DOCSLIB.ORG

Perceptual Thresholds and Priming in Amnesia

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Perceptual Thresholds and Priming in Amnesia Neuropsychology In the public domain 1995, Vol. 9, No. 1,3-15 Perceptual Thresholds and Priming in Amnesia Stephan B. Hamann Larry R. Squire University of California, San Diego Veterans Affairs Medical Center, San Diego and University of California, San Diego Daniel L. Schacter Harvard University The widely accepted idea that perceptual priming is intact in amnesia was challenged recently by the suggestion that perceptual identification (PID) thresholds are elevated in amnesia and that this impairment could mask a priming deficit by artificially inflating priming scores. The authors examined the PID thresholds of amnesic patients across a wide range of stimulus conditions and accuracy levels. Baseline thresholds and priming effects were fully intact for all amnesic patients except in a condition using small stimuli (1.1° x 0.25° of visual angle). In that condition, only the patients with Korsakoff's syndrome were impaired. Accordingly, elevated perceptual thresholds are not a necessary consequence of amnesia, and normal priming in amnesia is not an artifact of threshold differences. The results support the conclusion that priming is independent of the brain structures important for declarative memory that are damaged in amnesia. Considerable evidence has accumulated in recent years for medial temporal lobe and diencephalic structures that are distinguishing between different kinds of memory that depend damaged in amnesia (Squire & Zola-Morgan, 1991; Zola- on multiple separate brain systems (Richardson-Klavehn & Morgan & Squire, 1993). Nondeclarative memory is indepen- Bjork, 1988; Schacter, 1987; Squire, 1982; Tulving, 1985; dent of these brain structures. Weiskrantz, 1990). The major distinction is between declara- The conclusion that nondeclarative memory is spared in tive (explicit) memory, which affords conscious recollection of amnesia is based on a considerable body of evidence compar- past facts or episodes, and nondeclarative (implicit) memory, ing normal and memory-impaired subjects. Perhaps the most which is assessed indirectly through performance (cf. Schacter, extensively studied form of nondeclarative memory is priming, 1994; Squire, Knowlton, & Musen, 1993). Although dissocia- the improvement in detecting or identifying a stimulus based tions can be demonstrated in normal subjects between these on its recent exposure (Schacter, Chiu, & Ochsner, 1993; two kinds of memory, amnesic patients provide a particularly Tulving & Schacter, 1990). In both normal subjects and compelling source of evidence for distinguishing between amnesic patients, priming has been demonstrated for familiar kinds of memory. Amnesic patients are severely impaired on and novel stimuli, including words, nonwords, simple line tests of declarative memory, but they perform normally on a patterns, and figures. These results can be summarized by the variety of nondeclarative memory tasks including skill learning statement that amnesic patients and control subjects exhibit (Brooks & Baddeley, 1976; Cohen & Squire, 1980; Musen, equivalent priming across many different tasks and types of Shimamura, & Squire, 1990; Nissen & Bullemer, 1987; Squire materials. & Frambach, 1990), adaptation level effects (Benzing & The notion that priming is intact in amnesic patients was Squire, 1989), artificial grammar learning and prototype learn- challenged recently, based on a study of correlations among ing (Knowlton & Squire, 1993; Knowlton, Ramus, & Squire, measures of priming, measures of recognition memory, and 1992), and priming (Shimamura, 1986; Tulving & Schacter, 1990). Declarative memory depends on the integrity of the quantitative magnetic resonance imaging (MRI) measures of brain damage in 3 groups of neurological patients (Jernigan & Ostergaard, 1993). The subject groups were patients with Stephan B. Hamann, Department of Psychiatry, University of California, San Diego; Larry R. Squire, Veterans Affairs Medical Alzheimer's disease, patients with Huntington's disease, amne- Center, San Diego, California, and Department of Psychiatry and sic patients, and control subjects. Priming was assessed with a Neurosciences, University of California, San Diego; Daniel L. Schacter, perceptual identification task (Cermak, Talbot, Chandler, & Department of Psychology, Harvard University. Wolbarst, 1985) in which previously studied words and new This research was supported by the Medical Research Service of the words were initially presented briefly and then for increasing Department of Veterans Affairs, National Institute of Mental Health durations until subjects could identify each word. (NIMH) Grants MH24600 and MH45398, the Office of Naval Re- Contrary to what might have been expected from previous search, and the McKnight