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Larry R Squire - One of the best experts on this subject based on the ideXlab platform.

  • conscious and unconscious Memory systems
    Cold Spring Harbor Perspectives in Biology, 2015
    Co-Authors: Larry R Squire, Adam J O Dede
    Abstract:

    : The idea that Memory is not a single mental faculty has a long and interesting history but became a topic of experimental and biologic inquiry only in the mid-20th century. It is now clear that there are different kinds of Memory, which are supported by different brain systems. One major distinction can be drawn between working Memory and long-term Memory. Long-term Memory can be separated into declarative (explicit) Memory and a collection of Nondeclarative (implicit) forms of Memory that include habits, skills, priming, and simple forms of conditioning. These Memory systems depend variously on the hippocampus and related structures in the parahippocampal gyrus, as well as on the amygdala, the striatum, cerebellum, and the neocortex. This work recounts the discovery of declarative and Nondeclarative Memory and then describes the nature of declarative Memory, working Memory, Nondeclarative Memory, and the relationship between Memory systems.

  • Recognition without awareness: An elusive phenomenon
    Learning & Memory, 2010
    Co-Authors: Annette Jeneson, C. Brock Kirwan, Larry R Squire
    Abstract:

    Two recent studies described conditions under which recognition Memory performance appeared to be driven by Nondeclarative Memory. Specifically, participants successfully discriminated old images from highly similar new images even when no conscious Memory for the images could be retrieved. Paradoxically, recognition performance was better when images were studied with divided attention than when images were studied with full attention. Furthermore, recognition performance was better when decisions were rated as guesses than when decisions were associated with low or high confidence. In three experiments, we adopted the paradigm used in the earlier studies in an attempt to repeat this intriguing work. Our attempts were unsuccessful. In all experiments, recognition was better when images were studied with full attention than when images were studied with divided attention. Recognition was also better when participants indicated high or low confidence in their decision than when they indicated that their decision was a guess. Thus, our results conformed to what typically has been reported in studies of recognition Memory, and we were unable to demonstrate recognition without awareness. We encourage others to explore this paradigm, and to try to identify conditions under which the phenomenon might be demonstrated.

  • amnesia declarative and Nondeclarative Memory
    Reference Module in Neuroscience and Biobehavioral Psychology#R##N#Encyclopedia of Neuroscience, 2009
    Co-Authors: Larry R Squire, Peter J. Bayley, Christine N Smith
    Abstract:

    Amnesia refers to difficulty in acquiring new declarative (conscious) knowledge and in remembering the recent past. This condition results from bilateral damage to the medial temporal lobe or diencephalic midline. Memory impairment can occur as a well-circumscribed disorder against a background of otherwise intact intellectual and cognitive functions. Older memories that have undergone a process of consolidation and reorganization are usually intact in amnesic patients and are stored in the neocortex independently of the medial temporal lobe. Amnesic patients retain the ability to learn Nondeclaratively (unconsciously), as in the case of habits and skills, in which Memory is expressed through performance rather than recollection.

  • the neuroanatomy and neuropsychology of declarative and Nondeclarative Memory
    2007
    Co-Authors: Peter J. Bayley, Larry R Squire
    Abstract:

    The hippocampus and anatomically related structures in the medial temporal lobe support the capacity for declarative Memory (Squire and Zola-Morgan 1991; Eichenbaum and Cohen 2001). Declarative Memory refers to the capacity to recollect facts and events and has the defining features of being consciously accessible and flexible in its expression. Declarative Memory can be contrasted to a collection of Nondeclarative forms of Memory that includes skills and habits, priming, and simple forms of conditioning. These forms of Memory are supported by brain structures outside the medial temporal lobe. Nondeclarative Memory is expressed through performance rather than recollection and what is learned is nonconscious and dependent on the original learning conditions for full expression.

