Science.gov

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. 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…

  3. 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…

  4. 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…

  5. 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…

  6. 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…

  7. 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…

  8. 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

  9. 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 all stages 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 that the 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 a memory 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

  10. 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

  11. 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

  12. 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…

  13. 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…

  14. The perceptual richness of complex memory episodes is compromised by medial temporal lobe damage.

    PubMed

    St-Laurent, Marie; Moscovitch, Morris; Jadd, Rachel; McAndrews, Mary Pat

    2014-05-01

    Perceptual richness, a defining feature of episodic memory, emerges from the reliving of multimodal sensory experiences. Although the importance of the medial temporal lobe (MTL) to episodic memory retrieval is well documented, the features that determine its engagement are not well characterized. The current study assessed the relationship between MTL function and episodic memory's perceptual richness. We designed a laboratory memory task meant to capture the complexity of memory for life episodes, while manipulating memory's perceptual content. Participants encoded laboratory episodes with rich (film clips) and impoverished (written narratives) perceptual content that were matched for other characteristics such as personal significance, emotionality and story content. At retrieval, participants were probed to describe the stories' perceptual features and storyline. Participants also recalled autobiographical memories (AMs) in a comparison condition. We compared the performance of patients with unilateral medial temporal lobe epilepsy (mTLE) and healthy controls to assess how damage to the MTL affects retrieval in these conditions. We observed an overall decrease in detail count in the mTLE group, along with a disproportionate deficit in perceptual details that was most acute in the AM and the perceptually enriched film clip conditions. Our results suggest that the impaired sense of reliving the past that accompanies MTL insult is mediated by a paucity of perceptual episodic memory details. We also introduce a new protocol that successfully mimics naturalistic memories while benefiting from the experimental control provided by using laboratory stimuli. PMID:24449286

  15. 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…

  16. 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…

  17. 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

  18. Perceptual asymmetries are preserved in short-term memory tasks

    PubMed Central

    Montaser-Kouhsari, Leila; Carrasco, Marisa

    2013-01-01

    Visual performance is heterogeneous at isoeccentric locations; it is better on the horizontal than on the vertical meridian and worse at the upper than at the lower region of the vertical meridian (Carrasco, Talgar, & Cameron, 2001; Talgar & Carrasco, 2002). It is unknown whether these performance inhomogeneities are also present in spatial frequency tasks and whether asymmetries present during encoding of visual information also emerge in visual short-term memory (VSTM) tasks. Here, we investigated the similarity of the perceptual and VSTM tasks in spatial frequency discrimination (Experiments 1 and 2) and perceived spatial frequency (Experiments 3 and 4). We found that (1) performance in both simultaneous (perceptual) and delayed (VSTM) spatial frequency discrimination tasks varies as a function of location; it is better along the horizontal than along the vertical meridian; and (2) perceived spatial frequency in both tasks is higher along the horizontal than along the vertical meridian. These results suggest that perceived spatial frequency may mediate performance differences in VSTM tasks across the visual field, implying that the quality with which we encode information affects VSTM. PMID:19933562

  19. 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…

  20. 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…

  1. 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

  2. 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

  3. 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

  4. 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

  5. Selection and Storage of Perceptual Groups Is Constrained by a Discrete Resource in Working Memory

    ERIC Educational Resources Information Center

    Anderson, David E.; Vogel, Edward K.; Awh, Edward

    2013-01-01

    Perceptual grouping can lead observers to perceive a multielement scene as a smaller number of hierarchical units. Past work has shown that grouping enables more elements to be stored in visual working memory (WM). Although this may appear to contradict so-called discrete resource models that argue for fixed item limits in WM storage, it is also…

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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.

  11. 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…

  12. 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…

  13. Working Memory Does Not Dissociate between Different Perceptual Categorization Tasks

    ERIC Educational Resources Information Center

    Lewandowsky, Stephan; Yang, Lee-Xieng; Newell, Ben R.; Kalish, Michael L.

    2012-01-01

    Working memory is crucial for many higher level cognitive functions, ranging from mental arithmetic to reasoning and problem solving. Likewise, the ability to learn and categorize novel concepts forms an indispensable part of human cognition. However, very little is known about the relationship between working memory and categorization. This…

  14. 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

  15. 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

  16. A memory and speed efficient CAVLC decoder

    NASA Astrophysics Data System (ADS)

    Qin, Xing; Yan, Xiaolang

    2005-07-01

    A memory and speed efficient CAVLC (context adaptive variable length coding) decoder for H.264/AVC baseline profile is proposed. Because the CAVLC consists of a kind of bit-level operations, general processor (like RISC or MIPS) and DSP incorporating multiple parallel arithmetic units (like SIMD or VLIW) are ineffective to decode it. Though the dedicated hardwires are very effective to decode the CAVLC, they are expensive and not programmable. Also, the size of the CAVLC lookup table is more than 400 bytes. Demand for highly flexible and fast implementations and lower memory size for CAVLC decoding is rising nowadays. The four instructions-ShowBits, GetBits, FlushBits and LeadingBits, are designed after the exploiting of the functions coverage. In order to reduce the codewords matching miss and the lookup table size, a new grouping, remainder generation method and a merged lookup table (LUT) are used; and the specific group decoding instruction GroupDecoding is also presented. In summary, a based instruction set level acceleration with the codewords group partition hardware architecture is proposed to speed up the CAVLC decoding. Based on those instructions and the hardware platform, the CAVLC decoding can be significantly accelerated compared with the method in H.264 reference software. Simulation results show that the architecture is sufficient for the CAVLC decoding of 30 frames HDTV (1902 × 1080 pixels) per second.

  17. Similarity-based distortion of visual short-term memory is due to perceptual averaging

    PubMed Central

    Dubé, Chad; Zhou, Feng; Kahana, Michael J.; Sekuler, Robert

    2014-01-01

    A task-irrelevant stimulus can distort recall from visual short-term memory (VSTM). Specifically, reproduction of a task-relevant memory item is biased in the direction of the irrelevant memory item (Huang and Sekuler, 2010a). The present study addresses the hypothesis that such effects reflect the influence of neural averaging under conditions of uncertainty about the contents of VSTM (Alvarez, 2011; Ball and Sekuler, 1980). We manipulated subjects’ attention to relevant and irrelevant study items whose similarity relationships were held constant, while varying how similar the study items were to a subsequent recognition probe. On each trial, subjects were shown one or two Gabor patches, followed by the probe; their task was to indicate whether the probe matched one of the study items. A brief cue told subjects which Gabor, first or second, would serve as that trial’s target item. Critically, this cue appeared either before, between, or after the study items. A distributional analysis of the resulting mnemometric functions showed an inflation in probability density in the region spanning the spatial frequency of the average of the two memory items. This effect, due to an elevation in false alarms to probes matching the perceptual average, was diminished when cues were presented before both study items. These results suggest that a) perceptual averages are computed obligatorily and b) perceptual averages are relied upon to a greater extent when item representations are weakened. Implications of these results for theories of VSTM are discussed. PMID:24395020

  18. 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

  19. The Influence of Perceptual Training on Working Memory in Older Adults

    PubMed Central

    Berry, Anne S.; Zanto, Theodore P.; Clapp, Wesley C.; Hardy, Joseph L.; Delahunt, Peter B.; Mahncke, Henry W.; Gazzaley, Adam

    2010-01-01

    Normal aging is associated with a degradation of perceptual abilities and a decline in higher-level cognitive functions, notably working memory. To remediate age-related deficits, cognitive training programs are increasingly being developed. However, it is not yet definitively established if, and by what mechanisms, training ameliorates effects of cognitive aging. Furthermore, a major factor impeding the success of training programs is a frequent failure of training to transfer benefits to untrained abilities. Here, we offer the first evidence of direct transfer-of-benefits from perceptual discrimination training to working memory performance in older adults. Moreover, using electroencephalography to evaluate participants before and after training, we reveal neural evidence of functional plasticity in older adult brains, such that training-induced modifications in early visual processing during stimulus encoding predict working memory accuracy improvements. These findings demonstrate the strength of the perceptual discrimination training approach by offering clear psychophysical evidence of transfer-of-benefit and a neural mechanism underlying cognitive improvement. PMID:20644719

  20. Perceptual match effects in direct tests of memory: The role of contextual fan

    PubMed Central

    REDER, LYNNE M.; DONAVOS, DIMITRIOS K.; ERICKSON, MICHAEL A.

    2008-01-01

    The aim of the present study was to determine whether physical attributes of a memory representation would affect explicit memory performance and, if so, what type of factors would affect the size of a perceptual match effect. Subjects studied words in different, uncommon fonts and were later asked whether the word had been studied earlier. Words could be re-presented in the original font, a font studied with another word, or a font not seen earlier. In two additional experiments, we varied the numbers of words studied in the same unusual font (1 vs. 12 words per font). Recognition memory for the words was better if the test and study fonts matched, and this effect was larger for fonts not shared with other words. Moreover, old judgments were most likely to be classified as remember responses when words were re-presented in the same font when it had not been studied with other words. Although we found a significant effect of levels of processing, this factor did not interact with whether the font matched between study and test. These results are consistent with the predictions of the source of activation confusion model of memory and suggest that perceptual information operates according to the same memory principles as conceptual information. PMID:12035893

  1. 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

  2. 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

  3. 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

  4. 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…

  5. 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

  6. High-speed spatially multimode atomic memory

    SciTech Connect

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

    2011-05-15

    We study the coherent storage and retrieval of a very short multimode light pulse in an atomic ensemble. We consider a quantum memory process based on the conversion of a signal pulse into a long-lived spin coherence via light matter interaction in an on-resonant {Lambda} -type system. In order to study the writing and reading processes we analytically solve the partial differential equations describing the evolution of the field and of the atomic coherence in time as well as in space. We show how to optimize the process for writing as well as for reading. If the medium length is fixed, for each length, there is an optimal value of the pulse duration. We discuss the information capacity of this memory scheme and we estimate the number of transverse modes that can be stored as a quantum hologram.

  7. 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…

  8. Long-Term Perceptual Memory in Educable and Trainable Retardates and Children with Learning Disabilities. Final Report.

    ERIC Educational Resources Information Center

    Raskin, Larry M.

    Three short studies were conducted on long-term effects of visual perception training on perceptual memory, involving the visual illusion of apparent movement, in educable and trainable mentally retarded children (EMR and TMR) and in learning disabled children (LD). Variables were lengths of training session and retention interval. Tables…

  9. 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

  10. 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.

  11. 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…

  12. 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.

  13. 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

  14. Towards representation of a perceptual color manifold using associative memory for color constancy.

    PubMed

    Seow, Ming-Jung; Asari, Vijayan K

    2009-01-01

    In this paper, we propose the concept of a manifold of color perception through empirical observation that the center-surround properties of images in a perceptually similar environment define a manifold in the high dimensional space. Such a manifold representation can be learned using a novel recurrent neural network based learning algorithm. Unlike the conventional recurrent neural network model in which the memory is stored in an attractive fixed point at discrete locations in the state space, the dynamics of the proposed learning algorithm represent memory as a nonlinear line of attraction. The region of convergence around the nonlinear line is defined by the statistical characteristics of the training data. This learned manifold can then be used as a basis for color correction of the images having different color perception to the learned color perception. Experimental results show that the proposed recurrent neural network learning algorithm is capable of color balance the lighting variations in images captured in different environments successfully. PMID:18995987

  15. 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

  16. 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.

  17. 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.

  18. 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

  19. 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

  20. High speed, nondestructive readout from thin-film ferroelectric memory

    NASA Technical Reports Server (NTRS)

    Thakoor, Sarita

    1992-01-01

    High-speed polarization-direction-dependent photoresponse from ferroelectric lead zirconate titanate (PbZr(0.53)Ti(0.47)O3) thin films sandwiched between conducting electrodes to form a memory capacitor is reported. Laser pulses with a full width at half maximum of around 10 ns at 532-nm wavelength are utilized to readout the photoresponse signal from individual polarized elements. Such readout is repeated over a million times, with no detectable degradation in the photoresponse or the remanent polarization suggesting its potential as a nondestructive readout (NDRO) of nonvolatile polarization state in thin-film ferroelectric memories. In principle both electronic as well as thermal mechanisms could be triggered by such photon exposure of ferroelectric thin films. A comparison of the photoresponse from capacitors with semitransparent and opaque top electrodes suggests that the observed NDRO signal is primarily due to thermally triggered mechanisms.

  1. 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

  2. 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

  3. 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

  4. 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

  5. The Phenotypic and Genotypic Relation between Working Memory Speed and Capacity

    ERIC Educational Resources Information Center

    Polderman, Tinca J. C.; Stins, John F.; Posthuma, Danielle; Gosso, M. Florencia; Verhulst, Frank C.; Boomsma, Dorret I.

    2006-01-01

    This study examined the phenotypic and genotypic relationship between working memory speed (WMS) and working memory capacity (WMC) in 12-year-old twins and their siblings (N = 409). To asses WMS all children performed a reaction time task with three memory loads from which a basic mental speed measure and the derived slope were used. WMC was…

  6. 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

  7. 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

  8. 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…

  9. 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

  10. 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

  11. Simulator evaluation of drivers' speed, deceleration and lateral position at rural intersections in relation to different perceptual cues.

    PubMed

    Montella, Alfonso; Aria, Massimo; D'Ambrosio, Antonio; Galante, Francesco; Mauriello, Filomena; Pernetti, Mariano

    2011-11-01

    Aim of the study was to investigate, by means of a driving simulator experiment, drivers' behaviour in terms of speed, deceleration, and lateral position on major approaches of rural intersections in relation to different perceptual cues. In the experiment, ten different design conditions with and without speed-reducing treatments along the approach to the intersection were tested. Twenty-three drivers drove a test route two times and data from the second drive were used for comparison. The order of the ten design conditions was counterbalanced for all the drivers to minimize the presentation order effect. Three different data analysis techniques were used: (a) cluster analysis of speed and lateral position data, (b) statistical tests of speed and lateral position data, and (c) categorical analysis of deceleration behaviour patterns. The most effective treatments were the dragon teeth markings (based on the principle of optical road narrowing), the colored intersection area (based on the principle of intersection highlighting), and the raised median island (based on the principle of physical road narrowing). These measures, in comparison to the base intersection, produced: (1) a significant speed reduction starting from 250 m before the intersection in the range between 13 and 23 km/h, (2) a significant change in the deceleration behaviour with a reduction in the proportion of drivers which did not decelerate, and (3) a shift away from the intersection of the deceleration beginning. Given the significant effects on drivers' behaviour, the dragon teeth markings, the colored intersection area, and the raised median island are strongly recommended for real world implementation. PMID:21819837

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

    PubMed Central

    Dambacher, Michael; Hübner, Ronald; Schlösser, 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

  13. 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…

  14. Global Processing Speed as a Mediator of Developmental Changes in Children's Auditory Memory Span

    ERIC Educational Resources Information Center

    Ferguson, A.N.; Bowey, J.A.

    2005-01-01

    This study examined the role of global processing speed in mediating age increases in auditory memory span in 5- to 13-year-olds. Children were tested on measures of memory span, processing speed, single-word speech rate, phonological sensitivity, and vocabulary. Structural equation modeling supported a model in which age-associated increases in…

  15. High-speed all-optical long-term memory using SOA MZIs: Simulation and experiment

    NASA Astrophysics Data System (ADS)

    Yang, Xuelin; Weng, Qiwei; Hu, Weisheng

    2012-09-01

    We propose and demonstrate a novel all-optical memory to store high-speed optical data for long term. The key elements of the memory are Mach-Zehnder Interferometers (MZIs) incorporating semiconductor optical amplifiers (SOAs), acting as AND gate and regenerator in a loop configuration. The simulations show that the memory can be operated up to 80 Gb/s. In addition, the memory was demonstrated at 21.3 Gb/s.

  16. 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…

  17. 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…

  18. 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

  19. 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

  20. 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 ?4 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; ?4 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

  1. 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…

  2. 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…

  3. 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…

  4. 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

  5. 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

  6. 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.

  7. 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…

  8. 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

  9. 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.

  10. The role of processing speed in the Brief Visuospatial Memory Test - revised.

    PubMed

    Tam, Joyce W; Schmitter-Edgecombe, Maureen

    2013-01-01

    The Brief Visuospatial Memory Test - Revised (BVMT-R) is a commonly used, commercialized, assessment tool to measure visuospatial learning and memory abilities across research and clinical settings. In this study we evaluated the influence of processing speed and executive functioning on BVMT-R learning, memory, and percent retention scores. A total of 141 cognitively healthy older adults completed the BVMT-R along with measures of visuoconstructional abilities (BVMT-R copy), speeded processing (Symbol Digit Modalities Test-oral), and executive function (FAS). After controlling for age and visuoconstructional abilities, hierarchical regression models showed that the processing speed measure was a unique predictor of both BVMT-R learning and memory performances, while the executive function measure was not. The visuoconstructional measure was the only unique predictor of BVMT-R percent retention. The findings suggest that, when interpreting the BVMT-R learning and memory scores of patients who exhibit speeded processing deficits, the impact of slowed processing speed on performance should be considered. PMID:23682755

  11. Genetic variance in processing speed drives variation in aging of spatial and memory abilities.

    PubMed

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

    2009-05-01

    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 for processing speed and cognitive abilities. Longitudinal twin data from the Swedish Adoption/Twin Study of Aging, including up to 5 measurement occasions covering a 16-year period, were available from 806 participants ranging in age from 50 to 88 years at the 1st measurement wave. Factors were generated to tap 4 cognitive domains: verbal ability, spatial ability, memory, and processing speed. Model-fitting indicated that genetic variance for processing speed was a leading indicator of variation in age changes for spatial and memory ability, providing additional support for processing speed theories of cognitive aging. PMID:19413434

  12. 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

  13. 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.

  14. 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.

  15. 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.…

  16. 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.

  17. 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…

  18. 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.