Foundation. work, a multiple regression analysis found an association We thank Nicole Champagne, Brent Kronenberg, {Camilla Willoughby, and Joyce Zouzounis for research assistance. between priming and damage to "temporolimbic" structures Correspondence concerning this article should be addressed to (this region was reported to include the hippocampus, amyg- Larry R. Squire, Veterans Affairs Medical Center, 3350 La Jolla dala, and adjacent gray matter in the medial temporal lobe). Village Drive, San Diego, California 92161. Electronic mail may be The association between priming and temporolimbic damage sent to [email protected]. was not apparent in a simple correlational measure but S. HAMANN, L. SQUIRE, AND D. SCHACTER became significant in the multiple regression analysis, when comprehensive studies have not been conducted to investigate volume loss in the caudate nucleus was also taken into account. baseline performance levels of amnesic patients in priming The finding across subject groups was that loss of caudate tasks. nucleus volume was associated with improved priming scores, The finding of intact baseline performance scores in amnesic and temporolimbic damage was associated with poorer prim- patients in earlier studies, which were not designed specifically ing scores. These two influences (caudate nucleus damage and to assess baseline performance, is not sufficient to decide the temporolimbic damage) exerted opposing effects of similar issue. These studies commonly assessed baseline performance magnitude on priming. Accordingly, the two effects canceled under only one experimental condition, not across a wide each other and would have gone undetected unless they had range of performance. For example, in a recent study of been considered together in a multiple regression analysis. perceptual priming for words and nonwords (Haist, Musen, & On the basis of these results, Jernigan and Ostergaard Squire, 1991), amnesic patients exhibited fully intact baseline (1993) proposed that previous findings of intact priming in word identification performance in a condition that yielded amnesic patients may have been complicated by the presence approximately 50% correct identification accuracy. Yet, it is of undetected striatal damage. Specifically, it was proposed possible that at some other difficulty level a deficit in baseline that striatal damage should impair baseline performance performance would have been detected in the amnesic pa- scores in priming studies. As a result, priming scores would be tients. spuriously inflated, and any deficit in priming would thereby be In four experiments, we examined the possibility that masked. amnesic patients have a deficit in baseline performance that It is well known that baseline performance differences can could affect their scores on tests of priming. We assessed pose problems when comparing subject groups (Cermak et al., baseline and primed performance in amnesic patients and 1985; Cermak, Verfaellie, Milberg, & Letourneau, 1991; Chap- control subjects, using a perceptual identification task that man, Chapman, Curran, & Miller, 1994; Ellis & Young, 1988, sampled a wide range of difficulty levels from near 0% to near p. 284; Loftus, 1985; Snodgrass, 1989). If one group initially 100% performance accuracy. The logic behind this approach is performs more poorly than another, it may be easier for the simple. If normal baseline performance and normal priming poorer group to improve than the group that initially performs can be demonstrated for amnesic patients across a wide range well. For example, in one report (Heindel, Salmon, & Butters, of difficulty levels, then preserved priming in amnesic patients 1990), patients with Huntington's disease (HD) were impaired cannot be attributed to a deficit in baseline performance. relative to control subjects on a task of identifying fragmented In Experiment 1, we compared baseline perceptual identifi- pictures. Following a study phase, the HD patients exhibited cation ability in amnesic patients and control subjects, testing greater priming than control subjects. This result was ex- across a wide range of performance levels. We used an plained by noting that the HD patients were initially slower unusually small stimulus size to ensure that performance and less efficient than control subjects at the baseline task of would reach very low levels with brief exposure durations. In identifying the fragmented pictures. Accordingly, it was easier Experiment 2, the procedure for assessing baseline perfor- for their performance to improve. Although this example and mance was modified to conform to the procedure used in a the study by Jernigan and Ostergaard (1993) focus on the previous study that had found normal perceptual identification importance of striatal pathology
Load more

Recommended publications
  • Implicit Memory in Amnesic Patients: When Is Auditory Priming Spared?