  • The anatomy of amnesia: Neurohistological analysis of three new cases
    Learning & Memory, 2006
    Co-Authors: Jeffrey J. Gold, Larry R Squire
    Abstract:

    : The most useful information about the anatomy of human Memory comes from cases where there has been extensive neuropsychological testing followed by detailed post-mortem neurohistological analysis. To our knowledge, only eight such cases have been reported (four with medial temporal lobe damage and four with diencephalic damage). Here we present neuropsychological and post-mortem neurohistological findings for one patient (NC) with bilateral damage to the medial temporal lobe and two patients (MG, PN) with diencephalic damage due to bilateral thalamic infarction and Korsakoff's syndrome, respectively. All three patients exhibited a similar phenotype of amnesia with markedly impaired declarative Memory (anterograde and retrograde) but normal performance on tests of Nondeclarative Memory (e.g., priming and adaptation-level effects) as well as on tests of other cognitive functions. Patient NC had damage to the hippocampus (dentate gyrus and the CA1 and CA3 fields) and layer III of the entorhinal cortex, but with relative sparing of the CA2 field and the subiculum. Patient MG had damage to the internal medullary lamina and mediodorsal thalamic nuclei. Patient PN had damage to the mammillary nuclei, mammillothalamic tracts, and the anterior thalamic nuclei. These findings illuminate several issues regarding the relation between diencephalic and medial temporal lobe amnesia, the status of recognition Memory in amnesia, and the neuroanatomy of Memory.

Paul J Reber - One of the best experts on this subject based on the ideXlab platform.

  • cognitive neuroscience of declarative and Nondeclarative Memory
    Advances in psychology, 2008
    Co-Authors: Paul J Reber
    Abstract:

    Publisher Summary The study of Memory within cognitive neuroscience is an attempt to synthesize an account of both the fundamental mnemonic component processes and the neural basis of these processes. This chapter focuses on cognitive neuroscience of declarative and Nondeclarative Memory. Declarative Memory refers to the acquisition and retrieval of facts, events, and episodes. A nearly synonymous term, explicit Memory, emphasizes the fact that these types of Memory are available to awareness—that is, one can consciously recall these memories during retrieval. The bulk of what is thought of as the ordinary, everyday operation of Memory depends on declarative Memory. The conventional use of the term Memory generally refers to the retrieval process, but before memories can be retrieved, they have to be acquired (stored), and this process depends on the intact function of the MTL (medial temporal lobe). The terms Nondeclarative and implicit Memory are synonymous (but not completely). The chapter reviews the examples of this type of Memory from a neuroanatomical perspective as Nondeclarative Memory. In different paradigms, Nondeclarative Memory phenomena have been shown to depend on a number of different brain regions, indicating that this type of Memory is not a single coherent system, but is rather a collection of phenomena with different neural substrates.

  • Artificial grammar learning in Alzheimer’s disease
    Cognitive Affective & Behavioral Neuroscience, 2003
    Co-Authors: Paul J Reber, Lucy A. Martinez, Sandra Weintraub
    Abstract:

    Patients with early Alzheimer’s disease (AD) exhibit impaired declarative Memory although some forms of Nondeclarative Memory are intact. Performance on perceptual Nondeclarative Memory tasks is often preserved in AD, whereas conceptual Nondeclarative Memory is often impaired. A conceptual Nondeclarative learning task that has been studied in amnesic patients is the artificial grammar learning (AGL) task. Healthy participants and patients with impaired declarative Memory both acquire information about an underlying rule structure in this task and exhibit the ability to identify rule-conforming items, despite the subjective experience of guessing at the response. In this study, 12 patients diagnosed with early AD were tested on the AGL task and a matched recognition task. The patients were able to reliably distinguish rule-conforming items from others, indicating successful AGL. Performance of the AD patients was impaired, relative to controls, on a similar recognition task, although they were found to use information about the grammaticality of study items in an attempt to improve their recognition performance. The AD patients showed a dissociation similar to that seen in anterograde amnesia: impaired recognition Memory in conjunction with successful AGL. This finding suggests that the brain areas that support AGL are not compromised early in the course of AD. In addition, the Nondeclarative Memory of the AD patients acquired during AGL appeared to influence their performance on a declarative Memory task, suggesting an interaction between this Nondeclarative Memory task and declarative Memory.