  19. Genetic covariance among measures of information processing speed, working memory, and IQ.

    PubMed

    Luciano, M; Wright, M; Smith, G A; Geffen, G M; Geffen, L B; Martin, N G

    2001-11-01

    The genetic relationship between lower (information processing speed), intermediate (working memory), and higher levels (complex cognitive processes as indexed by IQ) of mental ability was studied in a classical twin design comprising 166 monozygotic and 190 dizygotic twin pairs. Processing speed was measured by a choice reaction time (RT) task (2-, 4-, and 8-choice), working memory by a visual-spatial delayed response task, and IQ by the Multidimensional Aptitude Battery. Multivariate analysis, adjusted for test-retest reliability, showed the presence of a genetic factor influencing all variables and a genetic factor influencing 4- and 8-choice RTs, working memory, and IQ. There were also genetic factors specific to 8-choice RT, working memory, and IQ. The results confirmed a strong relationship between choice RT and IQ (phenotypic correlations: -0.31 to -0.53 in females, -0.32 to -0.56 in males; genotypic correlations: -0.45 to -0.70) and a weaker but significant association between working memory and IQ (phenotypic: 0.26 in females, 0.13 in males; genotypic: 0.34). A significant part of the genetic variance (43%) in IQ was not related to either choice RT or delayed response performance, and may represent higher order cognitive processes. PMID:11838535

  20. Working Memory, Short-Term Memory, and Naming Speed as Predictors of Children's Mathematical Performance

    ERIC Educational Resources Information Center

    Swanson, Lee; Kim, Kenny

    2007-01-01

    Working memory (WM) has been associated with the acquisition of arithmetic skills, however, the components of WM that underlie this acquisition have not been explored. This study explored the contribution of two WM systems (the phonological loop and the central executive) to mathematical performance in young children. The results showed that a…

  1. Magnetically aligned carbon nanotube in nanopaper enabled shape-memory nanocomposite for high speed electrical actuation

    NASA Astrophysics Data System (ADS)

    Lu, Haibao; Gou, Jihua; Leng, Jinsong; Du, Shanyi

    2011-04-01

    A new shape-memory nanocomposite that exhibits rapid electrical actuation capabilities is fabricated by incorporating self-assembly multiwalled carbon nanotube (MWCNT) nanopaper and magnetic CNTs into a styrene-based shape-memory polymer (SMP). The MWCNT nanopaper was coated on the surface to give high electrical conductivity to SMP. Electromagnetic CNTs were blended with and, vertically aligned into the SMP resin upon a magnetic field, to facilitate the heat transfer from the nanopaper to the underlying SMP. This not only significantly enhances heat transfer but also gives high speed electrical actuation.

  2. 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

  3. 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…

  4. Delayed Perceptual Awareness in Rapid Perceptual Decisions

    PubMed Central

    Gregori-Grgi?, 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

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. 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.

  10. 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,…

  11. 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,…

  12. Pseudobinary Al2Te3-Sb2Te3 material for high speed phase change memory application

    NASA Astrophysics Data System (ADS)

    Ren, Kun; Rao, Feng; Song, Zhitang; Lv, Shilong; Cheng, Yan; Wu, Liangcai; Peng, Cheng; Zhou, Xilin; Xia, Mengjiao; Liu, Bo; Feng, Songlin

    2012-01-01

    Al2Sb2Te6 is a pseudobinary material constructed by Sb2Te3 (fast crystallization speed but thermally unstable) and Al2Te3 (thermally stable but without memory switching ability). Al2Sb2Te6 material possesses advantages of these two binary compounds showing good memory switching ability with fast switching speed and good thermal stability. These improvements are believed to be closely related to the coordination situations of Al atoms in Al2Sb2Te6 material. Phase change memory device using Al2Sb2Te6 showed high speed (˜5 ns), low power consumption, and high endurance (˜106 cycles). Thus, we consider that Al2Sb2Te6 can be one of the most promising materials for phase change memory use.

  13. A novel 2 T P-channel nano-crystal memory for low power/high speed embedded NVM applications

    NASA Astrophysics Data System (ADS)

    Junyu, Zhang; Yong, Wang; Jing, Liu; Manhong, Zhang; Zhongguang, Xu; Zongliang, Huo; Ming, Liu

    2012-08-01

    We introduce a novel 2 T P-channel nano-crystal memory structure for low power and high speed embedded non-volatile memory (NVM) applications. By using the band-to-band tunneling-induced hot-electron (BTBTIHE) injection scheme, both high-speed and low power programming can be achieved at the same time. Due to the use of a select transistor, the “erased states" can be set to below 0 V, so that the periphery HV circuit (high-voltage generating and management) and read-out circuit can be simplified. Good memory cell performance has also been achieved, including a fast program/erase (P/E) speed (a 1.15 V memory window under 10 ?s program pulse), an excellent data retention (only 20% charge loss for 10 years). The data shows that the device has strong potential for future embedded NVM applications.

  14. 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.

  15. 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,…

  16. 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,…

  17. Comprehension of Linguistic Dependencies: Speed-Accuracy Tradeoff Evidence for Direct-Access Retrieval From Memory

    PubMed Central

    Foraker, Stephani; McElree, Brian

    2012-01-01

    Comprehenders can rapidly and efficiently interpret expressions with various types of non-adjacent dependencies. In the sentence The boy that the teacher warned fell, boy is readily interpreted as the subject of the verb fall despite the fact that a relative clause, that the teacher warned, intervenes between the two dependent elements. We review research investigating three memory operations proposed for resolving this and other types of non-adjacent dependencies: serial search retrieval, in which the dependent constituent is recovered by a search process through representations in memory, direct-access retrieval in which the dependent constituent is recovered directly by retrieval cue operations without search, and active maintenance of the dependent constituent in focal attention. Studies using speed-accuracy tradeoff methodology to examine the full timecourse of interpreting a wide range of non-adjacent dependencies indicate that comprehenders retrieve dependent constituents with a direct-access operation, consistent with the claim that representations formed during comprehension are accessed with a cue-driven, content-addressable retrieval process. The observed timecourse profiles are inconsistent with a broad class of models based on several search operations for retrieval. The profiles are also inconsistent with active maintenance of a constituent while concurrently processing subsequent material, and suggest that, with few exceptions, direct-access retrieval is required to process non-adjacent dependencies. PMID:22448181

  18. 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).

  19. 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

  20. 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

  1. 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…

  2. 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

  3. 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.

  4. 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

  5. Working memory and intraindividual variability in processing speed: A lifespan developmental and individual-differences study.

    PubMed

    Mella, Nathalie; Fagot, Delphine; Lecerf, Thierry; de Ribaupierre, Anik

    2015-04-01

    Working memory (WM) and intraindividual variability (IIV) in processing speed are both hypothesized to reflect general attentional processes. In the present study, we aimed at exploring the relationship between WM capacity and IIV in reaction times (RTs) and its possible variation with development across the lifespan. Two WM tasks and six RT tasks of varying complexity were analyzed in a sample of 539 participants, consisting of five age groups: two groups of children (9-10 and 11-12 years of age), one group of young adults, and two groups of older adults (59-69 and 70-89 years of age). Two approaches were adopted. First, low-span and high-span individuals were identified, and analyses of variance were conducted comparing these two groups within each age group and for each RT task. The results consistently showed a span effect in the youngest children and oldest adults: High-span individuals were significantly faster and less variable than low-span individuals. In contrast, in young adults no difference was observed between high- and low-span individuals, whether in terms of their means or IIV. Second, multivariate analyses were conducted on the entire set of tasks, to determine whether IIV in RTs brought different information than the mean RT. The results showed that, although very strongly correlated, the mean and IIV in speed should be kept separate in terms of how they account for individual differences in WM. Overall, our results support the assumption of a link between WM capacity and IIV in RT, more strongly so in childhood and older adulthood. PMID:25537952

  6. 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.

  7. High-speed and localized resistive switching characteristics of double-layer SrZrO3 memory devices

    NASA Astrophysics Data System (ADS)

    Lin, Meng-Han; Wu, Ming-Chi; Huang, Chun-Yang; Lin, Chen-Hsi; Tseng, Tseung-Yuen

    2010-07-01

    The fabrication of SrZrO3 (SZO) memory devices with oxygen-rich (OR) and oxygen-deficient (OD) double layers, their resistive switching (RS) characteristics and mechanisms are investigated in this study. Due to the difference in oxygen content between the OR and OD layers formed by an oxygen flow control (OFC) process during SZO deposition, the RS region is effectively reduced and localized within the OR layer, which leads to a low operation voltage and stable RS behaviours. Furthermore, the OFC SZO device exhibits high-speed switching (10 ns) over 400 times and long retention (>106 s), showing promising potential for next-generation nonvolatile memory applications.

  8. 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

  9. 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

  10. Perceptual inference through global lexical similarity.

    PubMed

    Johns, Brendan T; Jones, Michael N

    2012-01-01

    The literature contains a disconnect between accounts of how humans learn lexical semantic representations for words. Theories generally propose that lexical semantics are learned either through perceptual experience or through exposure to regularities in language. We propose here a model to integrate these two information sources. Specifically, the model uses the global structure of memory to exploit the redundancy between language and perception in order to generate inferred perceptual representations for words with which the model has no perceptual experience. We test the model on a variety of different datasets from grounded cognition experiments and demonstrate that this diverse set of results can be explained as perceptual simulation (cf. Barsalou, Simmons, Barbey, & Wilson, 2003) within a global memory model. PMID:22253184

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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…

  16. 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.

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

    DOEpatents

    Baumbaugh, Alan E. (Batavia, IL); Knickerbocker, Kelly L. (Aurora, IL)

    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.

  18. 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

  19. 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.

  20. 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…

  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. 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)

  3. 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

  4. Retraining Memory Strategies.

    ERIC Educational Resources Information Center

    Parente, Rick; Herrmann, Douglas

    1996-01-01

    A variety of memory strategies can be used to retrain an individual's ability to process information in working memory. This article provides step-by-step instructions for various memory encoding strategies. These strategies include training in perceptual grouping of number series, organization, mediation, mental imagery, and associative memory

  5. 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…

  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. 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…

  9. 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…

  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. 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.

  12. 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

  13. 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.

  14. 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

  15. 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…

  16. 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…

  17. 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…

  18. 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.

  19. Effects of load and maintenance duration on the time course of information encoding and retrieval in working memory: from perceptual analysis to post-categorization processes

    PubMed Central

    Pinal, Diego; Zurrón, Montserrat; Díaz, Fernando

    2014-01-01

    Working memory (WM) involves three cognitive events: information encoding, maintenance, and retrieval; these are supported by brain activity in a network of frontal, parietal and temporal regions. Manipulation of WM load and duration of the maintenance period can modulate this activity. Although such modulations have been widely studied using the event-related potentials (ERP) technique, a precise description of the time course of brain activity during encoding and retrieval is still required. Here, we used this technique and principal component analysis to assess the time course of brain activity during encoding and retrieval in a delayed match to sample task. We also investigated the effects of memory load and duration of the maintenance period on ERP activity. Brain activity was similar during information encoding and retrieval and comprised six temporal factors, which closely matched the latency and scalp distribution of some ERP components: P1, N1, P2, N2, P300, and a slow wave. Changes in memory load modulated task performance and yielded variations in frontal lobe activation. Moreover, the P300 amplitude was smaller in the high than in the low load condition during encoding and retrieval. Conversely, the slow wave amplitude was higher in the high than in the low load condition during encoding, and the same was true for the N2 amplitude during retrieval. Thus, during encoding, memory load appears to modulate the processing resources for context updating and post-categorization processes, and during retrieval it modulates resources for stimulus classification and context updating. Besides, despite the lack of differences in task performance related to duration of the maintenance period, larger N2 amplitude and stronger activation of the left temporal lobe after long than after short maintenance periods were found during information retrieval. Thus, results regarding the duration of maintenance period were complex, and future work is required to test the time-based decay theory predictions. PMID:24744715

  20. 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…

  1. 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

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

    PubMed Central

    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

  3. 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…

  4. 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…

  5. 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

  6. 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

  7. Memory

    MedlinePLUS

    Your mind works 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 ...

  8. 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.

  9. 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,…

  10. 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

  11. Frequent video game players resist perceptual interference.

    PubMed

    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

  12. 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

  13. 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

  14. 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)

  15. 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,…

  16. "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…

  17. "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…

  18. Associative fear learning and perceptual discrimination: a perceptual pathway in the development of chronic pain.

    PubMed

    Zaman, Jonas; Vlaeyen, Johan W S; Van Oudenhove, Lukas; Wiech, Katja; Van Diest, Ilse

    2015-04-01

    Recent neuropsychological theories emphasize the influence of maladaptive learning and memory processes on pain perception. However, the precise relationship between these processes as well as the underlying mechanisms remain poorly understood; especially the role of perceptual discrimination and its modulation by associative fear learning has received little attention so far. Experimental work with exteroceptive stimuli consistently points to effects of fear learning on perceptual discrimination acuity. In addition, clinical observations have revealed that in individuals with chronic pain perceptual discrimination is impaired, and that tactile discrimination training reduces pain. Based on these findings, we present a theoretical model of which the central tenet is that associative fear learning contributes to the development of chronic pain through impaired interoceptive and proprioceptive discrimination acuity. PMID:25603316

  19. 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

  20. 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)…

  1. 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)…

  2. 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…

  3. 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…

  4. 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…

  5. 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

  6. 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

  7. 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

  8. 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…

  9. 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…

  10. Spatial memory following prenatal alcohol exposure: more than a material specific memory deficit.

    PubMed

    Kaemingk, K L; Halverson, P T

    2000-06-01

    Spatial memory deficits have been reported following prenatal alcohol exposure and animal studies have demonstrated hippocampal vulnerability to alcohol. This study examined spatial memory in children diagnosed with fetal alcohol syndrome (FAS) or fetal alcohol effects (FAE) and matched controls. Spatial memory was examined with location recall measures. Since visual perceptual skills and nonspecific memory impairment could impact spatial memory, tasks assessing perception and verbal memory were administered. Analyses revealed group differences on perceptual and verbal and spatial memory tasks. There was no significant difference in spatial memory once perceptual and verbal memory task performance was taken into account, suggesting that differences in spatial memory were not solely attributable to a material specific memory deficit. PMID:16210208

  11. 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. Poincaré 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.

  12. 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…

  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 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…

  15. 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…

  16. 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…

  17. 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…

  18. 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)

  19. 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

  20. 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

  1. 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

  2. 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.

  3. 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…

  4. 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…

  5. Computer-Based Cognitive Programs for Improvement of Memory, Processing Speed and Executive Function during Age-Related Cognitive Decline: A Meta-Analysis

    PubMed Central

    Shao, Yan-kun; Mang, Jing; Li, Pei-lan; Wang, Jie; Deng, Ting; Xu, Zhong-xin

    2015-01-01

    Background Several studies have assessed the effects of computer-based cognitive programs (CCP) in the management of age-related cognitive decline, but the role of CCP remains controversial. Therefore, this systematic review evaluated the evidence on the efficacy of CCP for age-related cognitive decline in healthy older adults. Methods Six electronic databases (through October 2014) were searched. The risk of bias was assessed using the Cochrane Collaboration tool. The standardized mean difference (SMD) and 95% confidence intervals (CI) of a random-effects model were calculated. The heterogeneity was assessed using the Cochran Q statistic and quantified with the I2 index. Results Twelve studies were included in the current review and were considered as moderate to high methodological quality. The aggregated results indicate that CCP improves memory performance (SMD, 0.31; 95% CI 0.16 to 0.45; p < 0.0001) and processing speed (SMD, 0.50; 95% CI 0.14 to 0.87; p = 0.007) but not executive function (SMD, -0.12; 95% CI -0.33 to 0.09; p = 0.27). Furthermore, there were long-term gains in memory performance (SMD, 0.59; 95% CI 0.13 to 1.05; p = 0.01). Conclusion CCP may be a valid complementary and alternative therapy for age-related cognitive decline, especially for memory performance and processing speed. However, more studies with longer follow-ups are warranted to confirm the current findings. PMID:26098943

  6. Balance in machine architecture: Bandwidth on board and offboard, integer/control speed and flops versus memory

    SciTech Connect

    Fischler, M.

    1992-04-01

    The issues to be addressed here are those of balance'' in machine architecture. By this, we mean how much emphasis must be placed on various aspects of the system to maximize its usefulness for physics. There are three components that contribute to the utility of a system: How the machine can be used, how big a problem can be attacked, and what the effective capabilities (power) of the hardware are like. The effective power issue is a matter of evaluating the impact of design decisions trading off architectural features such as memory bandwidth and interprocessor communication capabilities. What is studied is the effect these machine parameters have on how quickly the system can solve desired problems. There is a reasonable method for studying this: One selects a few representative algorithms and computes the impact of changing memory bandwidths, and so forth. The only room for controversy here is in the selection of representative problems. The issue of how big a problem can be attacked boils down to a balance of memory size versus power. Although this is a balance issue it is very different than the effective power situation, because no firm answer can be given at this time. The power to memory ratio is highly problem dependent, and optimizing it requires several pieces of physics input, including: how big a lattice is needed for interesting results; what sort of algorithms are best to use; and how many sweeps are needed to get valid results. We seem to be at the threshold of learning things about these issues, but for now, the memory size issue will necessarily be addressed in terms of best guesses, rules of thumb, and researchers' opinions.

  7. Balance in machine architecture: Bandwidth on board and offboard, integer/control speed and flops versus memory

    SciTech Connect

    Fischler, M.

