategies that children employ to recognize faces, less is known about the principles governing the organization of face exemplars in perceptual memory. In this study, we tested a novel, child-friendly paradigm for investigating the organization of face, bird and car exemplars. Children ages

  17. A Developmental Examination of Basic Perceptual Processes in Reading. Final Report.

    ERIC Educational Resources Information Center

    Lefton, Lester A.

    This report summarizes four groups of experiments examining the nature of basic perceptual processes in reading. The first group examined the relationship of English orthography to reading, specifically the transfer of information from the icon to short-term memory. The second group of experiments examined the use of peripheral information…

  18. Caffeine attenuates scopolamine-induced memory impairment in humans.

    PubMed

    Riedel, W; Hogervorst, E; Leboux, R; Verhey, F; van Praag, H; Jolles, J

    1995-11-01

    Caffeine consumption can be beneficial for cognitive functioning. Although caffeine is widely recognized as a mild CNS stimulant drug, the most important consequence of its adenosine antagonism is cholinergic stimulation, which might lead to improvement of higher cognitive functions, particularly memory. In this study, the scopolamine model of amnesia was used to test the cholinergic effects of caffeine, administered as three cups of coffee. Subjects were 16 healthy volunteers who received 250 mg caffeine and 2 mg nicotine separately, in a placebo-controlled double-blind cross-over design. Compared to placebo, nicotine attenuated the scopolamine-induced impairment of storage in short-term memory and attenuated the scopolamine-induced slowing of speed of short-term memory scanning. Nicotine also attenuated the scopolamine-induced slowing of reaction time in a response competition task. Caffeine attenuated the scopolamine-induced impairment of free recall from short- and long-term memory, quality and speed of retrieval from long-term memory in a word learning task, and other cognitive and non-cognitive measures, such as perceptual sensitivity in visual search, reading speed, and rate of finger-tapping. On the basis of these results it was concluded that caffeine possesses cholinergic cognition enhancing properties. Caffeine could be used as a control drug in studies using the scopolamine paradigm and possibly also in other experimental studies of cognitive enhancers, as the effects of a newly developed cognition enhancing drug should at least be superior to the effects of three cups of coffee. PMID:8848531

  19. Perceptual learning modifies untrained pursuit eye movements

    PubMed Central

    Szpiro, Sarit F. A.; Spering, Miriam; Carrasco, Marisa

    2014-01-01

    Perceptual learning improves detection and discrimination of relevant visual information in mature humans, revealing sensory plasticity. Whether visual perceptual learning affects motor responses is unknown. Here we implemented a protocol that enabled us to address this question. We tested a perceptual response (motion direction estimation, in which observers overestimate motion direction away from a reference) and a motor response (voluntary smooth pursuit eye movements). Perceptual training led to greater overestimation and, remarkably, it modified untrained smooth pursuit. In contrast, pursuit training did not affect overestimation in either pursuit or perception, even though observers in both training groups were exposed to the same stimuli for the same time period. A second experiment revealed that estimation training also improved discrimination, indicating that overestimation may optimize perceptual sensitivity. Hence, active perceptual training is necessary to alter perceptual responses, and an acquired change in perception suffices to modify pursuit, a motor response. PMID:25002412

  20. Old dogs, new tricks: training the perceptual skills of senior tennis players.

    PubMed

    Caserta, Ryan J; Young, Jessica; Janelle, Christopher M

    2007-08-01

    The purpose of the study was to determine whether multidimensional perceptual-cognitive skills training, including situational awareness, anticipation, and decision making, improves on-court performance in older adults when compared with a physical training program, including stroke and footwork development. Senior tennis players (N = 27) were randomly assigned to one of three groups: perceptual-cognitive skills training, technique-footwork training, or no training. Results indicated that participants receiving perceptual-cognitive skills training had significantly faster response speeds, higher percentage of accurate responses, and higher percentage of performance decision making in posttest match situations. Findings provide clear evidence that perceptual-cognitive skills can be trained in aged individuals. Implications and suggestions for future research are offered. PMID:17968049

  1. Referenceless Prediction of Perceptual Fog Density and Perceptual Image Defogging.

    PubMed

    Choi, Lark Kwon; You, Jaehee; Bovik, Alan Conrad

    2015-11-01

    We propose a referenceless perceptual fog density prediction model based on natural scene statistics (NSS) and fog aware statistical features. The proposed model, called Fog Aware Density Evaluator (FADE), predicts the visibility of a foggy scene from a single image without reference to a corresponding fog-free image, without dependence on salient objects in a scene, without side geographical camera information, without estimating a depth-dependent transmission map, and without training on human-rated judgments. FADE only makes use of measurable deviations from statistical regularities observed in natural foggy and fog-free images. Fog aware statistical features that define the perceptual fog density index derive from a space domain NSS model and the observed characteristics of foggy images. FADE not only predicts perceptual fog density for the entire image, but also provides a local fog density index for each patch. The predicted fog density using FADE correlates well with human judgments of fog density taken in a subjective study on a large foggy image database. As applications, FADE not only accurately assesses the performance of defogging algorithms designed to enhance the visibility of foggy images, but also is well suited for image defogging. A new FADE-based referenceless perceptual image defogging, dubbed DEnsity of Fog Assessment-based DEfogger (DEFADE) achieves better results for darker, denser foggy images as well as on standard foggy images than the state of the art defogging methods. A software release of FADE and DEFADE is available online for public use: http://live.ece.utexas.edu/research/fog/index.html. PMID:26186784

  2. Linking perceptual learning with identical stimuli to imagery perceptual learning.

    PubMed

    Grzeczkowski, Lukasz; Tartaglia, Elisa M; Mast, Fred W; Herzog, Michael H

    2015-01-01

    Perceptual learning is usually thought to be exclusively driven by the stimuli presented during training (and the underlying synaptic learning rules). In some way, we are slaves of our visual experiences. However, learning can occur even when no stimuli are presented at all. For example, Gabor contrast detection improves when only a blank screen is presented and observers are asked to imagine Gabor patches. Likewise, performance improves when observers are asked to imagine the nonexisting central line of a bisection stimulus to be offset either to the right or left. Hence, performance can improve without stimulus presentation. As shown in the auditory domain, performance can also improve when the very same stimulus is presented in all learning trials and observers were asked to discriminate differences which do not exist (observers were not told about the set up). Classic models of perceptual learning cannot handle these situations since they need proper stimulus presentation, i.e., variance in the stimuli, such as a left versus right offset in the bisection stimulus. Here, we show that perceptual learning with identical stimuli occurs in the visual domain, too. Second, we linked the two paradigms by telling observers that only the very same bisection stimulus was presented in all trials and asked them to imagine the central line to be offset either to the left or right. As in imagery learning, performance improved. PMID:26501405

  3. Social influence and perceptual decision making: a diffusion model analysis.

    PubMed

    Germar, Markus; Schlemmer, Alexander; Krug, Kristine; Voss, Andreas; Mojzisch, Andreas

    2014-02-01

    Classic studies on social influence used simple perceptual decision-making tasks to examine how the opinions of others change individuals' judgments. Since then, one of the most fundamental questions in social psychology has been whether social influence can alter basic perceptual processes. To address this issue, we used a diffusion model analysis. Diffusion models provide a stochastic approach for separating the cognitive processes underlying speeded binary decisions. Following this approach, our study is the first to disentangle whether social influence on decision making is due to altering the uptake of available sensory information or due to shifting the decision criteria. In two experiments, we found consistent evidence for the idea that social influence alters the uptake of available sensory evidence. By contrast, participants did not adjust their decision criteria. PMID:24154917

  4. Motor and Tactile-Perceptual Skill Differences between Individuals with High-Functioning Autism and Typically Developing Individuals Ages 5-21

    ERIC Educational Resources Information Center

    Abu-Dahab, Sana M. N.; Skidmore, Elizabeth R.; Holm, Margo B.; Rogers, Joan C.; Minshew, Nancy J.

    2013-01-01

    We examined motor and tactile-perceptual skills in individuals with high-functioning autism (IHFA) and matched typically developing individuals (TDI) ages 5-21years. Grip strength, motor speed and coordination were impaired in IHFA compared to matched TDI, and the differences between groups varied with age. Although tactile-perceptual skills of

  5. Motor and Tactile-Perceptual Skill Differences between Individuals with High-Functioning Autism and Typically Developing Individuals Ages 5-21

    ERIC Educational Resources Information Center

    Abu-Dahab, Sana M. N.; Skidmore, Elizabeth R.; Holm, Margo B.; Rogers, Joan C.; Minshew, Nancy J.

    2013-01-01

    We examined motor and tactile-perceptual skills in individuals with high-functioning autism (IHFA) and matched typically developing individuals (TDI) ages 5-21 years. Grip strength, motor speed and coordination were impaired in IHFA compared to matched TDI, and the differences between groups varied with age. Although tactile-perceptual skills of…

  6. Speed(s).

    ERIC Educational Resources Information Center

    Levy-Leblond, Jean-Marc

    1980-01-01

    Presents three simple distinct operational procedures for transforming the empirical notion of speed into a formal concept. The relationship between these three procedures and Galilean velocity and Einsteinian relativity is also included. (HM)

  7. Exploiting perceptual redundancy in images

    NASA Astrophysics Data System (ADS)

    Liu, Hongyi; Chen, Zhenzhong

    2015-03-01

    Exploiting perceptual redundancy plays an important role in image processing. Conventional JND models describe the visibility of the minimally perceptible difference by assuming that the visual acuity is consistent over the whole image. Some earlier work considers the space-variant properties of HVS-based on the non-uniform density of photoreceptor cells. In this paper, we aim to exploit the relationship between the masking effects and the foveation properties of HVS. We design the psychophysical experiments which are conducted to model the foveation properties in response to the masking effects. The experiment examines the reduction of visual sensitivity in HVS due to the increased retinal eccentricity. Based on these experiments, the developed Foveated JND model measures the perceptible difference of images according to masking effects therefore provides the information to quantify the perceptual redundancy in the images. Subjective evaluations validate the proposed FJND model.

  8. Perceptual Color Characterization of Cameras

    PubMed Central

    Vazquez-Corral, Javier; Connah, David; Bertalmío, Marcelo

    2014-01-01

    Color camera characterization, mapping outputs from the camera sensors to an independent color space, such as XY Z, is an important step in the camera processing pipeline. Until now, this procedure has been primarily solved by using a 3 × 3 matrix obtained via a least-squares optimization. In this paper, we propose to use the spherical sampling method, recently published by Finlayson et al., to perform a perceptual color characterization. In particular, we search for the 3 × 3 matrix that minimizes three different perceptual errors, one pixel based and two spatially based. For the pixel-based case, we minimize the CIE ΔE error, while for the spatial-based case, we minimize both the S-CIELAB error and the CID error measure. Our results demonstrate an improvement of approximately 3% for the ΔE error, 7% for the S-CIELAB error and 13% for the CID error measures. PMID:25490586

  9. Perceptual color characterization of cameras.

    PubMed

    Vazquez-Corral, Javier; Connah, David; Bertalmío, Marcelo

    2014-01-01

    Color camera characterization, mapping outputs from the camera sensors to an independent color space, such as XYZ, is an important step in the camera processing pipeline. Until now, this procedure has been primarily solved by using a 3 × 3 matrix obtained via a least-squares optimization. In this paper, we propose to use the spherical sampling method, recently published by Finlayson et al., to perform a perceptual color characterization. In particular, we search for the 3 × 3 matrix that minimizes three different perceptual errors, one pixel based and two spatially based. For the pixel-based case, we minimize the CIE ΔE error, while for the spatial-based case, we minimize both the S-CIELAB error and the CID error measure. Our results demonstrate an improvement of approximately 3% for the ΔE error, 7% for the S-CIELAB error and 13% for the CID error measures. PMID:25490586

  10. Minimalist approach to perceptual interactions.

    PubMed

    Lenay, Charles; Stewart, John

    2012-01-01

    WORK AIMED AT STUDYING SOCIAL COGNITION IN AN INTERACTIONIST PERSPECTIVE OFTEN ENCOUNTERS SUBSTANTIAL THEORETICAL AND METHODOLOGICAL DIFFICULTIES: identifying the significant behavioral variables; recording them without disturbing the interaction; and distinguishing between: (a) the necessary and sufficient contributions of each individual partner for a collective dynamics to emerge; (b) features which derive from this collective dynamics and escape from the control of the individual partners; and (c) the phenomena arising from this collective dynamics which are subsequently appropriated and used by the partners. We propose a minimalist experimental paradigm as a basis for this conceptual discussion: by reducing the sensory inputs to a strict minimum, we force a spatial and temporal deployment of the perceptual activities, which makes it possible to obtain a complete recording and control of the dynamics of interaction. After presenting the principles of this minimalist approach to perception, we describe a series of experiments on two major questions in social cognition: recognizing the presence of another intentional subject; and phenomena of imitation. In both cases, we propose explanatory schema which render an interactionist approach to social cognition clear and explicit. Starting from our earlier work on perceptual crossing we present a new experiment on the mechanisms of reciprocal recognition of the perceptual intentionality of the other subject: the emergent collective dynamics of the perceptual crossing can be appropriated by each subject. We then present an experimental study of opaque imitation (when the subjects cannot see what they themselves are doing). This study makes it possible to characterize what a properly interactionist approach to imitation might be. In conclusion, we draw on these results, to show how an interactionist approach can contribute to a fully social approach to social cognition. PMID:22582041

  11. Olfactory perceptual stability and discrimination.

    PubMed

    Barnes, Dylan C; Hofacer, Rylon D; Zaman, Ashiq R; Rennaker, Robert L; Wilson, Donald A

    2008-12-01

    No two roses smell exactly alike, but our brain accurately bundles these variations into a single percept 'rose'. We found that ensembles of rat olfactory bulb neurons decorrelate complex mixtures that vary by as little as a single missing component, whereas olfactory (piriform) cortical neural ensembles perform pattern completion in response to an absent component, essentially filling in the missing information and allowing perceptual stability. This piriform cortical ensemble activity predicts olfactory perception. PMID:18978781

  12. Minimalist Approach to Perceptual Interactions

    PubMed Central

    Lenay, Charles; Stewart, John

    2012-01-01

    Work aimed at studying social cognition in an interactionist perspective often encounters substantial theoretical and methodological difficulties: identifying the significant behavioral variables; recording them without disturbing the interaction; and distinguishing between: (a) the necessary and sufficient contributions of each individual partner for a collective dynamics to emerge; (b) features which derive from this collective dynamics and escape from the control of the individual partners; and (c) the phenomena arising from this collective dynamics which are subsequently appropriated and used by the partners. We propose a minimalist experimental paradigm as a basis for this conceptual discussion: by reducing the sensory inputs to a strict minimum, we force a spatial and temporal deployment of the perceptual activities, which makes it possible to obtain a complete recording and control of the dynamics of interaction. After presenting the principles of this minimalist approach to perception, we describe a series of experiments on two major questions in social cognition: recognizing the presence of another intentional subject; and phenomena of imitation. In both cases, we propose explanatory schema which render an interactionist approach to social cognition clear and explicit. Starting from our earlier work on perceptual crossing we present a new experiment on the mechanisms of reciprocal recognition of the perceptual intentionality of the other subject: the emergent collective dynamics of the perceptual crossing can be appropriated by each subject. We then present an experimental study of opaque imitation (when the subjects cannot see what they themselves are doing). This study makes it possible to characterize what a properly interactionist approach to imitation might be. In conclusion, we draw on these results, to show how an interactionist approach can contribute to a fully social approach to social cognition. PMID:22582041

  13. Generalization of multisensory perceptual learning.

    PubMed

    Powers Iii, Albert R; Hillock-Dunn, Andrea; Wallace, Mark T

    2016-01-01

    Life in a multisensory world requires the rapid and accurate integration of stimuli across the different senses. In this process, the temporal relationship between stimuli is critical in determining which stimuli share a common origin. Numerous studies have described a multisensory temporal binding window-the time window within which audiovisual stimuli are likely to be perceptually bound. In addition to characterizing this window's size, recent work has shown it to be malleable, with the capacity for substantial narrowing following perceptual training. However, the generalization of these effects to other measures of perception is not known. This question was examined by characterizing the ability of training on a simultaneity judgment task to influence perception of the temporally-dependent sound-induced flash illusion (SIFI). Results do not demonstrate a change in performance on the SIFI itself following training. However, data do show an improved ability to discriminate rapidly-presented two-flash control conditions following training. Effects were specific to training and scaled with the degree of temporal window narrowing exhibited. Results do not support generalization of multisensory perceptual learning to other multisensory tasks. However, results do show that training results in improvements in visual temporal acuity, suggesting a generalization effect of multisensory training on unisensory abilities. PMID:27000988

  14. Motor Cost Influences Perceptual Decisions.

    PubMed

    Marcos, Encarni; Cos, Ignasi; Girard, Benoît; Verschure, Paul F M J

    2015-01-01

    Perceptual decision making has been widely studied using tasks in which subjects are asked to discriminate a visual stimulus and instructed to report their decision with a movement. In these studies, performance is measured by assessing the accuracy of the participants' choices as a function of the ambiguity of the visual stimulus. Typically, the reporting movement is considered as a mere means of reporting the decision with no influence on the decision-making process. However, recent studies have shown that even subtle differences of biomechanical costs between movements may influence how we select between them. Here we investigated whether this purely motor cost could also influence decisions in a perceptual discrimination task in detriment of accuracy. In other words, are perceptual decisions only dependent on the visual stimulus and entirely orthogonal to motor costs? Here we show the results of a psychophysical experiment in which human subjects were presented with a random dot motion discrimination task and asked to report the perceived motion direction using movements of different biomechanical cost. We found that the pattern of decisions exhibited a significant bias towards the movement of lower cost, even when this bias reduced performance accuracy. This strongly suggests that motor costs influence decision making in visual discrimination tasks for which its contribution is neither instructed nor beneficial. PMID:26673222

  15. Motor Cost Influences Perceptual Decisions

    PubMed Central

    Marcos, Encarni; Cos, Ignasi; Girard, Benoît; Verschure, Paul F. M. J.

    2015-01-01

    Perceptual decision making has been widely studied using tasks in which subjects are asked to discriminate a visual stimulus and instructed to report their decision with a movement. In these studies, performance is measured by assessing the accuracy of the participants’ choices as a function of the ambiguity of the visual stimulus. Typically, the reporting movement is considered as a mere means of reporting the decision with no influence on the decision-making process. However, recent studies have shown that even subtle differences of biomechanical costs between movements may influence how we select between them. Here we investigated whether this purely motor cost could also influence decisions in a perceptual discrimination task in detriment of accuracy. In other words, are perceptual decisions only dependent on the visual stimulus and entirely orthogonal to motor costs? Here we show the results of a psychophysical experiment in which human subjects were presented with a random dot motion discrimination task and asked to report the perceived motion direction using movements of different biomechanical cost. We found that the pattern of decisions exhibited a significant bias towards the movement of lower cost, even when this bias reduced performance accuracy. This strongly suggests that motor costs influence decision making in visual discrimination tasks for which its contribution is neither instructed nor beneficial. PMID:26673222

  16. Generalization of multisensory perceptual learning

    PubMed Central

    Powers III, Albert R.; Hillock-Dunn, Andrea; Wallace, Mark T.

    2016-01-01

    Life in a multisensory world requires the rapid and accurate integration of stimuli across the different senses. In this process, the temporal relationship between stimuli is critical in determining which stimuli share a common origin. Numerous studies have described a multisensory temporal binding window—the time window within which audiovisual stimuli are likely to be perceptually bound. In addition to characterizing this window’s size, recent work has shown it to be malleable, with the capacity for substantial narrowing following perceptual training. However, the generalization of these effects to other measures of perception is not known. This question was examined by characterizing the ability of training on a simultaneity judgment task to influence perception of the temporally-dependent sound-induced flash illusion (SIFI). Results do not demonstrate a change in performance on the SIFI itself following training. However, data do show an improved ability to discriminate rapidly-presented two-flash control conditions following training. Effects were specific to training and scaled with the degree of temporal window narrowing exhibited. Results do not support generalization of multisensory perceptual learning to other multisensory tasks. However, results do show that training results in improvements in visual temporal acuity, suggesting a generalization effect of multisensory training on unisensory abilities. PMID:27000988

  17. Reading Aloud and Solving Simple Arithmetic Calculation Intervention (Learning Therapy) Improves Inhibition, Verbal Episodic Memory, Focus Attention and Processing Speed in Healthy Elderly People: Evidence from a Randomized Controlled Trial

    PubMed Central

    Nouchi, Rui; Taki, Yasuyuki; Takeuchi, Hikaru; Nozawa, Takayuki; Sekiguchi, Atsushi; Kawashima, Ryuta

    2016-01-01

    Background: Previous reports have described that simple cognitive training using reading aloud and solving simple arithmetic calculations, so-called “learning therapy”, can improve executive functions and processing speed in the older adults. Nevertheless, it is not well-known whether learning therapy improve a wide range of cognitive functions or not. We investigated the beneficial effects of learning therapy on various cognitive functions in healthy older adults. Methods: We used a single-blinded intervention with two groups (learning therapy group: LT and waiting list control group: WL). Sixty-four elderly were randomly assigned to LT or WL. In LT, participants performed reading Japanese aloud and solving simple calculations training tasks for 6 months. WL did not participate in the intervention. We measured several cognitive functions before and after 6 months intervention periods. Results: Compared to WL, results revealed that LT improved inhibition performance in executive functions (Stroop: LT (Mean = 3.88) vs. WL (Mean = 1.22), adjusted p = 0.013 and reverse Stroop LT (Mean = 3.22) vs. WL (Mean = 1.59), adjusted p = 0.015), verbal episodic memory (Logical Memory (LM): LT (Mean = 4.59) vs. WL (Mean = 2.47), adjusted p = 0.015), focus attention (D-CAT: LT (Mean = 2.09) vs. WL (Mean = −0.59), adjusted p = 0.010) and processing speed compared to the WL control group (digit symbol coding: LT (Mean = 5.00) vs. WL (Mean = 1.13), adjusted p = 0.015 and Symbol Search (SS): LT (Mean = 3.47) vs. WL (Mean = 1.81), adjusted p = 0.014). Discussion: This randomized controlled trial (RCT) can be showed the benefit of LT on inhibition of executive functions, verbal episodic memory, focus attention and processing speed in healthy elderly people. Our results were discussed under overlapping hypothesis.