  • Artificial grammar learning in Alzheimer's disease.
    Cognitive Affective & Behavioral Neuroscience, 2003
    Co-Authors: Paul J Reber, Lucy A. Martinez, Sandra Weintraub
    Abstract:

    Patients with early Alzheimer’s disease (AD) exhibit impaired declarative Memory although some forms of Nondeclarative Memory are intact. Performance on perceptual Nondeclarative Memory tasks is often preserved in AD, whereas conceptual Nondeclarative Memory is often impaired. A conceptual Nondeclarative learning task that has been studied in amnesic patients is the artificial grammar learning (AGL) task. Healthy participants and patients with impaired declarative Memory both acquire information about an underlying rule structure in this task and exhibit the ability to identify rule-conforming items, despite the subjective experience of guessing at the response. In this study, 12 patients diagnosed with early AD were tested on the AGL task and a matched recognition task. The patients were able to reliably distinguish rule-conforming items from others, indicating successful AGL. Performance of the AD patients was impaired, relative to controls, on a similar recognition task, although they were found to use information about the grammaticality of study items in an attempt to improve their recognition performance. The AD patients showed a dissociation similar to that seen in anterograde amnesia: impaired recognition Memory in conjunction with successful AGL. This finding suggests that the brain areas that support AGL are not compromised early in the course of AD. In addition, the Nondeclarative Memory of the AD patients acquired during AGL appeared to influence their performance on a declarative Memory task, suggesting an interaction between this Nondeclarative Memory task and declarative Memory.

  • Neural correlates of artificial grammar learning.
    NeuroImage, 2002
    Co-Authors: Patrick D. Skosnik, F. Mirza, Darren R. Gitelman, Todd B. Parrish, M.-marsel Mesulam, Paul J Reber
    Abstract:

    Artificial grammar learning (AGL) is a form of Nondeclarative Memory that involves the nonconscious acquisition of abstract rules. While data from amnesic patients indicate that AGL does not depend on the medial temporal lobe, the neural basis of this type of Memory is unknown and was therefore examined using event-related fMRI. Prior to scanning, participants studied letter strings constructed according to an artificial grammar. Participants then made grammaticality judgments about novel grammatical and nongrammatical strings while fMRI data were collected. The participants successfully acquired knowledge of the grammar, as evidenced by correct identification of the grammatical letter strings (57.4% correct; SE 1.9). During grammaticality judgments, widespread increases in activity were observed throughout the occipital, posterior temporal, parietal, and prefrontal cortical areas, reflecting the cognitive demands of the task. More specific analyses contrasting grammatical and nongrammatical strings identified greater activity in left superior occipital cortex and the right fusiform gyrus for grammatical stimuli. Increased activity was also observed in the left superior occipital and left angular gyrus for correct responses compared to incorrect. Comparing activity during grammaticality judgments versus a matched recognition control task again identified greater activation in the left angular gyrus. The network of areas exhibiting increased activity for grammatical stimuli appears to have more in common with studies examining word-form processing or mental calculation than the fluency effects previously reported for Nondeclarative Memory tasks such as priming and visual categorization. These results suggest that a novel Nondeclarative Memory mechanism supporting AGL exists in the left superior occipital and inferior parietal cortex.

  • Relaxing decision criteria does not improve recognition Memory in amnesic patients.
    Memory & Cognition, 1999
    Co-Authors: Paul J Reber, Larry R Squire
    Abstract:

    An important question about the organization of Memory is whether information available in Nondeclarative Memory can contribute to performance on tasks of declarative Memory. Dorfman, Kihlstrom, Cork, and Misiaszek (1995) described a circumstance in which the phenomenon of priming might benefit recognition Memory performance. They reported that patients receiving electroconvulsive therapy improved their recognition performance when they were encouraged to relax their criteria for endorsing test items as familiar. It was suggested that priming improved recognition by making information available about the familiarity of test items. In three experiments, we sought unsuccessfully to reproduce this phenomenon in amnesic patients. In Experiment 3, we reproduced the methods and procedure used by Dorfman et al. but still found no evidence for improved recognition Memory following the manipulation of decision criteria. Although negative findings have their own limitations, our findings suggest that the phenomenon reported by Dorfman et al. does not generalize well. Our results agree with several recent findings that suggest that priming is independent of recognition Memory and does not contribute to recognition Memory scores.