    1992-04-01

    The issues to be addressed here are those of ``balance`` in machine architecture. By this, we mean how much emphasis must be placed on various aspects of the system to maximize its usefulness for physics. There are three components that contribute to the utility of a system: How the machine can be used, how big a problem can be attacked, and what the effective capabilities (power) of the hardware are like. The effective power issue is a matter of evaluating the impact of design decisions trading off architectural features such as memory bandwidth and interprocessor communication capabilities. What is studied is the effect these machine parameters have on how quickly the system can solve desired problems. There is a reasonable method for studying this: One selects a few representative algorithms and computes the impact of changing memory bandwidths, and so forth. The only room for controversy here is in the selection of representative problems. The issue of how big a problem can be attacked boils down to a balance of memory size versus power. Although this is a balance issue it is very different than the effective power situation, because no firm answer can be given at this time. The power to memory ratio is highly problem dependent, and optimizing it requires several pieces of physics input, including: how big a lattice is needed for interesting results; what sort of algorithms are best to use; and how many sweeps are needed to get valid results. We seem to be at the threshold of learning things about these issues, but for now, the memory size issue will necessarily be addressed in terms of best guesses, rules of thumb, and researchers` opinions.

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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.

  13. 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

  14. 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

  15. Learning efficient perceptual sampling.

    PubMed

    Nardini, Marko; Jones, Pete; Landin, Linnea; Juni, Mordechai; Maloney, Laurence; Dekker, Tessa

    2015-09-01

    We tested adults and children aged 7-9 and 10-12 years in a stochastic judgment task. Adult observers compensate in part for perceptual uncertainty. However, the manner in which perceptual systems represent and compute with probabilistic estimates remains largely unknown. Developmental studies provide insight into the nature and origins of these capabilities. In our task, subjects could earn a reward by touching an invisible target circle marked by dots (cues) drawn from a Gaussian distribution centred on the target. Subjects could sample up to 20 cues but each cue reduced the possible reward by a fixed amount. Each additional cue improved the reliability of the location estimate by reducing the standard error of the mean. Subjects therefore had to trade off localization accuracy against the cost of additional cues. There were two conditions that differed in the variance of the Gaussian. We computed the optimal sample size that maximized expected reward in each condition: 4 cues (low variance) and 8 cues (high). We assumed that observers aimed for the mean location of each dot cloud; control conditions showed that deviations from this strategy were small across all age groups. Strikingly, across both variance conditions, in both child and adult groups, numbers of cues sampled were indistinguishable from optimal. However, sampling in child groups was more variable trial-to-trial, with a cost to their final rewards as compared with adults. Children's relatively mature abilities to compute with probabilistic estimates here contrast with their much poorer abilities to take uncertainty into account in difficult perceptual and motor tasks (e.g. Nardini et al, PNAS 2010; Dekker et al, VSS 2012). This apparent dissociation suggests that probabilities dependent mainly on external factors (samples of dots, in this task) are computed separately to those dependent mainly on internal noise (sensory uncertainty, in previous tasks). Meeting abstract presented at VSS 2015. PMID:26326431

  16. 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.

  17. 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.

  18. Conflict-Induced Perceptual Filtering

    ERIC Educational Resources Information Center

    Wendt, Mike; Luna-Rodriguez, Aquiles; Jacobsen, Thomas

    2012-01-01

    In a variety of conflict paradigms, target and distractor stimuli are defined in terms of perceptual features. Interference evoked by distractor stimuli tends to be reduced when the ratio of congruent to incongruent trials is decreased, suggesting conflict-induced perceptual filtering (i.e., adjusting the processing weights assigned to stimuli…

  19. Differential frontal involvement in shifts of internal and perceptual attention

    PubMed Central

    Tanoue, Ryan T.; Jones, Kevin T.; Peterson, Dwight J.; Berryhill, Marian E.

    2012-01-01

    Background Perceptual attention enhances the processing of items in the environment, whereas internal attention enhances processing of items encoded in visual working memory. In perceptual and internal attention cueing paradigms, cues indicate the to-be-probed item before (pre-cueing) or after (retro-cueing) the memory display, respectively. Pre- and retro- cues confer similar behavioral accuracy benefits (pre-: 14–19%, retro-: 11–17%) and neuroimaging data show that they activate overlapping frontoparietal networks (1). Yet reports of behavioral and neuroimaging differences suggest that pre- and retro-cueing differentially recruit frontal and parietal cortices (1). Objective/Hypothesis This study examined whether perceptual and internal attention are equally disrupted by neurostimulation to frontal and parietal cortices. We hypothesized that neurostimulation applied to frontal cortex would disrupt internal attention to a greater extent than perceptual attention. Methods Cathodal transcranial direct current stimulation (tDCS) was applied to frontal or parietal cortices. After stimulation, participants completed a change detection task coupled with either pre- or retro- cues. Results Cathodal tDCS across site (frontal, parietal) hindered performance. However, frontal tDCS had a greater negative impact on the retro-cued trials demonstrating greater frontal involvement during shifts of internal attention. Conclusions These results complement the neuroimaging data and provide further evidence suggesting that perceptual and internal attention are not identical processes. We conclude that although internal and perceptual attention are mediated by similar frontoparietal networks, the weight of contribution of these structures differs, with internal attention relying more heavily on the frontal cortex. PMID:23266133

  20. 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.

  1. 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.

  2. Visual Scanning Strategies of Perceptually Impaired and Normal Children Viewing the Motor-Free Visual Perception Test.

    ERIC Educational Resources Information Center

    Locher, Paul J.; Worms, Peter F.

    1981-01-01

    Clear quantitative and qualitative differences in visual scanning strategies were found between the groups and discussed with respect to differences between perceptually impaired and normal children's rates of encoding information and reliance upon visual memory. (Author)

  3. Perceptual qualities and material classes.

    PubMed

    Fleming, Roland W; Wiebel, Christiane; Gegenfurtner, Karl

    2013-01-01

    Under typical viewing conditions, we can easily group materials into distinct classes (e.g., woods, plastics, textiles). Additionally, we can also make many other judgments about material properties (e.g., hardness, rigidity, colorfulness). Although these two types of judgment (classification and inferring material properties) have different requirements, they likely facilitate one another. We conducted two experiments to investigate the interactions between material classification and judgments of material qualities in both the visual and semantic domains. In Experiment 1, nine students viewed 130 images of materials from 10 different classes. For each image, they rated nine subjective properties (glossiness, transparency, colorfulness, roughness, hardness, coldness, fragility, naturalness, prettiness). In Experiment 2, 65 subjects were given the verbal names of six material classes, which they rated in terms of 42 adjectives describing material qualities. In both experiments, there was notable agreement between subjects, and a relatively small number of factors (weighted combinations of different qualities) were substantially independent of one another. Despite the difficulty of classifying materials from images (Liu, Sharan, Adelson, & Rosenholtz, 2010), the different classes were well clustered in the feature space defined by the subjective ratings. K-means clustering could correctly identify class membership for over 90% of the samples, based on the average ratings across subjects. We also found a high degree of consistency between the two tasks, suggesting subjects access similar information about materials whether judging their qualities visually or from memory. Together, these findings show that perceptual qualities are well defined, distinct, and systematically related to material class membership. PMID:23847302

  4. Different time scales of motion integration for anticipatory smooth pursuit and perceptual adaptation

    PubMed Central

    Maus, Gerrit W.; Potapchuk, Elena; Watamaniuk, Scott N. J.; Heinen, Stephen J.

    2015-01-01

    When repeatedly exposed to moving stimuli, the oculomotor system elicits anticipatory smooth pursuit (ASP) eye movements, even before the stimulus moves. ASP is affected oppositely to perceptual speed judgments of repetitive moving stimuli: After a sequence of fast stimuli, ASP velocity increases, whereas perceived speed decreases. These two effects—perceptual adaptation and oculomotor priming—could result from adapting a single common internal speed representation that is used for perceptual comparisons and for generating ASP. Here we test this hypothesis by assessing the temporal dependence of both effects on stimulus history. Observers performed speed discriminations on moving random dot stimuli, either while pursuing the movement or maintaining steady fixation. In both cases, responses showed perceptual adaptation: Stimuli preceded by fast speeds were perceived as slower, and vice versa. To evaluate oculomotor priming, we analyzed ASP velocity as a function of average stimulus speed in preceding trials and found strong positive dependencies. Interestingly, maximal priming occurred over short stimulus histories (?two trials), whereas adaptation was maximal over longer histories (?15 trials). The temporal dissociation of adaptation and priming suggests different underlying mechanisms. It may be that perceptual adaptation integrates over a relatively long period to robustly calibrate the operating range of the motion system, thereby avoiding interference from transient changes in stimulus speed. On the other hand, the oculomotor system may rapidly prime anticipatory velocity to efficiently match it to that of the pursuit target. PMID:25761334

  5. 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.

  6. 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

  7. Perceptual Load Modulates Object-Based Attention

    ERIC Educational Resources Information Center

    Ho, Ming-Chou; Atchley, Paul

    2009-01-01

    Two experimental series are reported using both reaction time (RT) and a data-limited perceptual report to examine the effects of perceptual load on object-based attention. Perceptual load was manipulated across 3 levels by increasing the complexity of perceptual judgments. Data from the RT-based experiments showed object-based effects when the…

  8. 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.

  9. 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

  10. 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.

  11. 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

  12. 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

  13. Perceptual anomalies in schizophrenia: integrating phenomenology and cognitive neuroscience.

    PubMed

    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

  14. 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

  15. Perceptual and Conceptual Distortions of Implicit Hand Maps.

    PubMed

    Longo, Matthew R; Mattioni, Stefania; Ganea, Nata?a

    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

  16. 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

  17. Sex Differences in Phonological Coding: Alphabet Transformation Speed

    ERIC Educational Resources Information Center

    Majeres, Raymond L.

    2007-01-01

    A previous explanation of the sex difference on so-called perceptual speed tests was in terms of a female advantage in accessing and using phonological name codes in making item comparisons. That explanation was extended to a task involving alphabetical transformations without the requirement for comparison of perceptually available items. A…

  18. 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

  19. 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

  20. Mental imagery of speech: linking motor and perceptual systems through internal simulation and estimation

    PubMed Central

    Tian, Xing; Poeppel, David

    2012-01-01

    The neural basis of mental imagery has been investigated by localizing the underlying neural networks, mostly in motor and perceptual systems, separately. However, how modality-specific representations are top-down induced and how the action and perception systems interact in the context of mental imagery is not well understood. Imagined speech production (“articulation imagery”), which induces the kinesthetic feeling of articulator movement and its auditory consequences, provides a new angle because of the concurrent involvement of motor and perceptual systems. On the basis of previous findings in mental imagery of speech, we argue for the following regarding the induction mechanisms of mental imagery and the interaction between motor and perceptual systems: (1) Two distinct top-down mechanisms, memory retrieval and motor simulation, exist to induce estimation in perceptual systems. (2) Motor simulation is sufficient to internally induce the representation of perceptual changes that would be caused by actual movement (perceptual associations); however, this simulation process only has modulatory effects on the perception of external stimuli, which critically depends on context and task demands. Considering the proposed simulation-estimation processes as common mechanisms for interaction between motor and perceptual systems, we outline how mental imagery (of speech) relates to perception and production, and how these hypothesized mechanisms might underpin certain neural disorders. PMID:23226121

  1. 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.

  2. Neural networks and perceptual learning

    PubMed Central

    Tsodyks, Misha; Gilbert, Charles

    2005-01-01

    Sensory perception is a learned trait. The brain strategies we use to perceive the world are constantly modified by experience. With practice, we subconsciously become better at identifying familiar objects or distinguishing fine details in our environment. Current theoretical models simulate some properties of perceptual learning, but neglect the underlying cortical circuits. Future neural network models must incorporate the top-down alteration of cortical function by expectation or perceptual tasks. These newly found dynamic processes are challenging earlier views of static and feedforward processing of sensory information. PMID:15483598

  3. Perceptual analysis for music segmentation

    NASA Astrophysics Data System (ADS)

    Jian, Min-Hong; Lin, Chia-Han; Chen, Arbee L. P.

    2003-12-01

    In this paper, a music segmentation framework is proposed to segment music streams based on human perception. In the proposed framework, three perceptual features corresponding to four perceptual properties are extracted. By analyzing the trajectory of feature values, the cutting points of a music stream can be identified. According to the complementary characteristics of the three features, a ranking algorithm is designed to achieve a better accuracy. We perform a series of experiments to evaluate the Complementary Characteristics and the effectiveness of the proposed framework.

  4. Prediction of Later Cognitive Behavior from Early School Perceptual-Motor, Perceptual, and Cognitive Performances.

    ERIC Educational Resources Information Center

    Belka, David E.; Williams, Harriet G.

    1979-01-01

    The battery of perceptual and perceptual-motor tests (including one fine and two gross perceptual-motor tasks, and one visual and two auditory perceptual tasks) were useful for prediction of cognitive performance one year later at kindergarten age. However, cognitive achievement in first grade, and even more so in second grade, was best predicted…

  5. 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.

  6. 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…

  7. 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…

  8. 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,…

  9. 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…

  10. 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

  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. 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

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. 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…

  18. 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

  19. 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

  20. 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…

  1. 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…

  2. 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…

  3. Increased Signal Complexity Improves the Breadth of Generalization in Auditory Perceptual Learning

    PubMed Central

    Brown, David J.; Proulx, Michael J.

    2013-01-01

    Perceptual learning can be specific to a trained stimulus or optimally generalized to novel stimuli with the breadth of generalization being imperative for how we structure perceptual training programs. Adapting an established auditory interval discrimination paradigm to utilise complex signals, we trained human adults on a standard interval for either 2, 4, or 10 days. We then tested the standard, alternate frequency, interval, and stereo input conditions to evaluate the rapidity of specific learning and breadth of generalization over the time course. In comparison with previous research using simple stimuli, the speed of perceptual learning and breadth of generalization were more rapid and greater in magnitude, including novel generalization to an alternate temporal interval within stimulus type. We also investigated the long term maintenance of learning and found that specific and generalized learning was maintained over 3 and 6 months. We discuss these findings regarding stimulus complexity in perceptual learning and how they can inform the development of effective training protocols. PMID:24349800

  4. 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

  5. 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

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

    PubMed

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

    2015-07-01

    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

  7. 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…

  8. 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)

  9. The Role of Visual Processing Speed in Reading Speed Development

    PubMed Central

    Lobier, Muriel; Dubois, Matthieu; Valdois, Sylviane

    2013-01-01

    A steady increase in reading speed is the hallmark of normal reading acquisition. However, little is known of the influence of visual attention capacity on children's reading speed. The number of distinct visual elements that can be simultaneously processed at a glance (dubbed the visual attention span), predicts single-word reading speed in both normal reading and dyslexic children. However, the exact processes that account for the relationship between the visual attention span and reading speed remain to be specified. We used the Theory of Visual Attention to estimate visual processing speed and visual short-term memory capacity from a multiple letter report task in eight and nine year old children. The visual attention span and text reading speed were also assessed. Results showed that visual processing speed and visual short term memory capacity predicted the visual attention span. Furthermore, visual processing speed predicted reading speed, but visual short term memory capacity did not. Finally, the visual attention span mediated the effect of visual processing speed on reading speed. These results suggest that visual attention capacity could constrain reading speed in elementary school children. PMID:23593117

  10. 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.

  11. 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.

  12. 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

  13. Working memory across nostrils.

    PubMed

    Yeshurun, Yaara; Dudai, Yadin; Sobel, Noam

    2008-10-01

    Whether olfactory working memory involves verbal representations or neural images of odor per se remains unclear. This study investigated whether verbal representation influences performance in an olfactory delayed-match-to-sample task and used monorhinal presentation to generate hypotheses as to the underlying anatomy of this mechanism. The main findings were that (a) nameable odorants were easier to remember than hard-to-name odorants and (b) the nameability effect was more pronounced when the evaluation was done across nostrils. Considering these results within a proposed model implies dual representation in olfactory working memory: All odors, nameable and hard to name, are represented both perceptually and verbally. PMID:18823160

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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,…

  19. 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,…

  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. 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…

  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. 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

  5. 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

  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. 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.

  9. Building online brand perceptual map.

    PubMed

    Chiang, I-Ping; Lin, Chih-Ying; Wang, Kaisheng M

    2008-10-01

    Many companies have launched their products or services online as a new business focus, but only a few of them have survived the competition and made profits. The most important key to an online business's success is to create "brand value" for the customers. Although the concept of online brand has been discussed in previous studies, there is no empirical study on the measurement of online branding. As Web 2.0 emerges to be critical to online branding, the purpose of this study was to measure Taiwan's major Web sites with a number of personality traits to build a perceptual map for online brands. A pretest identified 10 most representative online brand perceptions. The results of the correspondence analysis showed five groups in the perceptual map. This study provided a practical view of the associations and similarities among online brands for potential alliance or branding strategies. The findings also suggested that brand perceptions can be used with identified consumer needs and behaviors to better position online services. The brand perception map in the study also contributed to a better understanding of the online brands in Taiwan. PMID:18785819

  10. 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.

  11. 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

  12. 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…

  13. Continuity and Discontinuity of Perceptual Development.

    ERIC Educational Resources Information Center

    Fischer, Hardi

    Despite external changes such as those of magnitudes, the functional properties of the visual system also improve with increased age. According to Jean Piaget's centration/decentration theory, the process of perceptual development might continue until adulthood and even after. However, perceptual development should not be understood in all of its…

  14. 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)

  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. Episodically defined organization of visual memory.

