The Experts below are selected from a list of 204 Experts worldwide ranked by ideXlab platform
Daniel C Javitt - One of the best experts on this subject based on the ideXlab platform.
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normal time course of auditory recognition in schizophrenia despite impaired precision of the auditory sensory Echoic Memory code
Journal of Abnormal Psychology, 1999Co-Authors: Lucy March, Nelson Cowan, Walter Ritter, Angel Cienfuegos, Lyra Goldbloom, Daniel C JavittAbstract:Prior studies have demonstrated impaired precision of processing within the auditory sensory Memory (ASM) system in schizophrenia. This study used auditory backward masking to evaluate the degree to which such deficits resulted from impaired overall precision versus premature decay of information within the short-term auditory store. ASM performance was evaluated in 14 schizophrenic participants and 16 controls. Schizophrenic participants were severely impaired in their ability to match tones following delay. However, when no-mask performance was equated across participants, schizophrenic participants were no more susceptible to the effects of backward maskers than were controls. Thus, despite impaired precision of ASM performance, schizophrenic participants showed no deficits in the time course over which short-term representations could be used within the ASM system.
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impaired mismatch negativity mmn generation in schizophrenia as a function of stimulus deviance probability and interstimulus interdeviant interval
Electroencephalography and Clinical Neurophysiology, 1998Co-Authors: Daniel C Javitt, Sandra Grochowski, A M Shelley, Walter RitterAbstract:Schizophrenia is a severe mental disorder associated with disturbances in perception and cognition. Event-related potentials (ERP) provide a mechanism for evaluating potential mechanisms underlying neurophysiological dysfunction in schizophrenia. Mismatch negativity (MMN) is a short-duration auditory cognitive ERP component that indexes operation of the auditory sensory ('Echoic') Memory system. Prior studies have demonstrated impaired MMN generation in schizophrenia along with deficits in auditory sensory Memory performance. MMN is elicited in an auditory oddball paradigm in which a sequence of repetitive standard tones is interrupted infrequently by a physically deviant ('oddball') stimulus. The present study evaluates MMN generation as a function of deviant stimulus probability, interstimulus interval, interdeviant interval and the degree of pitch separation between the standard and deviant stimuli. The major findings of the present study are first, that MMN amplitude is decreased in schizophrenia across a broad range of stimulus conditions, and second, that the degree of deficit in schizophrenia is largest under conditions when MMN is normally largest. The pattern of deficit observed in schizophrenia differs from the pattern observed in other conditions associated with MMN dysfunction, including Alzheimer's disease, stroke, and alcohol intoxication.
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Impaired precision, but normal retention, of auditory sensory (Echoic) Memory information in schizophrenia
Journal of abnormal psychology, 1997Co-Authors: Daniel C Javitt, Rael D Strous, Walter Ritter, Sandra Grochowski, Nelson CowanAbstract:Working Memory is the type of Memory that allows one to hold information in mind while working on a task or problem. The present study investigated attention-independent auditory sensory ("Echoic") Memory in 18 schizophrenic participants and 17 controls. Schizophrenic participants showed impaired delayed tone matching performance in comparison with controls. However, when groups were matched for performance at 1 s by varying the difficulty of the task across groups, schizophrenic participants showed normal retention of information as reflected in normal tone matching performance. These findings demonstrate that schizophrenic may be in the sensitivity of the system rather than the duration for which Memory traces were retained.
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auditory sensory Echoic Memory dysfunction in schizophrenia
American Journal of Psychiatry, 1995Co-Authors: Rael D Strous, Nelson Cowan, Walter Ritter, Daniel C JavittAbstract:Objective: Studies of working Memory dysfunction in schizophrenia have focused largely on prefrontal components. This study investigated the integrity ofauditory sensory (“Echoic “) Memory, a component that shows little dependence on prefrontal functioning. Method: Echoic Memory was investigated in 20 schizophrenic subjects and 20 age- and IQ-matched normal comparison subjects with the use of nondelayed and delayed tone matching. Results: Schizophrenic subjects were markedly impaired in their ability to match two tones after an extremely brief delay between them (300 msec) but were unimpaired when there was no delay between tones. Conclusions: Working Memory dysfunction in schizophrenia affects brain regions outside the prefrontal cortex as well as within. (AmJ Psychiatry 1995; 152:1517-1519)
Richard C. Saunders - One of the best experts on this subject based on the ideXlab platform.