  18. Cognitive Processes Supporting Episodic Memory Formation in Childhood: The Role of Source Memory, Binding, and Executive Functioning

    ERIC Educational Resources Information Center

    Raj, Vinaya; Bell, Martha Ann

    2010-01-01

    Episodic memories contain various forms of contextual detail (e.g., perceptual, emotional, cognitive details) that need to become integrated. Each of these contextual features can be used to attribute a memory episode to its source, or origin of information. Memory for source information is one critical component in the formation of episodic…

  19. Optical memory: Phase-change memory

    NASA Astrophysics Data System (ADS)

    Kuramochi, Eiichi; Notomi, Masaya

    2015-11-01

    Integrated nano-optical memories may help overcome the limitations of communication speeds and energy costs in electronic chips. Now, using nanoscale phase-change materials researchers have realized the first multi-bit all-optical non-volatile memories with a very small footprint.

  20. Priming and implicit recognition depend on similar temporal changes in perceptual representations.

    PubMed

    Miyoshi, Kiyofumi; Ashida, Hiroshi

    2014-05-01

    Previous studies have reported that longer stimulus presentation decreases the magnitude of priming. In the present study, we used meaningless kaleidoscope images, which were reported to minimize conceptual processing, to investigate the mechanism of the phenomenon. We assessed the impact of stimulus duration on perceptual priming (Experiment 1) and implicit recognition memory (Experiment 2). Both the magnitude of priming and the accuracy of implicit recognition were lower with the longer stimulus presentation (350 ms) compared with the shorter presentation (250 ms). This coincidence of temporal dynamics between priming and implicit recognition suggests similar underlying memory mechanisms. In both cases, the decrease of performance with longer presentation can be explained by either changes in perceptual processes or interference from explicit memory retrieval. PMID:24486801

  1. Optimizing Linked Perceptual Class Formation and Transfer of Function

    ERIC Educational Resources Information Center

    Fields, Lanny; Garruto, Michelle

    2009-01-01

    A linked perceptual class consists of two distinct perceptual classes, A' and B', the members of which have become related to each other. For example, a linked perceptual class might be composed of many pictures of a woman (one perceptual class) and the sounds of that woman's voice (the other perceptual class). In this case, any sound of the

  2. No evidence of intelligence improvement after working memory training: a randomized, placebo-controlled study.

    PubMed

    Redick, Thomas S; Shipstead, Zach; Harrison, Tyler L; Hicks, Kenny L; Fried, David E; Hambrick, David Z; Kane, Michael J; Engle, Randall W

    2013-05-01

    Numerous recent studies seem to provide evidence for the general intellectual benefits of working memory training. In reviews of the training literature, Shipstead, Redick, and Engle (2010, 2012) argued that the field should treat recent results with a critical eye. Many published working memory training studies suffer from design limitations (no-contact control groups, single measures of cognitive constructs), mixed results (transfer of training gains to some tasks but not others, inconsistent transfer to the same tasks across studies), and lack of theoretical grounding (identifying the mechanisms responsible for observed transfer). The current study compared young adults who received 20 sessions of practice on an adaptive dual n-back program (working memory training group) or an adaptive visual search program (active placebo-control group) with a no-contact control group that received no practice. In addition, all subjects completed pretest, midtest, and posttest sessions comprising multiple measures of fluid intelligence, multitasking, working memory capacity, crystallized intelligence, and perceptual speed. Despite improvements on both the dual n-back and visual search tasks with practice, and despite a high level of statistical power, there was no positive transfer to any of the cognitive ability tests. We discuss these results in the context of previous working memory training research and address issues for future working memory training studies. PMID:22708717

  3. Learning to Control Collisions: The Role of Perceptual Attunement and Action Boundaries

    ERIC Educational Resources Information Center

    Fajen, Brett R.; Devaney, Michael C.

    2006-01-01

    The authors investigated the role of perceptual attunement in an emergency braking task in which participants waited until the last possible moment to slam on the brakes. Effects of the size of the approached object and initial speed on the initiation of braking were used to identify the optical variables on which participants relied at various…

  4. Synesthesia and Memory: Color Congruency, Von Restorff, and False Memory Effects

    ERIC Educational Resources Information Center

    Radvansky, Gabriel A.; Gibson, Bradley S.; McNerney, M. Windy

    2011-01-01

    In the current study, we explored the influence of synesthesia on memory for word lists. We tested 10 grapheme-color synesthetes who reported an experience of color when reading letters or words. We replicated a previous finding that memory is compromised when synesthetic color is incongruent with perceptual color. Beyond this, we found that,…

  5. Synesthesia and Memory: Color Congruency, Von Restorff, and False Memory Effects

    ERIC Educational Resources Information Center

    Radvansky, Gabriel A.; Gibson, Bradley S.; McNerney, M. Windy

    2011-01-01

    In the current study, we explored the influence of synesthesia on memory for word lists. We tested 10 grapheme-color synesthetes who reported an experience of color when reading letters or words. We replicated a previous finding that memory is compromised when synesthetic color is incongruent with perceptual color. Beyond this, we found that,

  6. The effect of perceptual grouping on haptic numerosity perception.

    PubMed

    Verlaers, K; Wagemans, J; Overvliet, K E

    2015-01-01

    We used a haptic enumeration task to investigate whether enumeration can be facilitated by perceptual grouping in the haptic modality. Eight participants were asked to count tangible dots as quickly and accurately as possible, while moving their finger pad over a tactile display. In Experiment 1, we manipulated the number and organization of the dots, while keeping the total exploration area constant. The dots were either evenly distributed on a horizontal line (baseline condition) or organized into groups based on either proximity (dots placed in closer proximity to each other) or configural cues (dots placed in a geometric configuration). In Experiment 2, we varied the distance between the subsets of dots. We hypothesized that when subsets of dots can be grouped together, the enumeration time will be shorter and accuracy will be higher than in the baseline condition. The results of both experiments showed faster enumeration for the configural condition than for the baseline condition, indicating that configural grouping also facilitates haptic enumeration. In Experiment 2, faster enumeration was also observed for the proximity condition than for the baseline condition. Thus, perceptual grouping speeds up haptic enumeration by both configural and proximity cues, suggesting that similar mechanisms underlie perceptual grouping in both visual and haptic enumeration. PMID:25248621

  7. Adaptive and perceptual learning technologies in medical education and training.

    PubMed

    Kellman, Philip J

    2013-10-01

    Recent advances in the learning sciences offer remarkable potential to improve medical education and maximize the benefits of emerging medical technologies. This article describes 2 major innovation areas in the learning sciences that apply to simulation and other aspects of medical learning: Perceptual learning (PL) and adaptive learning technologies. PL technology offers, for the first time, systematic, computer-based methods for teaching pattern recognition, structural intuition, transfer, and fluency. Synergistic with PL are new adaptive learning technologies that optimize learning for each individual, embed objective assessment, and implement mastery criteria. The author describes the Adaptive Response-Time-based Sequencing (ARTS) system, which uses each learner's accuracy and speed in interactive learning to guide spacing, sequencing, and mastery. In recent efforts, these new technologies have been applied in medical learning contexts, including adaptive learning modules for initial medical diagnosis and perceptual/adaptive learning modules (PALMs) in dermatology, histology, and radiology. Results of all these efforts indicate the remarkable potential of perceptual and adaptive learning technologies, individually and in combination, to improve learning in a variety of medical domains. PMID:24084310

  8. Musically cued gait-training improves both perceptual and motor timing in Parkinson's disease.

    PubMed

    Benoit, Charles-Etienne; Dalla Bella, Simone; Farrugia, Nicolas; Obrig, Hellmuth; Mainka, Stefan; Kotz, Sonja A

    2014-01-01

    It is well established that auditory cueing improves gait in patients with idiopathic Parkinson's disease (IPD). Disease-related reductions in speed and step length can be improved by providing rhythmical auditory cues via a metronome or music. However, effects on cognitive aspects of motor control have yet to be thoroughly investigated. If synchronization of movement to an auditory cue relies on a supramodal timing system involved in perceptual, motor, and sensorimotor integration, auditory cueing can be expected to affect both motor and perceptual timing. Here, we tested this hypothesis by assessing perceptual and motor timing in 15 IPD patients before and after a 4-week music training program with rhythmic auditory cueing. Long-term effects were assessed 1 month after the end of the training. Perceptual and motor timing was evaluated with a battery for the assessment of auditory sensorimotor and timing abilities and compared to that of age-, gender-, and education-matched healthy controls. Prior to training, IPD patients exhibited impaired perceptual and motor timing. Training improved patients' performance in tasks requiring synchronization with isochronous sequences, and enhanced their ability to adapt to durational changes in a sequence in hand tapping tasks. Benefits of cueing extended to time perception (duration discrimination and detection of misaligned beats in musical excerpts). The current results demonstrate that auditory cueing leads to benefits beyond gait and support the idea that coupling gait to rhythmic auditory cues in IPD patients relies on a neuronal network engaged in both perceptual and motor timing. PMID:25071522

  9. Shared Neural Substrates of Emotionally Enhanced Perceptual and Mnemonic Vividness

    PubMed Central

    Todd, Rebecca M.; Schmitz, Taylor W.; Susskind, Josh; Anderson, Adam K.

    2013-01-01

    It is well-known that emotionally salient events are remembered more vividly than mundane ones. Our recent research has demonstrated that such memory vividness (Mviv) is due in part to the subjective experience of emotional events as more perceptually vivid, an effect we call emotionally enhanced vividness (EEV). The present study built on previously reported research in which fMRI data were collected while participants rated relative levels of visual noise overlaid on emotionally salient and neutral images. Ratings of greater EEV were associated with greater activation in the amygdala and visual cortex. In the present study, we measured BOLD activation that predicted recognition Mviv for these same images 1 week later. Results showed that, after controlling for differences between scenes in low-level objective features, hippocampus activation uniquely predicted subsequent Mviv. In contrast, amygdala and visual cortex regions that were sensitive to EEV were also modulated by subsequent ratings of Mviv. These findings suggest shared neural substrates for the influence of emotional salience on perceptual and mnemonic vividness, with amygdala and visual cortex activation at encoding contributing to the experience of both perception and subsequent memory. PMID:23653601

  10. Does perceptual learning require consciousness or attention?

    PubMed

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

    2013-10-01

    It has been proposed that visual attention and consciousness are separate [Koch, C., & Tsuchiya, N. Attention and consciousness: Two distinct brain processes. Trends in Cognitive Sciences, 11, 16-22, 2007] and possibly even orthogonal processes [Lamme, V. A. F. Why visual attention and awareness are different. Trends in Cognitive Sciences, 7, 12-18, 2003]. Attention and consciousness converge when conscious visual percepts are attended and hence become available for conscious report. In such a view, a lack of reportability can have two causes: the absence of attention or the absence of a conscious percept. This raises an important question in the field of perceptual learning. It is known that learning can occur in the absence of reportability [Gutnisky, D. A., Hansen, B. J., Iliescu, B. F., & Dragoi, V. Attention alters visual plasticity during exposure-based learning. Current Biology, 19, 555-560, 2009; Seitz, A. R., Kim, D., & Watanabe, T. Rewards evoke learning of unconsciously processed visual stimuli in adult humans. Neuron, 61, 700-707, 2009; Seitz, A. R., & Watanabe, T. Is subliminal learning really passive? Nature, 422, 36, 2003; Watanabe, T., Náñez, J. E., & Sasaki, Y. Perceptual learning without perception. Nature, 413, 844-848, 2001], but it is unclear which of the two ingredients-consciousness or attention-is not necessary for learning. We presented textured figure-ground stimuli and manipulated reportability either by masking (which only interferes with consciousness) or with an inattention paradigm (which only interferes with attention). During the second session (24 hr later), learning was assessed neurally and behaviorally, via differences in figure-ground ERPs and via a detection task. Behavioral and neural learning effects were found for stimuli presented in the inattention paradigm and not for masked stimuli. Interestingly, the behavioral learning effect only became apparent when performance feedback was given on the task to measure learning, suggesting that the memory trace that is formed during inattention is latent until accessed. The results suggest that learning requires consciousness, and not attention, and further strengthen the idea that consciousness is separate from attention. PMID:23691987

  11. Perceptual estimation obeys Occam's razor

    PubMed Central

    Gershman, Samuel J.; Niv, Yael

    2013-01-01

    Theoretical models of unsupervised category learning postulate that humans “invent” categories to accommodate new patterns, but tend to group stimuli into a small number of categories. This “Occam's razor” principle is motivated by normative rules of statistical inference. If categories influence perception, then one should find effects of category invention on simple perceptual estimation. In a series of experiments, we tested this prediction by asking participants to estimate the number of colored circles on a computer screen, with the number of circles drawn from a color-specific distribution. When the distributions associated with each color overlapped substantially, participants' estimates were biased toward values intermediate between the two means, indicating that subjects ignored the color of the circles and grouped different-colored stimuli into one perceptual category. These data suggest that humans favor simpler explanations of sensory inputs. In contrast, when the distributions associated with each color overlapped minimally, the bias was reduced (i.e., the estimates for each color were closer to the true means), indicating that sensory evidence for more complex explanations can override the simplicity bias. We present a rational analysis of our task, showing how these qualitative patterns can arise from Bayesian computations. PMID:24137136

  12. Dynamics of individual perceptual decisions.

    PubMed

    Merfeld, Daniel M; Clark, Torin K; Lu, Yue M; Karmali, Faisal

    2016-01-01

    Perceptual decision making is fundamental to a broad range of fields including neurophysiology, economics, medicine, advertising, law, etc. Although recent findings have yielded major advances in our understanding of perceptual decision making, decision making as a function of time and frequency (i.e., decision-making dynamics) is not well understood. To limit the review length, we focus most of this review on human findings. Animal findings, which are extensively reviewed elsewhere, are included when beneficial or necessary. We attempt to put these various findings and data sets, which can appear to be unrelated in the absence of a formal dynamic analysis, into context using published models. Specifically, by adding appropriate dynamic mechanisms (e.g., high-pass filters) to existing models, it appears that a number of otherwise seemingly disparate findings from the literature might be explained. One hypothesis that arises through this dynamic analysis is that decision making includes phasic (high pass) neural mechanisms, an evidence accumulator and/or some sort of midtrial decision-making mechanism (e.g., peak detector and/or decision boundary). PMID:26467513

  13. Perceptually lossy compression of documents

    NASA Astrophysics Data System (ADS)

    Beretta, Giordano B.; Bhaskaran, Vasudev; Konstantinides, Konstantinos; Natarajan, Balas R.

    1997-06-01

    The main cost of owning a facsimile machine consists of the telephone charges for the communications, thus short transmission times are a key feature for facsimile machines. Similarly, on a packet-routed service such as the Internet, a low number of packets is essential to avoid operator wait times. Concomitantly, the user expectations have increased considerably. In facsimile, the switch from binary to full color increases the data size by a factor of 24. On the Internet, the switch from plain text American Standard Code for Information Interchange (ASCII) encoded files to files marked up in the Hypertext Markup Language (HTML) with ample embedded graphics has increased the size of transactions by several orders of magnitude. A common compressing method for raster files in these applications in the Joint Photographic Experts Group (JPEG) method, because efficient implementations are readily available. In this method the implementors design the discrete quantization tables (DQT) and the Huffman tables (HT) to maximize the compression factor while maintaining the introduced artifacts at the threshold of perceptual detectability. Unfortunately the achieved compression rates are unsatisfactory for applications such as color facsimile and World Wide Web (W3) browsing. We present a design methodology for image-independent DQTs that while producing perceptually lossy data, does not impair the reading performance of users. Combined with a text sharpening algorithm that compensates for scanning device limitations, the methodology presented in this paper allows us to achieve compression ratios near 1:100.

  14. Collapse models and perceptual processes

    NASA Astrophysics Data System (ADS)

    Carlo Ghirardi, Gian; Romano, Raffaele

    2014-04-01

    Theories including a collapse mechanism have been presented various years ago. They are based on a modification of standard quantum mechanics in which nonlinear and stochastic terms are added to the evolution equation. Their principal merits derive from the fact that they are mathematically precise schemes accounting, on the basis of a unique universal dynamical principle, both for the quantum behavior of microscopic systems as well as for the reduction associated to measurement processes and for the classical behavior of macroscopic objects. Since such theories qualify themselves not as new interpretations but as modifications of the standard theory they can be, in principle, tested against quantum mechanics. Recently, various investigations identifying possible crucial test have been discussed. In spite of the extreme difficulty to perform such tests it seems that recent technological developments allow at least to put precise limits on the parameters characterizing the modifications of the evolution equation. Here we will simply mention some of the recent investigations in this direction, while we will mainly concentrate our attention to the way in which collapse theories account for definite perceptual process. The differences between the case of reductions induced by perceptions and those related to measurement procedures by means of standard macroscopic devices will be discussed. On this basis, we suggest a precise experimental test of collapse theories involving conscious observers. We make plausible, by discussing in detail a toy model, that the modified dynamics can give rise to quite small but systematic errors in the visual perceptual process.

  15. Visual study of perceptually optimized displays

    NASA Astrophysics Data System (ADS)

    Van Metter, Richard L.; Kocher, Thomas E.

    1997-04-01

    Perceptually linear displays have been proposed as a standard for medical imaging. Current displays (display driver/monitor) have intrinsic display characteristics that differ from this proposal. Visual comparisons of the proposed perceptually linear displays and current technology have not been made to date. The subjective assessment presented in this paper is the first such comparison. Clinical images were printed on a 12-bit laser printer to simulate the display characteristics of perceptually linear and currently available 8-bit medium-resolution gray-scale displays. Images were compared subjectively and by means of a 4-alternative forced choice (4-AFC) protocol. In addition, predictions of visible differences were made with Daly's Visible Differences Predictor model. We find that currently available displays can produce clinical images that are visually indistinguishable from those that would be displayed on a perceptually linear display when viewed at currently available monitor luminance levels (200 nits). Therefore, intrinsic display functions may be sufficiently close to perceptually optimized performance that the expense associated with the design and fabrication of special perceptually linear display cards and/or monitors would not be justified. In any case, substantial deviation from perceptual linearity may be tolerable before visible differences will be discerned as long as the image is correctly mapped to the appropriate display function. Further study of the diagnostic benefits claimed for perceptually linear displays would be prudent before human visual models are adopted as the basis for display standardization.

  16. Perceptual Differences between Hippies and College Students

    ERIC Educational Resources Information Center

    Brothers, Robert; Gaines, Rosslyn

    1973-01-01

    Perceptual differences were investigated between 50 college students who were non-drug users and 50 hippies who used LSD. The major hypothesis predicted was that hippies would score differently from college students in a specific direction on each of the perceptual tasks. (Author)

  17. Enhanced Perceptual Processing of Speech in Autism

    ERIC Educational Resources Information Center

    Jarvinen-Pasley, Anna; Wallace, Gregory L.; Ramus, Franck; Happe, Francesca; Heaton, Pamela

    2008-01-01

    Theories of autism have proposed that a bias towards low-level perceptual information, or a featural/surface-biased information-processing style, may compromise higher-level language processing in such individuals. Two experiments, utilizing linguistic stimuli with competing low-level/perceptual and high-level/semantic information, tested…

  18. Enhanced perceptual processing of speech in autism.

    PubMed

    Järvinen-Pasley, Anna; Wallace, Gregory L; Ramus, Franck; Happé, Francesca; Heaton, Pamela

    2008-01-01

    Theories of autism have proposed that a bias towards low-level perceptual information, or a featural/surface-biased information-processing style, may compromise higher-level language processing in such individuals. Two experiments, utilizing linguistic stimuli with competing low-level/perceptual and high-level/semantic information, tested processing biases in children with autism and matched controls. Whereas children with autism exhibited superior perceptual processing of speech relative to controls, and showed no evidence of either a perceptual or semantic processing bias, controls showed a tendency to process speech semantically. The data provide partial support to the perceptual theories of autism. It is additionally proposed that the pattern of results may reflect different patterns of attentional focusing towards single or multiple stimulus cues in speech between children with autism and controls. PMID:18171373

  19. Episodically defined organization of visual memory.

    PubMed

    Antonelli, Karla; Williams, Carrick

    2015-01-01

    One theory proposed to account for the remarkable capacity and fidelity of visual memory is that visual memories are supported by an underlying structure of conceptual knowledge around which visual information is organized. However, some findings of visual memory learned in visual search tasks are not well explained by this theory. This study examines the importance of episodic, task-relevant, visual information in the organizational structure of visual memory. In two experiments, participants learned 36 target objects (750 ms presentation) in serial presentation search tasks, followed by additional searches containing varying numbers of new exemplars of the targets to introduce retroactive interference for the original search targets. Following the search trials, participants completed a 2-AFC memory test. The critical difference between the two experiments was the form of search instructions given. In Experiment 1, search instructions identified targets by color and conceptual category, making a perceptual feature, (i.e., color), relevant to the task, whereas in Experiment 2, the target was defined by the conceptual category alone making the perceptual feature irrelevant. In Experiment 1, memory test results showed that new exemplars that matched learned objects on both color and conceptual category induced more interference (80%) than those matched on conceptual category alone (87%). Experiment 2, in contrast, showed that new exemplar objects that matched only on conceptual category induced the same amount of interference (78%) as those matched on both color and conceptual category (77%). Results indicate that when made task-relevant, perceptual, as well as conceptual, information contributes to the organization of visual long-term memory. However, when made episodically non-relevant, perceptual information does not contribute to memory organization, and memory defaults to conceptual category organization. This finding supports a theory of an episodically defined organizational structure in visual long-term memory that is overlaid upon an underlying conceptual structure. Meeting abstract presented at VSS 2015. PMID:26325768

  20. Exogenous Attention Enables Perceptual Learning

    PubMed Central

    Szpiro, Sarit F. A.; Carrasco, Marisa

    2015-01-01

    Practice can improve visual perception, and these improvements are considered to be a form of brain plasticity. Training-induced learning is time-consuming and requires hundreds of trials across multiple days. The process of learning acquisition is understudied. Can learning acquisition be potentiated by manipulating visual attentional cues? We developed a protocol in which we used task-irrelevant cues for between-groups manipulation of attention during training. We found that training with exogenous attention can enable the acquisition of learning. Remarkably, this learning was maintained even when observers were subsequently tested under neutral conditions, which indicates that a change in perception was involved. Our study is the first to isolate the effects of exogenous attention and to demonstrate its efficacy to enable learning. We propose that exogenous attention boosts perceptual learning by enhancing stimulus encoding. PMID:26502745

  1. Interdisciplinary Adventures in Perceptual Ecology

    NASA Astrophysics Data System (ADS)

    Bocast, Christopher S.