    PubMed

    Antonelli, Karla; Williams, Carrick

    2015-09-01

    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

  17. Perceptual Calibration for Immersive Display Environments

    PubMed Central

    Ponto, Kevin; Gleicher, Michael; Radwin, Robert G.; Shin, Hyun Joon

    2013-01-01

    The perception of objects, depth, and distance has been repeatedly shown to be divergent between virtual and physical environments. We hypothesize that many of these discrepancies stem from incorrect geometric viewing parameters, specifically that physical measurements of eye position are insufficiently precise to provide proper viewing parameters. In this paper, we introduce a perceptual calibration procedure derived from geometric models. While most research has used geometric models to predict perceptual errors, we instead use these models inversely to determine perceptually correct viewing parameters. We study the advantages of these new psychophysically determined viewing parameters compared to the commonly used measured viewing parameters in an experiment with 20 subjects. The perceptually calibrated viewing parameters for the subjects generally produced new virtual eye positions that were wider and deeper than standard practices would estimate. Our study shows that perceptually calibrated viewing parameters can significantly improve depth acuity, distance estimation, and the perception of shape. PMID:23428454

  18. Visual Working Memory Contents Bias Ambiguous Structure from Motion Perception

    PubMed Central

    Scocchia, Lisa; Valsecchi, Matteo; Gegenfurtner, Karl R.; Triesch, Jochen

    2013-01-01

    The way we perceive the visual world depends crucially on the state of the observer. In the present study we show that what we are holding in working memory (WM) can bias the way we perceive ambiguous structure from motion stimuli. Holding in memory the percept of an unambiguously rotating sphere influenced the perceived direction of motion of an ambiguously rotating sphere presented shortly thereafter. In particular, we found a systematic difference between congruent dominance periods where the perceived direction of the ambiguous stimulus corresponded to the direction of the unambiguous one and incongruent dominance periods. Congruent dominance periods were more frequent when participants memorized the speed of the unambiguous sphere for delayed discrimination than when they performed an immediate judgment on a change in its speed. The analysis of dominance time-course showed that a sustained tendency to perceive the same direction of motion as the prior stimulus emerged only in the WM condition, whereas in the attention condition perceptual dominance dropped to chance levels at the end of the trial. The results are explained in terms of a direct involvement of early visual areas in the active representation of visual motion in WM. PMID:23527141

  19. 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

  20. 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.

  1. 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…

  2. 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.

  3. 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

  4. 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…

  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. Modeling Recognition Memory Using the Similarity Structure of Natural Input

    ERIC Educational Resources Information Center

    Lacroix, Joyca P. W.; Murre, Jaap M. J.; Postma, Eric O.; van den Herik, H. Jaap

    2006-01-01

    The natural input memory (NAM) model is a new model for recognition memory that operates on natural visual input. A biologically informed perceptual preprocessing method takes local samples (eye fixations) from a natural image and translates these into a feature-vector representation. During recognition, the model compares incoming preprocessed…

  7. 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)

  8. 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,…

  9. 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,…

  10. 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

  11. High Speed Six-Transistor Static Random Access Memory Cells Using Single Grain Thin Film Transistors Fabricated at Low Temperature Process

    NASA Astrophysics Data System (ADS)

    Golshani, Negin; Derakhshandeh, Jaber; Ishihara, Ryoichi; Beenakker, Cees I. M.

    2010-03-01

    In this paper we will report successfully fabricated six transistor static random access memory (6T SRAM) cells using single-grain thin film transistors (TFTs). SRAM cells have been designed by analytical calculations and verified by DC and transient simulations. TFTs are fabricated by µ-Czochralski process that consists of making grain filter and Excimer laser crystallization at temperatures below 550 °C. The gate length of transistors are 2 µm. Fabricated SRAM cells based on single grain TFTs, show good read and write static noise margin (SNM and WNM) equal to 0.55 and 0.75 V at 3.3 V power supply, respectively. Finally, excellent read and write access times equal to 13 and 8 ns in 87 MHz worldline frequency were obtained.

  12. High Speed Six-Transistor Static Random Access Memory Cells Using Single Grain Thin Film Transistors Fabricated at Low Temperature Process

    NASA Astrophysics Data System (ADS)

    Negin Golshani,; Jaber Derakhshandeh,; Ryoichi Ishihara,; Cees I. M. Beenakker,

    2010-03-01

    In this paper we will report successfully fabricated six transistor static random access memory (6T SRAM) cells using single-grain thin film transistors (TFTs). SRAM cells have been designed by analytical calculations and verified by DC and transient simulations. TFTs are fabricated by ?-Czochralski process that consists of making grain filter and Excimer laser crystallization at temperatures below 550 °C. The gate length of transistors are 2 ?m. Fabricated SRAM cells based on single grain TFTs, show good read and write static noise margin (SNM and WNM) equal to 0.55 and 0.75 V at 3.3 V power supply, respectively. Finally, excellent read and write access times equal to 13 and 8 ns in 87 MHz worldline frequency were obtained.

  13. An Event Related Potentials Study of the Effects of Age, Load and Maintenance Duration on Working Memory Recognition.

    PubMed

    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

  14. 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

  15. 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

  16. 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

  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. 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

  19. 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

  20. 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

  1. Gender differences in perceptual-motor performance.

    PubMed

    Tirre, W C; Raouf, K K

    1994-05-01

    Do gender differences exist in perceptual-motor performance, and, if so, are the differences as substantial as those observed in trade/technical knowledge tests? What roles do general cognitive ability and videogame experience have in determining perceptual-motor performance? To address these questions, we administered a battery of computer-based tests requiring multilimb coordination and perceptual matching to a sample of 392 USAF enlistees (72% male). Our main findings were that general cognitive ability had the expected positive main effect on performance and gender and videogame experience had an interactive effect, such that videogame experience benefited men's but not women's performance. The role of experience on perceptual-motor performance merits further attention, especially with regard to gender differences. PMID:8018079

  2. 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

  3. 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

  4. 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

  5. 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

  6. WAIS-IV Verbal Comprehension Index and Perceptual Reasoning Index performance is unaffected by cold-pressor pain induction.

    PubMed

    Etherton, Joseph

    2015-01-01

    Cognitive complaints are frequently reported by patients with chronic pain, but studies of the effects of pain on different forms of cognition have been inconsistent. In two studies, cold-pressor pain was induced in nonclinical undergraduate volunteers who, under normal conditions, took Verbal Comprehension Index (VCI) subtests (Study 1, n=57) or Perceptual Reasoning Index (PRI) subtests (Study 2, n=59) followed by a different VCI or PRI subtest taken during either cold-pressor pain induction or a nonpainful control condition. Pain was not associated with significant reduction in subtest scaled score performance. Results indicate that cold-pressor pain in nonclinical volunteers does not impair Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) VCI or PRI performance and suggest that pain per se should not be expected to substantially influence these cognitive abilities. Viewed together with previous Processing Speed Index and Working Memory Index studies, no cognitive or intellectual functions measured by the WAIS-IV are affected by induced pain. Generalizability of these findings may be limited by the fact that patients with chronic pain may differ in their pain experience from nonclinical volunteers with induced pain. PMID:25529592

  7. 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

  8. Childhood Anxiety and Memory Functioning: A Comparison of Systemic and Processing Accounts.

    ERIC Educational Resources Information Center

    Daleiden, Eric L.

    1998-01-01

    Examined relationship between anxiety and memory in 160 high- and low-trait-anxious sixth through eighth graders. Found that anxiety predicted memory bias toward negative relative to neutral information during conceptual but not perceptual tasks. Anxiety predicted memory bias toward positive relative to neutral information on procedural tasks and…

  9. Memory for the Conditioned Response: The Effects of Potential Interference Introduced Before and After Original Conditioning

    ERIC Educational Resources Information Center

    Wickens, Delos D.; And Others

    1977-01-01

    Investigates the possibility that memory for the conditioned response (CR) may be subject to the same sorts of interference that have been found to operate in verbal and perceptual-motor memory situations. Considers the implications for developing a general theory of memory. (Editor/RK)

  10. 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…

  11. 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…

  12. Can Attention be Divided Between Perceptual Groups?

    NASA Technical Reports Server (NTRS)

    McCann, Robert S.; Foyle, David C.; Johnston, James C.; Hart, Sandra G. (Technical Monitor)

    1994-01-01

    Previous work using Head-Up Displays (HUDs) suggests that the visual system parses the HUD and the outside world into distinct perceptual groups, with attention deployed sequentially to first one group and then the other. New experiments show that both groups can be processed in parallel in a divided attention search task, even though subjects have just processed a stimulus in one perceptual group or the other. Implications for models of visual attention will be discussed.

  13. Is perceptual space inherently non-Euclidean?

    PubMed

    Fernandez, Julian Martin; Farell, Bart

    2009-04-01

    It is often assumed that the space we perceive is Euclidean, although this idea has been challenged by many authors. Here we show that, if spatial cues are combined as described by Maximum Likelihood Estimation, Bayesian, or equivalent models, as appears to be the case, then Euclidean geometry cannot describe our perceptual experience. Rather, our perceptual spatial structure would be better described as belonging to an arbitrarily curved Riemannian space. PMID:20161280

  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. 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

  16. Dissociable perceptual effects of visual adaptation.

    PubMed

    Müller, Kai-Markus; Schillinger, Frieder; Do, David H; Leopold, David A

    2009-01-01

    Neurons in the visual cortex are responsive to the presentation of oriented and curved line segments, which are thought to act as primitives for the visual processing of shapes and objects. Prolonged adaptation to such stimuli gives rise to two related perceptual effects: a slow change in the appearance of the adapting stimulus (perceptual drift), and the distortion of subsequently presented test stimuli (adaptational aftereffects). Here we used a psychophysical nulling technique to dissociate and quantify these two classical observations in order to examine their underlying mechanisms and their relationship to one another. In agreement with previous work, we found that during adaptation horizontal and vertical straight lines serve as attractors for perceived orientation and curvature. However, the rate of perceptual drift for different stimuli was not predictive of the corresponding aftereffect magnitudes, indicating that the two perceptual effects are governed by distinct neural processes. Finally, the rate of perceptual drift for curved line segments did not depend on the spatial scale of the stimulus, suggesting that its mechanisms lie outside strictly retinotopic processing stages. These findings provide new evidence that the visual system relies on statistically salient intrinsic reference stimuli for the processing of visual patterns, and point to perceptual drift as an experimental window for studying the mechanisms of visual perception. PMID:19593384

  17. 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.

  18. Cognitive Rehabilitation: Help for Attention, Memory, and Other Problems with Thinking

    MedlinePLUS

    ... areas: attention and memory, reasoning and problem-solving, visual-spatial functions, language functions, sensory/perceptual functions, motor ... may instead be problems with attention or with visual or auditory processing. For problems that are caused ...

  19. Where do we store the memory representations that guide attention?

    PubMed Central

    Woodman, Geoffrey F.; Carlisle, Nancy B.; Reinhart, Robert M. G.

    2013-01-01

    During the last decade one of the most contentious and heavily studied topics in the attention literature has been the role that working memory representations play in controlling perceptual selection. The hypothesis has been advanced that to have attention select a certain perceptual input from the environment, we only need to represent that item in working memory. Here we summarize the work indicating that the relationship between what representations are maintained in working memory and what perceptual inputs are selected is not so simple. First, it appears that attentional selection is also determined by high-level task goals that mediate the relationship between working memory storage and attentional selection. Second, much of the recent work from our laboratory has focused on the role of long-term memory in controlling attentional selection. We review recent evidence supporting the proposal that working memory representations are critical during the initial configuration of attentional control settings, but that after those settings are established long-term memory representations play an important role in controlling which perceptual inputs are selected by mechanisms of attention. PMID:23444390

  20. 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.

  1. 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

  2. Cognitive architecture of perceptual organization: from neurons to gnosons.

    PubMed

    van der Helm, Peter A

    2012-02-01

    What, if anything, is cognitive architecture and how is it implemented in neural architecture? Focusing on perceptual organization, this question is addressed by way of a pluralist approach which, supported by metatheoretical considerations, combines complementary insights from representational, connectionist, and dynamic systems approaches to cognition. This pluralist approach starts from a representationally inspired model which implements the intertwined but functionally distinguishable subprocesses of feedforward feature encoding, horizontal feature binding, and recurrent feature selection. As sustained by a review of neuroscientific evidence, these are the subprocesses that are believed to take place in the visual hierarchy in the brain. Furthermore, the model employs a special form of processing, called transparallel processing, whose neural signature is proposed to be gamma-band synchronization in transient horizontal neural assemblies. In neuroscience, such assemblies are believed to mediate binding of similar features. Their formal counterparts in the model are special input-dependent distributed representations, called hyperstrings, which allow many similar features to be processed in a transparallel fashion, that is, simultaneously as if only one feature were concerned. This form of processing does justice to both the high combinatorial capacity and the high speed of the perceptual organization process. A naturally following proposal is that those temporarily synchronized neural assemblies are "gnosons", that is, constituents of flexible self-organizing cognitive architecture in between the relatively rigid level of neurons and the still elusive level of consciousness. PMID:22086351

  3. 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

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. Perceptual Consequences of Elongated Eyes.

    PubMed

    Maiello, Guido; Harrison, William; Vera-Diaz, Fuensanta; Bex, Peter

    2015-09-01

    Myopic eyes are elongated compared to the eyes of normally-sighted, emmetropic observers. This simple observation gives rise to an empirical question: what are the physiological and perceptual consequences of an elongated retinal surface? To address this question, we developed a geometric model of emmetropic and myopic retinae, based on magnetic resonance imaging (MRI) data [Atchison et al. (2005)], from which we derived psychophysically-testable predictions about visual function. We input range image data of natural scenes [Howe and Purves (2002)] to the geometric model to statistically estimate where in the visual periphery perception may be altered due to the different shapes of myopic and emmetropic eyes. The model predicts that central visual function should be similar for the two eye types, but myopic peripheral vision should differ regardless of optical correction. We tested this hypothesis by measuring the fall-off in contrast sensitivity with retinal eccentricity in emmetropes and best-corrected myopes. The full contrast sensitivity function (CSF) was assessed at 5, 10 and 15 degrees eccentricity using an adaptive testing procedure [Vul et al. (2010)]. Consistent with our model predictions, the area under the log CSF decreases in the periphery at a faster rate in best-corrected myopic observers than in emmetropes. Our modeling also revealed that a target at a given eccentricity projects onto a larger area of peripheral retinal for myopic than emmetropic eyes. This raises the possibility that crowding zones - the area over which features are integrated - may differ between eye types. We measured crowding zones at 5, 10 and 15 degrees of eccentricity using a 26 AFC letter identification task and found no significant differences between myopic and emmetropic observers. This suggests that crowding depends on spatial rather than retinal feature separation, which implies differences in the retino-cortical transformations in myopes and emmetropes. Meeting abstract presented at VSS 2015. PMID:26325799

  9. 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…

  10. 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…

  11. 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,…

  12. 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,…

  13. 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

  14. 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

  15. Perceptual Contrast Enhancement with Dynamic Range Adjustment

    PubMed Central

    Zhang, Hong; Li, Yuecheng; Chen, Hao; Yuan, Ding; Sun, Mingui

    2013-01-01

    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

  16. 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

  17. Perceptual Modeling and Reproduction of Gloss

    NASA Astrophysics Data System (ADS)

    Fores Herranz, Adria

    The reproduction of gloss on displays is generally not based on perception and as a consequence does not guarantee the best visualization of a real material. The reproduction is composed of four different steps: measurement, modeling, rendering, and display. The minimum number of measurements required to approximate a real material is unknown. The error metrics used to approximate measurements with analytical BRDF models are not based on perception, and the best visual approximation is not always obtained. Finally, the gloss perception difference between real objects and objects seen on displays has not sufficiently been studied and might be influencing the observer judgement. This thesis proposes a systematic, scalable, and perceptually based workflow to represent real materials on displays. First, the gloss perception difference between real objects and objects seen on displays was studied. Second, the perceptual performance of the error metrics currently in use was evaluated. Third, a projection into a perceptual gloss space was defined, enabling the computation of a perceptual gloss distance measure. Fourth, the uniformity of the gloss space was improved by defining a new gloss difference equation. Finally, a systematic, scalable, and perceptually based workflow was defined using cost-effective instruments.

  18. Some visual, optometric and perceptual effects of coloured glasses.

    PubMed

    Wilkins, A; Neary, C

    1991-04-01

    We examined 20 individuals who had worn coloured glasses (Irlen filters) for a period of at least 3 months and who claimed to find them beneficial. Sixteen had a history of reading difficulties. The performance of a variety of visual tasks was compared: (1) using the coloured lenses; (2) using neutral density filters of similar photopic transmittance; and (3) using trial lenses to correct any residual refractive error. The coloured lenses appeared to reduce discomfort and susceptibility to anomalous perceptual effects upon viewing grating patterns. They also improved the speed of visual search by a small amount. The lenses had idiosyncratic effects on ocular muscle balance and acuity. They did not affect contrast sensitivity at a spatial frequency of 4 c/deg. PMID:2062541

  19. Reducing the vigilance decrement: The effects of perceptual variability.

    PubMed

    Thomson, David R; Smilek, Daniel; Besner, Derek

    2015-05-01

    The longer we are required to monitor for rare but critical events, the accuracy and speed with which we detect such events tend to suffer (the 'vigilance decrement') with more difficult tasks yielding larger decrements. Here, we present a striking example of a situation in which increasing the difficulty and complexity of a novel vigilance task actually decreases the vigilance decrement. In a 'Stable' condition participants monitored for the same critical target throughout the task, whereas in a 'Variable' condition, participants monitored for many possible instantiations of the critical target. Despite the fact that the Variable condition was objectively more difficult, the vigilance decrement was significantly reduced in response times relative to the Stable condition. We discuss these findings in light of 'overload' and 'underload' theories of the vigilance decrement and suggest that perceptual variability may provide bottom-up support for the maintenance of attentional resource allocation to an external task. PMID:25749256

  20. 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

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. Quantum-Computation for Perceptual Control Architecture

    NASA Astrophysics Data System (ADS)

    Ivancevic, Vladimir G.; Reid, Darryn J.

    2015-11-01

    In this Chapter, we propose a quantum-dynamical modeling approach to Perceptual Control Architecture, using large networks of Josephson Junctions and their category-theoretic generalizations with fuzzy associative functors Our approach provides the basis for composing modular multi-layered perceptual control architectures using Josephson Junction Networks, employing intuitively appealing category-theoretic abstractions to hide the algebraic details from the designer while nonetheless being able to rigorously ensure functional composition correctness. That is, our approach ensures that Josephson Junction Networks, as a modeling primitive, can be composed into formally correct multi-layered perceptual control architectures, while hiding the underlying algebraic systems of equations from the designer under a blanket of category-theoretic abstraction.