    Journal of the International Neuropsychological Society (1995), 1, 434-442. Copyright © 1995 INS. Published by Cambridge University Press. Printed in the USA. Implicit memory in amnesic patients: When is auditory priming spared? DANIEL L. SCHACTER1 AND BARBARA CHURCH2 1 Harvard University and Memory Disorders Research Center, Veterans Administration Medical Center, Cambridge, MA 02138 2 University of Illinois, Champaign, IL 61820 (RECEIVED February 16, 1995; ACCEPTED March 2, 1995) Abstract Amnesic patients often exhibit spared priming effects on implicit memory tests despite poor explicit memory. In previous research, we found normal auditory priming in amnesic patients on a task in which the magnitude of priming in control subjects was independent of whether speaker's voice was same or different at study and test, and found impaired voice-specific priming on a task in which priming in control subjects is higher when speaker's voice is the same at study and test than when it is different. The present experiments provide further evidence of spared auditory priming in amnesia, demonstrate that normal priming effects are not an artifact of low levels of baseline performance, and provide suggestive evidence that amnesic patients can exhibit voice-specific priming when experimental conditions do not require them to interactively bind together word and voice information. (JINS, 1995, 7, 434-442.) Keywords: Amnesia, Priming, Implicit memory Introduction jects heard a list of spoken words and judged either the category to which each word belongs (semantic encoding It is well known that amnesic patients can exhibit robust task) or the pitch of the speaker's voice (nonsemantic en- implicit memory despite impaired explicit memory.
    [Show full text]
  • Discovery Misattribution: When Solving Is Confused with Remembering
    Journal of Experimental Psychology: General Copyright 2007 by the American Psychological Association 2007, Vol. 136, No. 4, 577–592 0096-3445/07/$12.00 DOI: 10.1037/0096-3445.136.4.577 Discovery Misattribution: When Solving Is Confused With Remembering Sonya Dougal Jonathan W. Schooler New York University University of British Columbia This study explored the discovery misattribution hypothesis, which posits that the experience of solving an insight problem can be confused with recognition. In Experiment 1, solutions to successfully solved anagrams were more likely to be judged as old on a recognition test than were solutions to unsolved anagrams regardless of whether they had been studied. Experiment 2 demonstrated that anagram solving can increase the proportion of “old” judgments relative to words presented outright. Experiment 3 revealed that under certain conditions, solving anagrams influences the proportion of “old” judgments to unrelated items immediately following the solved item. In Experiment 4, the effect of solving was reduced by the introduction of a delay between solving the anagrams and the recognition judgments. Finally, Experiments 5 and 6 demonstrated that anagram solving leads to an illusion of recollection. Keywords: recognition, memory misattribution, recollection, insight problem There is something very similar about the experience of recol- found that increasing the perceptual fluency of items on a recog- lection and that of discovery. In both cases, a thought comes to nition test by preceding them with subliminally
    [Show full text]
  • Neuropsychologia Repetition Priming in Amnesia
    1HXURSV\FKRORJLD[[[ [[[[ [[[²[[[ Contents lists available at ScienceDirect Neuropsychologia journal homepage: www.elsevier.com/locate/neuropsychologia Repetition priming in amnesia: Distinguishing associative learning at different levels of abstraction Elizabeth Racea,b,⁎, Keely Burkeb, Mieke Verfaellieb a Department of Psychology, Tufts University, Medford, MA 02150, United States b Memory Disorders Research Center, VA Boston Healthcare System and Boston University School of Medicine, Boston, MA 02130, United States ARTICLE INFO ABSTRACT Keywords: Learned associations between stimuli and responses make important contributions to priming. The current study Repetition priming aimed to determine whether medial temporal lobe (MTL) binding mechanisms mediate this learning. Prior Hippocampus studies implicating the MTL in stimulus-response (S-R) learning have not isolated associative learning at the Memory response level from associative learning at other levels of representation (e.g., task sets or decisions). The current S-R binding study investigated whether the MTL is specifically involved in associative learning at the response level by testing a group of amnesic patients with MTL damage on a priming paradigm that isolates associative learning at the response level. Patients demonstrated intact priming when associative learning was isolated to the stimulus- response level. In contrast, their priming was reduced when associations between stimuli and more abstract representations (e.g., stimulus-task or stimulus-decision associations) could contribute to performance. These results provide novel neuropsychological evidence that S-R contributions to priming can be supported by regions outside the MTL, and suggest that the MTL may play a critical role in linking stimuli to more abstract tasks or decisions during priming. 1. Introduction et al., 2014) or “event files” (Hommel, 1998).