    A portfolio dissertation that began as acoustic ecology and matured into perceptual ecology, centered on ecomusicology, bioacoustics, and translational audio-based media works with environmental perspectives. The place of music in Western eco-cosmology through time provides a basis for structuring an environmental history of human sound perception. That history suggests that music may stabilize human mental activity, and that an increased musical practice may be essential for the human project. An overview of recent antecedents preceding the emergence of acoustic ecology reveals structural foundations from 20th century culture that underpin modern sound studies. The contextual role that Aldo Leopold, Jacob von Uexkull, John Cage, Marshall McLuhan, and others played in anticipating the development of acoustic ecology as an interdiscipline is detailed. This interdisciplinary aspect of acoustic ecology is defined and defended, while new developments like soundscape ecology are addressed, though ultimately sound studies will need to embrace a broader concept of full-spectrum "sensory" or "perceptual" ecology. The bioacoustic fieldwork done on spawning sturgeon emphasized this necessity. That study yielded scientific recordings and spectrographic analyses of spawning sounds produced by lake sturgeon, Acipenser fulvescens, during reproduction in natural habitats in the Lake Winnebago watershed in Wisconsin. Recordings were made on the Wolf and Embarrass River during the 2011-2013 spawning seasons. Several specimens were dissected to investigate possible sound production mechanisms; no sonic musculature was found. Drumming sounds, ranging from 5 to 7 Hz fundamental frequency, verified the infrasonic nature of previously undocumented "sturgeon thunder". Other characteristic noises of sturgeon spawning including low-frequency rumbles and hydrodynamic sounds were identified. Intriguingly, high-frequency signals resembling electric organ discharges were discovered. These sounds create a distinctive acoustic signature of sturgeon spawning. Media files include concert performance video, sturgeon audio samples, podcasts, radio pieces, music recordings, sound design, and a time-lapse soundscape reconstructed from Aldo Leopold's notes.

  2. How "Central" Is Central Coherence?: Preliminary Evidence on the Link between Conceptual and Perceptual Processing in Children with Autism

    ERIC Educational Resources Information Center

    Lopez, Beatriz; Leekam, Susan R.; Arts, Gerda R. J.

    2008-01-01

    This study aimed to test the assumption drawn from weak central coherence theory that a central cognitive mechanism is responsible for integrating information at both conceptual and perceptual levels. A visual semantic memory task and a face recognition task measuring use of holistic information were administered to 15 children with autism and 16…

  3. Repetition blindness has a perceptual locus: evidence from online processing of targets in RSVP streams

    NASA Technical Reports Server (NTRS)

    Johnston, James C.; Hochhaus, Larry; Ruthruff, Eric

    2002-01-01

    Four experiments tested whether repetition blindness (RB; reduced accuracy reporting repetitions of briefly displayed items) is a perceptual or a memory-recall phenomenon. RB was measured in rapid serial visual presentation (RSVP) streams, with the task altered to reduce memory demands. In Experiment 1 only the number of targets (1 vs. 2) was reported, eliminating the need to remember target identities. Experiment 2 segregated repeated and nonrepeated targets into separate blocks to reduce bias against repeated targets. Experiments 3 and 4 required immediate "online" buttonpress responses to targets as they occurred. All 4 experiments showed very strong RB. Furthermore, the online response data showed clearly that the 2nd of the repeated targets is the one missed. The present results show that in the RSVP paradigm, RB occurs online during initial stimulus encoding and decision making. The authors argue that RB is indeed a perceptual phenomenon.

  4. Oxygen-doped Si15Sb85 thin film for good data retention and high speed phase-change memory application

    NASA Astrophysics Data System (ADS)

    Zhang, Yin; Feng, Jie; Cai, Bingchu

    2009-04-01

    Te-free SixSb100-x (x = 5, 15, 25, 42) thin films are proposed for electronic phase-change memory application and the oxygen doping effect on Si15Sb85 film is investigated in detail. Improved electrical properties are obtained when the oxygen partial pressure ratio is 10%. The crystalline resistivity of Si15Sb85 film is enhanced and the amorphous/crystalline resistivity ratio is also increased to more than 104. The crystallization temperature of the oxygen-doped Si15Sb85 film is 229 °C and maximum temperature for a 10 year lifetime is estimated to be 129 °C with crystallization activation energy of 3.11 eV, which promises better data retention than conventional Ge2Sb2Te5 film. X-ray diffraction patterns indicate that both pure and oxygen-doped Si15Sb85 films crystallize into a hexagonal phase similar to Sb. A phase-change memory device using oxygen-doped Si15Sb85 film can be successfully switched with a 100 ns-1.4 V SET pulse and a 20 ns-7 V RESET pulse. And a SET process as fast as 40 ns is achieved along with a RESET/SET resistance ratio of about 35.

  5. Perceptual Training Strongly Improves Visual Motion Perception in Schizophrenia

    ERIC Educational Resources Information Center

    Norton, Daniel J.; McBain, Ryan K.; Ongur, Dost; Chen, Yue

    2011-01-01

    Schizophrenia patients exhibit perceptual and cognitive deficits, including in visual motion processing. Given that cognitive systems depend upon perceptual inputs, improving patients' perceptual abilities may be an effective means of cognitive intervention. In healthy people, motion perception can be enhanced through perceptual learning, but it

  6. Perceptual Training Strongly Improves Visual Motion Perception in Schizophrenia

    ERIC Educational Resources Information Center

    Norton, Daniel J.; McBain, Ryan K.; Ongur, Dost; Chen, Yue

    2011-01-01

    Schizophrenia patients exhibit perceptual and cognitive deficits, including in visual motion processing. Given that cognitive systems depend upon perceptual inputs, improving patients' perceptual abilities may be an effective means of cognitive intervention. In healthy people, motion perception can be enhanced through perceptual learning, but it…

  7. Broad-based visual benefits from training with an integrated perceptual-learning video game

    PubMed Central

    Deveau, Jenni; Lovcik, Gary; Seitz, Aaron R.

    2014-01-01

    Perception is the window through which we understand all information about our environment, and therefore deficits in perception due to disease, injury, stroke or aging can have significant negative impacts on individuals’ lives. Research in the field of perceptual learning has demonstrated that vision can be improved in both normally seeing and visually impaired individuals, however, a limitation of most perceptual learning approaches is their emphasis on isolating particular mechanisms. In the current study, we adopted an integrative approach where the goal is not to achieve highly specific learning but instead to achieve general improvements to vision. We combined multiple perceptual learning approaches that have individually contributed to increasing the speed, magnitude and generality of learning into a perceptual-learning based video-game. Our results demonstrate broad-based benefits of vision in a healthy adult population. Transfer from the game includes; improvements in acuity (measured with self-paced standard eye-charts), improvement along the full contrast sensitivity function, and improvements in peripheral acuity and contrast thresholds. The use of this type of this custom video game framework built up from psychophysical approaches takes advantage of the benefits found from video game training while maintaining a tight link to psychophysical designs that enable understanding of mechanisms of perceptual learning and has great potential both as a scientific tool and as therapy to help improve vision. PMID:24406157

  8. Broad-based visual benefits from training with an integrated perceptual-learning video game.

    PubMed

    Deveau, Jenni; Lovcik, Gary; Seitz, Aaron R

    2014-06-01

    Perception is the window through which we understand all information about our environment, and therefore deficits in perception due to disease, injury, stroke or aging can have significant negative impacts on individuals' lives. Research in the field of perceptual learning has demonstrated that vision can be improved in both normally seeing and visually impaired individuals, however, a limitation of most perceptual learning approaches is their emphasis on isolating particular mechanisms. In the current study, we adopted an integrative approach where the goal is not to achieve highly specific learning but instead to achieve general improvements to vision. We combined multiple perceptual learning approaches that have individually contributed to increasing the speed, magnitude and generality of learning into a perceptual-learning based video-game. Our results demonstrate broad-based benefits of vision in a healthy adult population. Transfer from the game includes; improvements in acuity (measured with self-paced standard eye-charts), improvement along the full contrast sensitivity function, and improvements in peripheral acuity and contrast thresholds. The use of this type of this custom video game framework built up from psychophysical approaches takes advantage of the benefits found from video game training while maintaining a tight link to psychophysical designs that enable understanding of mechanisms of perceptual learning and has great potential both as a scientific tool and as therapy to help improve vision. PMID:24406157

  9. False Memories for Suggestions: The Impact of Conceptual Elaboration

    PubMed Central

    Zaragoza, Maria S.; Mitchell, Karen J.; Payment, Kristie; Drivdahl, Sarah

    2010-01-01

    Relatively little attention has been paid to the potential role that reflecting on the meaning and implications of suggested events (i.e., conceptual elaboration) might play in promoting the creation of false memories. Two experiments assessed whether encouraging repeated conceptual elaboration, would, like perceptual elaboration, increase false memory for suggested events. Results showed that conceptual elaboration of suggested events more often resulted in high confidence false memories (Experiment 1) and false memories that were accompanied by the phenomenal experience of remembering them (Experiment 2) than did surface-level processing. Moreover, conceptual elaboration consistently led to higher rates of false memory than did perceptual elaboration. The false memory effects that resulted from conceptual elaboration were highly dependent on the organization of the postevent interview questions, such that conceptual elaboration only increased false memory beyond surface level processing when participants evaluated both true and suggested information in relation to the same theme or dimension. PMID:21103451

  10. Poor Anchoring Limits Dyslexics' Perceptual, Memory, and Reading Skills

    ERIC Educational Resources Information Center

    Oganian, Yulia; Ahissar, Merav

    2012-01-01

    The basic deficits underlying the severe and persistent reading difficulties in dyslexia are still highly debated. One of the major topics of debate is whether these deficits are language specific, or affect both verbal and non-verbal stimuli. Recently, Ahissar and colleagues proposed the "anchoring-deficit hypothesis" (Ahissar, Lubin,…

  11. Studying real-world perceptual expertise

    PubMed Central

    Shen, Jianhong; Mack, Michael L.; Palmeri, Thomas J.

    2014-01-01

    Significant insights into visual cognition have come from studying real-world perceptual expertise. Many have previously reviewed empirical findings and theoretical developments from this work. Here we instead provide a brief perspective on approaches, considerations, and challenges to studying real-world perceptual expertise. We discuss factors like choosing to use real-world versus artificial object domains of expertise, selecting a target domain of real-world perceptual expertise, recruiting experts, evaluating their level of expertise, and experimentally testing experts in the lab and online. Throughout our perspective, we highlight expert birding (also called birdwatching) as an example, as it has been used as a target domain for over two decades in the perceptual expertise literature. PMID:25147533

  12. From perceptual to language-mediated categorization

    PubMed Central

    Westermann, Gert; Mareschal, Denis

    2014-01-01

    From at least two months onwards, infants can form perceptual categories. During the first year of life, object knowledge develops from the ability to represent individual object features to representing correlations between attributes and to integrate information from different sources. At the end of the first year, these representations are shaped by labels, opening the way to conceptual knowledge. Here, we review the development of object knowledge and object categorization over the first year of life. We then present an artificial neural network model that models the transition from early perceptual categorization to categories mediated by labels. The model informs a current debate on the role of labels in object categorization by suggesting that although labels do not act as object features they nevertheless affect perceived similarity of perceptually distinct objects sharing the same label. The model presents the first step of an integrated account from early perceptual categorization to language-based concept learning. PMID:24324235

  13. Perceptual Incongruence Influences Bistability and Cortical Activation

    PubMed Central

    Brouwer, Gijs Joost; Tong, Frank; Hagoort, Peter; van Ee, Raymond

    2009-01-01

    We employed a parametric psychophysical design in combination with functional imaging to examine the influence of metric changes in perceptual incongruence on perceptual alternation rates and cortical responses. Subjects viewed a bistable stimulus defined by incongruent depth cues; bistability resulted from incongruence between binocular disparity and monocular perspective cues that specify different slants (slant rivalry). Psychophysical results revealed that perceptual alternation rates were positively correlated with the degree of perceived incongruence. Functional imaging revealed systematic increases in activity that paralleled the psychophysical results within anterior intraparietal sulcus, prior to the onset of perceptual alternations. We suggest that this cortical activity predicts the frequency of subsequent alternations, implying a putative causal role for these areas in initiating bistable perception. In contrast, areas implicated in form and depth processing (LOC and V3A) were sensitive to the degree of slant, but failed to show increases in activity when these cues were in conflict. PMID:19333385

  14. Prior expectations facilitate metacognition for perceptual decision.

    PubMed

    Sherman, M T; Seth, A K; Barrett, A B; Kanai, R

    2015-09-01

    The influential framework of 'predictive processing' suggests that prior probabilistic expectations influence, or even constitute, perceptual contents. This notion is evidenced by the facilitation of low-level perceptual processing by expectations. However, whether expectations can facilitate high-level components of perception remains unclear. We addressed this question by considering the influence of expectations on perceptual metacognition. To isolate the effects of expectation from those of attention we used a novel factorial design: expectation was manipulated by changing the probability that a Gabor target would be presented; attention was manipulated by instructing participants to perform or ignore a concurrent visual search task. We found that, independently of attention, metacognition improved when yes/no responses were congruent with expectations of target presence/absence. Results were modeled under a novel Bayesian signal detection theoretic framework which integrates bottom-up signal propagation with top-down influences, to provide a unified description of the mechanisms underlying perceptual decision and metacognition. PMID:25973773

  15. From perceptual to language-mediated categorization.

    PubMed

    Westermann, Gert; Mareschal, Denis

    2014-01-01

    From at least two months onwards, infants can form perceptual categories. During the first year of life, object knowledge develops from the ability to represent individual object features to representing correlations between attributes and to integrate information from different sources. At the end of the first year, these representations are shaped by labels, opening the way to conceptual knowledge. Here, we review the development of object knowledge and object categorization over the first year of life. We then present an artificial neural network model that models the transition from early perceptual categorization to categories mediated by labels. The model informs a current debate on the role of labels in object categorization by suggesting that although labels do not act as object features they nevertheless affect perceived similarity of perceptually distinct objects sharing the same label. The model presents the first step of an integrated account from early perceptual categorization to language-based concept learning. PMID:24324235

  16. The Perceptual Cues that Reshape Expert Reasoning

    PubMed Central

    Harré, Michael; Bossomaier, Terry; Snyder, Allan

    2012-01-01

    The earliest stages in our perception of the world have a subtle but powerful influence on later thought processes; they provide the contextual cues within which our thoughts are framed and they adapt to many different environments throughout our lives. Understanding the changes in these cues is crucial to understanding how our perceptual ability develops, but these changes are often difficult to quantify in sufficiently complex tasks where objective measures of development are available. Here we simulate perceptual learning using neural networks and demonstrate fundamental changes in these cues as a function of skill. These cues are cognitively grouped together to form perceptual templates that enable rapid ‘whole scene' categorisation of complex stimuli. Such categories reduce the computational load on our capacity limited thought processes, they inform our higher cognitive processes and they suggest a framework of perceptual pre-processing that captures the central role of perception in expertise. PMID:22792435

  17. Visual Neuroscience: The Puzzle of Perceptual Stability.

    PubMed

    Zimmermann, Eckart; Bremmer, Frank

    2016-03-01

    Our world appears stable, although our eyes constantly shift its image across the retina. What brain mechanisms allow for this perceptual stability? A recent study has brought us a step closer to answering this millennial question. PMID:26954439

  18. Development of Auditory-Vocal Perceptual Skills in Songbirds

    PubMed Central

    Miller-Sims, Vanessa C.; Bottjer, Sarah W.

    2012-01-01

    Songbirds are one of the few groups of animals that learn the sounds used for vocal communication during development. Like humans, songbirds memorize vocal sounds based on auditory experience with vocalizations of adult “tutors”, and then use auditory feedback of self-produced vocalizations to gradually match their motor output to the memory of tutor sounds. In humans, investigations of early vocal learning have focused mainly on perceptual skills of infants, whereas studies of songbirds have focused on measures of vocal production. In order to fully exploit songbirds as a model for human speech, understand the neural basis of learned vocal behavior, and investigate links between vocal perception and production, studies of songbirds must examine both behavioral measures of perception and neural measures of discrimination during development. Here we used behavioral and electrophysiological assays of the ability of songbirds to distinguish vocal calls of varying frequencies at different stages of vocal learning. The results show that neural tuning in auditory cortex mirrors behavioral improvements in the ability to make perceptual distinctions of vocal calls as birds are engaged in vocal learning. Thus, separate measures of neural discrimination and behavioral perception yielded highly similar trends during the course of vocal development. The timing of this improvement in the ability to distinguish vocal sounds correlates with our previous work showing substantial refinement of axonal connectivity in cortico-basal ganglia pathways necessary for vocal learning. PMID:23285011

  19. Perceptual skill in soccer: implications for talent identification and development.

    PubMed

    Williams, A M

    2000-09-01

    In this review, key components of perceptual skill in soccer are identified and implications for talent identification and development highlighted. Skilled soccer players can recall and recognize patterns of play more effectively than their less skilled counterparts. This ability to encode, retrieve and recognize sport-specific information is due to complex and discriminating long-term memory structures and is crucial to anticipation in soccer. Similarly, experts use their knowledge of situational probabilities (i.e. expectations) to anticipate future events. They have a better than average idea of what is likely to happen given a particular set of circumstances. Also, proficiency-related differences in visual search strategy are observed. Skilled players use their superior knowledge to control the eye movement patterns necessary for seeking and picking up important sources of information. The nature of the task plays an important role in constraining the type of search used. Skilled soccer players use different search strategies when viewing the whole field (i.e. 11 vs 11 situations) compared with micro-states of the game (i.e. 1 vs 1, 3 vs 3 situations). Visual search behaviour also differs between defensive and offensive plays. These observations have implications for the development of perceptual training programmes and the identification of potential elite soccer players. PMID:11043899

  20. Sex Differences in Sleep-Dependent Perceptual Learning

    PubMed Central

    McDevitt, Elizabeth A.; Rokem, Ariel; Silver, Michael A.; Mednick, Sara C.

    2015-01-01

    Sex differences in learning and memory suggest differences between men and women in mechanisms of neural plasticity. Such differences have been reported in a variety of explicit memory tasks, but implicit memory has not been studied in this context. We investigated differences between men and women in offline consolidation of perceptual learning (PL) of motion direction discrimination. Initially, discrimination thresholds were measured for two opposite directions of motion, followed by approximately forty minutes of training on one of the directions. During a post-training consolidation period, subjects either took a nap or remained awake. Thresholds were then reassessed for both directions of motion. We found that rapid eye movement (REM) sleep facilitates consolidation of PL but that the pattern of specificity in the REM condition differed between men and women. PL for men whose naps contained REM sleep was highly specific to the trained direction of motion, whereas REM sleep in women resulted in generalized learning to the untrained direction as well as to a novel direction that was not previously tested. Moreover, for subjects in the REM condition, men exhibited greater PL than women for the trained direction. Our findings provide the first evidence of sex differences in the magnitude and specificity of PL and in the role of REM sleep in implicit learning. Our results have important implications for optimization of educational and training strategies designed for males and females. PMID:24141074

  1. Differential effects of white noise in cognitive and perceptual tasks

    PubMed Central

    Herweg, Nora A.; Bunzeck, Nico

    2015-01-01

    Beneficial effects of noise on higher cognition have recently attracted attention. Hypothesizing an involvement of the mesolimbic dopamine system and its functional interactions with cortical areas, the current study aimed to demonstrate a facilitation of dopamine-dependent attentional and mnemonic functions by externally applying white noise in five behavioral experiments including a total sample of 167 healthy human subjects. During working memory, acoustic white noise impaired accuracy when presented during the maintenance period (Experiments 1–3). In a reward based long-term memory task, white noise accelerated perceptual judgments for scene images during encoding but left subsequent recognition memory unaffected (Experiment 4). In a modified Posner task (Experiment 5), the benefit due to white noise in attentional orienting correlated weakly with reward dependence, a personality trait that has been associated with the dopaminergic system. These results suggest that white noise has no general effect on cognitive functions. Instead, they indicate differential effects on perception and cognition depending on a variety of factors such as task demands and timing of white noise presentation. PMID:26579024

  2. Sex differences in sleep-dependent perceptual learning.

    PubMed

    McDevitt, Elizabeth A; Rokem, Ariel; Silver, Michael A; Mednick, Sara C

    2014-06-01

    Sex differences in learning and memory suggest differences between men and women in mechanisms of neural plasticity. Such differences have been reported in a variety of explicit memory tasks, but implicit memory has not been studied in this context. We investigated differences between men and women in offline consolidation of perceptual learning (PL) of motion direction discrimination. Initially, discrimination thresholds were measured for two opposite directions of motion, followed by approximately 40 minutes of training on one of the directions. During a post-training consolidation period, subjects either took a nap or remained awake. Thresholds were then reassessed for both directions of motion. We found that rapid eye movement (REM) sleep facilitates consolidation of PL but that the pattern of specificity in the REM condition differed between men and women. PL for men whose naps contained REM sleep was highly specific to the trained direction of motion, whereas REM sleep in women resulted in generalized learning to the untrained direction as well as to a novel direction that was not previously tested. Moreover, for subjects in the REM condition, men exhibited greater PL than women for the trained direction. Our findings provide the first evidence of sex differences in the magnitude and specificity of PL and in the role of REM sleep in implicit learning. Our results have important implications for optimization of educational and training strategies designed for males and females. PMID:24141074

  3. Embodied Memory Judgments: A Case of Motor Fluency

    ERIC Educational Resources Information Center

    Yang, Shu-Ju; Gallo, David A.; Beilock, Sian L.

    2009-01-01

    It is well known that perceptual and conceptual fluency can influence episodic memory judgments. Here, the authors asked whether fluency arising from the motor system also impacts recognition memory. Past research has shown that the perception of letters automatically activates motor programs of typing actions in skilled typists. In this study,…

  4. Does Conceptual Implicit Memory Develop? The Role of Processing Demands

    ERIC Educational Resources Information Center

    Barry, Elaine S.