  7. 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.

  8. 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.

  9. 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.

  10. Short-term memory affects color perception in context.

    PubMed

    Olkkonen, Maria; Allred, Sarah R

    2014-01-01

    Color-based object selection - for instance, looking for ripe tomatoes in the market - places demands on both perceptual and memory processes: it is necessary to form a stable perceptual estimate of surface color from a variable visual signal, as well as to retain multiple perceptual estimates in memory while comparing objects. Nevertheless, perceptual and memory processes in the color domain are generally studied in separate research programs with the assumption that they are independent. Here, we demonstrate a strong failure of independence between color perception and memory: the effect of context on color appearance is substantially weakened by a short retention interval between a reference and test stimulus. This somewhat counterintuitive result is consistent with Bayesian estimation: as the precision of the representation of the reference surface and its context decays in memory, prior information gains more weight, causing the retained percepts to be drawn toward prior information about surface and context color. This interaction implies that to fully understand information processing in real-world color tasks, perception and memory need to be considered jointly. PMID:24475131

  11. 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

  12. JPEG2000 encoding with perceptual distortion control.

    PubMed

    Liu, Zhen; Karam, Lina J; Watson, Andrew B

    2006-07-01

    In this paper, a new encoding approach is proposed to control the JPEG2000 encoding in order to reach a desired perceptual quality. The new method is based on a vision model that incorporates various masking effects of human visual perception and a perceptual distortion metric that takes spatial and spectral summation of individual quantization errors into account. Compared with the conventional rate-based distortion minimization JPEG2000 encoding, the new method provides a way to generate consistent quality images at a lower bit rate. PMID:16830900

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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

  18. Is perceptual learning associated with changes in a sensory region?

    PubMed Central

    Watanabe, Takeo

    2012-01-01

    Perceptual learning is defined as long-term improvement in perceptual abilities as a result of perceptual experiences. It is controversial as to whether perceptual learning is associated with changes in a sensory region of the brain or not. Here, we review research that supports, or otherwise, the sensory change hypothesis and discuss what needs to be done in the future to answer this question more definitively. PMID:23236341

  19. 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.

  20. Perceptual Learning for Speech: Is There a Return to Normal?

    ERIC Educational Resources Information Center

    Kraljic, Tanya; Samuel, Arthur G.

    2005-01-01

    Recent work on perceptual learning shows that listeners' phonemic representations dynamically adjust to reflect the speech they hear (Norris, McQueen, & Cutler, 2003). We investigate how the perceptual system makes such adjustments, and what (if anything) causes the representations to return to their pre-perceptual learning settings. Listeners are…

  1. 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…

  2. 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.

  3. 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…

  4. Improving Perceptual Skills with 3-Dimensional Animations.

    ERIC Educational Resources Information Center

    Johns, Janet Faye; Brander, Julianne Marie

    1998-01-01

    Describes three-dimensional computer aided design (CAD) models for every component in a representative mechanical system; the CAD models made it easy to generate 3-D animations that are ideal for teaching perceptual skills in multimedia computer-based technical training. Fifteen illustrations are provided. (AEF)

  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 Adaptation to Non-Native Speech

    ERIC Educational Resources Information Center

    Bradlow, Ann R.; Bent, Tessa

    2008-01-01

    This study investigated talker-dependent and talker-independent perceptual adaptation to foreign-accent English. Experiment 1 investigated talker-dependent adaptation by comparing native English listeners' recognition accuracy for Chinese-accented English across single and multiple talker presentation conditions. Results showed that the native…

  7. 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

  8. 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…

  9. 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…

  10. 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…

  11. 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…

  12. 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.

  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. 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

  15. 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…

  16. Perceptual crossing: the simplest online paradigm

    PubMed Central

    Auvray, Malika; Rohde, Marieke

    2012-01-01

    Researchers in social cognition increasingly realize that many phenomena cannot be understood by investigating offline situations only, focusing on individual mechanisms and an observer perspective. There are processes of dynamic emergence specific to online situations, when two or more persons are engaged in a real-time interaction that are more than just the sum of the individual capacities or behaviors, and these require the study of online social interaction. Auvray et al.'s (2009) perceptual crossing paradigm offers possibly the simplest paradigm for studying such online interactions: two persons, a one-dimensional space, one bit of information, and a yes/no answer. This study has provoked a lot of resonance in different areas of research, including experimental psychology, computer/robot modeling, philosophy, psychopathology, and even in the field of design. In this article, we review and critically assess this body of literature. We give an overview of both behavioral experimental research and simulated agent modeling done using the perceptual crossing paradigm. We discuss different contexts in which work on perceptual crossing has been cited. This includes the controversy about the possible constitutive role of perceptual crossing for social cognition. We conclude with an outlook on future research possibilities, in particular those that could elucidate the link between online interaction dynamics and individual social cognition. PMID:22723776

  17. 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)

  18. 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

  19. 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…

  20. 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

  1. 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,…

  2. 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…

  3. 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

  4. Word-type effects in word-stem priming: evidence for semantic processing in the perceptual representation system?

    PubMed

    Cooley, E L; Stringer, A Y

    1998-08-01

    While a presemantic Perceptual Representation System is believed to mediate implicit memory tasks such as word-stem priming, clinical studies suggest semantic information can be processed during priming. To clarify the nature of this system, we investigated word-type effects in word-stem priming in a nonclinical sample of 41 undergraduates who rated the pleasantness of threatening and nonthreatening words, performed implicit and explicit memory tasks, and completed measures of mood state. More nonthreatening words were primed and scores on the Beck Depression Inventory were negatively correlated with production of nonthreatening words. During cued recall, more threatening than nonthreatening words were remembered and ratings of state anxiety were negatively correlated with recall of nonthreatening words. Our findings support the contention that semantic information is processed during priming and that mood congruent biases also operate. These results may call for a reconceptualization of the Perceptual Representation System. PMID:9760655

  5. Healthy Older Observers Show Equivalent Perceptual-Cognitive Training Benefits to Young Adults for Multiple Object Tracking

    PubMed Central

    Legault, Isabelle; Allard, Rémy; Faubert, Jocelyn

    2013-01-01

    The capacity to process complex dynamic scenes is of critical importance in real life. For instance, traveling through a crowd while avoiding collisions and maintaining orientation and good motor control requires fluent and continuous perceptual-cognitive processing. It is well documented that effects of healthy aging can influence perceptual-cognitive processes (Faubert, 2002) and that the efficiency of such processes can improve with training even for older adults (Richards et al., 2006). Here we assess the capacity of older participants to improve their tracking speed thresholds in a dynamic, virtual reality environment. Results show that this capacity is significantly affected by healthy aging but that perceptual-cognitive training can significantly reduce age-related effects in older individuals, who show an identical learning function to younger healthy adults. Data support the notion that learning in healthy older persons is maintained for processing complex dynamic scenes. PMID:23761025

  6. 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

  7. 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

  8. 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.

  9. 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

  10. Visual short-term memory load strengthens selective attention.

    PubMed

    Roper, Zachary J J; Vecera, Shaun P

    2014-04-01

    Perceptual load theory accounts for many attentional phenomena; however, its mechanism remains elusive because it invokes underspecified attentional resources. Recent dual-task evidence has revealed that a concurrent visual short-term memory (VSTM) load slows visual search and reduces contrast sensitivity, but it is unknown whether a VSTM load also constricts attention in a canonical perceptual load task. If attentional selection draws upon VSTM resources, then distraction effects-which measure attentional "spill-over"-will be reduced as competition for resources increases. Observers performed a low perceptual load flanker task during the delay period of a VSTM change detection task. We observed a reduction of the flanker effect in the perceptual load task as a function of increasing concurrent VSTM load. These findings were not due to perceptual-level interactions between the physical displays of the two tasks. Our findings suggest that perceptual representations of distractor stimuli compete with the maintenance of visual representations held in memory. We conclude that access to VSTM determines the degree of attentional selectivity; when VSTM is not completely taxed, it is more likely for task-irrelevant items to be consolidated and, consequently, affect responses. The "resources" hypothesized by load theory are at least partly mnemonic in nature, due to the strong correspondence they share with VSTM capacity. PMID:24002967

  11. 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

  12. 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

  13. Does perceptual-motor calibration generalize across two different forms of locomotion? Investigations of walking and wheelchairs.

    PubMed

    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

  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. 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.

  16. 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 ...

  17. Memory loss

    MedlinePLUS

    ... loss. Such memory loss is due to other diseases. Memory loss can be caused by many things. To ... event Bipolar disorder Depression or other mental health disorders, such as schizophrenia Memory loss may be a sign of dementia . Dementia ...

  18. Repeated checking causes memory distrust.

    PubMed

    van den Hout, Marcel; Kindt, Merel

    2003-03-01

    This paper attempts to explain why in obsessive-compulsive disorder (OCD) checkers distrust in memory persists despite extensive checking. It is argued that: (1) repeated checking increases familiarity with the issues checked; (2) increased familiarity promotes conceptual processing which inhibits perceptual processing; (3) inhibited perceptual processing makes recollections less vivid and detailed and finally; (4) reduction in vividness and detail promotes distrust in memory. An interactive computer animation was developed in which participants had to perform checking rituals on a virtual gas stove. Two separate experiments were carried out with n=39 (Experiment I) and n=40 (Experiment II) healthy participants. In both studies, the control group and the experimental group were given the same pre-test and post-test on the virtual gas stove. In between, the experimental group engaged in 'relevant checking', i.e. checking the gas stove, while the control group engaged in 'irrelevant checking', i.e. checking virtual light bulbs. In both experiments there were powerful effects of repeated 'relevant checking': while actual memory accuracy remained unaffected, the vividness and detail of the recollections were greatly reduced. Most pertinently, in both experiments relevant checking undermined confidence in memory. No such effects were observed in the control group. One might argue that the pre-test/post-test design may have made the control group anticipate a memory assessment at the post-test and that this artifact made them relatively alert producing memory confidence at post test that was artificially high. A third experiment was carried out (n=2 x 20) in which no pre-test was given while, other than that, Experiment III was identical to the first two experiments. Results confirmed earlier findings: compared to the irrelevant checking control group, recollections in the relevant checking group were non-vivid, non-detailed while confidence in memory was low. The theory and data suggest an answer to the question 'why memory distrust persists despite repetitive checking'. In people who check extensively, memory distrust may persist as a result of repetitive checking. OCD checking may be motivated by the wish to reduce uncertainty, but checking appears to be a counter-productive safety strategy. Rather than reducing doubt, checking fosters doubt and ironically increases meta-memory problems. PMID:12600401

  19. 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…

  20. Effects of Aging on True and False Memory Formation: An fMRI Study

    ERIC Educational Resources Information Center

    Dennis, Nancy A.; Kim, Hongkeun; Cabeza, Roberto

    2007-01-01

    Compared to young, older adults are more likely to forget events that occurred in the past as well as remember events that never happened. Previous studies examining false memories and aging have shown that these memories are more likely to occur when new items share perceptual or semantic similarities with those presented during encoding. It is…

  1. 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

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. Perceptual and cognitive abnormalities in bulimia.

    PubMed

    Powers, P S; Schulman, R G; Gleghorn, A A; Prange, M E

    1987-11-01

    The authors compared 55 bulimic subjects and 55 normal control subjects using the Beck Depression Inventory, a new scale designed to detect cognitive distortions (the Bulimia Cognitive Distortion Scale), and several perceptual and attitudinal measures of body image. There were significant differences between the bulimic and control groups on all measures except estimates of face width. These findings are discussed in terms of a multifactorial theory of the psychopathogenesis of bulimia. PMID:3674227

  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. Atypicalities in perceptual adaptation in autism do not extend to perceptual causality.

    PubMed

    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

  9. Generalized perceptual features for animal vocalization classification

    NASA Astrophysics Data System (ADS)

    Clemins, Patrick J.; Johnson, Michael T.

    2001-05-01

    Two sets of generalized, perceptual-based features are investigated for use in classifying animal vocalizations. Since many species, especially mammals, share similar physical sound perception mechanisms which vary in size, two features sets commonly used in human speech processing, mel-frequency cepstral coefficients (MFCCs) and perceptual linear prediction (PLP) analysis, are modified for use in other species. One modification made to the feature extraction process is incorporating the frequency range of hearing and length of the basilar membrane of the animal in order to correctly determine the width and location of the critical band filters used for signal processing. Experimentally determined critical bands (equivalent rectangular bandwidth) and equal loudness curves (audiograms) can also be incorporated directly into the feature extraction process. Experiments are performed on African elephant (Loxodonta africana) vocalizations using a hidden Markov model (HMM) based classifier showing increased classification accuracy when using features sets based on the specific animals perceptual abilities compared to the original human perception-based feature sets.

  10. The role of objects in perceptual grouping.

    PubMed

    Feldman, J

    1999-09-01

    Perceptual organization can be viewed as the selection of the best or "most reasonable" parse of a given scene. However, the principles that determine which interpretation is most reasonable have resisted most attempts to define them formally. This paper summarizes a formal theory of human perceptual organization, called minimal model theory, in which the best interpretation of a given scene is expressed as the formally minimal interpretation in a well-defined space of possible interpretations. We then focus specifically on the role of types of grouping units, in particular the difficult notion of "object". Although grouping is often thought of as the process of dividing the image into objects, most research in perceptual grouping actually focuses on simpler types of units, such as contours and surfaces. Minimal model theory characterizes grouping units at a logical level, demonstrating how formal assumptions about units induce the observer to place a certain preference ranking on interpretations. The theory is then applied to the more subtle problem of objects, culminating in a definition for objects that is formally rigorous but at the same time captures some of the flexibility of human intuitions about objects. PMID:10504879

  11. 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

  12. 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.

  13. Perceptual asymmetries and handedness: a neglected link?

    PubMed Central

    Marzoli, Daniele; Prete, Giulia; Tommasi, Luca

    2014-01-01

    Healthy individuals tend to weigh in more the left than the right side of visual space in a variety of contexts, ranging from pseudoneglect to perceptual asymmetries for faces. Among the common explanations proposed for the attentional and perceptual advantages of the left visual field, a link with the prevalence of right-handedness in humans has never been suggested, although some evidence seems to converge in favor of a bias of spatial attention toward the region most likely coincident with another person’s right hand during a face-to-face interaction. Such a bias might imply an increased efficiency in monitoring both communicative and aggressive acts, the right limb being more used than the left in both types of behavior. Although attentional and perceptual asymmetries could be linked to right-handedness at the level of phylogeny because of the evolutionarily advantage of directing attention toward the region where others’ dominant hand usually operates, it is also legitimate to question whether, at the ontogenetic level, frequent exposure to right-handed individuals may foster leftward biases. These views are discussed in the light of extant literature, and a number of tests are proposed in order to assess our hypotheses. PMID:24592250

  14. 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

  15. 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

  16. 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

  17. 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

  18. Influence of early attentional modulation on working memory.

    PubMed

    Gazzaley, Adam

    2011-05-01

    It is now established that attention influences working memory (WM) at multiple processing stages. This liaison between attention and WM poses several interesting empirical questions. Notably, does attention impact WM via its influences on early perceptual processing? If so, what are the critical factors at play in this attention-perception-WM interaction. I review recent data from our laboratory utilizing a variety of techniques (electroencephalography (EEG), functional MRI (fMRI) and transcranial magnetic stimulation (TMS)), stimuli (features and complex objects), novel experimental paradigms, and research populations (younger and older adults), which converge to support the conclusion that top-down modulation of visual cortical activity at early perceptual processing stages (100-200 ms after stimulus onset) impacts subsequent WM performance. Factors that affect attentional control at this stage include cognitive load, task practice, perceptual training, and aging. These developments highlight the complex and dynamic relationships among perception, attention, and memory. PMID:21184764

  19. Influence of early attentional modulation on working memory

    PubMed Central

    Gazzaley, Adam

    2011-01-01

    It is now established that attention influences working memory (WM) at multiple processing stages. This liaison between attention and WM poses several interesting empirical questions. Notably, does attention impact WM via its influences on early perceptual processing? If so, what are the critical factors at play in this attention-perception-WM interaction. I review recent data from our laboratory utilizing a variety of techniques (electroencephalography (EEG), functional MRI (fMRI) and transcranial magnetic stimulation (TMS)), stimuli (features and complex objects), novel experimental paradigms, and research populations (younger and older adults), which converge to support the conclusion that top-down modulation of visual cortical activity at early perceptual processing stages (100–200 ms after stimulus onset) impacts subsequent WM performance. Factors that affect attentional control at this stage include cognitive load, task practice, perceptual training, and aging. These developments highlight the complex and dynamic relationships among perception, attention, and memory. PMID:21184764

  20. Size-Sensitive Perceptual Representations Underlie Visual and Haptic Object Recognition

    PubMed Central

    Craddock, Matt; Lawson, Rebecca

    2009-01-01

    A variety of similarities between visual and haptic object recognition suggests that the two modalities may share common representations. However, it is unclear whether such common representations preserve low-level perceptual features or whether transfer between vision and haptics is mediated by high-level, abstract representations. Two experiments used a sequential shape-matching task to examine the effects of size changes on unimodal and crossmodal visual and haptic object recognition. Participants felt or saw 3D plastic models of familiar objects. The two objects presented on a trial were either the same size or different sizes and were the same shape or different but similar shapes. Participants were told to ignore size changes and to match on shape alone. In Experiment 1, size changes on same-shape trials impaired performance similarly for both visual-to-visual and haptic-to-haptic shape matching. In Experiment 2, size changes impaired performance on both visual-to-haptic and haptic-to-visual shape matching and there was no interaction between the cost of size changes and direction of transfer. Together the unimodal and crossmodal matching results suggest that the same, size-specific perceptual representations underlie both visual and haptic object recognition, and indicate that crossmodal memory for objects must be at least partly based on common perceptual representations. PMID:19956685