    [Show full text]
  • Priming and the Brain Review
    Neuron, Vol. 20, 185±195, February, 1998, Copyright 1998 by Cell Press Priming and the Brain Review Daniel L. Schacter*§ and Randy L. Buckner²³ minutes to several hours, subjects are given three-letter *Department of Psychology word stems with multiple possible completions and are Harvard University asked to complete each stem with the first word that Cambridge, Massachusetts 02138 comes to mind (e.g., mot___ for the target word ªmotelº). ² Department of Psychology Priming occurs when subjects complete the stem with Washington University a designated target completion more often for words St. Louis, Missouri 63130 that had been studied earlier than for words that were ³ MGH-NMR Center not studied previously. In a related kind of experiment, Charlestown, Massachusetts 02129 subjects study a list of words and are later given a word identification test, where words are flashed briefly (e.g., Introduction for 35 ms) and subjects attempt to identify them. Priming occurs when subjects identify more previously studied Research in cognitive psychology, neuropsychology, words than nonstudied words. Similar kinds of tasks and neuroscience has converged recently on the idea have been developed for examining priming of numer- that memory is composed of dissociable forms and sys- ous different types of stimuli, including pseudowords tems (Squire, 1992; Roediger and McDermott, 1993; (Keane et al., 1995; Bowers, 1996), familiar and unfa- Schacter and Tulving, 1994; Willingham, 1997). This con- miliar objects (Biederman and Cooper, 1991; Srinivas, clusion has been based on experimental and theoretical 1993; Schacter et al., 1993b), visual patterns (Musen analyses of a variety of different phenomena of learning and Squire, 1992), and environmental sounds (Chiu and and memory.
    [Show full text]
  • 2.33 Implicit Memory and Priming W
    2.33 Implicit Memory and Priming W. D. Stevens, G. S. Wig, and D. L. Schacter, Harvard University, Cambridge, MA, USA ª 2008 Elsevier Ltd. All rights reserved. 2.33.1 Introduction 623 2.33.2 Influences of Explicit Versus Implicit Memory 624 2.33.3 Top-Down Attentional Effects on Priming 626 2.33.3.1 Priming: Automatic/Independent of Attention? 626 2.33.3.2 Priming: Modulated by Attention 627 2.33.3.3 Neural Mechanisms of Top-Down Attentional Modulation 629 2.33.4 Specificity of Priming 630 2.33.4.1 Stimulus Specificity 630 2.33.4.2 Associative Specificity 632 2.33.4.3 Response Specificity 632 2.33.5 Priming-Related Increases in Neural Activation 634 2.33.5.1 Negative Priming 634 2.33.5.2 Familiar Versus Unfamiliar Stimuli 635 2.33.5.3 Sensitivity Versus Bias 636 2.33.6 Correlations between Behavioral and Neural Priming 637 2.33.7 Summary and Conclusions 640 References 641 2.33.1 Introduction stimulus that result from a previous encounter with the same or a related stimulus. Priming refers to an improvement or change in the When considering the link between behavioral identification, production, or classification of a stim- and neural priming, it is important to acknowledge ulus as a result of a prior encounter with the same or that functional neuroimaging relies on a number of a related stimulus (Tulving and Schacter, 1990). underlying assumptions. First, changes in informa- Cognitive and neuropsychological evidence indi- tion processing result in changes in neural activity cates that priming reflects the operation of implicit within brain regions subserving these processing or nonconscious processes that can be dissociated operations.