    2007-01-01

    The author investigated the importance of processing considerations within implicit memory in a developmental design. Second-graders (n = 87) and college students (n = 81) completed perceptual (word stem completion) and conceptual (category generation) implicit memory tests after studying target items either nonsemantically (read) or semantically…

  5. The Nature and Development of Nonverbal Implicit Memory.

    ERIC Educational Resources Information Center

    Hayes, Brett K.; Hennessy, Ruth

    1996-01-01

    Examines the degree to which implicit memory performance is dependent upon the storage of specific perceptual information in a sample of 4-, 5-, and 10-year-old children. Suggested that the processes that subserve pictorial repetition priming and recognition memory develop at different rates, and that such priming is dependent upon access to…

  6. Development Changes in Short-Term Recognition Memory

    ERIC Educational Resources Information Center

    Kirsner, Kim

    1972-01-01

    Auditory and visual recognition were studied in subjects ranging in age from 10 to 60 years. In comparison with perceptual and response factors, memory scanning time is relatively insensitive to age differences, and auditory recognition involves the use of a pre-linguistic memory system insensitive to age differences. (Author/MF)

  7. An Event Related Potentials Study of the Effects of Age, Load and Maintenance Duration on Working Memory Recognition

    PubMed Central

    Pinal, Diego; Zurrón, Montserrat; Díaz, Fernando

    2015-01-01

    Age-related decline in cognitive capacities has been attributed to a generalized slowing of processing speed and a reduction in working memory (WM) capacity. Nevertheless, it is unclear how age affects visuospatial WM recognition and its underlying brain electrical activity. Whether age modulates the effects of memory load or information maintenance duration, which determine the limits of WM, remains also elusive. In this exploratory study, performance in a delayed match to sample task declined with age, particularly in conditions with high memory load. Event related potentials analysis revealed longer N2 and P300 latencies in old than in young adults during WM recognition, which may reflect slowing of stimulus evaluation and classification processes, respectively. Although there were no differences between groups in N2 or P300 amplitudes, the latter was more homogeneously distributed in old than in young adults, which may indicate an age-related increased reliance in frontal vs parietal resources during WM recognition. This was further supported by an age-related reduced posterior cingulate activation and increased superior frontal gyrus activation revealed through standardized low resolution electromagnetic tomography. Memory load and maintenance duration effects on brain activity were similar in both age groups. These behavioral and electrophysiological results add evidence in support of age-related decline in WM recognition theories, with a slowing of processing speed that may be limited to stimulus evaluation and categorization processes -with no effects on perceptual processes- and a posterior to anterior shift in the recruitment of neural resources. PMID:26569113

  8. The therapeutic benefits of perceptual learning

    PubMed Central

    Deveau, Jenni; Lovcik, Gary; Seitz, Aaron R.

    2014-01-01

    The modern field of perceptual learning addresses improvements of sensory and perceptual functioning in adult observers and provides powerful tools to ameliorate the effects of neurological conditions that involve a sensory or attentional deficit. While the sensory systems were once thought to be plastic only during early development, modern research demonstrates a great deal of plasticity in the adult brain. Here we discuss the value of perceptual learning as a method to improve sensory and attentional function, with a brief overview of the current approaches in the field, including how perceptual learning can be highly specific to the training set, and also how new training approaches can overcome this specificity and transfer learning effects to untrained tasks. We discuss these in the context of extant applications of perceptual learning as a treatment for neurological conditions and how new knowledge mechanisms (including attention, exposure based learning, reinforcement learning and multisensory facilitation) that allow or restrict learning in the visual system can lead to enhanced treatment approaches. We suggest new approaches that integrate multiple mechanisms of perceptual learning that promise greater learning and more generalization to real world conditions. PMID:25580062

  9. Perceptual quantization of chromatic components

    NASA Astrophysics Data System (ADS)

    Saadane, Abdelhakim; Bedat, Laurent; Barba, Dominique

    1998-07-01

    In order to achieve a color image coding based on the human visual system features, we have been interested by the design of a perceptually based quantizer. The cardinal directions Ach, Cr1 and Cr2, designed by Krauskopf from habituation experiments and validated in our lab from spatial masking experiments, have been used to characterize color images. The achromatic component, already considered in previous study, will not be considered here. The same methodology has been applied to the two chromatic components to specify the decision thresholds and the reconstruction levels which ensure that the degradations induced will be lower than their visibility thresholds. Two observers have been used for each of the two components. From the values obtained for Cr1 component one should notice that the decision thresholds and reconstruction levels follow a linear law even at higher levels. However, for Cr2 component the values seem following a monotonous increasing function. To determine if these behaviors are frequency dependent, further experiments have been conducted with stimulus frequencies varying from 1cy/deg to 4cy/deg. The measured values show no significant variations. Finally, instead of sinusoidal stimuli, filtered textures have been used to take into account the spatio-frequential combination. The same laws (linear for Cr1 and monotonous increasing for Cr2) have been observed even if a variation in the quantization intervals is reported.

  10. Perceptually adapted MPEG video encoding

    NASA Astrophysics Data System (ADS)

    Bordes, Philippe; Guillotel, Philippe

    2000-06-01

    In picture quality assessment, the amount of distortion perceived by a human observer differs from one region to another according to its particular local content. This subjective perception can be explained/predicted by considering some simple psychovisual properties (masking) of the Human Visual System (HVS). We have implemented a HVS model based on a pyramid decomposition for extracting the spatial frequencies, associated with a multi-resolution motion representation. Then the visibility of the decoded errors is computed by exploiting the Kelly's contrast sensitivity spatio-velocity model. The resulting data is called a 'Quality-map.' Special attention has been paid to temporal/moving effects since, in the case of video sequences, motion strongly influences the subjective quality assessment. The quality of the motion information is thus preponderant. In the second part, two possible uses of these psychovisual properties for improving MPEG video encoding performances are depicted: (1) The pre-processing of the pictures to remove non-visible information using a motion adapted filtering. This process is efficient in term of bits saved and degradation is not significant especially on consumer electronic TV sets. (2) A perceptual quantizer based on a local adaptation scheme in order to obtain Quality-maps as uniform as possible (homogeneous perceived distortion), at constant bit-rate. Further improvements have been considered, especially when the viewer is tracking a moving object in the scene.

  11. Coarse-to-Fine Encoding of Spatial Frequency Information Into Visual Short-Term Memory for Faces but Impartial Decay

    PubMed Central

    Gao, Zaifeng; Bentin, Shlomo

    2011-01-01

    Face perception studies investigated how spatial frequencies (SF) are extracted from retinal display while forming a perceptual representation, or their selective use during task-imposed categorization. Here we focused on the order of encoding low-spatial frequencies (LSF) and high-spatial frequencies (HSF) from perceptual representations into visual short-term memory (VSTM). We also investigated whether different SF-ranges decay from VSTM at different rates during a study-test stimulus-onset asynchrony. An old/new VSTM paradigm was used in which two broadband faces formed the positive set and the probes preserved either low or high SF ranges. Exposure time of 500 ms was sufficient to encode both HSF and LSF in the perceptual representation (experiment 1). Nevertheless, when the positive-set was exposed for 500 ms, LSF-probes were better recognized in VSTM compared with HSF-probes; this effect vanished at 800-ms exposure time (experiment 2). Backward masking the positive set exposed for 800 ms re-established the LSF-probes advantage (experiment 3). The speed of decay up to 10 seconds was similar for LSF- and HSF-probes (experiment 4). These results indicate that LSF are extracted and consolidated into VSTM faster than HSF, supporting a coarse-to-fine order, while the decay from VSTM is not governed by SF. PMID:21500938

  12. Computer Use and Its Effect on the Memory Process in Young and Adults

    ERIC Educational Resources Information Center

    Alliprandini, Paula Mariza Zedu; Straub, Sandra Luzia Wrobel; Brugnera, Elisangela; de Oliveira, Tânia Pitombo; Souza, Isabela Augusta Andrade

    2013-01-01

    This work investigates the effect of computer use in the memory process in young and adults under the Perceptual and Memory experimental conditions. The memory condition involved the phases acquisition of information and recovery, on time intervals (2 min, 24 hours and 1 week) on situations of pre and post-test (before and after the participants…

  13. Action Control: Independent Effects of Memory and Monocular Viewing on Reaching Accuracy

    ERIC Educational Resources Information Center

    Westwood, D.A.; Robertson, C.; Heath, M.

    2005-01-01

    Evidence suggests that perceptual networks in the ventral visual pathway are necessary for action control when targets are viewed with only one eye, or when the target must be stored in memory. We tested whether memory-linked (i.e., open-loop versus memory-guided actions) and monocular-linked effects (i.e., binocular versus monocular actions) on…

  14. The future of memory

    NASA Astrophysics Data System (ADS)

    Marinella, M.

    In the not too distant future, the traditional memory and storage hierarchy of may be replaced by a single Storage Class Memory (SCM) device integrated on or near the logic processor. Traditional magnetic hard drives, NAND flash, DRAM, and higher level caches (L2 and up) will be replaced with a single high performance memory device. The Storage Class Memory paradigm will require high speed (< 100 ns read/write), excellent endurance (> 1012), nonvolatility (retention > 10 years), and low switching energies (< 10 pJ per switch). The International Technology Roadmap for Semiconductors (ITRS) has recently evaluated several potential candidates SCM technologies, including Resistive (or Redox) RAM, Spin Torque Transfer RAM (STT-MRAM), and phase change memory (PCM). All of these devices show potential well beyond that of current flash technologies and research efforts are underway to improve the endurance, write speeds, and scalabilities to be on-par with DRAM. This progress has interesting implications for space electronics: each of these emerging device technologies show excellent resistance to the types of radiation typically found in space applications. Commercially developed, high density storage class memory-based systems may include a memory that is physically radiation hard, and suitable for space applications without major shielding efforts. This paper reviews the Storage Class Memory concept, emerging memory devices, and possible applicability to radiation hardened electronics for space.

  15. Movement and perceptual strategies to intercept virtual sound sources.

    PubMed

    Komeilipoor, Naeem; Rodger, Matthew W M; Cesari, Paola; Craig, Cathy M

    2015-01-01

    To intercept a moving object, one needs to be in the right place at the right time. In order to do this, it is necessary to pick up and use perceptual information that specifies the time to arrival of an object at an interception point. In the present study, we examined the ability to intercept a laterally moving virtual sound object by controlling the displacement of a sliding handle and tested whether and how the interaural time difference (ITD) could be the main source of perceptual information for successfully intercepting the virtual object. The results revealed that in order to accomplish the task, one might need to vary the duration of the movement, control the hand velocity and time to reach the peak velocity (speed coupling), while the adjustment of movement initiation did not facilitate performance. Furthermore, the overall performance was more successful when subjects employed a time-to-contact (tau) coupling strategy. This result shows that prospective information is available in sound for guiding goal-directed actions. PMID:25999805

  16. Movement and perceptual strategies to intercept virtual sound sources

    PubMed Central

    Komeilipoor, Naeem; Rodger, Matthew W. M.; Cesari, Paola; Craig, Cathy M.

    2015-01-01

    To intercept a moving object, one needs to be in the right place at the right time. In order to do this, it is necessary to pick up and use perceptual information that specifies the time to arrival of an object at an interception point. In the present study, we examined the ability to intercept a laterally moving virtual sound object by controlling the displacement of a sliding handle and tested whether and how the interaural time difference (ITD) could be the main source of perceptual information for successfully intercepting the virtual object. The results revealed that in order to accomplish the task, one might need to vary the duration of the movement, control the hand velocity and time to reach the peak velocity (speed coupling), while the adjustment of movement initiation did not facilitate performance. Furthermore, the overall performance was more successful when subjects employed a time-to-contact (tau) coupling strategy. This result shows that prospective information is available in sound for guiding goal-directed actions. PMID:25999805

  17. Memory’s Aging Echo: Age-related Decline in Neural Reactivation of Perceptual Details During Recollection

    PubMed Central

    McDonough, Ian M.; Cervantes, Sasha N.; Gray, Stephen J.; Gallo, David A.

    2014-01-01

    Episodic memory decline is a hallmark of normal cognitive aging. Here, we report the first event-related fMRI study to directly investigate age differences in the neural reactivation of qualitatively rich perceptual details during recollection. Younger and older adults studied pictures of complex scenes at different presentation durations along with descriptive verbal labels, and these labels subsequently were used during fMRI scanning to cue picture recollections of varying perceptual detail. As expected from prior behavioral work, the two groups subjectively rated their recollections as containing similar amounts of perceptual detail, despite objectively measured recollection impairment in older adults. In both age groups, comparisons of retrieval trials that varied in recollected detail revealed robust activity in brain regions previously linked to recollection, including hippocampus and both medial and lateral regions of the prefrontal and posterior parietal cortex. Critically, this analysis also revealed recollection-related activity in visual processing regions that were active in an independent picture-perception task, and these regions showed age-related reductions in activity during recollection that cannot be attributed to age differences in response criteria. These fMRI findings provide new evidence that aging reduces the absolute quantity of perceptual details that are reactivated from memory, and they help to explain why aging reduces the reliability of subjective memory judgments. PMID:24828546

  18. Using a multinomial tree model for detecting mixtures in perceptual detection

    PubMed Central

    Chechile, Richard A.

    2014-01-01

    In the area of memory research there have been two rival approaches for memory measurement—signal detection theory (SDT) and multinomial processing trees (MPT). Both approaches provide measures for the quality of the memory representation, and both approaches provide for corrections for response bias. In recent years there has been a strong case advanced for the MPT approach because of the finding of stochastic mixtures on both target-present and target-absent tests. In this paper a case is made that perceptual detection, like memory recognition, involves a mixture of processes that are readily represented as a MPT model. The Chechile (2004) 6P memory measurement model is modified in order to apply to the case of perceptual detection. This new MPT model is called the Perceptual Detection (PD) model. The properties of the PD model are developed, and the model is applied to some existing data of a radiologist examining CT scans. The PD model brings out novel features that were absent from a standard SDT analysis. Also the topic of optimal parameter estimation on an individual-observer basis is explored with Monte Carlo simulations. These simulations reveal that the mean of the Bayesian posterior distribution is a more accurate estimator than the corresponding maximum likelihood estimator (MLE). Monte Carlo simulations also indicate that model estimates based on only the data from an individual observer can be improved upon (in the sense of being more accurate) by an adjustment that takes into account the parameter estimate based on the data pooled across all the observers. The adjustment of the estimate for an individual is discussed as an analogous statistical effect to the improvement over the individual MLE demonstrated by the James–Stein shrinkage estimator in the case of the multiple-group normal model. PMID:25018741

  19. Pupil size tracks perceptual content and surprise.

    PubMed

    Kloosterman, Niels A; Meindertsma, Thomas; van Loon, Anouk M; Lamme, Victor A F; Bonneh, Yoram S; Donner, Tobias H

    2015-04-01

    Changes in pupil size at constant light levels reflect the activity of neuromodulatory brainstem centers that control global brain state. These endogenously driven pupil dynamics can be synchronized with cognitive acts. For example, the pupil dilates during the spontaneous switches of perception of a constant sensory input in bistable perceptual illusions. It is unknown whether this pupil dilation only indicates the occurrence of perceptual switches, or also their content. Here, we measured pupil diameter in human subjects reporting the subjective disappearance and re-appearance of a physically constant visual target surrounded by a moving pattern ('motion-induced blindness' illusion). We show that the pupil dilates during the perceptual switches in the illusion and a stimulus-evoked 'replay' of that illusion. Critically, the switch-related pupil dilation encodes perceptual content, with larger amplitude for disappearance than re-appearance. This difference in pupil response amplitude enables prediction of the type of report (disappearance vs. re-appearance) on individual switches (receiver-operating characteristic: 61%). The amplitude difference is independent of the relative durations of target-visible and target-invisible intervals and subjects' overt behavioral report of the perceptual switches. Further, we show that pupil dilation during the replay also scales with the level of surprise about the timing of switches, but there is no evidence for an interaction between the effects of surprise and perceptual content on the pupil response. Taken together, our results suggest that pupil-linked brain systems track both the content of, and surprise about, perceptual events. PMID:25754528

  20. Stress Effects on Working Memory, Explicit Memory, and Implicit Memory for Neutral and Emotional Stimuli in Healthy Men

    PubMed Central

    Luethi, Mathias; Meier, Beat; Sandi, Carmen

    2008-01-01

    Stress is a strong modulator of memory function. However, memory is not a unitary process and stress seems to exert different effects depending on the memory type under study. Here, we explored the impact of social stress on different aspects of human memory, including tests for explicit memory and working memory (for neutral materials), as well as implicit memory (perceptual priming, contextual priming and classical conditioning for emotional stimuli). A total of 35 young adult male students were randomly assigned to either the stress or the control group, with stress being induced by the Trier Social Stress Test (TSST). Salivary cortisol levels were assessed repeatedly throughout the experiment to validate stress effects. The results support previous evidence indicating complex effects of stress on different types of memory: A pronounced working memory deficit was associated with exposure to stress. No performance differences between groups of stressed and unstressed subjects were observed in verbal explicit memory (but note that learning and recall took place within 1 h and immediately following stress) or in implicit memory for neutral stimuli. Stress enhanced classical conditioning for negative but not positive stimuli. In addition, stress improved spatial explicit memory. These results reinforce the view that acute stress can be highly disruptive for working memory processing. They provide new evidence for the facilitating effects of stress on implicit memory for negative emotional materials. Our findings are discussed with respect to their potential relevance for psychiatric disorders, such as post traumatic stress disorder. PMID:19169362

  1. Perceptual Image Compression in Telemedicine

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B.; Ahumada, Albert J., Jr.; Eckstein, Miguel; Null, Cynthia H. (Technical Monitor)

    1996-01-01

    The next era of space exploration, especially the "Mission to Planet Earth" will generate immense quantities of image data. For example, the Earth Observing System (EOS) is expected to generate in excess of one terabyte/day. NASA confronts a major technical challenge in managing this great flow of imagery: in collection, pre-processing, transmission to earth, archiving, and distribution to scientists at remote locations. Expected requirements in most of these areas clearly exceed current technology. Part of the solution to this problem lies in efficient image compression techniques. For much of this imagery, the ultimate consumer is the human eye. In this case image compression should be designed to match the visual capacities of the human observer. We have developed three techniques for optimizing image compression for the human viewer. The first consists of a formula, developed jointly with IBM and based on psychophysical measurements, that computes a DCT quantization matrix for any specified combination of viewing distance, display resolution, and display brightness. This DCT quantization matrix is used in most recent standards for digital image compression (JPEG, MPEG, CCITT H.261). The second technique optimizes the DCT quantization matrix for each individual image, based on the contents of the image. This is accomplished by means of a model of visual sensitivity to compression artifacts. The third technique extends the first two techniques to the realm of wavelet compression. Together these two techniques will allow systematic perceptual optimization of image compression in NASA imaging systems. Many of the image management challenges faced by NASA are mirrored in the field of telemedicine. Here too there are severe demands for transmission and archiving of large image databases, and the imagery is ultimately used primarily by human observers, such as radiologists. In this presentation I will describe some of our preliminary explorations of the applications of our technology to the special problems of telemedicine.

  2. Disruptive colouration and perceptual grouping.

    PubMed

    Espinosa, Irene; Cuthill, Innes C

    2014-01-01

    Camouflage is the primary defence of many animals and includes multiple strategies that interfere with figure-ground segmentation and object recognition. While matching background colours and textures is widespread and conceptually straightforward, less well explored are the optical 'tricks', collectively called disruptive colouration, that exploit perceptual grouping mechanisms. Adjacent high contrast colours create false edges, but this is not sufficient for an object's shape to be broken up; some colours must blend with the background. We test the novel hypothesis that this will be particularly effective when the colour patches on the animal appear to belong to, not merely different background colours, but different background objects. We used computer-based experiments where human participants had to find cryptic targets on artificial backgrounds. Creating what appeared to be bi-coloured foreground objects on bi-coloured backgrounds, we generated colour boundaries that had identical local contrast but either lay within or between (illusory) objects. As predicted, error rates for targets matching what appeared to be different background objects were higher than for targets which had otherwise identical local contrast to the background but appeared to belong to single background objects. This provides evidence for disruptive colouration interfering with higher-level feature integration in addition to previously demonstrated low-level effects involving contour detection. In addition, detection was impeded in treatments where targets were on or in close proximity to multiple background colour or tone boundaries. This is consistent with other studies which show a deleterious influence of visual 'clutter' or background complexity on search. PMID:24466337

  3. Perceptual Factors Influence Visual Search for Meaningful Symbols in Individuals with Intellectual Disabilities and Down Syndrome or Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Wilkinson, Krista M.; McIlvane, William J.

    2013-01-01

    Augmentative and alternative communication (AAC) systems often supplement oral communication for individuals with intellectual and communication disabilities. Research with preschoolers without disabilities has demonstrated that two visual--perceptual factors influence speed and/or accuracy of finding a target: the internal color and spatial

  4. Perceptual Factors Influence Visual Search for Meaningful Symbols in Individuals with Intellectual Disabilities and Down Syndrome or Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Wilkinson, Krista M.; McIlvane, William J.

    2013-01-01

    Augmentative and alternative communication (AAC) systems often supplement oral communication for individuals with intellectual and communication disabilities. Research with preschoolers without disabilities has demonstrated that two visual--perceptual factors influence speed and/or accuracy of finding a target: the internal color and spatial…

  5. Effects of Perceptual and Conceptual Similarity in Lexical Priming of Young Children Who Stutter: Preliminary Findings

    ERIC Educational Resources Information Center

    Hartfield, Kia N.; Conture, Edward G.

    2006-01-01

    The purpose of this study was to investigate the influence of conceptual and perceptual properties of words on the speed and accuracy of lexical retrieval of children who do (CWS) and do not stutter (CWNS) during a picture-naming task. Participants consisted of 13 3-5-year-old CWS and the same number of CWNS. All participants had speech, language,…

  6. Exploring the use of memory colors for image enhancement

    NASA Astrophysics Data System (ADS)

    Xue, Su; Tan, Minghui; McNamara, Ann; Dorsey, Julie; Rushmeier, Holly

    2014-02-01

    Memory colors refer to those colors recalled in association with familiar objects. While some previous work introduces this concept to assist digital image enhancement, their basis, i.e., on-screen memory colors, are not appropriately investigated. In addition, the resulting adjustment methods developed are not evaluated from a perceptual view of point. In this paper, we first perform a context-free perceptual experiment to establish the overall distributions of screen memory colors for three pervasive objects. Then, we use a context-based experiment to locate the most representative memory colors; at the same time, we investigate the interactions of memory colors between different objects. Finally, we show a simple yet effective application using representative memory colors to enhance digital images. A user study is performed to evaluate the performance of our technique.