  1. 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

  2. Stimulus Roving and Flankers Affect Perceptual Learning of Contrast Discrimination in Macaca mulatta

    PubMed Central

    Thiele, Alexander

    2014-01-01

    ‘Stimulus roving’ refers to a paradigm in which the properties of the stimuli to be discriminated vary from trial to trial, rather than being kept constant throughout a block of trials. Rhesus monkeys have previously been shown to improve their contrast discrimination performance on a non-roving task, in which they had to report the contrast of a test stimulus relative to that of a fixed-contrast sample stimulus. Human psychophysics studies indicate that roving stimuli yield little or no perceptual learning. Here, we investigate how stimulus roving influences perceptual learning in macaque monkeys and how the addition of flankers alters performance under roving conditions. Animals were initially trained on a contrast discrimination task under non-roving conditions until their performance levels stabilized. The introduction of roving contrast conditions resulted in a pronounced drop in performance, which suggested that subjects initially failed to heed the sample contrast and performed the task using an internal memory reference. With training, significant improvements occurred, demonstrating that learning is possible under roving conditions. To investigate the notion of flanker-induced perceptual learning, flanker stimuli (30% fixed-contrast iso-oriented collinear gratings) were presented jointly with central (roving) stimuli. Presentation of flanker stimuli yielded substantial performance improvements in one subject, but deteriorations in the other. Finally, after the removal of flankers, performance levels returned to their pre-flanker state in both subjects, indicating that the flanker-induced changes were contingent upon the continued presentation of flankers. PMID:25340335

  3. Memory Skills of Deaf Learners: Implications and Applications

    ERIC Educational Resources Information Center

    Hamilton, Harley

    2011-01-01

    This paper will review research on working memory and short-term memory abilities of deaf individuals delineating strengths and weaknesses. The areas of memory reviewed include weaknesses such as sequential recall, processing speed, attention, and memory load. Strengths include free recall, visuospatial recall, imagery and dual encoding.…

  4. Statistical and perceptual updating: correlated impairments in right brain injury.

    PubMed

    Stöttinger, Elisabeth; Filipowicz, Alex; Marandi, Elahe; Quehl, Nadine; Danckert, James; Anderson, Britt

    2014-06-01

    It has been hypothesized that many of the cognitive impairments commonly seen after right brain damage (RBD) can be characterized as a failure to build or update mental models. We (Danckert et al. in Neglect as a disorder of representational updating. NOVA Open Access, New York, 2012a; Cereb Cortex 22:2745-2760, 2012b) were the first to directly assess the association between RBD and updating and found that RBD patients were unable to exploit a strongly biased play strategy in their opponent in the children's game rock, paper, scissors. Given that this game required many other cognitive capacities (i.e., working memory, sustained attention, reward processing), RBD patients could have failed this task for various reasons other than a failure to update. To assess the generality of updating deficits after RBD, we had RBD, left brain-damaged (LBD) patients and healthy controls (HCs) describe line drawings that evolved gradually from one figure (e.g., rabbit) to another (e.g., duck) in addition to the RPS updating task. RBD patients took significantly longer to alter their perceptual report from the initial object to the final object than did LBD patients and HCs. Although both patient groups performed poorly on the RPS task, only the RBD patients showed a significant correlation between the two, very different, updating tasks. We suggest these data indicate a general deficiency in the ability to update mental representations following RBD. PMID:24615155

  5. The Dilution Effect and Information Integration in Perceptual Decision Making

    PubMed Central

    Hotaling, Jared M.; Cohen, Andrew L.; Shiffrin, Richard M.; Busemeyer, Jerome R.

    2015-01-01

    In cognitive science there is a seeming paradox: On the one hand, studies of human judgment and decision making have repeatedly shown that people systematically violate optimal behavior when integrating information from multiple sources. On the other hand, optimal models, often Bayesian, have been successful at accounting for information integration in fields such as categorization, memory, and perception. This apparent conflict could be due, in part, to different materials and designs that lead to differences in the nature of processing. Stimuli that require controlled integration of information, such as the quantitative or linguistic information (commonly found in judgment studies), may lead to suboptimal performance. In contrast, perceptual stimuli may lend themselves to automatic processing, resulting in integration that is closer to optimal. We tested this hypothesis with an experiment in which participants categorized faces based on resemblance to a family patriarch. The amount of evidence contained in the top and bottom halves of each test face was independently manipulated. These data allow us to investigate a canonical example of sub-optimal information integration from the judgment and decision making literature, the dilution effect. Splitting the top and bottom halves of a face, a manipulation meant to encourage controlled integration of information, produced farther from optimal behavior and larger dilution effects. The Multi-component Information Accumulation model, a hybrid optimal/averaging model of information integration, successfully accounts for key accuracy, response time, and dilution effects. PMID:26406323

  6. Forced to remember: when memory is biased by salient information.

    PubMed

    Santangelo, Valerio

    2015-04-15

    The last decades have seen a rapid growing in the attempt to understand the key factors involved in the internal memory representation of the external world. Visual salience have been found to provide a major contribution in predicting the probability for an item/object embedded in a complex setting (i.e., a natural scene) to be encoded and then remembered later on. Here I review the existing literature highlighting the impact of perceptual- (based on low-level sensory features) and semantics-related salience (based on high-level knowledge) on short-term memory representation, along with the neural mechanisms underpinning the interplay between these factors. The available evidence reveal that both perceptual- and semantics-related factors affect attention selection mechanisms during the encoding of natural scenes. Biasing internal memory representation, both perceptual and semantics factors increase the probability to remember high- to the detriment of low-saliency items. The available evidence also highlight an interplay between these factors, with a reduced impact of perceptual-related salience in biasing memory representation as a function of the increasing availability of semantics-related salient information. The neural mechanisms underpinning this interplay involve the activation of different portions of the frontoparietal attention control network. Ventral regions support the assignment of selection/encoding priorities based on high-level semantics, while the involvement of dorsal regions reflects priorities assignment based on low-level sensory features. PMID:25595422

  7. Encoding, Memory, and Transcoding Deficits in Childhood Apraxia of Speech

    ERIC Educational Resources Information Center

    Shriberg, Lawrence D.; Lohmeier, Heather L.; Strand, Edythe A.; Jakielski, Kathy J.

    2012-01-01

    A central question in Childhood Apraxia of Speech (CAS) is whether the core phenotype is limited to transcoding (planning/programming) deficits or if speakers with CAS also have deficits in auditory-perceptual "encoding" (representational) and/or "memory" (storage and retrieval of representations) processes. We addressed this and other questions…

  8. Encoding, Memory, and Transcoding Deficits in Childhood Apraxia of Speech

    ERIC Educational Resources Information Center

    Shriberg, Lawrence D.; Lohmeier, Heather L.; Strand, Edythe A.; Jakielski, Kathy J.

    2012-01-01

    A central question in Childhood Apraxia of Speech (CAS) is whether the core phenotype is limited to transcoding (planning/programming) deficits or if speakers with CAS also have deficits in auditory-perceptual "encoding" (representational) and/or "memory" (storage and retrieval of representations) processes. We addressed this and other questions…

  9. Event Boundaries in Perception Affect Memory Encoding and Updating

    ERIC Educational Resources Information Center

    Swallow, Khena M.; Zacks, Jeffrey M.; Abrams, Richard A.

    2009-01-01

    Memory for naturalistic events over short delays is important for visual scene processing, reading comprehension, and social interaction. The research presented here examined relations between how an ongoing activity is perceptually segmented into events and how those events are remembered a few seconds later. In several studies, participants…

  10. Working Memory Enhances Visual Perception: Evidence from Signal Detection Analysis

    ERIC Educational Resources Information Center

    Soto, David; Wriglesworth, Alice; Bahrami-Balani, Alex; Humphreys, Glyn W.

    2010-01-01

    We show that perceptual sensitivity to visual stimuli can be modulated by matches between the contents of working memory (WM) and stimuli in the visual field. Observers were presented with an object cue (to hold in WM or to merely attend) and subsequently had to identify a brief target presented within a colored shape. The cue could be…

  11. Intersensory Redundancy Enhances Memory in Bobwhite Quail Embryos

    ERIC Educational Resources Information Center

    Lickliter, Robert; Bahrick, Lorraine E.; Honeycutt, Hunter

    2004-01-01

    Information presented concurrently and redundantly to 2 or more senses (intersensory redundancy) has been shown to recruit attention and promote perceptual learning of amodal stimulus properties in animal embryos and human infants. This study examined whether the facilitative effect of intersensory redundancy also extends to the domain of memory

  12. Intersensory Redundancy Enhances Memory in Bobwhite Quail Embryos

    ERIC Educational Resources Information Center

    Lickliter, Robert; Bahrick, Lorraine E.; Honeycutt, Hunter

    2004-01-01

    Information presented concurrently and redundantly to 2 or more senses (intersensory redundancy) has been shown to recruit attention and promote perceptual learning of amodal stimulus properties in animal embryos and human infants. This study examined whether the facilitative effect of intersensory redundancy also extends to the domain of memory.…

  13. Beta oscillations define discrete perceptual cycles in the somatosensory domain.

    PubMed

    Baumgarten, Thomas J; Schnitzler, Alfons; Lange, Joachim

    2015-09-29

    Whether seeing a movie, listening to a song, or feeling a breeze on the skin, we coherently experience these stimuli as continuous, seamless percepts. However, there are rare perceptual phenomena that argue against continuous perception but, instead, suggest discrete processing of sensory input. Empirical evidence supporting such a discrete mechanism, however, remains scarce and comes entirely from the visual domain. Here, we demonstrate compelling evidence for discrete perceptual sampling in the somatosensory domain. Using magnetoencephalography (MEG) and a tactile temporal discrimination task in humans, we find that oscillatory alpha- and low beta-band (8-20 Hz) cycles in primary somatosensory cortex represent neurophysiological correlates of discrete perceptual cycles. Our results agree with several theoretical concepts of discrete perceptual sampling and empirical evidence of perceptual cycles in the visual domain. Critically, these results show that discrete perceptual cycles are not domain-specific, and thus restricted to the visual domain, but extend to the somatosensory domain. PMID:26324922

  14. Perceptual Learning of Dysarthric Speech: A Review of Experimental Studies

    PubMed Central

    Borrie, Stephanie A.; McAuliffe, Megan J.; Liss, Julie M.

    2013-01-01

    Purpose This review article provides a theoretical overview of the characteristics of perceptual learning, reviews perceptual learning studies that pertain to dysarthric populations, and identifies directions for future research that consider the application of perceptual learning to the management of dysarthria. Method A critical review of the literature was conducted that summarized and synthesized previously published research in the area of perceptual learning with atypical speech. Literature related to perceptual learning of neurologically degraded speech was emphasized with the aim of identifying key directions for future research with this population. Conclusions Familiarization with unfamiliar or ambiguous speech signals can facilitate perceptual learning of that same speech signal. There is a small but growing body of evidence that perceptual learning also occurs for listeners familiarized with dysarthric speech. Perceptual learning of the dysarthric signal is both theoretically and clinically significant. In order to establish the efficacy of exploiting perceptual learning paradigms for rehabilitative gain in dysarthria management, research is required to build on existing empirical evidence and develop a theoretical framework for learning to better recognize neurologically degraded speech. PMID:22199185

  15. Perception of Self-Motion and Regulation of Walking Speed in Young-Old Adults.

    PubMed

    Lalonde-Parsi, Marie-Jasmine; Lamontagne, Anouk

    2015-07-01

    Whether a reduced perception of self-motion contributes to poor walking speed adaptations in older adults is unknown. In this study, speed discrimination thresholds (perceptual task) and walking speed adaptations (walking task) were compared between young (19-27 years) and young-old individuals (63-74 years), and the relationship between the performance on the two tasks was examined. Participants were evaluated while viewing a virtual corridor in a helmet-mounted display. Speed discrimination thresholds were determined using a staircase procedure. Walking speed modulation was assessed on a self-paced treadmill while exposed to different self-motion speeds ranging from 0.25 to 2 times the participants' comfortable speed. For each speed, participants were instructed to match the self-motion speed described by the moving corridor. On the walking task, participants displayed smaller walking speed errors at comfortable walking speeds compared with slower of faster speeds. The young-old adults presented larger speed discrimination thresholds (perceptual experiment) and larger walking speed errors (walking experiment) compared with young adults. Larger walking speed errors were associated with higher discrimination thresholds. The enhanced performance on the walking task at comfortable speed suggests that intersensory calibration processes are influenced by experience, hence optimized for frequently encountered conditions. The altered performance of the young-old adults on the perceptual and walking tasks, as well as the relationship observed between the two tasks, suggest that a poor perception of visual motion information may contribute to the poor walking speed adaptations that arise with aging. PMID:25029587

  16. Increasing Speed of Processing With Action Video Games

    PubMed Central

    Dye, Matthew W.G.; Green, C. Shawn; Bavelier, Daphne

    2010-01-01

    In many everyday situations, speed is of the essence. However, fast decisions typically mean more mistakes. To this day, it remains unknown whether reaction times can be reduced with appropriate training, within one individual, across a range of tasks, and without compromising accuracy. Here we review evidence that the very act of playing action video games significantly reduces reaction times without sacrificing accuracy. Critically, this increase in speed is observed across various tasks beyond game situations. Video gaming may therefore provide an efficient training regimen to induce a general speeding of perceptual reaction times without decreases in accuracy of performance. PMID:20485453

  17. Perceptual basis of redundancy gains in visual pop-out search.

    PubMed

    Töllner, Thomas; Zehetleitner, Michael; Krummenacher, Joseph; Müller, Hermann J

    2011-01-01

    The redundant-signals effect (RSE) refers to a speed-up of RT when the response is triggered by two, rather than just one, response-relevant target elements. Although there is agreement that in the visual modality RSEs observed with dimensionally redundant signals originating from the same location are generated by coactive processing architectures, there has been a debate as to the exact stage(s)--preattentive versus postselective--of processing at which coactivation arises. To determine the origin(s) of redundancy gains in visual pop-out search, the present study combined mental chronometry with electrophysiological markers that reflect purely preattentive perceptual (posterior-contralateral negativity [PCN]), preattentive and postselective perceptual plus response selection-related (stimulus-locked lateralized readiness potential [LRP]), or purely response production-related processes (response-locked LRP). As expected, there was an RSE on target detection RTs, with evidence for coactivation. At the electrophysiological level, this pattern was mirrored by an RSE in PCN latencies, whereas stimulus-locked LRP latencies showed no RSE over and above the PCN effect. Also, there was no RSE on the response-locked LRPs. This pattern demonstrates a major contribution of preattentive perceptual processing stages to the RSE in visual pop-out search, consistent with parallel-coactive coding of target signals in multiple visual dimensions [Müller, H. J., Heller, D., & Ziegler, J. Visual search for singleton feature targets within and across feature dimensions. PMID:20044891

  18. The Effect of Set Size on the Relation Between Saccadic and Perceptual Decisions During Search

    NASA Technical Reports Server (NTRS)

    Eckstein, M. P.; Beutter, B. R.; Stone, L. S.; Wenzel, Beth (Technical Monitor)

    1998-01-01

    We have shown that when searching for a disk in noise at one of 10 locations, the accuracy of the I st saccade is similar to that of the perceptual decision at the time of saccadic programming. The present study has two goals: 1) to test whether this linden - extends to a contrast-discrimination task without noise, and 2) to measure the effect of set size on the relation between saccadic and perceptual decisions. Methods: Three observers searched over a grey background (34.5 cd/sq m) for a bright disk (63.2 cd/sq m) among dim disks (54.1 cd/sq m) along the circumference of a circle (r = 5.9 deg.) centered on a fixation cress. Four set sizes (2, 4, 6, 12) were used. In the 1st condition, stimuli were presented for 1 sec. and observers used natural eye movements. We then measured the accuracy of the first saccade (% correct using a shortest-distance criterion). In the 2nd condition, observers fixated a central cross at all times and the stimulus duration was approx. 70 as less than the median latency of the first saccade in the 1st condition (saccadic programming time). We then recorded perceptual performance and discarded trials in which observers broke fixation. Results: For set sizes of 2, 4, 8, and 12, the mean d' across observers for the perceptual decision was 2.03, 1.96, 1.94, 1.71, respectively, while the mean d' of the first saccade was only 0.73, 1.40, 1.23, 1.17. Conclusions: Unlike detection of a disk in noise, for all observers and set-sizes, the perceptual accuracy at the time of saccadic programming is better than that of the lst saccade. For set-sizes of 4, 6, and 12, the amount of information available to the perceptual system relative to that available to the saccadic system is approximately constant (fixed do ratio). For these higher set sizes, the constancy in do across set size for both perception and saccadic decisions is consistent with a simple signal detection theory (SDT) model that processes noisy signals in parallel. However, for 2 observers, at a set-size of 2, saccadic targeting appears to be worse than the SDT model prediction, perhaps due to speed-accuracy trade-off.