    [Show full text]
  • Semantic Priming in Schizophrenia: a Review and Synthesis
    Journal of the International Neuropsychological Society (2002), 8, 699–720. Copyright © 2002 INS. Published by Cambridge University Press. Printed in the USA. DOI: 10.1017.S1355617702801357 CRITICAL REVIEW Semantic priming in schizophrenia: A review and synthesis MICHAEL J. MINZENBERG,1 BETH A. OBER,2 and SOPHIA VINOGRADOV1 1Department of Psychiatry, University of California, San Francisco and Department of Veterans Affairs Medical Center, San Francisco, California 2Department of Human and Community Development, University of California, Davis and Department of Veterans Affairs Northern California Health Care System, Martinez, California (Received October 9, 2000; Revised June 4, 2001; Accepted June 5, 2001) Abstract In this paper, we present a review of semantic priming experiments in schizophrenia. Semantic priming paradigms show utility in assessing the role of deficits in semantic memory network access in the pathology of schizophrenia. The studies are placed in the context of current models of information processing. In this review we include all English-language reports (from peer-reviewed journals) of single-word semantic priming studies involving participants with schizophrenia. The studies to date show schizophrenic patients to exhibit variable semantic priming effects under automatic processing conditions, and consistent impairments under controlled0attentional conditions. We also describe associations with other neurocognitive dysfunction, neurochemical and electrophysiological disturbances, and clinical manifestations (such as thought disorder). (JINS, 2002, 8, 699–720.) Keywords: Semantic priming, Schizophrenia, Semantic memory, Language, Information processing INTRODUCTION Semantic Memory and Spreading Schizophrenia is primarily a disorder of thinking and lan- Activation Network Models guage. Indeed, investigators have suggested that a defect in All information processing models posit the existence of a language information processing may be pathognomonic of long-term memory system.
    [Show full text]
  • Metamemory in a Familiar Place: the Effects of Environmental Context on Feeling of Knowing
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Nottingham Trent Institutional Repository (IRep) Journal of Experimental Psychology: © 2016 The Author(s) Learning, Memory, and Cognition 0278-7393/16/$12.00 http://dx.doi.org/10.1037/xlm0000292 2016, Vol. 42, No. 6, 000 Metamemory in a Familiar Place: The Effects of Environmental Context on Feeling of Knowing Maciej Hanczakowski, Katarzyna Zawadzka, Harriet Collie, and Bill Macken Cardiff University Feeling-of-knowing (FOK) judgments are judgments of future recognizability of currently inaccessible information. They are known to depend both on the access to partial information about a target of retrieval and on the familiarity of the cue that is used as a memory probe. In the present study we assessed whether FOK judgments could also be shaped by incidental environmental context in which these judgments are made. To this end, we investigated 2 phenomena previously documented in studies on recognition memory—a context familiarity effect and a context reinstatement effect—in the procedure used to investigate FOK judgments. In 2experiments,wefoundthatFOKjudgmentsincreaseinthepresenceofafamiliarenvironmentalcontext. The results of both experiments further revealed still higher FOK judgments when made in the presence of environmental context matching the encoding context of both cue and its associated target. The effect of context familiarity on FOK judgment was paralleled by an effect on the latencies of an unsuccessful memory search, but the effect of context reinstatement was not. Importantly, the elevated feeling of knowing in reinstated and familiar contexts was not accompanied by an increase in the accuracy of those judgments.