  7. Retention of perceptual generalization of fear extinction.

    PubMed

    Pappens, Meike; Schroijen, Mathias; Van den Bergh, Omer; Van Diest, Ilse

    2015-12-01

    Fear reduction obtained during a fear extinction procedure can generalize from the extinction stimulus to other perceptually similar stimuli. Perceptual generalization of fear extinction typically follows a perceptual gradient, with increasing levels of fear reduction the more a stimulus resembles the extinction stimulus. The current study aimed to investigate whether perceptual generalization of fear extinction can be observed also after a retention interval of 24h. Fear was acquired to three geometrical figures of different sizes (CS(+), CS1(+) and CS2(+)) by consistently pairing them with a short-lasting suffocation experience (US). Three other geometrical figures that were never followed by the US served as control stimuli (CS(-), CS1(-), CS2(-)). Next, only the CS(+) was extinguished by presenting it in the absence of the US. One day later, fear responses to all stimuli were assessed without any US-presentation. Outcome measures included startle blink EMG, skin conductance, US expectancy, respiratory rate and tidal volume. On day 2 spontaneous recovery of fear was observed in US expectancy and tidal volume, but not in the other outcomes. Evidence for the retention of fear extinction generalization was present in US expectancy and skin conductance, but a perceptual gradient in the retention of generalized fear extinction could not be observed. PMID:25623628

  8. Perceptual Contrast Enhancement with Dynamic Range Adjustment.

    PubMed

    Zhang, Hong; Li, Yuecheng; Chen, Hao; Yuan, Ding; Sun, Mingui

    2013-12-01

    Recent years, although great efforts have been made to improve its performance, few Histogram equalization (HE) methods take human visual perception (HVP) into account explicitly. The human visual system (HVS) is more sensitive to edges than brightness. This paper proposes to take use of this nature intuitively and develops a perceptual contrast enhancement approach with dynamic range adjustment through histogram modification. The use of perceptual contrast connects the image enhancement problem with the HVS. To pre-condition the input image before the HE procedure is implemented, a perceptual contrast map (PCM) is constructed based on the modified Difference of Gaussian (DOG) algorithm. As a result, the contrast of the image is sharpened and high frequency noise is suppressed. A modified Clipped Histogram Equalization (CHE) is also developed which improves visual quality by automatically detecting the dynamic range of the image with improved perceptual contrast. Experimental results show that the new HE algorithm outperforms several state-of-the-art algorithms in improving perceptual contrast and enhancing details. In addition, the new algorithm is simple to implement, making it suitable for real-time applications. PMID:24339452

  9. ViA: a perceptual visualization assistant

    NASA Astrophysics Data System (ADS)

    Healey, Chris G.; St. Amant, Robert; Elhaddad, Mahmoud S.

    2000-05-01

    This paper describes an automated visualized assistant called ViA. ViA is designed to help users construct perceptually optical visualizations to represent, explore, and analyze large, complex, multidimensional datasets. We have approached this problem by studying what is known about the control of human visual attention. By harnessing the low-level human visual system, we can support our dual goals of rapid and accurate visualization. Perceptual guidelines that we have built using psychophysical experiments form the basis for ViA. ViA uses modified mixed-initiative planning algorithms from artificial intelligence to search of perceptually optical data attribute to visual feature mappings. Our perceptual guidelines are integrated into evaluation engines that provide evaluation weights for a given data-feature mapping, and hints on how that mapping might be improved. ViA begins by asking users a set of simple questions about their dataset and the analysis tasks they want to perform. Answers to these questions are used in combination with the evaluation engines to identify and intelligently pursue promising data-feature mappings. The result is an automatically-generated set of mappings that are perceptually salient, but that also respect the context of the dataset and users' preferences about how they want to visualize their data.

  10. Limits on perceptual encoding can be predicted from known receptive field properties of human visual cortex.

    PubMed

    Cohen, Michael A; Rhee, Juliana Y; Alvarez, George A

    2016-01-01

    Human cognition has a limited capacity that is often attributed to the brain having finite cognitive resources, but the nature of these resources is usually not specified. Here, we show evidence that perceptual interference between items can be predicted by known receptive field properties of the visual cortex, suggesting that competition within representational maps is an important source of the capacity limitations of visual processing. Across the visual hierarchy, receptive fields get larger and represent more complex, high-level features. Thus, when presented simultaneously, high-level items (e.g., faces) will often land within the same receptive fields, while low-level items (e.g., color patches) will often not. Using a perceptual task, we found long-range interference between high-level items, but only short-range interference for low-level items, with both types of interference being weaker across hemifields. Finally, we show that long-range interference between items appears to occur primarily during perceptual encoding and not during working memory maintenance. These results are naturally explained by the distribution of receptive fields and establish a link between perceptual capacity limits and the underlying neural architecture. (PsycINFO Database Record PMID:26322687

  11. Musically Cued Gait-Training Improves Both Perceptual and Motor Timing in Parkinson’s Disease

    PubMed Central

    Benoit, Charles-Etienne; Dalla Bella, Simone; Farrugia, Nicolas; Obrig, Hellmuth; Mainka, Stefan; Kotz, Sonja A.

    2014-01-01

    It is well established that auditory cueing improves gait in patients with idiopathic Parkinson’s disease (IPD). Disease-related reductions in speed and step length can be improved by providing rhythmical auditory cues via a metronome or music. However, effects on cognitive aspects of motor control have yet to be thoroughly investigated. If synchronization of movement to an auditory cue relies on a supramodal timing system involved in perceptual, motor, and sensorimotor integration, auditory cueing can be expected to affect both motor and perceptual timing. Here, we tested this hypothesis by assessing perceptual and motor timing in 15 IPD patients before and after a 4-week music training program with rhythmic auditory cueing. Long-term effects were assessed 1 month after the end of the training. Perceptual and motor timing was evaluated with a battery for the assessment of auditory sensorimotor and timing abilities and compared to that of age-, gender-, and education-matched healthy controls. Prior to training, IPD patients exhibited impaired perceptual and motor timing. Training improved patients’ performance in tasks requiring synchronization with isochronous sequences, and enhanced their ability to adapt to durational changes in a sequence in hand tapping tasks. Benefits of cueing extended to time perception (duration discrimination and detection of misaligned beats in musical excerpts). The current results demonstrate that auditory cueing leads to benefits beyond gait and support the idea that coupling gait to rhythmic auditory cues in IPD patients relies on a neuronal network engaged in both perceptual and motor timing. PMID:25071522

  12. Mapping the Perceptual Grain of the Human Retina

    PubMed Central

    Tuten, William S.; Roorda, Austin; Sincich, Lawrence C.

    2014-01-01

    In humans, experimental access to single sensory receptors is difficult to achieve, yet it is crucial for learning how the signals arising from each receptor are transformed into perception. By combining adaptive optics microstimulation with high-speed eye tracking, we show that retinal function can be probed at the level of the individual cone photoreceptor in living eyes. Classical psychometric functions were obtained from cone-sized microstimuli targeted to single photoreceptors. Revealed psychophysically, the cone mosaic also manifests a variable sensitivity to light across its surface that accords with a simple model of cone light capture. Because this microscopic grain of vision could be detected on the perceptual level, it suggests that photoreceptors can act individually to shape perception, if the normally suboptimal relay of light by the eye's optics is corrected. Thus the precise arrangement of cones and the exact placement of stimuli onto those cones create the initial retinal limits on signals mediating spatial vision. PMID:24741057

  13. Changes across the psychometric function following perceptual learning of an RSVP reading task

    PubMed Central

    Coates, Daniel R.; Chung, Susana T. L.

    2014-01-01

    Several recent studies have shown that perceptual learning can result in improvements in reading speed for people with macular disease (e.g., Chung, 2011; Tarita-Nistor et al., 2014). The improvements were reported as an increase in reading speed defined by specific criteria; however, little is known about how other properties of the reading performance or the participants' perceptual responses change as a consequence of learning. In this paper, we performed detailed analyses of data following perceptual learning using an RSVP (rapid serial visual presentation) reading task, looking beyond the change in reading speed defined by the threshold at a given accuracy on a psychometric function relating response accuracy with word exposure duration. Specifically, we explored the statistical characteristics of the response data to address two specific questions: was there a change in the slope of the psychometric function and did the improvements in performance occur consistently across different word exposure durations? Our results show that there is a general steepening of the slope of the psychometric function, leading to non-uniform improvements across stimulus levels. PMID:25566119

  14. Distortions in memory for visual displays

    NASA Technical Reports Server (NTRS)

    Tversky, Barbara

    1989-01-01

    Systematic errors in perception and memory present a challenge to theories of perception and memory and to applied psychologists interested in overcoming them as well. A number of systematic errors in memory for maps and graphs are reviewed, and they are accounted for by an analysis of the perceptual processing presumed to occur in comprehension of maps and graphs. Visual stimuli, like verbal stimuli, are organized in comprehension and memory. For visual stimuli, the organization is a consequence of perceptual processing, which is bottom-up or data-driven in its earlier stages, but top-down and affected by conceptual knowledge later on. Segregation of figure from ground is an early process, and figure recognition later; for both, symmetry is a rapidly detected and ecologically valid cue. Once isolated, figures are organized relative to one another and relative to a frame of reference. Both perceptual (e.g., salience) and conceptual factors (e.g., significance) seem likely to affect selection of a reference frame. Consistent with the analysis, subjects perceived and remembered curves in graphs and rivers in maps as more symmetric than they actually were. Symmetry, useful for detecting and recognizing figures, distorts map and graph figures alike. Top-down processes also seem to operate in that calling attention to the symmetry vs. asymmetry of a slightly asymmetric curve yielded memory errors in the direction of the description. Conceptual frame of reference effects were demonstrated in memory for lines embedded in graphs. In earlier work, the orientation of map figures was distorted in memory toward horizontal or vertical. In recent work, graph lines, but not map lines, were remembered as closer to an imaginary 45 deg line than they had been. Reference frames are determined by both perceptual and conceptual factors, leading to selection of the canonical axes as a reference frame in maps, but selection of the imaginary 45 deg as a reference frame in graphs.

  15. A memory advantage for property.

    PubMed

    DeScioli, Peter; Rosa, Nicole M; Gutchess, Angela H

    2015-01-01

    People's access to resources depends on their status as the owner of particular items. To respect property, people need to remember who owns which objects. We test the hypothesis that people possess enhanced memory for ownership relations compared to unrelated objects. Participants viewed a sequence of 10 person-object pairs before completing a surprise associative memory test in which they matched each person with the previously paired object. We varied the description of the person-object pairs in the instructions. Across three experiments, participants showed better recall when the person was described as the owner of the object compared to being unrelated. Furthermore, memory for property was better than a physical relation (bumping), whereas it did not differ from mental relations (wanting and thinking). These patterns were observed both for memory of items (Experiments 1 and 2) and perceptual details (Experiment 3). We discuss implications for how people remember other people's property. PMID:25986536

  16. Using Virtual Reality to Characterize Episodic Memory Profiles in Amnestic Mild Cognitive Impairment and Alzheimer's Disease: Influence of Active and Passive Encoding

    ERIC Educational Resources Information Center

    Plancher, G.; Tirard, A.; Gyselinck, V.; Nicolas, S.; Piolino, P.

    2012-01-01

    Most neuropsychological assessments of episodic memory bear little similarity to the events that patients actually experience as memories in daily life. The first aim of this study was to use a virtual environment to characterize episodic memory profiles in an ecological fashion, which includes memory for central and perceptual details,

  17. Using Virtual Reality to Characterize Episodic Memory Profiles in Amnestic Mild Cognitive Impairment and Alzheimer's Disease: Influence of Active and Passive Encoding

    ERIC Educational Resources Information Center

    Plancher, G.; Tirard, A.; Gyselinck, V.; Nicolas, S.; Piolino, P.

    2012-01-01

    Most neuropsychological assessments of episodic memory bear little similarity to the events that patients actually experience as memories in daily life. The first aim of this study was to use a virtual environment to characterize episodic memory profiles in an ecological fashion, which includes memory for central and perceptual details,…

  18. Familiar interacting object pairs are perceptually grouped.

    PubMed

    Green, Collin; Hummel, John E

    2006-10-01

    Identification of objects in a scene may be influenced by functional relations among those objects. In this study, observers indicated whether a target object matched a label. Each target was presented with a distractor object, and these were sometimes arranged to interact (as if being used together) and sometimes not to interact. When the distractor was semantically related to the label, identification was more accurate for targets arranged to interact with that distractor. This effect depended on observers' ability to perceptually integrate the stimulus objects, suggesting that it was perceptual in nature. The effect was not attributable to attentional cuing and did not depend on expectation of certain object pairs. These data suggest that familiar functional groupings of objects are perceptually grouped. PMID:17002525

  19. Perceptually-Based Adaptive JPEG Coding

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B.; Rosenholtz, Ruth; Null, Cynthia H. (Technical Monitor)

    1996-01-01

    An extension to the JPEG standard (ISO/IEC DIS 10918-3) allows spatial adaptive coding of still images. As with baseline JPEG coding, one quantization matrix applies to an entire image channel, but in addition the user may specify a multiplier for each 8 x 8 block, which multiplies the quantization matrix, yielding the new matrix for the block. MPEG 1 and 2 use much the same scheme, except there the multiplier changes only on macroblock boundaries. We propose a method for perceptual optimization of the set of multipliers. We compute the perceptual error for each block based upon DCT quantization error adjusted according to contrast sensitivity, light adaptation, and contrast masking, and pick the set of multipliers which yield maximally flat perceptual error over the blocks of the image. We investigate the bitrate savings due to this adaptive coding scheme and the relative importance of the different sorts of masking on adaptive coding.

  20. Angular relation of axes in perceptual space

    NASA Technical Reports Server (NTRS)

    Bucher, Urs

    1992-01-01

    The geometry of perceptual space needs to be known to model spatial orientation constancy or to create virtual environments. To examine one main aspect of this geometry, the angular relation between the three spatial axes was measured. Experiments were performed consisting of a perceptual task in which subjects were asked to set independently their apparent vertical and horizontal plane. The visual background provided no other stimuli to serve as optical direction cues. The task was performed in a number of different body tilt positions with pitches and rolls varied in steps of 30 degs. The results clearly show the distortion of orthogonality of the perceptual space for nonupright body positions. Large interindividual differences were found. Deviations from orthogonality up to 25 deg were detected in the pitch as well as in the roll direction. Implications of this nonorthogonality on further studies of spatial perception and on the construction of virtual environments for human interaction is also discussed.

  1. Perceived visual speed constrained by image segmentation.

    PubMed

    Verghese, P; Stone, L S

    1996-05-01

    Little is known about how or where the visual system parses the visual scene into objects or surfaces. However, it is generally assumed that the segmentation and grouping of pieces of the image into discrete entities is due to 'later' processing stages, after the 'early' processing of the visual image by local mechanisms selective for attributes such as colour, orientation, depth, and motion. Speed perception is also thought to be mediated by early mechanisms tuned for speed. Here we show that manipulating the way in which an image is parsed changes the way in which local speed information is processed. Manipulations that cause multiple stimuli to appear as parts of a single patch degrade speed discrimination, whereas manipulations that perceptually divide a single large stimulus into parts improve discrimination. These results indicate that processes as early as speed perception may be constrained by the parsing of the visual image into discrete entities. PMID:8610014

  2. Perceived visual speed constrained by image segmentation

    NASA Technical Reports Server (NTRS)

    Verghese, P.; Stone, L. S.

    1996-01-01

    Little is known about how or where the visual system parses the visual scene into objects or surfaces. However, it is generally assumed that the segmentation and grouping of pieces of the image into discrete entities is due to 'later' processing stages, after the 'early' processing of the visual image by local mechanisms selective for attributes such as colour, orientation, depth, and motion. Speed perception is also thought to be mediated by early mechanisms tuned for speed. Here we show that manipulating the way in which an image is parsed changes the way in which local speed information is processed. Manipulations that cause multiple stimuli to appear as parts of a single patch degrade speed discrimination, whereas manipulations that perceptually divide a single large stimulus into parts improve discrimination. These results indicate that processes as early as speed perception may be constrained by the parsing of the visual image into discrete entities.

  3. Image Data Compression Having Minimum Perceptual Error

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B. (Inventor)

    1997-01-01

    A method is presented for performing color or grayscale image compression that eliminates redundant and invisible image components. The image compression uses a Discrete Cosine Transform (DCT) and each DCT coefficient yielded by the transform is quantized by an entry in a quantization matrix which determines the perceived image quality and the bit rate of the image being compressed. The quantization matrix comprises visual masking by luminance and contrast technique all resulting in a minimum perceptual error for any given bit rate, or minimum bit rate for a given perceptual error.

  4. Perceptual and Cognitive Impairments and Driving

    PubMed Central

    Korner-Bitensky, Nicol; Coopersmith, Henry; Mayo, Nancy; Leblanc, Ginette; Kaizer, Franceen

    1990-01-01

    Perceptual and cognitive disorders that frequently accompany stroke and head injury influence an individual's ability to drive a motor vehicle. Canadian physicians are legally responsible for identifying patients who are potentially unsafe to drive and, if they fail to do so, may be held liable in a civil action suit. The authors review the guidelines for physicians evaluating a patient's fitness to drive after brain injury. They also examine the actions a physician should take when a patient with perceptual and cognitive problems wants to drive. Ultimately, by taking these actions, physicians will help to prevent driving accidents. PMID:21234047

  5. Image data compression having minimum perceptual error

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B. (Inventor)

    1995-01-01

    A method for performing image compression that eliminates redundant and invisible image components is described. The image compression uses a Discrete Cosine Transform (DCT) and each DCT coefficient yielded by the transform is quantized by an entry in a quantization matrix which determines the perceived image quality and the bit rate of the image being compressed. The present invention adapts or customizes the quantization matrix to the image being compressed. The quantization matrix comprises visual masking by luminance and contrast techniques and by an error pooling technique all resulting in a minimum perceptual error for any given bit rate, or minimum bit rate for a given perceptual error.

  6. A perceptual account of symbolic reasoning

    PubMed Central

    Landy, David; Allen, Colin; Zednik, Carlos

    2014-01-01

    People can be taught to manipulate symbols according to formal mathematical and logical rules. Cognitive scientists have traditionally viewed this capacity—the capacity for symbolic reasoning—as grounded in the ability to internally represent numbers, logical relationships, and mathematical rules in an abstract, amodal fashion. We present an alternative view, portraying symbolic reasoning as a special kind of embodied reasoning in which arithmetic and logical formulae, externally represented as notations, serve as targets for powerful perceptual and sensorimotor systems. Although symbolic reasoning often conforms to abstract mathematical principles, it is typically implemented by perceptual and sensorimotor engagement with concrete environmental structures. PMID:24795662

  7. Recovering and preventing loss of detailed memory: differential rates of forgetting for detail types in episodic memory.

    PubMed

    Sekeres, Melanie J; Bonasia, Kyra; St-Laurent, Marie; Pishdadian, Sara; Winocur, Gordon; Grady, Cheryl; Moscovitch, Morris

    2016-02-01

    Episodic memories undergo qualitative changes with time, but little is known about how different aspects of memory are affected. Different types of information in a memory, such as perceptual detail, and central themes, may be lost at different rates. In patients with medial temporal lobe damage, memory for perceptual details is severely impaired, while memory for central details is relatively spared. Given the sensitivity of memory to loss of details, the present study sought to investigate factors that mediate the forgetting of different types of information from naturalistic episodic memories in young healthy adults. The study investigated (1) time-dependent loss of "central" and "peripheral" details from episodic memories, (2) the effectiveness of cuing with reminders to reinstate memory details, and (3) the role of retrieval in preventing forgetting. Over the course of 7 d, memory for naturalistic events (film clips) underwent a time-dependent loss of peripheral details, while memory for central details (the core or gist of events) showed significantly less loss. Giving brief reminders of the clips just before retrieval reinstated memory for peripheral details, suggesting that loss of details is not always permanent, and may reflect both a storage and retrieval deficit. Furthermore, retrieving a memory shortly after it was encoded prevented loss of both central and peripheral details, thereby promoting retention over time. We consider the implications of these results for behavioral and neurobiological models of retention and forgetting. PMID:26773100

  8. Rihamark: perceptual image hash benchmarking

    NASA Astrophysics Data System (ADS)

    Zauner, Christoph; Steinebach, Martin; Hermann, Eckehard

    2011-02-01

    We identify which hash function has the best characteristics for various applications. In some of those the computation speed may be the most important, in others the ability to distinguish similar images, and sometimes the robustness of the hash against attacks is the primary goal. We compare the hash functions and provide test results. The block mean value based image hash function outperforms the other hash functions in terms of speed. The discrete cosine transform (DCT) based image hash function is the slowest. Although the Marr- Hildreth operator based image hash function is neither the fastest nor the most robust, it offers by far the best discriminative abilities. Interestingly enough, the performance in terms of discriminative ability does not depend on the content of the images. That is, no matter whether the visual appearance of the images compared was very similar or not, the performance of the particular hash function did not change significantly. Different image operations, like horizontal flipping, rotating or resizing, were used to test the robustness of the image hash functions. An interesting result is that none of the tested image hash function is robust against flipping an image horizontally.

  9. Explicit pre-training instruction does not improve implicit perceptual-motor sequence learning

    PubMed Central

    Sanchez, Daniel J.; Reber, Paul J.