  19. The Role of Textured Material in Supporting Perceptual-Motor Functions

    PubMed Central

    Orth, Dominic; Davids, Keith; Wheat, Jon; Seifert, Ludovic; Liukkonen, Jarmo; Jaakkola, Timo; Ashford, Derek; Kerr, Graham

    2013-01-01

    Simple deformation of the skin surface with textured materials can improve human perceptual-motor performance. The implications of these findings are inexpensive, adaptable and easily integrated clothing, equipment and tools for improving perceptual-motor functionality. However, some clarification is needed because mixed results have been reported in the literature, highlighting positive, absent and/or negative effects of added texture on measures of perceptual-motor performance. Therefore the aim of this study was to evaluate the efficacy of textured materials for enhancing perceptual-motor functionality. The systematic review uncovered two variables suitable for sub-group analysis within and between studies: participant age (groupings were 18–51 years and 64.7–79.4 years) and experimental task (upright balance and walking). Evaluation of studies that observed texture effects during upright balance tasks, uncovered two additional candidate sub-groups for future work: vision (eyes open and eyes closed) and stability (stable and unstable). Meta-analysis (random effects) revealed that young participants improve performance by a small to moderate amount in upright balance tasks with added texture (SMD?=?0.28, 95%CI?=?0.46–0.09, Z?=?2.99, P?=?0.001; Tau2?=?0.02; Chi2?=?9.87, df?=?6, P?=?0.13; I2?=?39.22). Significant heterogeneity was found in, the overall effect of texture: Tau2?=?0.13; Chi2?=?130.71, df?=?26, P<0.0001; I2?=?85.98%, pooled samples in upright balance tasks: Tau2?=?0.09; Chi2?=?101.57, df?=?13, P<0.001; I2?=?72.67%, and in elderly in upright balance tasks: Tau2?=?0.16; Chi2?=?39.42, df?=?5, P<0.001; I2?=?83.05%. No effect was shown for walking tasks: Tau2?=?0.00; Chi2?=?3.45, df?=?4, P?=?0.27, I2?=?22.99%. Data provides unequivocal support for utilizing textured materials in young healthy populations for improving perceptual-motor performance. Future research is needed in young healthy populations under conditions where visual and proprioceptive information is challenged, as in high-speed movements, or where use of equipment mediates the performer-environment interaction or where dysfunctional information sources ‘compete’ for attention. In elderly and ailing populations data suggests further research is required to better understand contexts where texture can facilitate improved perceptual-motor performance. PMID:23565232

  20. Exploring Perceptual Skills in Children with Autism Spectrum Disorders: From Target Detection to Dynamic Perceptual Discrimination

    ERIC Educational Resources Information Center

    Miller, Louisa; McGonigle-Chalmers, Maggie

    2014-01-01

    Perceptual processing in autism is associated with both "strengths" and "weaknesses" but within a literature that varies widely in terms of the assessments used. We report data from 12 children with autism spectrum disorders (ASD) and 12 age and IQ matched neurotypical controls tested on a set of tasks using the same stimuli…

  1. Perceptual Discrimination in Static and Dynamic Noise: The Temporal Relation between Perceptual Encoding and Decision Making

    ERIC Educational Resources Information Center

    Ratcliff, Roger; Smith, Philip L.

    2010-01-01

    The authors report 9 new experiments and reanalyze 3 published experiments that investigate factors affecting the time course of perceptual processing and its effects on subsequent decision making. Stimuli in letter-discrimination and brightness-discrimination tasks were degraded with static and dynamic noise. The onset and the time course of…

  2. Perceptual advantage for category-relevant perceptual dimensions: the case of shape and motion

    PubMed Central

    Folstein, Jonathan R.; Palmeri, Thomas J.; Gauthier, Isabel

    2014-01-01

    Category learning facilitates perception along relevant stimulus dimensions, even when tested in a discrimination task that does not require categorization. While this general phenomenon has been demonstrated previously, perceptual facilitation along dimensions has been documented by measuring different specific phenomena in different studies using different kinds of objects. Across several object domains, there is support for acquired distinctiveness, the stretching of a perceptual dimension relevant to learned categories. Studies using faces and studies using simple separable visual dimensions have also found evidence of acquired equivalence, the shrinking of a perceptual dimension irrelevant to learned categories, and categorical perception, the local stretching across the category boundary. These later two effects are rarely observed with complex non-face objects. Failures to find these effects with complex non-face objects may have been because the dimensions tested previously were perceptually integrated. Here we tested effects of category learning with non-face objects categorized along dimensions that have been found to be processed by different areas of the brain, shape and motion. While we replicated acquired distinctiveness, we found no evidence for acquired equivalence or categorical perception. PMID:25520691

  3. Perceptual advantage for category-relevant perceptual dimensions: the case of shape and motion.

    PubMed

    Folstein, Jonathan R; Palmeri, Thomas J; Gauthier, Isabel

    2014-01-01

    Category learning facilitates perception along relevant stimulus dimensions, even when tested in a discrimination task that does not require categorization. While this general phenomenon has been demonstrated previously, perceptual facilitation along dimensions has been documented by measuring different specific phenomena in different studies using different kinds of objects. Across several object domains, there is support for acquired distinctiveness, the stretching of a perceptual dimension relevant to learned categories. Studies using faces and studies using simple separable visual dimensions have also found evidence of acquired equivalence, the shrinking of a perceptual dimension irrelevant to learned categories, and categorical perception, the local stretching across the category boundary. These later two effects are rarely observed with complex non-face objects. Failures to find these effects with complex non-face objects may have been because the dimensions tested previously were perceptually integrated. Here we tested effects of category learning with non-face objects categorized along dimensions that have been found to be processed by different areas of the brain, shape and motion. While we replicated acquired distinctiveness, we found no evidence for acquired equivalence or categorical perception. PMID:25520691

  4. Perceptual, categorical, and affective processing of ambiguous smiling facial expressions.

    PubMed

    Calvo, Manuel G; Fernández-Martín, Andrés; Nummenmaa, Lauri

    2012-12-01

    Why is a face with a smile but non-happy eyes likely to be interpreted as happy? We used blended expressions in which a smiling mouth was incongruent with the eyes (e.g., angry eyes), as well as genuine expressions with congruent eyes and mouth (e.g., both happy or angry). Tasks involved detection of a smiling mouth (perceptual), categorization of the expression (semantic), and valence evaluation (affective). The face stimulus display duration and stimulus onset asynchrony (SOA) were varied to assess the time course of each process. Results indicated that (a) a smiling mouth was visually more salient than the eyes both in truly happy and blended expressions; (b) a smile led viewers to categorize blended expressions as happy similarly for upright and inverted faces; (c) truly happy, but not blended, expressions primed the affective evaluation of probe scenes 550 ms following face onset; (d) both truly happy and blended expressions primed the detection of a smile in a probe scene by 170 ms post-stimulus; and (e) smile detection and expression categorization had similar processing thresholds and preceded affective evaluation. We conclude that the saliency of single physical features such as the mouth shape makes the smile quickly accessible to the visual system, which initially speeds up expression categorization regardless of congruence with the eyes. Only when the eye expression is later configurally integrated with the mouth, will affective discrimination begin. The present research provides support for serial models of facial expression processing. PMID:22939734

  5. A perceptual map for understanding concern about unsafe driving behaviours.

    PubMed

    Vanlaar, Ward; Simpson, Herb; Robertson, Robyn

    2008-09-01

    The objective of this paper is to develop a model that can help explain the public's level of concern associated with six dangerous driving behaviours (drinking and driving, speeding, distracted driving, using a cell phone while driving, fatigued or drowsy driving, and using illegal drugs while driving). Understanding the genesis of concern can be useful in addressing it and leveraging it to improve safe driving. Building on a risk perception model that was developed previously, the study investigated the relationship between the level of concern about the unsafe driving behaviours and the perceived level of concern of others about the dangerous driving behaviours, the perception of the prevalence of the dangerous driving behaviours, the perception of the level of risk imposed by these dangerous driving behaviours, and the perception of the severity of injuries that can result from them. Data from two independent samples were modeled using multidimensional scaling and logistic regression analysis. Both samples come from telephone surveys; one was administered to a random sample of 750 drivers in the province of Ontario, Canada in November 2006, the other to a random sample of 1201 drivers across Canada in September 2006. Two dimensions in particular were found to fit the data well: perceived risk and the perceived level of concern of others. The results from these analyses are summarized using a perceptual map. The relevance of such a map is illustrated by explaining the factors that impact levels of concern regarding several of the unsafe driving behaviours. PMID:18760094

  6. Ongoing behavior predicts perceptual report of interval duration

    PubMed Central

    Gouvêa, Thiago S.; Monteiro, Tiago; Soares, Sofia; Atallah, Bassam V.; Paton, Joseph J.

    2014-01-01

    The ability to estimate the passage of time is essential for adaptive behavior in complex environments. Yet, it is not known how the brain encodes time over the durations necessary to explain animal behavior. Under temporally structured reinforcement schedules, animals tend to develop temporally structured behavior, and interval timing has been suggested to be accomplished by learning sequences of behavioral states. If this is true, trial to trial fluctuations in behavioral sequences should be predictive of fluctuations in time estimation. We trained rodents in an duration categorization task while continuously monitoring their behavior with a high speed camera. Animals developed highly reproducible behavioral sequences during the interval being timed. Moreover, those sequences were often predictive of perceptual report from early in the trial, providing support to the idea that animals may use learned behavioral patterns to estimate the duration of time intervals. To better resolve the issue, we propose that continuous and simultaneous behavioral and neural monitoring will enable identification of neural activity related to time perception that is not explained by ongoing behavior. PMID:24672473

  7. Spatially Localized Time Shifts of the Perceptual Stream

    PubMed Central

    Hogendoorn, Hinze; Verstraten, Frans A.J.; Johnston, Alan

    2010-01-01

    Visual events trigger representations in different locations and times in the brain. In experience, however, these various neural responses refer to a single unified cause. To investigate how representations might be brought into temporal alignment, we attempted to locally manipulate neural processing in such a way that identical, simultaneous sequences would appear temporally misaligned. After adaptation to a 20?Hz sequentially expanding and contracting concentric grating, a running clock presented in the adapted region of the visual field appeared advanced relative to an identical clock presented simultaneously in an unadapted region. No such effect was observed following 5-Hz adaptation. Clock time reports following an exogenous cue showed the same effect of adaptation on perceived time, demonstrating that the apparent temporal misalignment was not mediated by differences in target selection or allocation of attention. This effect was not mediated by the apparent speed of the adapted clock: a clock in a 20-Hz-adapted spatial location appeared slower than a clock in a 5-Hz-adapted location, rather than faster. Furthermore, reaction times for a clock-hand orientation discrimination task were the same following 5- and 20-Hz adaptation, indicating that neural processing latencies were not differentially affected. Altogether, these findings suggest that the fragmented perceptual stream might be actively brought into temporal alignment through adaptive local mechanisms operating in spatially segregated regions of the visual field. PMID:21833242

  8. JPEG 2000 Encoding with Perceptual Distortion Control

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B.; Liu, Zhen; Karam, Lina J.

    2008-01-01

    An alternative approach has been devised for encoding image data in compliance with JPEG 2000, the most recent still-image data-compression standard of the Joint Photographic Experts Group. Heretofore, JPEG 2000 encoding has been implemented by several related schemes classified as rate-based distortion-minimization encoding. In each of these schemes, the end user specifies a desired bit rate and the encoding algorithm strives to attain that rate while minimizing a mean squared error (MSE). While rate-based distortion minimization is appropriate for transmitting data over a limited-bandwidth channel, it is not the best approach for applications in which the perceptual quality of reconstructed images is a major consideration. A better approach for such applications is the present alternative one, denoted perceptual distortion control, in which the encoding algorithm strives to compress data to the lowest bit rate that yields at least a specified level of perceptual image quality. Some additional background information on JPEG 2000 is prerequisite to a meaningful summary of JPEG encoding with perceptual distortion control. The JPEG 2000 encoding process includes two subprocesses known as tier-1 and tier-2 coding. In order to minimize the MSE for the desired bit rate, a rate-distortion- optimization subprocess is introduced between the tier-1 and tier-2 subprocesses. In tier-1 coding, each coding block is independently bit-plane coded from the most-significant-bit (MSB) plane to the least-significant-bit (LSB) plane, using three coding passes (except for the MSB plane, which is coded using only one "clean up" coding pass). For M bit planes, this subprocess involves a total number of (3M - 2) coding passes. An embedded bit stream is then generated for each coding block. Information on the reduction in distortion and the increase in the bit rate associated with each coding pass is collected. This information is then used in a rate-control procedure to determine the contribution of each coding block to the output compressed bit stream.

  9. Perceptual-components architecture for digital video

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B.

    1990-01-01

    A perceptual-components architecture for digital video partitions the image stream into signal components in a manner analogous to that used in the human visual system. These components consist of achromatic and opponent color channels, divided into static and motion channels, further divided into bands of particular spatial frequency and orientation. Bits are allocated to an individual band in accord with visual sensitivity to that band and in accord with the properties of visual masking. This architecture is argued to have desirable features such as efficiency, error tolerance, scalability, device independence, and extensibility.

  10. Perceptually based approach to color quantization

    NASA Astrophysics Data System (ADS)

    Gu, Erdan; Xu, Duanqing; Wang, Jingbin; Chen, Chun

    2001-09-01

    The process of selecting a small number of representative colors from an image of higher color resolution is called color image quantization. The ultimate goal of color image quantization is to minimize visible distortion. While its application as a frame buffer technique requires that algorithm efficiency is crucial. In this paper, a significantly faster quantization strategy than previous methods: median cut, variance, or octree-based algorithms, etc., is suggested. The new perceptually algorithm integrated with gamma correction produces result approximately as accurate as previous methods. Overall, the new proposed method is a preferable tradeoff between the quantizer complexity and visible distortion of the quantized image.

  11. Auditory Perceptual Learning for Speech Perception Can be Enhanced by Audiovisual Training.

    PubMed

    Bernstein, Lynne E; Auer, Edward T; Eberhardt, Silvio P; Jiang, Jintao

    2013-01-01

    Speech perception under audiovisual (AV) conditions is well known to confer benefits to perception such as increased speed and accuracy. Here, we investigated how AV training might benefit or impede auditory perceptual learning of speech degraded by vocoding. In Experiments 1 and 3, participants learned paired associations between vocoded spoken nonsense words and nonsense pictures. In Experiment 1, paired-associates (PA) AV training of one group of participants was compared with audio-only (AO) training of another group. When tested under AO conditions, the AV-trained group was significantly more accurate than the AO-trained group. In addition, pre- and post-training AO forced-choice consonant identification with untrained nonsense words showed that AV-trained participants had learned significantly more than AO participants. The pattern of results pointed to their having learned at the level of the auditory phonetic features of the vocoded stimuli. Experiment 2, a no-training control with testing and re-testing on the AO consonant identification, showed that the controls were as accurate as the AO-trained participants in Experiment 1 but less accurate than the AV-trained participants. In Experiment 3, PA training alternated AV and AO conditions on a list-by-list basis within participants, and training was to criterion (92% correct). PA training with AO stimuli was reliably more effective than training with AV stimuli. We explain these discrepant results in terms of the so-called "reverse hierarchy theory" of perceptual learning and in terms of the diverse multisensory and unisensory processing resources available to speech perception. We propose that early AV speech integration can potentially impede auditory perceptual learning; but visual top-down access to relevant auditory features can promote auditory perceptual learning. PMID:23515520

  12. Auditory Perceptual Learning for Speech Perception Can be Enhanced by Audiovisual Training

    PubMed Central

    Bernstein, Lynne E.; Auer, Edward T.; Eberhardt, Silvio P.; Jiang, Jintao

    2013-01-01

    Speech perception under audiovisual (AV) conditions is well known to confer benefits to perception such as increased speed and accuracy. Here, we investigated how AV training might benefit or impede auditory perceptual learning of speech degraded by vocoding. In Experiments 1 and 3, participants learned paired associations between vocoded spoken nonsense words and nonsense pictures. In Experiment 1, paired-associates (PA) AV training of one group of participants was compared with audio-only (AO) training of another group. When tested under AO conditions, the AV-trained group was significantly more accurate than the AO-trained group. In addition, pre- and post-training AO forced-choice consonant identification with untrained nonsense words showed that AV-trained participants had learned significantly more than AO participants. The pattern of results pointed to their having learned at the level of the auditory phonetic features of the vocoded stimuli. Experiment 2, a no-training control with testing and re-testing on the AO consonant identification, showed that the controls were as accurate as the AO-trained participants in Experiment 1 but less accurate than the AV-trained participants. In Experiment 3, PA training alternated AV and AO conditions on a list-by-list basis within participants, and training was to criterion (92% correct). PA training with AO stimuli was reliably more effective than training with AV stimuli. We explain these discrepant results in terms of the so-called “reverse hierarchy theory” of perceptual learning and in terms of the diverse multisensory and unisensory processing resources available to speech perception. We propose that early AV speech integration can potentially impede auditory perceptual learning; but visual top-down access to relevant auditory features can promote auditory perceptual learning. PMID:23515520

  13. Multiprocessor memory contention

    SciTech Connect

    Knadler, C.E. Jr.

    1989-01-01

    Caches are frequently incorporated in processor architectures to increase the effective memory speed and to reduce memory contention. However, task switches and the coherency problems of large n-way, mainframe-class multiprocessors lessen the effectiveness of cache architectures for general-purpose applications. A proposed alternative approach is to increase the effective memory bandwidth and decrease memory-access delays through instruction prefetch, operand buffering, highly interleave memory, and multiple-word width processor-memory data paths. This approach was evaluated by comparing cache and noncache system performance, using discrete-event simulation. Since the performance of a multiprocessor architecture is a function of its operating environment was well as its design, the system workload was defined. General-purpose applications, running under multitasking operating systems, were characterized with respect to addressing patterns, paging rates, and frequency of input/output operations. The proposed noncache architecture was found to have performance comparable to that of the cache architectures and obviated then need to solve the cache coherency problem.