Bruce V Beninger - One of the best experts on this subject based on the ideXlab platform.

  • typical and atypical antipsychotic medications differentially affect two Nondeclarative Memory tasks in schizophrenic patients a double dissociation
    Schizophrenia Research, 2003
    Co-Authors: Richard J Beninger, James Wasserman, Katherine Zanibbi, Danielle Charbonneau, Jennifer A Mangels, Bruce V Beninger
    Abstract:

    Nondeclarative Memory (NDM) has subtypes associated with different brain regions; learning of a probabilistic classification task is impaired by striatal damage and learning of a gambling task is impaired by ventromedial prefrontocortical damage. Typical and atypical antipsychotic medications differentially affect immediate early gene expression in the striatum and frontal cortex in normal rats. This suggested the hypothesis that schizophrenic patients treated with typical antipsychotics will have impaired probabilistic classification learning (PCL) and that similar patients treated with atypical antipsychotics will have impaired learning of the gambling task. Groups of schizophrenia patients treated with typical or atypical antipsychotics did not differ from each other on the Brief Psychiatric Rating Scale (BPRS), Mini Mental State Exam (MMSE) or a number of indexes of the Wisconsin Card Sorting Task (WCST) but performed worse than normal controls on these instruments. In the first study, patients treated with typicals (n=20) but not atypicals (n=20) or normal controls (n=32) were impaired in probabilistic classification. In the second study, those treated with atypicals (n=18) but not typicals (n=18) or normal controls (n=18) were impaired in the gambling task. Results suggest that typical and atypical antipsychotics differentially affect Nondeclarative Memory mediated by different brain regions. D 2002 Elsevier Science B.V. All rights reserved.

  • Typical and atypical antipsychotic medications differentially affect two Nondeclarative Memory tasks in schizophrenic patients: a double dissociation.
    Schizophrenia research, 2003
    Co-Authors: Richard J Beninger, James Wasserman, Katherine Zanibbi, Danielle Charbonneau, Jennifer A Mangels, Bruce V Beninger
    Abstract:

    Nondeclarative Memory (NDM) has subtypes associated with different brain regions; learning of a probabilistic classification task is impaired by striatal damage and learning of a gambling task is impaired by ventromedial prefrontocortical damage. Typical and atypical antipsychotic medications differentially affect immediate early gene expression in the striatum and frontal cortex in normal rats. This suggested the hypothesis that schizophrenic patients treated with typical antipsychotics will have impaired probabilistic classification learning (PCL) and that similar patients treated with atypical antipsychotics will have impaired learning of the gambling task. Groups of schizophrenia patients treated with typical or atypical antipsychotics did not differ from each other on the Brief Psychiatric Rating Scale (BPRS), Mini Mental State Exam (MMSE) or a number of indexes of the Wisconsin Card Sorting Task (WCST) but performed worse than normal controls on these instruments. In the first study, patients treated with typicals (n=20) but not atypicals (n=20) or normal controls (n=32) were impaired in probabilistic classification. In the second study, those treated with atypicals (n=18) but not typicals (n=18) or normal controls (n=18) were impaired in the gambling task. Results suggest that typical and atypical antipsychotics differentially affect Nondeclarative Memory mediated by different brain regions.

Richard J Beninger - One of the best experts on this subject based on the ideXlab platform.

  • Effects of Parkinson disease on two putative Nondeclarative learning tasks: probabilistic classification and gambling.
    Cognitive and Behavioral Neurology, 2005
    Co-Authors: James G Perretta, Giovanna Pari, Richard J Beninger
    Abstract:

    Objective: To assess performance on two Nondeclarative (implicit) Memory tasks of Parkinson disease (PD) patients without dementia in the earlier or later stages of the disease (Hoehn and Yahr Scale scores of 1-2.5 or 3-4, respectively). Background: Different subtypes of Nondeclarative Memory appear to depend on different components of frontostriatal circuitry. Performance on a probabilistic classification learning (PCL) task was impaired by striatal damage (eg, in PD or Huntington disease) but not by circumscribed frontal lobe damage. On the other hand, performance on the Iowa Gambling Task (IGT) was impaired by damage to the prefrontal cortex. Method and Results: On the PCL, the learning of the control (age- and education-matched) group (n = 19) and the early PD group (n = 16) was comparable with each other, and both groups showed better performance than the later PD group (n = 16). On the IGT, the control group learned better than both of the PD groups. The control and early PD groups were similar on measures from the Wisconsin Card Sorting Test, Stroop Test, Mini-Mental State Examination, and Beck Depression Inventory II. Conclusions: The PCL and IGT tasks appear to rely on different parts of the frontostriatal circuitry in patients with early PD. The current finding that IGT performance was impaired in early PD implies ventromedial prefrontal cortical dysfunction early in the disease.

  • typical and atypical antipsychotic medications differentially affect two Nondeclarative Memory tasks in schizophrenic patients a double dissociation
    Schizophrenia Research, 2003
    Co-Authors: Richard J Beninger, James Wasserman, Katherine Zanibbi, Danielle Charbonneau, Jennifer A Mangels, Bruce V Beninger
    Abstract:

    Nondeclarative Memory (NDM) has subtypes associated with different brain regions; learning of a probabilistic classification task is impaired by striatal damage and learning of a gambling task is impaired by ventromedial prefrontocortical damage. Typical and atypical antipsychotic medications differentially affect immediate early gene expression in the striatum and frontal cortex in normal rats. This suggested the hypothesis that schizophrenic patients treated with typical antipsychotics will have impaired probabilistic classification learning (PCL) and that similar patients treated with atypical antipsychotics will have impaired learning of the gambling task. Groups of schizophrenia patients treated with typical or atypical antipsychotics did not differ from each other on the Brief Psychiatric Rating Scale (BPRS), Mini Mental State Exam (MMSE) or a number of indexes of the Wisconsin Card Sorting Task (WCST) but performed worse than normal controls on these instruments. In the first study, patients treated with typicals (n=20) but not atypicals (n=20) or normal controls (n=32) were impaired in probabilistic classification. In the second study, those treated with atypicals (n=18) but not typicals (n=18) or normal controls (n=18) were impaired in the gambling task. Results suggest that typical and atypical antipsychotics differentially affect Nondeclarative Memory mediated by different brain regions. D 2002 Elsevier Science B.V. All rights reserved.

  • Typical and atypical antipsychotic medications differentially affect two Nondeclarative Memory tasks in schizophrenic patients: a double dissociation.
    Schizophrenia research, 2003
    Co-Authors: Richard J Beninger, James Wasserman, Katherine Zanibbi, Danielle Charbonneau, Jennifer A Mangels, Bruce V Beninger
    Abstract:

    Nondeclarative Memory (NDM) has subtypes associated with different brain regions; learning of a probabilistic classification task is impaired by striatal damage and learning of a gambling task is impaired by ventromedial prefrontocortical damage. Typical and atypical antipsychotic medications differentially affect immediate early gene expression in the striatum and frontal cortex in normal rats. This suggested the hypothesis that schizophrenic patients treated with typical antipsychotics will have impaired probabilistic classification learning (PCL) and that similar patients treated with atypical antipsychotics will have impaired learning of the gambling task. Groups of schizophrenia patients treated with typical or atypical antipsychotics did not differ from each other on the Brief Psychiatric Rating Scale (BPRS), Mini Mental State Exam (MMSE) or a number of indexes of the Wisconsin Card Sorting Task (WCST) but performed worse than normal controls on these instruments. In the first study, patients treated with typicals (n=20) but not atypicals (n=20) or normal controls (n=32) were impaired in probabilistic classification. In the second study, those treated with atypicals (n=18) but not typicals (n=18) or normal controls (n=18) were impaired in the gambling task. Results suggest that typical and atypical antipsychotics differentially affect Nondeclarative Memory mediated by different brain regions.

Barbara J Knowlton - One of the best experts on this subject based on the ideXlab platform.