    2012-01-01

    Memory systems theory argues for separate neural systems supporting implicit and explicit memory in the human brain. Neuropsychological studies support this dissociation, but empirical studies of cognitively healthy participants generally observe that both kinds of memory are acquired to at least some extent, even in implicit learning tasks. A key question is whether this observation reflects parallel intact memory systems or an integrated representation of memory in healthy participants. Learning of complex tasks in which both explicit instruction and practice is used depends on both kinds of memory, and how these systems interact will be an important component of the learning process. Theories that posit an integrated, or single, memory system for both types of memory predict that explicit instruction should contribute directly to strengthening task knowledge. In contrast, if the two types of memory are independent and acquired in parallel, explicit knowledge should have no direct impact and may serve in a “scaffolding” role in complex learning. Using an implicit perceptual-motor sequence learning task, the effect of explicit pre-training instruction on skill learning and performance was assessed. Explicit pre-training instruction led to robust explicit knowledge, but sequence learning did not benefit from the contribution of pre-training sequence memorization. The lack of an instruction benefit suggests that during skill learning, implicit and explicit memory operate independently. While healthy participants will generally accrue parallel implicit and explicit knowledge in complex tasks, these types of information appear to be separately represented in the human brain consistent with multiple memory systems theory. PMID:23280147

  10. Reactivating a Reactivation Theory of Implicit Memory

    PubMed

    Bower

    1996-03-01

    Implicit and explicit memory tasks are interpreted within a traditional memory theory that distinguishes associations between different classes of memory units (sensory features, logogens, imagens, concepts, context tags). Associations from specific sensory features to logogens are strengthened by perceptual experiences, leading to specific perceptual priming. Associations among concepts are strengthened by use, leading to specific conceptual priming. Activating associations from concepts to logogens leads to semantic and associative priming. Item presentation also establishes a new association from it to a representation of the personal context, comprising an "episodic memory." Such contextual associations play a major role in explicit memory tasks such as recall or recognition. A critical assumption of the theory is that presentation of a given item strengthens its sensory and contextual associations independently; this permits the theory to explain various dissociations of implicit and explicit memory measures. Furthermore, by assuming that brain-injured patients with global amnesia have a selective deficit in establishing novel associations to the context, the theory can explain their deficits in explicit memory along side their intact implicit memory. PMID:8978523

  11. It does not look odd to me: Perceptual impairments and eye movements in amnesic patients with medial temporal lobe damage

    PubMed Central

    Erez, Jonathan; Lee, Andy C.H.; Barense, Morgan D.

    2013-01-01

    Studies of people with memory impairments have shown that a specific set of brain structures in the medial temporal lobe (MTL) is vital for memory function. However, whether these structures have a role outside of memory remains contentious. Recent studies of amnesic patients with damage to two structures within the MTL, the hippocampus and the perirhinal cortex, indicated that these patients also performed poorly on perceptual tasks. More specifically, they performed worse than controls when discriminating between objects, faces and scenes with overlapping features. In order to investigate whether these perceptual deficits are reflected in their viewing strategies, we tested a group of amnesic patients with MTL damage that included the hippocampus and perirhinal cortex on a series of oddity discrimination tasks in which they had to select an odd item from a visual array. Participants' eye movements were monitored throughout the experiment. Results revealed that patients were impaired on tasks that required them to discriminate between items that shared many features, and tasks that required processing items from different viewpoints. An analysis of their eye movements revealed that they exhibited a similar viewing pattern as controls: they fixated more on the target item on trials answered correctly, but not on trials answered incorrectly. In addition, their impaired performance was not explained by an abnormal viewing-strategy that assessed their use of working memory. These results suggest that the perceptual deficits in the MTL patients are not a consequence of abnormal viewing patterns of the objects and scenes, but instead, could involve an inability to bind information gathered from several fixations into a cohesive percept. These data also support the view that MTL structures are important not only for long-term memory, but are also involved in perceptual tasks. PMID:23154380

  12. It does not look odd to me: perceptual impairments and eye movements in amnesic patients with medial temporal lobe damage.

    PubMed

    Erez, Jonathan; Lee, Andy C H; Barense, Morgan D

    2013-01-01

    Studies of people with memory impairments have shown that a specific set of brain structures in the medial temporal lobe (MTL) is vital for memory function. However, whether these structures have a role outside of memory remains contentious. Recent studies of amnesic patients with damage to two structures within the MTL, the hippocampus and the perirhinal cortex, indicated that these patients also performed poorly on perceptual tasks. More specifically, they performed worse than controls when discriminating between objects, faces and scenes with overlapping features. In order to investigate whether these perceptual deficits are reflected in their viewing strategies, we tested a group of amnesic patients with MTL damage that included the hippocampus and perirhinal cortex on a series of oddity discrimination tasks in which they had to select an odd item from a visual array. Participants' eye movements were monitored throughout the experiment. Results revealed that patients were impaired on tasks that required them to discriminate between items that shared many features, and tasks that required processing items from different viewpoints. An analysis of their eye movements revealed that they exhibited a similar viewing pattern as controls: they fixated more on the target item on trials answered correctly, but not on trials answered incorrectly. In addition, their impaired performance was not explained by an abnormal viewing-strategy that assessed their use of working memory. These results suggest that the perceptual deficits in the MTL patients are not a consequence of abnormal viewing patterns of the objects and scenes, but instead, could involve an inability to bind information gathered from several fixations into a cohesive percept. These data also support the view that MTL structures are important not only for long-term memory, but are also involved in perceptual tasks. PMID:23154380

  13. Dazzle camouflage affects speed perception.

    PubMed

    Scott-Samuel, Nicholas E; Baddeley, Roland; Palmer, Chloe E; Cuthill, Innes C

    2011-01-01

    Movement is the enemy of camouflage: most attempts at concealment are disrupted by motion of the target. Faced with this problem, navies in both World Wars in the twentieth century painted their warships with high contrast geometric patterns: so-called "dazzle camouflage". Rather than attempting to hide individual units, it was claimed that this patterning would disrupt the perception of their range, heading, size, shape and speed, and hence reduce losses from, in particular, torpedo attacks by submarines. Similar arguments had been advanced earlier for biological camouflage. Whilst there are good reasons to believe that most of these perceptual distortions may have occurred, there is no evidence for the last claim: changing perceived speed. Here we show that dazzle patterns can distort speed perception, and that this effect is greatest at high speeds. The effect should obtain in predators launching ballistic attacks against rapidly moving prey, or modern, low-tech battlefields where handheld weapons are fired from short ranges against moving vehicles. In the latter case, we demonstrate that in a typical situation involving an RPG7 attack on a Land Rover the reduction in perceived speed is sufficient to make the grenade miss where it was aimed by about a metre, which could be the difference between survival or not for the occupants of the vehicle. PMID:21673797

  14. Dazzle Camouflage Affects Speed Perception

    PubMed Central

    Scott-Samuel, Nicholas E.; Baddeley, Roland; Palmer, Chloe E.; Cuthill, Innes C.

    2011-01-01

    Movement is the enemy of camouflage: most attempts at concealment are disrupted by motion of the target. Faced with this problem, navies in both World Wars in the twentieth century painted their warships with high contrast geometric patterns: so-called “dazzle camouflage”. Rather than attempting to hide individual units, it was claimed that this patterning would disrupt the perception of their range, heading, size, shape and speed, and hence reduce losses from, in particular, torpedo attacks by submarines. Similar arguments had been advanced earlier for biological camouflage. Whilst there are good reasons to believe that most of these perceptual distortions may have occurred, there is no evidence for the last claim: changing perceived speed. Here we show that dazzle patterns can distort speed perception, and that this effect is greatest at high speeds. The effect should obtain in predators launching ballistic attacks against rapidly moving prey, or modern, low-tech battlefields where handheld weapons are fired from short ranges against moving vehicles. In the latter case, we demonstrate that in a typical situation involving an RPG7 attack on a Land Rover the reduction in perceived speed is sufficient to make the grenade miss where it was aimed by about a metre, which could be the difference between survival or not for the occupants of the vehicle. PMID:21673797

  15. Active exploration improves perceptual sensitivity for virtual 3D objects in visual recognition tasks.

    PubMed

    Meijer, Frank; Van der Lubbe, Rob H J

    2011-12-01

    Several studies demonstrated that active exploration as compared to passive observation of a variety of objects leads to improved performance concerning these actively studied objects later on. These results may be specifically due to an improvement in perceptual recognition but in principle they may also be due to a speeding up of responses to actively studied objects. Recently, however, it was suggested that the benefit of active exploration on perceptual recognition may be restricted to a specific class of (biologically relevant) stimuli. By employing measures derived from signal detection theory we were able to show in all our three experiments that active exploration of virtual 3D objects leads to improved perceptual sensitivity in a subsequent test phase. The improvement with these objects means that the benefit of active exploration is not restricted to a specific class of biologically relevant stimuli. The results of our second experiment further demonstrate that the benefit of active exploration is even strong enough to fully compensate for the effect of perceptual degradation, thereby emphasizing the major impact of active exploration. In our third experiment, we explored the possibility that effects of active exploration might be due to major changes in attentional strategies rather than to the action-related aspect. Results revealed that an attentional requirement left the active-passive difference by and large intact supporting the view that the advantage of active object exploration lies in the action itself. PMID:22005389

  16. Effects of attention on perceptual direction tuning curves in the human visual system.

    PubMed

    Busse, Laura; Katzner, Steffen; Tillmann, Christine; Treue, Stefan

    2008-01-01

    In sensory neurophysiology, reverse correlation analyses have advanced our understanding of the spatio-temporal structure of receptive fields (RFs) and the tuning properties of individual neurons. Here, we used a psychophysical variant of the motion reverse correlation technique to investigate how visual selective attention influences human perceptual tuning curves for direction of motion. Direction tuning functions were computed by reverse correlating speeded target-present responses of human observers with a random sequence of brief, fully coherent motion impulses. We found that attention enhanced the amplitude of perceptual tuning curves for direction of motion, while tuning width remained unaffected. Furthermore, the full direction tuning profile across time could be well fitted by a separable model of direction and temporal tuning. Attention enhanced both the direction tuning and its temporal profile, without shifts or changes in shape. Thus, attention exerts a multiplicative effect on human perceptual tuning curves for direction of motion. An analysis of second-order correlations revealed a boost in the likelihood of responses to the target direction when it was followed by a motion impulse in the opposite direction. This perceptual effect might be mediated by biphasic neurons that are preferentially activated by a rapid succession of opposite motion directions. PMID:18831638

  17. Processing Determinants of Reading Speed.

    ERIC Educational Resources Information Center

    Jackson, Mark D.; McClelland, James L.

    1979-01-01

    Two groups of undergraduates differing in reading ability were tested on a number of reaction-time tasks designed to determine the speed of encoding visual information at several different levels, tests of sensory functions, verbal and quantitative reasoning ability, short-term auditory memory span, and ability to comprehend spoken text.…

  18. Memory Processes in Learning Disability Subtypes of Children Born Preterm

    PubMed Central

    McCoy, Thomasin E.; Conrad, Amy L.; Richman, Lynn C.; Nopoulos, Peg C.; Bell, Edward F.

    2014-01-01

    The purpose of this study was to evaluate immediate auditory and visual memory processes in learning disability subtypes of 40 children born preterm. Three subgroups of children were examined: (a) primary language disability group (n = 13), (b) perceptual-motor disability group (n = 14), and (c) no learning disability diagnosis group without identified language or perceptual-motor learning disability (n = 13). Between-group comparisons indicate no significant differences in immediate auditory or visual memory performances between language and perceptual-motor learning disability groups. Within-group comparisons revealed that both learning disability groups performed significantly lower on a task of immediate memory when the mode of stimulus presentation and mode of response were visual. PMID:22375897

  19. Interference effects in short-term memory for timbre.

    PubMed

    Starr, G E; Pitt, M A

    1997-07-01

    Four experiments investigated memory for timbre using the interpolated-tone paradigm [Deutsch, Science 168, 1604-1605 (1970)], in which participants discriminate pairs of tones (standard and comparison) separated by intervening (interpolated) tones. Interpolated tones varied from the standard tone in spectral similarity (within-dimensional variation), fundamental frequency (cross-dimensional variation), and repetition frequency. While the latter two variables had negligible effects on timbre memory, interference with timbre memory increased with the spectral similarity of the interpolated tones to the standard tone. The findings closely parallel those found for pitch memory, and suggest that memory interference depends on perceptual similarity in both cases. PMID:9228812

  20. Conceptual Distinctiveness Supports Detailed Visual Long-Term Memory for Real-World Objects

    PubMed Central

    Konkle, Talia; Brady, Timothy F.; Alvarez, George A.; Oliva, Aude

    2012-01-01

    Humans have a massive capacity to store detailed information in visual long-term memory. The present studies explored the fidelity of these visual long-term memory representations and examined how conceptual and perceptual features of object categories support this capacity. Observers viewed 2,800 object images with a different number of exemplars presented from each category. At test, observers indicated which of 2 exemplars they had previously studied. Memory performance was high and remained quite high (82% accuracy) with 16 exemplars from a category in memory, demonstrating a large memory capacity for object exemplars. However, memory performance decreased as more exemplars were held in memory, implying systematic categorical interference. Object categories with conceptually distinctive exemplars showed less interference in memory as the number of exemplars increased. Interference in memory was not predicted by the perceptual distinctiveness of exemplars from an object category, though these perceptual measures predicted visual search rates for an object target among exemplars. These data provide evidence that observers’ capacity to remember visual information in long-term memory depends more on conceptual structure than perceptual distinctiveness. PMID:20677899

  1. Mechanical memory

    DOEpatents

    Gilkey, Jeffrey C.; Duesterhaus, Michelle A.; Peter, Frank J.; Renn, Rosemarie A.; Baker, Michael S.

    2006-08-15

    A first-in-first-out (FIFO) microelectromechanical memory apparatus (also termed a mechanical memory) is disclosed. The mechanical memory utilizes a plurality of memory cells, with each memory cell having a beam which can be bowed in either of two directions of curvature to indicate two different logic states for that memory cell. The memory cells can be arranged around a wheel which operates as a clocking actuator to serially shift data from one memory cell to the next. The mechanical memory can be formed using conventional surface micromachining, and can be formed as either a nonvolatile memory or as a volatile memory.

  2. Mechanical memory

    DOEpatents

    Gilkey, Jeffrey C.; Duesterhaus, Michelle A.; Peter, Frank J.; Renn, Rosemarie A.; Baker, Michael S.

    2006-05-16

    A first-in-first-out (FIFO) microelectromechanical memory apparatus (also termed a mechanical memory) is disclosed. The mechanical memory utilizes a plurality of memory cells, with each memory cell having a beam which can be bowed in either of two directions of curvature to indicate two different logic states for that memory cell. The memory cells can be arranged around a wheel which operates as a clocking actuator to serially shift data from one memory cell to the next. The mechanical memory can be formed using conventional surface micromachining, and can be formed as either a nonvolatile memory or as a volatile memory.

  3. Beyond Perceptual Symbols: A Call for Representational Pluralism

    ERIC Educational Resources Information Center

    Dove, Guy

    2009-01-01

    Recent evidence from cognitive neuroscience suggests that certain cognitive processes employ perceptual representations. Inspired by this evidence, a few researchers have proposed that cognition is inherently perceptual. They have developed an innovative theoretical approach that rests on the notion of perceptual simulation and marshaled several…

  4. Beyond Perceptual Symbols: A Call for Representational Pluralism

    ERIC Educational Resources Information Center

    Dove, Guy

    2009-01-01

    Recent evidence from cognitive neuroscience suggests that certain cognitive processes employ perceptual representations. Inspired by this evidence, a few researchers have proposed that cognition is inherently perceptual. They have developed an innovative theoretical approach that rests on the notion of perceptual simulation and marshaled several

  5. Perceptual Load Influences Selective Attention across Development

    ERIC Educational Resources Information Center

    Couperus, Jane W.

    2011-01-01

    Research suggests that visual selective attention develops across childhood. However, there is relatively little understanding of the neurological changes that accompany this development, particularly in the context of adult theories of selective attention, such as N. Lavie's (1995) perceptual load theory of attention. This study examined visual…

  6. Perceptual Simulation in Developing Language Comprehension

    ERIC Educational Resources Information Center

    Engelen, Jan A. A.; Bouwmeester, Samantha; de Bruin, Anique B. H.; Zwaan, Rolf A.

    2011-01-01

    We tested an embodied account of language proposing that comprehenders create perceptual simulations of the events they hear and read about. In Experiment 1, children (ages 7-13 years) performed a picture verification task. Each picture was preceded by a prerecorded spoken sentence describing an entity whose shape or orientation matched or…

  7. Infants Experience Perceptual Narrowing for Nonprimate Faces

    ERIC Educational Resources Information Center

    Simpson, Elizabeth A.; Varga, Krisztina; Frick, Janet E.; Fragaszy, Dorothy

    2011-01-01

    Perceptual narrowing--a phenomenon in which perception is broad from birth, but narrows as a function of experience--has previously been tested with primate faces. In the first 6 months of life, infants can discriminate among individual human and monkey faces. Though the ability to discriminate monkey faces is lost after about 9 months, infants…

  8. Eye Movements, Perceptual Span, and Reading Disability.

    ERIC Educational Resources Information Center

    Rayner, Keith

    1983-01-01

    Research is reviewed on eye movements during reading, on the perceptual span and control of eye movements during normal reading, and on the nature of eye movements in dyslexia. Rather than the cause of dyslexia, eye movements are said to reflect underlying cognitive or neurological problems. (CL)

  9. Perceptual dimensions for a dynamic tactile display

    NASA Astrophysics Data System (ADS)

    Pappas, Thrasyvoulos N.; Tartter, Vivien C.; Seward, Andrew G.; Genzer, Boris; Gourgey, Karen; Kretzschmar, Ilona

    2009-02-01

    We propose a new approach for converting graphical and pictorial information into tactile patterns that can be displayed in a static or dynamic tactile device. The key components of the proposed approach are (1) an algorithm that segments a scene into perceptually uniform segments; (2) a procedure for generating perceptually distinct tactile patterns; and (3) a mapping of the visual textures of the segments into tactile textures that convey similar concepts. We used existing digital halftoning and other techniques to generate a wide variety of tactile textures. We then conducted formal and informal subjective tests with sighted (but visually blocked) and visually-impaired subjects to determine the ability of human tactile perception to perceive differences among them. In addition to generating perceptually distinguishable tactile patterns, our goal is to identify significant dimensions of tactile texture perception, which will make it possible to map different visual attributes into independent tactile attributes. Our experimental results indicate that it is poosible to generate a number of perceptually distinguishable tactile patterns, and that different dimensions of tactile texture perception can indeed be identified.

  10. How visual perceptual grouping influences foot placement

    PubMed Central

    Fennell, John; Goodwin, Charlotte; Burn, Jeremy F.; Leonards, Ute

    2015-01-01

    Everybody would agree that vision guides locomotion; but how does vision influence choice when there are different solutions for possible foot placement? We addressed this question by investigating the impact of perceptual grouping on foot placement in humans. Participants performed a stepping stone task in which pathways consisted of target stones in a spatially regular path of foot falls and visual distractor stones in their proximity. Target and distractor stones differed in shape and colour so that each subset of stones could be easily grouped perceptually. In half of the trials, one target stone swapped shape and colour with a distractor in its close proximity. We show that in these ‘swapped’ conditions, participants chose the perceptually groupable, instead of the spatially regular, stepping location in over 40% of trials, even if the distance between perceptually groupable steps was substantially larger than normal step width/length. This reveals that the existence of a pathway that could be traversed without spatial disruption to periodic stepping is not sufficient to guarantee participants will select it and suggests competition between different types of visual input when choosing foot placement. We propose that a bias in foot placement choice in favour of visual grouping exists as, in nature, sudden changes in visual characteristics of the ground increase the uncertainty for stability. PMID:26587273

  11. Understanding perceptual boundaries in laparoscopic surgery.

    PubMed

    Lamata, Pablo; Gomez, Enrique J; Hernández, Félix Lamata; Oltra Pastor, Alfonso; Sanchez-Margallo, Francisco Miquel; Del Pozo Guerrero, Francisco

    2008-03-01

    Human perceptual capabilities related to the laparoscopic interaction paradigm are not well known. Its study is important for the design of virtual reality simulators, and for the specification of augmented reality applications that overcome current limitations and provide a supersensing to the surgeon. As part of this work, this article addresses the study of laparoscopic pulling forces. Two definitions are proposed to focalize the problem: the perceptual fidelity boundary, limit of human perceptual capabilities, and the Utile fidelity boundary, that encapsulates the perceived aspects actually used by surgeons to guide an operation. The study is then aimed to define the perceptual fidelity boundary of laparoscopic pulling forces. This is approached with an experimental design in which surgeons assess the resistance against pulling of four different tissues, which are characterized with both in vivo interaction forces and ex vivo tissue biomechanical properties. A logarithmic law of tissue consistency perception is found comparing subjective valorizations with objective parameters. A model of this perception is developed identifying what the main parameters are: the grade of fixation of the organ, the tissue stiffness, the amount of tissue bitten, and the organ mass being pulled. These results are a clear requirement analysis for the force feedback algorithm of a virtual reality laparoscopic simulator. Finally, some discussion is raised about the suitability of augmented reality applications around this surgical gesture. PMID:18334378

  12. Perceptual Conditioning for Decoding, 1975-1976.

    ERIC Educational Resources Information Center

    Lechowicz, Joseph S.

    The Perceptual Conditioning for Decoding Program, funded under a special grant from the New York State Legislature, was designed for the teaching of decoding as the first phase in learning to read to 1900 kindergarten through third grade students in eleven schools in Queens County, New York. For those target students not knowing the alphabet, a…

  13. Perceptual Completion in Newborn Human Infants

    ERIC Educational Resources Information Center

    Valenza, Eloisa; Leo, Irene; Gava, Lucia; Simion, Francesca

    2006-01-01

    Despite decades of studies of human infants, a still open question concerns the role of visual experience in the development of the ability to perceive complete shapes over partial occlusion. Previous studies show that newborns fail to manifest this ability, either because they lack the visual experience required for perceptual completion or…

  14. Microsaccades counteract perceptual filling-in.

    PubMed

    Troncoso, Xoana G; Macknik, Stephen L; Martinez-Conde, Susana

    2008-01-01

    Artificial scotomas positioned within peripheral dynamic noise fade perceptually during visual fixation (that is, the surrounding dynamic noise appears to fill-in the scotoma). Because the scotomas' edges are continuously refreshed by the dynamic noise background, this filling-in effect cannot be explained by low-level adaptation mechanisms (such as those that may underlie classical Troxler fading). We recently showed that microsaccades counteract Troxler fading and drive first-order visibility during fixation (S. Martinez-Conde, S. L. Macknik, X. G. Troncoso, & T. A. Dyar, 2006). Here we set out to determine whether microsaccades may counteract the perceptual filling-in of artificial scotomas and thus drive second-order visibility. If so, microsaccades may not only counteract low-level adaptation but also play a role in higher perceptual processes. We asked subjects to indicate, via button press/release, whether an artificial scotoma presented on a dynamic noise background was visible or invisible at any given time. The subjects' eye movements were simultaneously measured with a high precision video system. We found that increases in microsaccade production counteracted the perception of filling-in, driving the visibility of the artificial scotoma. Conversely, decreased microsaccades allowed perceptual filling-in to take place. Our results show that microsaccades do not solely overcome low-level adaptation mechanisms but they also contribute to maintaining second-order visibility during fixation. PMID:19146316

  15. Multielement Visual Tracking: Attention and Perceptual Organization.

    ERIC Educational Resources Information Center

    Yantis, Steven

    1992-01-01

    Presents 7 experiments with 118 undergraduates tracking multiple randomly moving visual elements under various conditions. Observers spontaneously grouped the target elements and directed attention toward this coherent nonrigid virtual object. Results support object-based theories of attention and show that perceptual grouping, a purely…

  16. Adaptive Criterion Setting in Perceptual Decision Making

    ERIC Educational Resources Information Center

    Stuttgen, Maik C.; Yildiz, Ali; Gunturkun, Onur

    2011-01-01

    Pigeons responded in a perceptual categorization task with six different stimuli (shades of gray), three of which were to be classified as "light" or "dark", respectively. Reinforcement probability for correct responses was varied from 0.2 to 0.6 across blocks of sessions and was unequal for correct light and dark responses. Introduction of a new…

  17. Improved perceptual-motor performance measurement system

    NASA Technical Reports Server (NTRS)

    Parker, J. F., Jr.; Reilly, R. E.