  14. Revisiting the empirical case against perceptual modularity

    PubMed Central

    Masrour, Farid; Nirshberg, Gregory; Schon, Michael; Leardi, Jason; Barrett, Emily

    2015-01-01

    Some theorists hold that the human perceptual system has a component that receives input only from units lower in the perceptual hierarchy. This thesis, that we shall here refer to as the encapsulation thesis, has been at the center of a continuing debate for the past few decades. Those who deny the encapsulation thesis often rely on the large body of psychological findings that allegedly suggest that perception is influenced by factors such as the beliefs, desires, goals, and the expectations of the perceiver. Proponents of the encapsulation thesis, however, often argue that, when correctly interpreted, these psychological findings are compatible with the thesis. In our view, the debate over the significance and the correct interpretation of these psychological findings has reached an impasse. We hold that this impasse is due to the methodological limitations over psychophysical experiments, and it is very unlikely that such experiments, on their own, could yield results that would settle the debate. After defending this claim, we argue that integrating data from cognitive neuroscience resolves the debate in favor of those who deny the encapsulation thesis. PMID:26583001

  15. Perceptual Adaptation to Non-Native Speech

    PubMed Central

    Bradlow, Ann R.; Bent, Tessa

    2008-01-01

    This study investigated talker-dependent and talker-independent perceptual adaptation to foreign-accent English. Experiment 1 investigated talker-dependent adaptation by comparing native English listeners' recognition accuracy for Chinese-accented English across single and multiple talker presentation conditions. Results showed that the native listeners adapted to the foreign-accented speech over the course of the single talker presentation condition with some variation in the rate and extent of this adaptation depending on the baseline sentence intelligibility of the foreign-accented talker. Experiment 2 investigated talker-independent perceptual adaptation to Chinese-accented English by exposing native English listeners to Chinese-accented English and then testing their perception of English produced by a novel Chinese-accented talker. Results showed that, if exposed to multiple talkers of Chinese-accented English during training, native English listeners could achieve talker-independent adaptation to Chinese-accented English. Taken together, these findings provide evidence for highly flexible speech perception processes that can adapt to speech that deviates substantially from the pronunciation norms in the native talker community along multiple acoustic-phonetic dimensions. PMID:17532315

  16. Perceptual categories enable pattern generalization in songbirds

    PubMed Central

    Comins, Jordan A.; Gentner, Timothy Q.

    2013-01-01

    Since Chomsky’s pioneering work on syntactic structures, comparative psychologists interested in the study of language evolution have targeted pattern complexity, using formal mathematical grammars, as the key to organizing language-relevant cognitive processes across species. This focus on formal syntactic complexity, however, often disregards the close interaction in real-world signals between the structure of a pattern and its constituent elements. Whether such features of natural auditory signals shape pattern generalization is unknown. In the present paper, we train birds to recognize differently patterned strings of natural signals (song motifs). Instead of focusing on the complexity of the overtly reinforced patterns, we ask how the perceptual groupings of pattern elements influence the generalization pattern knowledge. We find that learning and perception of training patterns is agnostic to the perceptual features of underlying elements. Surprisingly, however, these same features constrain the generalization of pattern knowledge, and thus its broader use. Our results demonstrate that the restricted focus of comparative language research on formal models of syntactic complexity is, at best, insufficient to understand pattern use. PMID:23669049

  17. Perceptual evaluation of different image fusion schemes

    NASA Astrophysics Data System (ADS)

    Toet, Alexander; IJspeert, Jan K.

    2001-08-01

    Human perceptual performance was tested with images of nighttime outdoor scenes. The scenes were registered both with a dual band (visual and near infrared) image intensified low-light CCD camera (DII) and with a thermal middle wavelength band (3-5 micrometers ) infrared (IR) camera. Fused imagery was produced through a pyramid image merging scheme, in combination with different color mappings. For all (individual and fused) image modalities, small patches of the scenes, displaying a range of different objects and materials, were briefly presented to human observers. The sensitivity of human observers was tested for different recognition tasks. The results show that grayscale image fusion yields improved performance levels for most perceptual tasks investigated here. When an appropriate color mapping scheme is applied, the addition of color to grayscale fused imagery significantly increases observer sensitivity for a given condition and a certain task. However, inappropriate use of color significantly decreases observer performance compared to straightforward grayscale image fusion. This suggests that color mapping should adapt to the visual task and the conditions (scene content) at hand.

  18. Perceptual learning: Toward a comprehensive theory

    PubMed Central

    Watanabe, Takeo; Sasaki, Yuka

    2014-01-01

    Visual perceptual learning (VPL) is long-term performance increase resulting from visual perceptual experience. Task-relevant VPL of a feature results from training of a task on the feature relevant to the task. Task-irrelevant VPL arises as a result of exposure to the feature irrelevant to the trained task. There are at least two serious problems. First, which stage of information processing is changed in association with task-relevant VPL is controversial. Second, no model has ever explained both task-relevant and task-irrelevant VPL. Here we propose a dual plasticity model, in which there are feature-based plasticity that is a change in a representation of the learned feature and task-based plasticity that is a change in processing of the trained task. While the two types of plasticity underlie task-relevant VPL, only feature-based plasticity lies under task-irrelevant VPL. This model provides a new comprehensive framework in which apparently contradictory results could be explained. PMID:25251494

  19. Facial expression recognition in perceptual color space.

    PubMed

    Lajevardi, Seyed Mehdi; Wu, Hong Ren

    2012-08-01

    This paper introduces a tensor perceptual color framework (TPCF) for facial expression recognition (FER), which is based on information contained in color facial images. The TPCF enables multi-linear image analysis in different color spaces and demonstrates that color components provide additional information for robust FER. Using this framework, the components (in either RGB, YCbCr, CIELab or CIELuv space) of color images are unfolded to two-dimensional (2- D) tensors based on multi-linear algebra and tensor concepts, from which the features are extracted by Log-Gabor filters. The mutual information quotient (MIQ) method is employed for feature selection. These features are classified using a multi-class linear discriminant analysis (LDA) classifier. The effectiveness of color information on FER using low-resolution and facial expression images with illumination variations is assessed for performance evaluation. Experimental results demonstrate that color information has significant potential to improve emotion recognition performance due to the complementary characteristics of image textures. Furthermore, the perceptual color spaces (CIELab and CIELuv) are better overall for facial expression recognition than other color spaces by providing more efficient and robust performance for facial expression recognition using facial images with illumination variation. PMID:22575677

  20. The perceptual responses to occluded exercise.

    PubMed

    Loenneke, J P; Balapur, A; Thrower, A D; Barnes, J T; Pujol, T J

    2011-03-01

    The purpose was to determine repetitions to failure and perceptual responses to exercise with and without occlusion. 15 subjects participated in a randomized crossover study of 3 trials. The first determined one repetition maximum (1RM) on the leg extension. Subjects were then assigned to an occlusion (OCC) or control (CON) group. After trial 2, subjects crossed over to the opposite trial. Knee wraps (KW) were placed around the upper thigh of each leg during OCC. Subjects completed 2 sets of leg extensions to failure at 30% 1RM, with 30 s rest between sets. Ratings of perceived exertion (RPE) and pain (P) were taken following each set. Data were analyzed using paired sample t-tests with an alpha level of 0.01. OCC repetitions were lower for the first and second set compared to CON (p=0.001). Total work completed was significantly lower with OCC compared to CON (p=0.001). OCC RPE were higher for both the first (p=0.01) and second set (p=0.003) compared to CON. P was not different following one set but was higher with OCC over CON following the second (p=0.009). In conclusion, KW provide an OCC stimulus allowing failure to occur sooner. However, the higher perceptual responses with OCC may limit its application to the highly motivated. PMID:21165798

  1. Perceptual evaluation of voice source models.

    PubMed

    Kreiman, Jody; Garellek, Marc; Chen, Gang; Alwan, Abeer; Gerratt, Bruce R

    2015-07-01

    Models of the voice source differ in their fits to natural voices, but it is unclear which differences in fit are perceptually salient. This study examined the relationship between the fit of five voice source models to 40 natural voices, and the degree of perceptual match among stimuli synthesized with each of the modeled sources. Listeners completed a visual sort-and-rate task to compare versions of each voice created with the different source models, and the results were analyzed using multidimensional scaling. Neither fits to pulse shapes nor fits to landmark points on the pulses predicted observed differences in quality. Further, the source models fit the opening phase of the glottal pulses better than they fit the closing phase, but at the same time similarity in quality was better predicted by the timing and amplitude of the negative peak of the flow derivative (part of the closing phase) than by the timing and/or amplitude of peak glottal opening. Results indicate that simply knowing how (or how well) a particular source model fits or does not fit a target source pulse in the time domain provides little insight into what aspects of the voice source are important to listeners. PMID:26233000

  2. Learning object models for adaptive perceptual systems

    NASA Astrophysics Data System (ADS)

    Bhandaru, Malini Krishnan

    1998-08-01

    Real world perceptual environments are characterized by objects that often co-occur, occlude one another, and display time-variant behavior. In addition there may be variations in the signal-to-noise ratio. Successful object recognition depends on the extraction of adequate disambiguating features, which are neither easily identifiable nor stationary in such environments. In an effort to improve recognition accuracy and do so efficiently, Adaptive Perceptual Systems have emerged that re-configure their signal processing in response to variations in the signal to ensure extraction of adequate features. Key to adaptive signal processing is determining when and in what manner to modify signal processing. Symbolic object models play a pivotal role in this process by serving to interpret data, predict signal behavior and account for interference from objects simultaneously present. Unfortunately, symbolic object models are typically hand-crafted, a tedious error-prone task that constitutes a knowledge acquisition bottleneck, which limits object database size and impedes deployment for new and changing environments. This thesis explores the integration of feature extraction with model construction, viewing the two processes as driving one another until the goal of producing unambiguous symbolic object models is satisfied. The paradigm has been fielded to acquire acoustic-event models for a sound understanding system.

  3. The Role of Response Bias in Perceptual Learning

    ERIC Educational Resources Information Center

    Jones, Pete R.; Moore, David R.; Shub, Daniel E.; Amitay, Sygal

    2015-01-01

    Sensory judgments improve with practice. Such perceptual learning is often thought to reflect an increase in perceptual sensitivity. However, it may also represent a decrease in response bias, with unpracticed observers acting in part on a priori hunches rather than sensory evidence. To examine whether this is the case, 55 observers practiced…

  4. Bayesian Face Recognition and Perceptual Narrowing in Face-Space

    ERIC Educational Resources Information Center

    Balas, Benjamin

    2012-01-01

    During the first year of life, infants' face recognition abilities are subject to "perceptual narrowing", the end result of which is that observers lose the ability to distinguish previously discriminable faces (e.g. other-race faces) from one another. Perceptual narrowing has been reported for faces of different species and different races, in…

  5. Neurological Evidence Linguistic Processes Precede Perceptual Simulation in Conceptual Processing

    PubMed Central

    Louwerse, Max; Hutchinson, Sterling

    2012-01-01

    There is increasing evidence from response time experiments that language statistics and perceptual simulations both play a role in conceptual processing. In an EEG experiment we compared neural activity in cortical regions commonly associated with linguistic processing and visual perceptual processing to determine to what extent symbolic and embodied accounts of cognition applied. Participants were asked to determine the semantic relationship of word pairs (e.g., sky – ground) or to determine their iconic relationship (i.e., if the presentation of the pair matched their expected physical relationship). A linguistic bias was found toward the semantic judgment task and a perceptual bias was found toward the iconicity judgment task. More importantly, conceptual processing involved activation in brain regions associated with both linguistic and perceptual processes. When comparing the relative activation of linguistic cortical regions with perceptual cortical regions, the effect sizes for linguistic cortical regions were larger than those for the perceptual cortical regions early in a trial with the reverse being true later in a trial. These results map upon findings from other experimental literature and provide further evidence that processing of concept words relies both on language statistics and on perceptual simulations, whereby linguistic processes precede perceptual simulation processes. PMID:23133427

  6. Estimating the Growth of Internal Evidence Guiding Perceptual Decisions

    ERIC Educational Resources Information Center

    Ludwig, Casimir J. H.; Davies, J. Rhys

    2011-01-01

    Perceptual decision-making is thought to involve a gradual accrual of noisy evidence. Temporal integration of the evidence reduces the relative contribution of dynamic internal noise to the decision variable, thereby boosting its signal-to-noise ratio. We aimed to estimate the internal evidence guiding perceptual decisions over time, using a novel…

  7. Active and Passive Perceptual Learning in the Visually Impaired.

    ERIC Educational Resources Information Center

    Conrod, Beverley E.; And Others

    1986-01-01

    Active and passive perceptual training methods were tested with 30 macular degeneration patients to improve their residual vision. The main conclusion was that perceptual training may contribute to successful visual adjustment and that the effect of training is not limited to a particular level of visual impairment. (Author/CL)

  8. Effects of Perceptual-Motor Programs on Children.

    ERIC Educational Resources Information Center

    Thomas, Jerry R.

    Practical implications for physical education teachers are drawn after a review of research on perceptual motor training programs for elementary school children. Three categories of theorists are identified: those who emphasize the intellectual involvement of the child in motoric functioning; those who stress development of perceptual motor bases…

  9. Verbal Counting Moderates Perceptual Biases Found in Children's Cardinality Judgments

    ERIC Educational Resources Information Center

    Posid, Tasha; Cordes, Sara

    2015-01-01

    A crucial component of numerical understanding is one's ability to abstract numerical properties regardless of varying perceptual attributes. Evidence from numerical match-to-sample tasks suggests that children find it difficult to match sets based on number in the face of varying perceptual attributes, yet it is unclear whether these findings are…

  10. Motoric Aids to Perceptual Training. The Slow Learner Series.

    ERIC Educational Resources Information Center

    Chaney, Clara M.; Kephart, Newell C.

    Written from a developmental viewpoint, this book for parents and teachers presents both a theoretical orientation and perceptual motor activities for training children with learning disabilities, both the brain injured and the retarded. The theoretical basis for training generalized motor responses is considered in terms of motor perceptual…

  11. A Guide for Perceptual-Motor Training Activities.

    ERIC Educational Resources Information Center

    South Euclid - Lyndhurst City Schools, Lyndhurst, OH.

    This document has been prepared as part of a kindergarten perceptual-training program of the South Euclid-Lyndhurst City School District near Cleveland, Ohio. The guide contains information on training and procedures related to perceptual-motor learning. This information is structured primarily into 150 lesson plans, devised as 30-minute sessions…

  12. The Role of Perceptual Load in Object Recognition

    ERIC Educational Resources Information Center

    Lavie, Nilli; Lin, Zhicheng; Zokaei, Nahid; Thoma, Volker

    2009-01-01

    Predictions from perceptual load theory (Lavie, 1995, 2005) regarding object recognition across the same or different viewpoints were tested. Results showed that high perceptual load reduces distracter recognition levels despite always presenting distracter objects from the same view. They also showed that the levels of distracter recognition were…

  13. Perceptual Learning: 12-Month-Olds' Discrimination of Monkey Faces

    ERIC Educational Resources Information Center

    Fair, Joseph; Flom, Ross; Jones, Jacob; Martin, Justin

    2012-01-01

    Six-month-olds reliably discriminate different monkey and human faces whereas 9-month-olds only discriminate different human faces. It is often falsely assumed that perceptual narrowing reflects a permanent change in perceptual abilities. In 3 experiments, ninety-six 12-month-olds' discrimination of unfamiliar monkey faces was examined. Following…

  14. Selective Attention to Perceptual Dimensions and Switching between Dimensions

    ERIC Educational Resources Information Center

    Meiran, Nachshon; Dimov, Eduard; Ganel, Tzvi

    2013-01-01

    In the present experiments, the question being addressed was whether switching attention between perceptual dimensions and selective attention to dimensions are processes that compete over a common resource? Attention to perceptual dimensions is usually studied by requiring participants to ignore a never-relevant dimension. Selection failure…

  15. Harnessing the Wandering Mind: The Role of Perceptual Load

    ERIC Educational Resources Information Center

    Forster, Sophie; Lavie, Nilli

    2009-01-01

    Perceptual load is a key determinant of distraction by task-irrelevant stimuli (e.g., Lavie, N. (2005). "Distracted and confused?: Selective attention under load." "Trends in Cognitive Sciences," 9, 75-82). Here we establish the role of perceptual load in determining an internal form of distraction by task-unrelated thoughts (TUTs or…

  16. Estimating the Growth of Internal Evidence Guiding Perceptual Decisions

    ERIC Educational Resources Information Center

    Ludwig, Casimir J. H.; Davies, J. Rhys

    2011-01-01

    Perceptual decision-making is thought to involve a gradual accrual of noisy evidence. Temporal integration of the evidence reduces the relative contribution of dynamic internal noise to the decision variable, thereby boosting its signal-to-noise ratio. We aimed to estimate the internal evidence guiding perceptual decisions over time, using a novel…

  17. Perceptual Specificity Effects in Rereading: Evidence from Eye Movements

    ERIC Educational Resources Information Center

    Sheridan, Heather; Reingold, Eyal M.

    2012-01-01

    The present experiments examined perceptual specificity effects using a rereading paradigm. Eye movements were monitored while participants read the same target word twice, in two different low-constraint sentence frames. The congruency of perceptual processing was manipulated by either presenting the target word in the same distortion typography…

  18. Extraneous Perceptual Information Interferes with Children's Acquisition of Mathematical Knowledge

    ERIC Educational Resources Information Center

    Kaminski, Jennifer A.; Sloutsky, Vladimir M.

    2013-01-01

    Educational material often includes engaging perceptual information. However, this perceptual information is often extraneous and may compete with the deeper to-be-learned structure, consequently hindering either the learning of relevant structure or its transfer to new situations. This hypothesis was tested in 4 experiments in which 6- to…

  19. Bayesian Face Recognition and Perceptual Narrowing in Face-Space

    ERIC Educational Resources Information Center

    Balas, Benjamin

    2012-01-01

    During the first year of life, infants' face recognition abilities are subject to "perceptual narrowing", the end result of which is that observers lose the ability to distinguish previously discriminable faces (e.g. other-race faces) from one another. Perceptual narrowing has been reported for faces of different species and different races, in…

  20. The Concept, "Perceptually Handicapped," Its Assets and Limitations.

    ERIC Educational Resources Information Center

    Blom, Gaston E.

    Perception is a process by which simple and complex information (stimuli) is experienced. We gain information about how such stimulus inputs are experienced by a child, for example, by his responses or outputs. Outputs are in the form of vocalizations and motor acts. Thus, the perceptual process is frequently called perceptual-motor. But the…