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monkey s short term auditory Memory nearly abolished by combined removal of the rostral superior temporal gyrus and rhinal cortices
Brain Research, 2016Co-Authors: Jonathan B. Fritz, Mortimer Mishkin, Megan Malloy, Richard C. SaundersAbstract:While monkeys easily acquire the rules for performing visual and tactile delayed matching-to-sample, a method for testing recognition Memory, they have extraordinary difficulty acquiring a similar rule in audition. Another striking difference between the modalities is that whereas bilateral ablation of the rhinal cortex (RhC) leads to profound impairment in visual and tactile recognition, the same lesion has no detectable effect on auditory recognition Memory (Fritz et al., 2005). In our previous study, a mild impairment in auditory Memory was obtained following bilateral ablation of the entire medial temporal lobe (MTL), including the RhC, and an equally mild effect was observed after bilateral ablation of the auditory cortical areas in the rostral superior temporal gyrus (rSTG). In order to test the hypothesis that each of these mild impairments was due to partial disconnection of acoustic input to a common target (e.g., the ventromedial prefrontal cortex), in the current study we examined the effects of a more complete auditory disconnection of this common target by combining the removals of both the rSTG and the MTL. We found that the combined lesion led to forgetting thresholds (performance at 75% accuracy) that fell precipitously from the normal retention duration of ~30 to 40s to a duration of ~1 to 2s, thus nearly abolishing auditory recognition Memory, and leaving behind only a residual Echoic Memory. This article is part of a Special Issue entitled SI: Auditory working Memory.
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Monkey׳s short-term auditory Memory nearly abolished by combined removal of the rostral superior temporal gyrus and rhinal cortices.
Brain research, 2015Co-Authors: Jonathan B. Fritz, Mortimer Mishkin, Megan Malloy, Richard C. SaundersAbstract:While monkeys easily acquire the rules for performing visual and tactile delayed matching-to-sample, a method for testing recognition Memory, they have extraordinary difficulty acquiring a similar rule in audition. Another striking difference between the modalities is that whereas bilateral ablation of the rhinal cortex (RhC) leads to profound impairment in visual and tactile recognition, the same lesion has no detectable effect on auditory recognition Memory (Fritz et al., 2005). In our previous study, a mild impairment in auditory Memory was obtained following bilateral ablation of the entire medial temporal lobe (MTL), including the RhC, and an equally mild effect was observed after bilateral ablation of the auditory cortical areas in the rostral superior temporal gyrus (rSTG). In order to test the hypothesis that each of these mild impairments was due to partial disconnection of acoustic input to a common target (e.g., the ventromedial prefrontal cortex), in the current study we examined the effects of a more complete auditory disconnection of this common target by combining the removals of both the rSTG and the MTL. We found that the combined lesion led to forgetting thresholds (performance at 75% accuracy) that fell precipitously from the normal retention duration of ~30 to 40s to a duration of ~1 to 2s, thus nearly abolishing auditory recognition Memory, and leaving behind only a residual Echoic Memory. This article is part of a Special Issue entitled SI: Auditory working Memory.
Jonathan B. Fritz - One of the best experts on this subject based on the ideXlab platform.
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monkey s short term auditory Memory nearly abolished by combined removal of the rostral superior temporal gyrus and rhinal cortices
Brain Research, 2016Co-Authors: Jonathan B. Fritz, Mortimer Mishkin, Megan Malloy, Richard C. SaundersAbstract:While monkeys easily acquire the rules for performing visual and tactile delayed matching-to-sample, a method for testing recognition Memory, they have extraordinary difficulty acquiring a similar rule in audition. Another striking difference between the modalities is that whereas bilateral ablation of the rhinal cortex (RhC) leads to profound impairment in visual and tactile recognition, the same lesion has no detectable effect on auditory recognition Memory (Fritz et al., 2005). In our previous study, a mild impairment in auditory Memory was obtained following bilateral ablation of the entire medial temporal lobe (MTL), including the RhC, and an equally mild effect was observed after bilateral ablation of the auditory cortical areas in the rostral superior temporal gyrus (rSTG). In order to test the hypothesis that each of these mild impairments was due to partial disconnection of acoustic input to a common target (e.g., the ventromedial prefrontal cortex), in the current study we examined the effects of a more complete auditory disconnection of this common target by combining the removals of both the rSTG and the MTL. We found that the combined lesion led to forgetting thresholds (performance at 75% accuracy) that fell precipitously from the normal retention duration of ~30 to 40s to a duration of ~1 to 2s, thus nearly abolishing auditory recognition Memory, and leaving behind only a residual Echoic Memory. This article is part of a Special Issue entitled SI: Auditory working Memory.