    1969-01-01

    Battery of tests determines the primary dimensions of perceptual-motor performance. Eighteen basic measures range from simple tests to sophisticated electronic devices. Improved system has one unit for the subject containing test display and response elements, and one for the experimenter where test setups, programming, and scoring are accomplished.

  18. Generalization of Perceptual Learning of Vocoded Speech

    ERIC Educational Resources Information Center

    Hervais-Adelman, Alexis G.; Davis, Matthew H.; Johnsrude, Ingrid S.; Taylor, Karen J.; Carlyon, Robert P.

    2011-01-01

    Recent work demonstrates that learning to understand noise-vocoded (NV) speech alters sublexical perceptual processes but is enhanced by the simultaneous provision of higher-level, phonological, but not lexical content (Hervais-Adelman, Davis, Johnsrude, & Carlyon, 2008), consistent with top-down learning (Davis, Johnsrude, Hervais-Adelman,…

  19. Infants Experience Perceptual Narrowing for Nonprimate Faces

    ERIC Educational Resources Information Center

    Simpson, Elizabeth A.; Varga, Krisztina; Frick, Janet E.; Fragaszy, Dorothy

    2011-01-01

    Perceptual narrowing--a phenomenon in which perception is broad from birth, but narrows as a function of experience--has previously been tested with primate faces. In the first 6 months of life, infants can discriminate among individual human and monkey faces. Though the ability to discriminate monkey faces is lost after about 9 months, infants

  20. Late Maturation of Auditory Perceptual Learning

    ERIC Educational Resources Information Center

    Huyck, Julia Jones; Wright, Beverly A.

    2011-01-01

    Adults can improve their performance on many perceptual tasks with training, but when does the response to training become mature? To investigate this question, we trained 11-year-olds, 14-year-olds and adults on a basic auditory task (temporal-interval discrimination) using a multiple-session training regimen known to be effective for adults. The…

  1. The Mirage of the Perceptually Handicapped Syndrome

    ERIC Educational Resources Information Center

    West, Malcolm

    1970-01-01

    Emphasize the importance of a positive diagnosis of perceptual handicap, rather than a wastebasket" diagnosis. The tendency to separate the child's handicap from his feelings about it is reflected in the treatment process. There exists little concern with the totality of the child's development in his total environment. (Author)

  2. Integration of perceptual information in word access.

    PubMed

    Richter, Tobias; Zwaan, Rolf A

    2010-01-01

    According to experiential theories of language comprehension, perceptual information plays an essential role when word meanings are accessed. We conducted four experiments to investigate how different types of perceptual information such as colour and shape are combined during word access. One possibility is that the colour and shape of a word's referent are activated independently from one another and are combined in an additive manner. Alternatively, words might activate perceptual representations via a multiplicative integration of colour and shape. Experiment 1 established that participants follow a multiplicative similarity rule when they judge the similarity of schematic pictures to actual fruits and vegetables. In Experiments 2 to 4, participants performed a classification task, a lexical decision task, or a word-naming task on names of fruits and vegetables that were superimposed on a background picture. Responses were facilitated only when both colour and shape of the picture matched the word's referents. Response times were associated negatively with mean similarity ratings and the consistency of these ratings obtained in the first experiment. These results suggest a multiplicative integration of different types of perceptual information during word access. PMID:19424906

  3. Predicting Odor Perceptual Similarity from Odor Structure

    PubMed Central

    Weiss, Tali; Frumin, Idan; Khan, Rehan M.; Sobel, Noam

    2013-01-01

    To understand the brain mechanisms of olfaction we must understand the rules that govern the link between odorant structure and odorant perception. Natural odors are in fact mixtures made of many molecules, and there is currently no method to look at the molecular structure of such odorant-mixtures and predict their smell. In three separate experiments, we asked 139 subjects to rate the pairwise perceptual similarity of 64 odorant-mixtures ranging in size from 4 to 43 mono-molecular components. We then tested alternative models to link odorant-mixture structure to odorant-mixture perceptual similarity. Whereas a model that considered each mono-molecular component of a mixture separately provided a poor prediction of mixture similarity, a model that represented the mixture as a single structural vector provided consistent correlations between predicted and actual perceptual similarity (r≥0.49, p<0.001). An optimized version of this model yielded a correlation of r = 0.85 (p<0.001) between predicted and actual mixture similarity. In other words, we developed an algorithm that can look at the molecular structure of two novel odorant-mixtures, and predict their ensuing perceptual similarity. That this goal was attained using a model that considers the mixtures as a single vector is consistent with a synthetic rather than analytical brain processing mechanism in olfaction. PMID:24068899

  4. Sustained Perceptual Deficits from Transient Sensory Deprivation

    PubMed Central

    Sanes, Dan H.

    2015-01-01

    Sensory pathways display heightened plasticity during development, yet the perceptual consequences of early experience are generally assessed in adulthood. This approach does not allow one to identify transient perceptual changes that may be linked to the central plasticity observed in juvenile animals. Here, we determined whether a brief period of bilateral auditory deprivation affects sound perception in developing and adult gerbils. Animals were reared with bilateral earplugs, either from postnatal day 11 (P11) to postnatal day 23 (P23) (a manipulation previously found to disrupt gerbil cortical properties), or from P23-P35. Fifteen days after earplug removal and restoration of normal thresholds, animals were tested on their ability to detect the presence of amplitude modulation (AM), a temporal cue that supports vocal communication. Animals reared with earplugs from P11-P23 displayed elevated AM detection thresholds, compared with age-matched controls. In contrast, an identical period of earplug rearing at a later age (P23-P35) did not impair auditory perception. Although the AM thresholds of earplug-reared juveniles improved during a week of repeated testing, a subset of juveniles continued to display a perceptual deficit. Furthermore, although the perceptual deficits induced by transient earplug rearing had resolved for most animals by adulthood, a subset of adults displayed impaired performance. Control experiments indicated that earplugging did not disrupt the integrity of the auditory periphery. Together, our results suggest that P11-P23 encompasses a critical period during which sensory deprivation disrupts central mechanisms that support auditory perceptual skills. SIGNIFICANCE STATEMENT Sensory systems are particularly malleable during development. This heightened degree of plasticity is beneficial because it enables the acquisition of complex skills, such as music or language. However, this plasticity comes with a cost: nervous system development displays an increased vulnerability to the sensory environment. Here, we identify a precise developmental window during which mild hearing loss affects the maturation of an auditory perceptual cue that is known to support animal communication, including human speech. Furthermore, animals reared with transient hearing loss display deficits in perceptual learning. Our results suggest that speech and language delays associated with transient or permanent childhood hearing loss may be accounted for, in part, by deficits in central auditory processing mechanisms. PMID:26224865

  5. The attentional boost effect and context memory.

    PubMed

    Mulligan, Neil W; Smith, S Adam; Spataro, Pietro

    2016-04-01

    Stimuli co-occurring with targets in a detection task are better remembered than stimuli co-occurring with distractors-the attentional boost effect (ABE). The ABE is of interest because it is an exception to the usual finding that divided attention during encoding impairs memory. The effect has been demonstrated in tests of item memory but it is unclear if context memory is likewise affected. Some accounts suggest enhanced perceptual encoding or associative binding, predicting an ABE on context memory, whereas other evidence suggests a more abstract, amodal basis of the effect. In Experiment 1, context memory was assessed in terms of an intramodal perceptual detail, the font and color of the study word. Experiment 2 examined context memory cross-modally, assessing memory for the modality (visual or auditory) of the study word. Experiments 3 and 4 assessed context memory with list discrimination, in which 2 study lists are presented and participants must later remember which list (if either) a test word came from. In all experiments, item (recognition) memory was also assessed and consistently displayed a robust ABE. In contrast, the attentional-boost manipulation did not enhance context memory, whether defined in terms of visual details, study modality, or list membership. There was some evidence that the mode of responding on the detection task (motoric response as opposed to covert counting of targets) may impact context memory but there was no evidence of an effect of target detection, per se. In sum, the ABE did not occur in context memory with verbal materials. (PsycINFO Database Record PMID:26348201

  6. Tactile Object Familiarity in the Blind Brain Reveals the Supramodal Perceptual-Mnemonic Nature of the Perirhinal Cortex

    PubMed Central

    Cacciamani, Laura; Likova, Lora T.

    2016-01-01

    This study is the first to investigate the neural underpinnings of tactile object familiarity in the blind during both perception and memory. In the sighted, the perirhinal cortex (PRC) has been implicated in the assessment of visual object familiarity—a crucial everyday task—as evidenced by reduced activation when an object becomes familiar. Here, to examine the PRC’s role in tactile object familiarity in the absence of vision, we trained blind participants on a unique memory-guided drawing technique and measured brain activity while they perceptually explored raised-line drawings, drew them from tactile memory, and scribbled (control). Functional magnetic resonance imaging (fMRI) before and after a week of training revealed a significant decrease in PRC activation from pre- to post-training (i.e., from unfamiliar to familiar) during perceptual exploration as well as memory-guided drawing, but not scribbling. This familiarity-based reduction is the first evidence that the PRC represents tactile object familiarity in the blind. Furthermore, the finding of this effect during both tactile perception and tactile memory provides the critical link in establishing the PRC as a structure whose representations are supramodal for both perception and memory. PMID:27148002

  7. Tactile Object Familiarity in the Blind Brain Reveals the Supramodal Perceptual-Mnemonic Nature of the Perirhinal Cortex.

    PubMed

    Cacciamani, Laura; Likova, Lora T

    2016-01-01

    This study is the first to investigate the neural underpinnings of tactile object familiarity in the blind during both perception and memory. In the sighted, the perirhinal cortex (PRC) has been implicated in the assessment of visual object familiarity-a crucial everyday task-as evidenced by reduced activation when an object becomes familiar. Here, to examine the PRC's role in tactile object familiarity in the absence of vision, we trained blind participants on a unique memory-guided drawing technique and measured brain activity while they perceptually explored raised-line drawings, drew them from tactile memory, and scribbled (control). Functional magnetic resonance imaging (fMRI) before and after a week of training revealed a significant decrease in PRC activation from pre- to post-training (i.e., from unfamiliar to familiar) during perceptual exploration as well as memory-guided drawing, but not scribbling. This familiarity-based reduction is the first evidence that the PRC represents tactile object familiarity in the blind. Furthermore, the finding of this effect during both tactile perception and tactile memory provides the critical link in establishing the PRC as a structure whose representations are supramodal for both perception and memory. PMID:27148002

  8. Time pressure affects the efficiency of perceptual processing in decisions under conflict.

    PubMed

    Dambacher, Michael; Hübner, Ronald

    2015-01-01

    The negative correlation between speed and accuracy in perceptual decision making is often explained as a tradeoff, where lowered decision boundaries under time pressure result in faster but more error-prone responses. Corresponding implementations in sequential sampling models confirmed the success of this account, which has led to the prevalent assumption that a second component of decision making, the efficiency of perceptual processing, is largely independent from temporal demands. To test the generality of this claim, we examined time pressure effects on decisions under conflict. Data from a flanker task were fit with a sequential sampling model that incorporates two successive phases of response selection, driven by the output of an early and late stage of stimulus selection, respectively. The fits revealed the canonical decrease of response boundaries with increasing time pressure. In addition, time pressure reduced the duration of non-decisional processes and impaired the early stage of stimulus selection, together with the subsequent first phase of response selection. The results show that the relation between speed and accuracy not only relies on the strategic adjustment of response boundaries but involves variations of processing efficiency. The findings support recent evidence of drift rate modulations in response to time pressure in simple perceptual decisions and confirm their validity in the context of more complex tasks. PMID:24487728

  9. A Bayesian Perceptual Model Replicates the Cutaneous Rabbit and Other Tactile Spatiotemporal Illusions

    PubMed Central

    Goldreich, Daniel

    2007-01-01

    Background When brief stimuli contact the skin in rapid succession at two or more locations, perception strikingly shrinks the intervening distance, and expands the elapsed time, between consecutive events. The origins of these perceptual space-time distortions are unknown. Methodology/Principal Findings Here I show that these illusory effects, which I term perceptual length contraction and time dilation, are emergent properties of a Bayesian observer model that incorporates prior expectation for speed. Rapidly moving stimuli violate expectation, provoking perceptual length contraction and time dilation. The Bayesian observer replicates the cutaneous rabbit illusion, the tau effect, the kappa effect, and other spatiotemporal illusions. Additionally, it shows realistic tactile temporal order judgment and spatial attention effects. Conclusions/Significance The remarkable explanatory power of this simple model supports the hypothesis, first proposed by Helmholtz, that the brain biases perception in favor of expectation. Specifically, the results suggest that the brain automatically incorporates prior expectation for speed in order to overcome spatial and temporal imprecision inherent in the sensorineural signal. PMID:17389923

  10. Attention in Active Vision: A Perspective on Perceptual Continuity Across Saccades.

    PubMed

    Rolfs, Martin

    2015-01-01

    Alfred L. Yarbus was among the first to demonstrate that eye movements actively serve our perceptual and cognitive goals, a crucial recognition that is at the heart of today's research on active vision. He realized that not the changes in fixation stick in memory but the changes in shifts of attention. Indeed, oculomotor control is tightly coupled to functions as fundamental as attention and memory. This tight relationship offers an intriguing perspective on transsaccadic perceptual continuity, which we experience despite the fact that saccades cause rapid shifts of the image across the retina. Here, I elaborate this perspective based on a series of psychophysical findings. First, saccade preparation shapes the visual system's priorities; it enhances visual performance and perceived stimulus intensity at the targets of the eye movement. Second, before saccades, the deployment of visual attention is updated, predictively facilitating perception at those retinal locations that will be relevant once the eyes land. Third, saccadic eye movements strongly affect the contents of visual memory, highlighting their crucial role for which parts of a scene we remember or forget. Together, these results provide insights on how attentional processes enable the visual system to cope with the retinal consequences of saccades. PMID:26562908

  11. The working memory Ponzo illusion: Involuntary integration of visuospatial information stored in visual working memory.

    PubMed

    Shen, Mowei; Xu, Haokui; Zhang, Haihang; Shui, Rende; Zhang, Meng; Zhou, Jifan

    2015-08-01

    Visual working memory (VWM) has been traditionally viewed as a mental structure subsequent to visual perception that stores the final output of perceptual processing. However, VWM has recently been emphasized as a critical component of online perception, providing storage for the intermediate perceptual representations produced during visual processing. This interactive view holds the core assumption that VWM is not the terminus of perceptual processing; the stored visual information rather continues to undergo perceptual processing if necessary. The current study tests this assumption, demonstrating an example of involuntary integration of the VWM content, by creating the Ponzo illusion in VWM: when the Ponzo illusion figure was divided into its individual components and sequentially encoded into VWM, the temporally separated components were involuntarily integrated, leading to the distorted length perception of the two horizontal lines. This VWM Ponzo illusion was replicated when the figure components were presented in different combinations and presentation order. The magnitude of the illusion was significantly correlated between VWM and perceptual versions of the Ponzo illusion. These results suggest that the information integration underling the VWM Ponzo illusion is constrained by the laws of visual perception and similarly affected by the common individual factors that govern its perception. Thus, our findings provide compelling evidence that VWM functions as a buffer serving perceptual processes at early stages. PMID:25912893

  12. The Neurobiology of Semantic Memory

    PubMed Central

    Binder, Jeffrey R.; Desai, Rutvik H.

    2011-01-01

    Semantic memory includes all acquired knowledge about the world and is the basis for nearly all human activity, yet its neurobiological foundation is only now becoming clear. Recent neuroimaging studies demonstrate two striking results: the participation of modality-specific sensory, motor, and emotion systems in language comprehension, and the existence of large brain regions that participate in comprehension tasks but are not modality-specific. These latter regions, which include the inferior parietal lobe and much of the temporal lobe, lie at convergences of multiple perceptual processing streams. These convergences enable increasingly abstract, supramodal representations of perceptual experience that support a variety of conceptual functions including object recognition, social cognition, language, and the remarkable human capacity to remember the past and imagine the future. PMID:22001867

  13. Solid State Memory Study Final Report

    NASA Technical Reports Server (NTRS)

    Katti, R.

    1994-01-01

    Existing and future solid state nonvolatile memory technologies are described and evaluated in this report. Solid state memory technologies can offer size, speed, power, weight, and ruggedness advantages over conventional moving media storage technologoies such as disk or tape. This technology list is a broad sampling of past, present, emerging, and future solid state memory technologies.

  14. Does Perceptual-Motor Calibration Generalize across Two Different Forms of Locomotion? Investigations of Walking and Wheelchairs

    PubMed Central

    Kunz, Benjamin R.; Creem-Regehr, Sarah H.; Thompson, William B.

    2013-01-01

    The relationship between biomechanical action and perception of self-motion during walking is typically consistent and well-learned but also adaptable. This perceptual-motor coupling can be recalibrated by creating a mismatch between the visual information for self-motion and walking speed. Perceptual-motor recalibration of locomotion has been demonstrated through effects on subsequent walking without vision, showing that learned perceptual-motor coupling influences a dynamic representation of one's spatial position during walking. Our present studies test whether recalibration of wheelchair locomotion, a novel form of locomotion for typically walking individuals, similarly influences subsequent wheelchair locomotion. Furthermore, we test whether adaptation to the pairing of visual information for self-motion during one form of locomotion transfers to a different locomotion modality. We find strong effects of perceptual-motor recalibration for matched locomotion modalities – walking/walking and wheeling/wheeling. Transfer across incongruent locomotion modalities showed weak recalibration effects. The results have implications both for theories of perceptual-motor calibration mechanisms and their effects on spatial orientation, as well as for practical applications in training and rehabilitation. PMID:23424615

  15. The role of memory in guiding attention during natural vision.

    PubMed

    Carmi, Ran; Itti, Laurent

    2006-01-01

    What is the time frame in which perceptual memory guides attention? Current estimates range from a few hundred milliseconds to several seconds, minutes, or even days. Here, we answer this question by establishing the time course of attentional selection in realistic viewing conditions. First, we transformed continuous video clips into MTV-style video clips by stringing together continuous clip segments using abrupt transitions (jump cuts). We then asked participants to visually explore either continuous or MTV-style clips and recorded their saccades as objective behavioral indicators of attentional selections. The utilization of perceptual memory was estimated across viewing conditions and over time by quantifying the agreement between human attentional selections and predictions made by a neurally grounded computational model. In the critical condition, jump cuts led to sharp declines in the impact of perceptual memory on attentional selection, followed by monotonic increases in memory utilization across seven consecutive saccades and 2.5 s. These results demonstrate that perceptual memory traces play an important role in guiding attention across several saccades during natural vision. We propose novel hypotheses and experiments using hybrid natural-artificial stimuli to further elucidate neurocomputational mechanisms of attentional selection. PMID:17083283

  16. Birth of projection neurons in adult avian brain may be related to perceptual or motor learning

    SciTech Connect

    Alvarez-Buylla, A.; Kirn, J.R.; Nottebohm, F. )

    1990-09-21

    Projection neurons that form part of the motor pathway for song control continue to be produced and to replace older projection neurons in adult canaries and zebra finches. This is shown by combining (3H)thymidine, a cell birth marker, and fluorogold, a retrogradely transported tracer of neuronal connectivity. Species and seasonal comparisons suggest that this process is related to the acquisition of perceptual or motor memories. The ability of an adult brain to produce and replace projection neurons should influence our thinking on brain repair.

  17. Monocular depth effects on perceptual fading.

    PubMed

    Hsu, Li-Chuan; Kramer, Peter; Yeh, Su-Ling

    2010-08-01

    After prolonged viewing, a static target among moving non-targets is perceived to repeatedly disappear and reappear. An uncrossed stereoscopic disparity of the target facilitates this Motion-Induced Blindness (MIB). Here we test whether monocular depth cues can affect MIB too, and whether they can also affect perceptual fading in static displays. Experiment 1 reveals an effect of interposition: more MIB when the target appears partially covered by, than when it appears to cover, its surroundings. Experiment 2 shows that the effect is indeed due to interposition and not to the target's contours. Experiment 3 induces depth with the watercolor illusion and replicates Experiment 1. Experiments 4 and 5 replicate Experiments 1 and 3 without the use of motion. Since almost any stimulus contains a monocular depth cue, we conclude that perceived depth affects perceptual fading in almost any stimulus, whether dynamic or static. PMID:20580732

  18. Perceptual color image coding with JPEG2000.

    PubMed

    Tan, D M; Tan, C S; Wu, H R

    2010-02-01

    A perceptual color image coder (PCIC) is presented for the YC(b)C(r) color space within the framework of JPEG2000. This coder employs a vision model based perceptual distortion metric (PDM) to approximate perceived error for rate-distortion (R-D) optimization in order to maximize the visual quality of coded images. The vision model employed in the PCIC is structurally based on an existing monochromatic multichannel vision model, which is extended for color image coding. Subjective tests with 30 viewers show that the PCIC provides superior picture quality at low to intermediate bitrates in comparison with a JPEG2000 compliant coder employing the mean squared error (MSE) and the visual distortion metric (Cvis) as distortion measures, respectively. PMID:20083452

  19. A perceptual metric for photo retouching.

    PubMed

    Kee, Eric; Farid, Hany

    2011-12-13

    In recent years, advertisers and magazine editors have been widely criticized for taking digital photo retouching to an extreme. Impossibly thin, tall, and wrinkle- and blemish-free models are routinely splashed onto billboards, advertisements, and magazine covers. The ubiquity of these unrealistic and highly idealized images has been linked to eating disorders and body image dissatisfaction in men, women, and children. In response, several countries have considered legislating the labeling of retouched photos. We describe a quantitative and perceptually meaningful metric of photo retouching. Photographs are rated on the degree to which they have been digitally altered by explicitly modeling and estimating geometric and photometric changes. This metric correlates well with perceptual judgments of photo retouching and can be used to objectively judge by how much a retouched photo has strayed from reality. PMID:22123980

  20. Perceptual Spaces: Mathematical Structures to Neural Mechanisms

    PubMed Central

    Victor, Jonathan; McDermott, Josh; Geffen, Maria; Bensmaia, Sliman; Cleland, Thomas A.