    [Show full text]
  • Self-Knowledge, Choice Blindness, and Confabulation
    University of Massachusetts Amherst ScholarWorks@UMass Amherst Doctoral Dissertations Dissertations and Theses July 2019 Self-Knowledge, Choice Blindness, and Confabulation Hayley F. Webster University of Massachusetts Amherst Follow this and additional works at: https://scholarworks.umass.edu/dissertations_2 Part of the Epistemology Commons Recommended Citation Webster, Hayley F., "Self-Knowledge, Choice Blindness, and Confabulation" (2019). Doctoral Dissertations. 1543. https://doi.org/10.7275/13524606 https://scholarworks.umass.edu/dissertations_2/1543 This Open Access Dissertation is brought to you for free and open access by the Dissertations and Theses at ScholarWorks@UMass Amherst. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of ScholarWorks@UMass Amherst. For more information, please contact [email protected]. SELF-KNOWLEDGE, CHOICE BLINDNESS, AND CONFABULATION A Dissertation Presented by HAYLEY FRANCES JOY WEBSTER Submitted to the Graduate School of the University of Massachusetts Amherst in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY May 2019 Philosophy © Copyright by Hayley. F. Webster 2019 All Rights Reserved SELF-KNOWLEDGE, CHOICE BLINDNESS, AND CONFABULATION A Dissertation Presented by HAYLEY FRANCES JOY WEBSTER Approved as to style and content by: ___________________________ Hilary Kornblith, Chair ___________________________ Joseph Levine, Member ___________________________ Christopher Meacham, Member ___________________________ Nilanjana Dasgupta, Member _________________________ Joseph Levine, Department Head Philosophy DEDICATION In loving memory of my Grandad, Peter Lamont. ACKNOWLEDGMENTS I would like to thank my advisor, Hilary Kornblith, for his steadfast support and guidance over the years. I would also like to express my gratitude to all the members of my committee – Joseph Levine, Christopher Meacham, and Nilanjana Dasgupta.
    [Show full text]
  • Our Unconscious Mind
    PSYCHOLOGY OurUnconscıous Unconscious impulses and desires impel Mindwhat we think and do in ways Freud never dreamed of By John A. Bargh 32 Scientific American, January 2014 Illustrations by Tim Bower Photograph by Tktk Tktk Illustration by Artist Name January 2014, ScientificAmerican.com 33 John A. Bargh is a professor of psychology at Yale University. His Automaticity in Cognition, Motivation, and Evaluation Lab at Yale researches unconscious influences on behavior and questions such as the extent to which free will really exists. hen psychologists try to understand the way our mind works, they frequently come to a conclusion that may seem startling: people W often make decisions without having given them much thought—or, more precisely, before they have thought about them consciously. When we decide how to vote, what to buy, where to go on vacation and myriad other things, unconscious thoughts that we are not even aware of typically play a big role. Research has recently brought to light just how profoundly our unconscious mind shapes our day-to-day interactions. One of the best-known studies to illustrate the power of the For more than 100 years the role of unconscious influences on unconscious focused on the process of deciding whether a candi- our thoughts and actions has preoccupied scientists who study date was fit to hold public office. A group of mock voters were giv- the mind. Sigmund Freud’s massive body of work emphasized en a split second to inspect portrait photographs from the Inter- the conscious as the locus of rational thought and emotion and net of U.S.
    [Show full text]
  • Memory & Cognition
    / Memory & Cognition Volume 47 · Number 4 · May 2019 Special Issue: Recognizing Five Decades of Cumulative The role of control processes in temporal Progress in Understanding Human Memory and semantic contiguity and its Control Processes Inspired by Atkinson M.K. Healey · M.G. Uitvlugt 719 and Shiffrin (1968) Auditory distraction does more than disrupt rehearsal Guest Editors: Kenneth J. Malmberg· processes in children's serial recall Jeroen G. W. Raaijmakers ·Richard M. Shiffrin A.M. AuBuchon · C.l. McGill · E.M. Elliott 738 50 years of research sparked by Atkinson The effect of working memory maintenance and Shiffrin (1968) on long-term memory K.J. Malmberg · J.G.W. Raaijmakers · R.M. Shiffrin 561 J.K. Hartshorne· T. Makovski 749 · From ·short-term store to multicomponent working List-strength effects in older adults in recognition memory: The role of the modal model and free recall A.D. Baddeley · G.J. Hitch · R.J. Allen 575 L. Sahakyan 764 Central tendency representation and exemplar Verbal and spatial acquisition as a function of distributed matching in visual short-term memory practice and code-specific interference C. Dube 589 A.P. Young· A.F. Healy· M. Jones· L.E. Bourne Jr. 779 Item repetition and retrieval processes in cued recall: Dissociating visuo-spatial and verbal working memory: Analysis of recall-latency distributions It's all in the features Y. Jang · H. Lee 792 ~1 . Poirier· J.M. Yearsley · J. Saint-Aubin· C. Fortin· G. Gallant · D. Guitard 603 Testing the primary and convergent retrieval model of recall: Recall practice produces faster recall Interpolated retrieval effects on list isolation: success but also faster recall failure IndiYiduaLdifferences in working memory capacity W.J.