  • Neural Representations of Nondeclarative Memories
    Current Directions in Psychological Science, 2008
    Co-Authors: Barbara J Knowlton, Karin Foerde
    Abstract:

    Nondeclarative learning refers to abilities characterized by a lack of awareness of what has been learned and an independence from medial temporal lobe structures that support conscious memories of facts and events. Neuroimaging approaches have been used extensively in two domains of Nondeclarative learning—priming and skill learning—to investigate the neural substrates supporting performance. Recent neuroimaging studies have attempted to understand what is being learned in different tasks in order to inform psychological theories of Nondeclarative Memory. For example, priming may be considered a form of perceptual learning or a form of stimulus–response learning, and correlations between performance and activation patterns in different regions may suggest the nature of the brain changes that support behavior. The attainment of expertise in a skill has been characterized as greater efficiency of processing in the same neural structures that support novice performance or, alternatively, as the recruitment ...

  • Implicit learning and Memory.
    Handbook of Clinical Neurology, 2008
    Co-Authors: Barbara J Knowlton, Daniel L. Greenberg
    Abstract:

    Publisher Summary Implicit Memory or Nondeclarative Memory does not involve conscious or deliberate retrieval. Although the different types of implicit Memory have different behavioral characteristics and depend on different neural systems, they all appear to be intact in amnesic patients, and are thus independent of the brain structures damaged in amnesia. Implicit Memory has been a focus in experimental psychology for more than two decades. More recently, implicit Memory has become an important concept in studies of clinical populations. There are multiple forms of implicit Memory that differ not only in terms of behavioral properties but also the brain systems that support them. The existence of multiple Memory systems and processes reveal the immense capacity for plasticity and adaptation in the human brain. Two forms of implicit Memory are studied such as priming (perceptual priming, conceptual priming, contamination from explicit Memory, priming in amnesia, alzheimer's disease, frontotemporal lobar dementia, and neural basis of priming) and procedural Memory. Procedural Memory generally refers to Memory for knowing how to do something. The knowledge in procedural memories is not accessible to awareness, but rather is manifested only through performance of a task. Like priming one is not necessarily aware of one's procedural knowledge. Unlike priming, which can occur after a single presentation of a stimulus, procedural memories are built up gradually and incrementally with practice.

  • dissociable properties of Memory systems differences in the flexibility of declarative and Nondeclarative knowledge
    Behavioral Neuroscience, 1996
    Co-Authors: Paul J Reber, Barbara J Knowlton, Larry R Squire
    Abstract:

    Amnesic patients (n = 8), who have severely impaired declarative Memory, learned a probabilistic classification task at the same rate as normal subjects (n = 16) but subsequently were impaired on transfer tests that required flexible use of their task knowledge. A second group of controls (n = 20) rated the questions on the transfer tests according to whether the questions simply reinstated the training conditions or required flexible use of task knowledge. The amnesic patients tended to be impaired on the same items that were rated as requiring indirect or flexible use of knowledge. Thus, control subjects acquired declarative knowledge about the task that could be applied flexibly to the transfer tests. The Nondeclarative Memory available to amnesic patients was relatively inflexible and available only in conditions that reinstantiated the conditions of training. These findings show that declarative Memory has different operating characteristics than Nondeclarative Memory.

  • dissociations within Nondeclarative Memory in huntington s disease
    Neuropsychology (journal), 1996
    Co-Authors: Barbara J Knowlton, Larry R Squire, Jane S Paulsen, Neal R Swerdlow, Michael R Swenson
    Abstract:

    Patients with Huntington's Disease (HD) were tested on 2 tasks, probabilistic classification learning and artificial grammar learning. Both tasks are performed normally by amnesic patients and are considered to be independent of declarative Memory. Patients with HD were severely impaired in probabilistic learning but performed normally in artificial grammar learning. The probabilistic classification task may be akin to habit-learning tasks that depend on the neostriatum, whereas artificial grammar learning may depend on changes within neocortex similar to what is thought to occur in perceptual priming. The deficit in the probabilistic classification task indicates that impaired Nondeclarative learning in patients with HD occurs not only in motor tasks but also in Nondeclarative learning tasks that have no motor component. Huntington's disease (HD) is an inherited progressive neurological disorder that is characterized by involuntary, choreiform movements, affective disturbance, and progressive cognitive and functional decline. The primary neuropathology