    2013-01-01

    A central goal of neuroscience is to understand how populations of neurons build and manipulate representations of percepts that provide useful information about the environment. This symposium explores the fundamental properties of these representations and the perceptual spaces in which they are organized. Spanning the domains of color, visual texture, environmental sound, music, tactile quality, and odor, we show how the geometric structures of perceptual spaces can be determined experimentally and how these structures provide insights into the principles of neural coding and the neural mechanisms that generate the codes, and into the neural processing of complex sensory stimuli. The diversity of the neural architecture in these different sensory systems provides an opportunity to compare their different solutions to common problems: the need for dimensionality reduction, strategies for topographic or nontopographic mapping, the utility of the higher-order statistical structure inherent in natural sensory stimuli, and the constraints of neural hardware. PMID:24198350

  1. Unconsciously learning task-irrelevant perceptual sequences.

    PubMed

    Guo, Xiuyan; Jiang, Shan; Wang, Hongyi; Zhu, Lei; Tang, Jinghua; Dienes, Zoltan; Yang, Zhiliang

    2013-03-01

    We demonstrated unconscious learning of task-irrelevant perceptual regularities in a Serial Reaction Time (SRT) task in both visual and auditory domains. Participants were required to respond to different letters ('F' or 'J', experiment 1) or syllables ('can' or 'you', experiment 2) which occurred in random order. Unbeknownst to participants, the color (red, green, blue or yellow) of the two letters or the tone (1-4) of the syllables varied according to certain rules. Reaction times indicated that people indeed learnt both the color and tonal regularities indicating that task-irrelevant sequence structure can be learned perceptually. In a subsequent prediction test of knowledge of the color or tonal cues using subjective measures, we showed that people could acquire task irrelevant knowledge unconsciously. PMID:23318647

  2. Perceptual Grouping of Object Contours Survives Saccades

    PubMed Central

    Demeyer, Maarten; De Graef, Peter; Verfaillie, Karl; Wagemans, Johan

    2011-01-01

    Human observers explore scenes by shifting their gaze from object to object. Before each eye movement, a peripheral glimpse of the next object to be fixated has however already been caught. Here we investigate whether the perceptual organization extracted from such a preview could guide the perceptual analysis of the same object during the next fixation. We observed that participants were indeed significantly faster at grouping together spatially separate elements into an object contour, when the same contour elements had also been grouped together in the peripheral preview display. Importantly, this facilitation occurred despite a change in the grouping cue defining the object contour (similarity versus collinearity). We conclude that an intermediate-level description of object shape persists in the visual system across gaze shifts, providing it with a robust basis for balancing efficiency and continuity during scene exploration. PMID:21713007

  3. A perceptual metric for photo retouching

    PubMed Central

    Kee, Eric; Farid, Hany

    2011-01-01

    In recent years, advertisers and magazine editors have been widely criticized for taking digital photo retouching to an extreme. Impossibly thin, tall, and wrinkle- and blemish-free models are routinely splashed onto billboards, advertisements, and magazine covers. The ubiquity of these unrealistic and highly idealized images has been linked to eating disorders and body image dissatisfaction in men, women, and children. In response, several countries have considered legislating the labeling of retouched photos. We describe a quantitative and perceptually meaningful metric of photo retouching. Photographs are rated on the degree to which they have been digitally altered by explicitly modeling and estimating geometric and photometric changes. This metric correlates well with perceptual judgments of photo retouching and can be used to objectively judge by how much a retouched photo has strayed from reality. PMID:22123980

  4. Perceptual uniformity of commonly used color spaces

    NASA Astrophysics Data System (ADS)

    Avanaki, Ali; Espig, Kathryn; Kimpe, Tom; Xthona, Albert; Marchessoux, Cedric; Rostang, Johan; Piepers, Bastian

    2014-03-01

    Use of color images in medical imaging has increased significantly the last few years. Color information is essential for applications such as ophthalmology, dermatology and clinical photography. Use of color at least brings benefits for other applications such as endoscopy, laparoscopy and digital pathology. Remarkably, as of today, there is no agreed standard on how color information needs to be visualized for medical applications. This lack of standardization results in large variability of how color images are visualized and it makes quality assurance a challenge. For this reason FDA and ICC recently organized a joint summit on color in medical imaging (CMI). At this summit, one of the suggestions was that modalities such as digital pathology could benefit from using a perceptually uniform color space (T. Kimpe, "Color Behavior of Medical Displays," CMI presentation, May 2013). Perceptually uniform spaces have already been used for many years in the radiology community where the DICOM GSDF standard provides linearity in luminance but not in color behavior. In this paper we quantify perceptual uniformity, using CIE's ΔE2000 as a color distance metric, of several color spaces that are typically used for medical applications. We applied our method to theoretical color spaces Gamma 1.8, 2.0, & 2.2, standard sRGB, and DICOM (correction LUT for gray applied to all primaries). In addition, we also measured color spaces (i.e., native behavior) of a high-end medical display (Barco Coronis Fusion 6MP DL, MDCC-6130), and a consumer display (Dell 1907FP). Our results indicate that sRGB & the native color space on the Barco Coronis Fusion exhibit the least non-uniformity within their group. However, the remaining degree of perceptual non-uniformity is still significant and there is room for improvement.

  5. The limits of arousal's memory impairing effects on nearby information

    PubMed Central

    Mather, Mara; Gorlick, Marissa; Nesmith, Kathryn

    2009-01-01

    Showing an arousing central stimulus in a scene often leads to enhanced memory for the arousing central information and impaired memory for peripheral details. However, it is not clear from previous work whether arousing stimuli impair memory for all non-arousing nearby information or just background information. In several experiments, we tested how emotionally arousing pictures affect memory for nearby pictures and for background information. We found that when two pictures were presented together, having one of the pictures be arousing did not affect item and location memory for the other picture. In contrast, an arousing picture impaired memory for a background pattern. These findings suggest that arousal impairs memory for information that is the target of perceptual suppression, such as background information when there is a figure-ground distinction, but does not impair memory for other foreground information. PMID:19827704

  6. Aging, source memory, and the experience of "remembering".

    PubMed

    Kuhlmann, Beatrice G; Boywitt, C Dennis

    2016-07-01

    In a previous study, we found source memory for perceptual features to differentiate between younger but not older adults' reports of recollective ("remember"; R) and "know" (K) experiences. In two experiments with younger (17-30 years) and older (64-81 years) participants, we examined whether memory for meaningful speaker sources would accompany older adults' recollective experience. Indeed, memory for male and female speakers (but not partial memory for gender; Experiment 1) as well as bound memory for speakers and their facial expressions (Experiment 2) distinguished between both younger and older adults' RK reports. Thus, memory for some sources forms a common basis for younger and older adults' retrieval experience. Nonetheless, older adults still showed lower objective source memory and lower subjective source-attribution confidence than younger adults when reporting recollective experiences, suggesting that source memory is less relevant to their retrieval experience than for younger adults. PMID:26653292

  7. Atypicalities in Perceptual Adaptation in Autism Do Not Extend to Perceptual Causality

    PubMed Central

    Karaminis, Themelis; Turi, Marco; Neil, Louise; Badcock, Nicholas A.; Burr, David; Pellicano, Elizabeth

    2015-01-01

    A recent study showed that adaptation to causal events (collisions) in adults caused subsequent events to be less likely perceived as causal. In this study, we examined if a similar negative adaptation effect for perceptual causality occurs in children, both typically developing and with autism. Previous studies have reported diminished adaptation for face identity, facial configuration and gaze direction in children with autism. To test whether diminished adaptive coding extends beyond high-level social stimuli (such as faces) and could be a general property of autistic perception, we developed a child-friendly paradigm for adaptation of perceptual causality. We compared the performance of 22 children with autism with 22 typically developing children, individually matched on age and ability (IQ scores). We found significant and equally robust adaptation aftereffects for perceptual causality in both groups. There were also no differences between the two groups in their attention, as revealed by reaction times and accuracy in a change-detection task. These findings suggest that adaptation to perceptual causality in autism is largely similar to typical development and, further, that diminished adaptive coding might not be a general characteristic of autism at low levels of the perceptual hierarchy, constraining existing theories of adaptation in autism. PMID:25774507

  8. Self-stimulatory behavior and perceptual reinforcement.

    PubMed Central

    Lovaas, I; Newsom, C; Hickman, C

    1987-01-01

    Self-stimulatory behavior is repetitive, stereotyped, functionally autonomous behavior seen in both normal and developmentally disabled populations, yet no satisfactory theory of its development and major characteristics has previously been offered. We present here a detailed hypothesis of the acquisition and maintenance of self-stimulatory behavior, proposing that the behaviors are operant responses whose reinforcers are automatically produced interoceptive and exteroceptive perceptual consequences. The concept of perceptual stimuli and reinforcers, the durability of self-stimulatory behaviors, the sensory extinction effect, the inverse relationship between self-stimulatory and other behaviors, the blocking effect of self-stimulatory behavior on new learning, and response substitution effects are discussed in terms of the hypothesis. Support for the hypothesis from the areas of sensory reinforcement and sensory deprivation is also reviewed. Limitations of major alternative theories are discussed, along with implications of the perceptual reinforcement hypothesis for the treatment of excessive self-stimulatory behavior and for theoretical conceptualizations of functionally related normal and pathological behaviors. PMID:3583964

  9. Perceptual and Neural Olfactory Similarity in Honeybees

    PubMed Central

    2005-01-01

    The question of whether or not neural activity patterns recorded in the olfactory centres of the brain correspond to olfactory perceptual measures remains unanswered. To address this question, we studied olfaction in honeybees Apis mellifera using the olfactory conditioning of the proboscis extension response. We conditioned bees to odours and tested generalisation responses to different odours. Sixteen odours were used, which varied both in their functional group (primary and secondary alcohols, aldehydes and ketones) and in their carbon-chain length (from six to nine carbons).The results obtained by presentation of a total of 16 × 16 odour pairs show that (i) all odorants presented could be learned, although acquisition was lower for short-chain ketones; (ii) generalisation varied depending both on the functional group and the carbon-chain length of odours trained; higher generalisation was found between long-chain than between short-chain molecules and between groups such as primary and secondary alcohols; (iii) for some odour pairs, cross-generalisation between odorants was asymmetric; (iv) a putative olfactory space could be defined for the honeybee with functional group and carbon-chain length as inner dimensions; (v) perceptual distances in such a space correlate well with physiological distances determined from optophysiological recordings of antennal lobe activity. We conclude that functional group and carbon-chain length are inner dimensions of the honeybee olfactory space and that neural activity in the antennal lobe reflects the perceptual quality of odours. PMID:15736975

  10. Brightness and darkness as perceptual dimensions.

    PubMed

    Vladusich, Tony; Lucassen, Marcel P; Cornelissen, Frans W

    2007-10-01

    A common-sense assumption concerning visual perception states that brightness and darkness cannot coexist at a given spatial location. One corollary of this assumption is that achromatic colors, or perceived grey shades, are contained in a one-dimensional (1-D) space varying from bright to dark. The results of many previous psychophysical studies suggest, by contrast, that achromatic colors are represented as points in a color space composed of two or more perceptual dimensions. The nature of these perceptual dimensions, however, presently remains unclear. Here we provide direct evidence that brightness and darkness form the dimensions of a two-dimensional (2-D) achromatic color space. This color space may play a role in the representation of object surfaces viewed against natural backgrounds, which simultaneously induce both brightness and darkness signals. Our 2-D model generalizes to the chromatic dimensions of color perception, indicating that redness and greenness (blueness and yellowness) also form perceptual dimensions. Collectively, these findings suggest that human color space is composed of six dimensions, rather than the conventional three. PMID:18237226

  11. Perceptual inferences about indeterminate arrangements of figures.

    PubMed

    Moreno-Ríos, Sergio; Rojas-Barahona, Cristian A; García-Madruga, Juan A

    2014-05-01

    Previous studies in spatial propositional reasoning showed that adults use a particular strategy for making representations and inferences from indeterminate descriptions (those consistent with different alternatives). They do not initially represent all the alternatives, but construct a unified mental representation that includes a kind of mental footnote. Only when the task requires access to alternatives is the unified representation re-inspected. The degree of generalisation of this proposal to other perceptual situations was evaluated in three experiments with children, adolescents and adults, using a perceptual inference task with diagrammatic premises that gave information about the location of one of three possible objects. Results obtained with this very quick perceptual task support the kind of representation proposed from propositional spatial reasoning studies. However, children and adults differed in accuracy, with the results gradually changing with age: indeterminacy leads adults to require extra time for understanding and inferring alternatives, whereas children commit errors. These results could help inform us of how people can make inferences from diagrammatic information and make wrong interpretations. PMID:24607441

  12. Perceptual limits in a simulated "Cocktail party".

    PubMed

    Kawashima, Takayuki; Sato, Takao

    2015-08-01

    Numerosity judgments of simultaneous talkers were examined. Listeners were required to report the number of talkers heard when this number varied (1 to 13). Spatial location of talkers (1 or 6 locations), duration of talker voices (0.8 s, 5.0 s, and 15.0 s), and gender arrangement of talkers also were manipulated in four experiments. In all experiments, the proportion of correct numerosity judgments monotonically decreased as talker numbers increased. Perceptual limits, defined as talker numbers with proportion correct scores of 0.5, varied between 3 to 5 talkers, on average, depending on listening conditions, and were significantly higher for spatially separated talkers, for the longer voices, and for the mixed gender voices (Experiments 1, 2, and 3). In addition, Experiment 4 found that average numerosity response times increased monotonically over a range of one to four talkers. These results support the idea that, before counting talkers, listeners perceptually segregate talkers to render numerosity judgments. They also suggest that our functional auditory world for simultaneous voices may consist of, at most, three to five talkers depending on listening situations. In light of these results, possible causes for such perceptual limits are discussed. PMID:25962457

  13. Learning problems, delayed perceptual development, and puberty

    NASA Astrophysics Data System (ADS)

    Wright, Beverly A.; Zecker, Steven G.; Reid, Miriam D.

    2003-04-01

    Language-based learning problems affect approximately one person in twelve with no other obvious signs of disorder. Many of these individuals have accompanying deficits in nonlinguistic perception. To determine whether age influences the magnitude of these deficits, thresholds on a set of auditory masking tasks were measured in individuals with learning problems and controls ranging in age from 6 years to adult. Performance improved with increasing age in both groups. However, the thresholds of the individuals with learning problems were most similar to those of controls approximately 2-4 years younger on every task, suggesting that the perceptual development of the affected individuals was delayed by a constant amount. Further, on the subset of conditions on which controls reached adult levels of performance after 10 years of age, the improvement of affected individuals halted at 10 years of age, suggesting that puberty may play a critical role in human perceptual development. Taken together, these data support the idea that some learning problems result from a neuromaturational delay, of unknown breadth, and indicate that neurological changes associated with puberty prevent the complete resolution of delayed perceptual development. [Work supported by NIH/NIDCD.

  14. Perceptual Consequences of Hidden Hearing Loss

    PubMed Central

    Barker, Daphne; Prendergast, Garreth

    2014-01-01

    Dramatic results from recent animal experiments show that noise exposure can cause a selective loss of high-threshold auditory nerve fibers without affecting absolute sensitivity permanently. This cochlear neuropathy has been described as hidden hearing loss, as it is not thought to be detectable using standard measures of audiometric threshold. It is possible that hidden hearing loss is a common condition in humans and may underlie some of the perceptual deficits experienced by people with clinically normal hearing. There is some evidence that a history of noise exposure is associated with difficulties in speech discrimination and temporal processing, even in the absence of any audiometric loss. There is also evidence that the tinnitus experienced by listeners with clinically normal hearing is associated with cochlear neuropathy, as measured using Wave I of the auditory brainstem response. To date, however, there has been no direct link made between noise exposure, cochlear neuropathy, and perceptual difficulties. Animal experiments also reveal that the aging process itself, in the absence of significant noise exposure, is associated with loss of auditory nerve fibers. Evidence from human temporal bone studies and auditory brainstem response measures suggests that this form of hidden loss is common in humans and may have perceptual consequences, in particular, regarding the coding of the temporal aspects of sounds. Hidden hearing loss is potentially a major health issue, and investigations are ongoing to identify the causes and consequences of this troubling condition. PMID:25204468

  15. Acoustic and perceptual correlates of syllable weight

    NASA Astrophysics Data System (ADS)

    Gordon, Matthew; Jany, Carmen; Nash, Carlos

    2005-09-01

    Differences between languages in the stress-attracting properties of various syllable types (syllable weight) are associated with phonetic differences. Certain languages that preferentially stress CVC syllables (i.e., treat CVC as heavy) fail to display substantial vowel shortening in CVC, unlike languages that treat CVC as non-stress-attracting or light [Broselow et al. (1997)]. Furthermore, CVC has greater energy (intensity integrated over time) in languages in which it is heavy relative to languages with light CVC [Gordon (2002)]. This paper compares multiple potential acoustic and perceptual correlates of syllable weight. A representative cross section of syllable types in words uttered by speakers of four languages was recorded. In two languages (Arabic, Hindi), CVC is heavy; in two languages (Mongolian, Malayalam), CVC is light. Three measurements were taken: duration of the syllable rime, acoustic intensity integrated over the rime, and a measure of perceptual energy of the rime incorporating various factors (e.g., temporal integration and adaptation, bandpass filtering). Results thus far indicate that a measure of prominence factoring in both intensity and duration better distinguishes languages on the basis of weight criterion than a simple measure of duration. The perceptual energy measure provides a slightly better fit than acoustic energy. [Work supported by NSF.

  16. Speeding up local correlation methods

    SciTech Connect

    Kats, Daniel

    2014-12-28

    We present two techniques that can substantially speed up the local correlation methods. The first one allows one to avoid the expensive transformation of the electron-repulsion integrals from atomic orbitals to virtual space. The second one introduces an algorithm for the residual equations in the local perturbative treatment that, in contrast to the standard scheme, does not require holding the amplitudes or residuals in memory. It is shown that even an interpreter-based implementation of the proposed algorithm in the context of local MP2 method is faster and requires less memory than the highly optimized variants of conventional algorithms.

  17. Audiovisual speech perception development at varying levels of perceptual processing.

    PubMed

    Lalonde, Kaylah; Holt, Rachael Frush

    2016-04-01

    This study used the auditory evaluation framework [Erber (1982). Auditory Training (Alexander Graham Bell Association, Washington, DC)] to characterize the influence of visual speech on audiovisual (AV) speech perception in adults and children at multiple levels of perceptual processing. Six- to eight-year-old children and adults completed auditory and AV speech perception tasks at three levels of perceptual processing (detection, discrimination, and recognition). The tasks differed in the level of perceptual processing required to complete them. Adults and children demonstrated visual speech influence at all levels of perceptual processing. Whereas children demonstrated the same visual speech influence at each level of perceptual processing, adults demonstrated greater visual speech influence on tasks requiring higher levels of perceptual processing. These results support previous research demonstrating multiple mechanisms of AV speech processing (general perceptual and speech-specific mechanisms) with independent maturational time courses. The results suggest that adults rely on both general perceptual mechanisms that apply to all levels of perceptual processing and speech-specific mechanisms that apply when making phonetic decisions and/or accessing the lexicon. Six- to eight-year-old children seem to rely only on general perceptual mechanisms across levels. As expected, developmental differences in AV benefit on this and other recognition tasks likely reflect immature speech-specific mechanisms and phonetic processing in children. PMID:27106318

  18. Exploring the perceptual spaces of faces, cars and birds in children and adults

    PubMed Central

    Tanaka, James W.; Meixner, Tamara L.; Kantner, Justin

    2011-01-01

    While much developmental research has focused on the strategies that children employ to recognize faces, less is known about the principles governing the organization of face exemplars in perceptual memory. In this study, we tested a novel, child-friendly paradigm for investigating the organization of face, bird and car exemplars. Children ages 3–4, 5–6, 7–8, 9–10, 11–12 and adults were presented with 50/50 morphs of typical and atypical face, bird and car parent images. Participants were asked to judge whether the 50/50 morph more strongly resembled the typical or the atypical parent image. Young and older children and adults showed a systematic bias to the atypical faces and birds, but no bias toward the atypical cars. Collectively, these findings argue that by the age of 3, children encode and organize faces, birds and cars in a perceptual space that is strikingly similar to that of adults. Category organization for both children and adults follows Krumhansl’s (1978) distance-density principle in which the similarity between two exemplars is jointly determined by their physical appearance and the density of neighboring exemplars in the perceptual space. PMID:21676096

  19. Memory Matters

    MedlinePLUS

    ... different parts. Some of them are important for memory. The hippocampus (say: hih-puh-KAM-pus) is one of the more important parts of the brain that processes memories. Old information and new information, or memories, are ...

  20. Conceptual Distinctiveness Supports Detailed Visual Long-Term Memory for Real-World Objects

    ERIC Educational Resources Information Center

    Konkle, Talia; Brady, Timothy F.; Alvarez, George A.; Oliva, Aude

    2010-01-01

    Humans have a massive capacity to store detailed information in visual long-term memory. The present studies explored the fidelity of these visual long-term memory representations and examined how conceptual and perceptual features of object categories support this capacity. Observers viewed 2,800 object images with a different number of exemplars…