    [Show full text]
  • Models of Memory
    To be published in H. Pashler & D. Medin (Eds.), Stevens’ Handbook of Experimental Psychology, Third Edition, Volume 2: Memory and Cognitive Processes. New York: John Wiley & Sons, Inc.. MODELS OF MEMORY Jeroen G.W. Raaijmakers Richard M. Shiffrin University of Amsterdam Indiana University Introduction Sciences tend to evolve in a direction that introduces greater emphasis on formal theorizing. Psychology generally, and the study of memory in particular, have followed this prescription: The memory field has seen a continuing introduction of mathematical and formal computer simulation models, today reaching the point where modeling is an integral part of the field rather than an esoteric newcomer. Thus anything resembling a comprehensive treatment of memory models would in effect turn into a review of the field of memory research, and considerably exceed the scope of this chapter. We shall deal with this problem by covering selected approaches that introduce some of the main themes that have characterized model development. This selective coverage will emphasize our own work perhaps somewhat more than would have been the case for other authors, but we are far more familiar with our models than some of the alternatives, and we believe they provide good examples of the themes that we wish to highlight. The earliest attempts to apply mathematical modeling to memory probably date back to the late 19th century when pioneers such as Ebbinghaus and Thorndike started to collect empirical data on learning and memory. Given the obvious regularities of learning and forgetting curves, it is not surprising that the question was asked whether these regularities could be captured by mathematical functions.
    [Show full text]
  • Semantic Priming in Mild Cognitive Impairment and Healthy Subjects: Effect of Different Time of Presentation of Word-Pairs
    Journal of Personalized Medicine Article Semantic Priming in Mild Cognitive Impairment and Healthy Subjects: Effect of Different Time of Presentation of Word-Pairs Valeria Guglielmi 1, Davide Quaranta 1,*, Ilaria Mega 2, Emanuele Maria Costantini 2, Claudia Carrarini 2, Alice Innocenti 2 and Camillo Marra 2,3 1 Neurology Unit, Fondazione Policlinico Agostino Gemelli-IRCCS, 00168 Rome, Italy; [email protected] 2 Department of Neuroscience, Catholic University of Sacred Heart, 00168 Rome, Italy; [email protected] (I.M.); [email protected] (E.M.C.); [email protected] (C.C.); [email protected] (A.I.); [email protected] (C.M.) 3 Memory Clinic, Fondazione Policlinico Universitario Agostino Gemelli-IRCCS, 00168 Rome, Italy * Correspondence: [email protected] Received: 24 May 2020; Accepted: 25 June 2020; Published: 29 June 2020 Abstract: Introduction: Semantic memory is impaired in mild cognitive impairment (MCI). Two main hypotheses about this finding are debated and refer to the degradation of stored knowledge versus the impairment of semantic access mechanisms. The aim of our study is to evaluate semantic impairment in MCI versus healthy subjects (HS) by an experiment evaluating semantic priming. Methods: We enrolled 27 MCI and 20 HS. MCI group were divided, according to follow up, into converters-MCI and non converters-MCI. The semantic task consisted of 108 pairs of words, 54 of which were semantically associated. Stimuli were presented 250 or 900 ms later the appearance of the target in a randomized manner. Data were analyzed using factorial ANOVA. Results: Both HS and MCI answered more quickly for word than for non-word at both stimulus onset asynchrony (SOA) intervals.
    [Show full text]