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Monkey׳s short-term auditory Memory nearly abolished by combined removal of the rostral superior temporal gyrus and rhinal cortices.
Brain research, 2015Co-Authors: Jonathan B. Fritz, Mortimer Mishkin, Megan Malloy, Richard C. SaundersAbstract:While monkeys easily acquire the rules for performing visual and tactile delayed matching-to-sample, a method for testing recognition Memory, they have extraordinary difficulty acquiring a similar rule in audition. Another striking difference between the modalities is that whereas bilateral ablation of the rhinal cortex (RhC) leads to profound impairment in visual and tactile recognition, the same lesion has no detectable effect on auditory recognition Memory (Fritz et al., 2005). In our previous study, a mild impairment in auditory Memory was obtained following bilateral ablation of the entire medial temporal lobe (MTL), including the RhC, and an equally mild effect was observed after bilateral ablation of the auditory cortical areas in the rostral superior temporal gyrus (rSTG). In order to test the hypothesis that each of these mild impairments was due to partial disconnection of acoustic input to a common target (e.g., the ventromedial prefrontal cortex), in the current study we examined the effects of a more complete auditory disconnection of this common target by combining the removals of both the rSTG and the MTL. We found that the combined lesion led to forgetting thresholds (performance at 75% accuracy) that fell precipitously from the normal retention duration of ~30 to 40s to a duration of ~1 to 2s, thus nearly abolishing auditory recognition Memory, and leaving behind only a residual Echoic Memory. This article is part of a Special Issue entitled SI: Auditory working Memory.
Walter Ritter - One of the best experts on this subject based on the ideXlab platform.
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normal time course of auditory recognition in schizophrenia despite impaired precision of the auditory sensory Echoic Memory code
Journal of Abnormal Psychology, 1999Co-Authors: Lucy March, Nelson Cowan, Walter Ritter, Angel Cienfuegos, Lyra Goldbloom, Daniel C JavittAbstract:Prior studies have demonstrated impaired precision of processing within the auditory sensory Memory (ASM) system in schizophrenia. This study used auditory backward masking to evaluate the degree to which such deficits resulted from impaired overall precision versus premature decay of information within the short-term auditory store. ASM performance was evaluated in 14 schizophrenic participants and 16 controls. Schizophrenic participants were severely impaired in their ability to match tones following delay. However, when no-mask performance was equated across participants, schizophrenic participants were no more susceptible to the effects of backward maskers than were controls. Thus, despite impaired precision of ASM performance, schizophrenic participants showed no deficits in the time course over which short-term representations could be used within the ASM system.
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impaired mismatch negativity mmn generation in schizophrenia as a function of stimulus deviance probability and interstimulus interdeviant interval
Electroencephalography and Clinical Neurophysiology, 1998Co-Authors: Daniel C Javitt, Sandra Grochowski, A M Shelley, Walter RitterAbstract:Schizophrenia is a severe mental disorder associated with disturbances in perception and cognition. Event-related potentials (ERP) provide a mechanism for evaluating potential mechanisms underlying neurophysiological dysfunction in schizophrenia. Mismatch negativity (MMN) is a short-duration auditory cognitive ERP component that indexes operation of the auditory sensory ('Echoic') Memory system. Prior studies have demonstrated impaired MMN generation in schizophrenia along with deficits in auditory sensory Memory performance. MMN is elicited in an auditory oddball paradigm in which a sequence of repetitive standard tones is interrupted infrequently by a physically deviant ('oddball') stimulus. The present study evaluates MMN generation as a function of deviant stimulus probability, interstimulus interval, interdeviant interval and the degree of pitch separation between the standard and deviant stimuli. The major findings of the present study are first, that MMN amplitude is decreased in schizophrenia across a broad range of stimulus conditions, and second, that the degree of deficit in schizophrenia is largest under conditions when MMN is normally largest. The pattern of deficit observed in schizophrenia differs from the pattern observed in other conditions associated with MMN dysfunction, including Alzheimer's disease, stroke, and alcohol intoxication.
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Impaired precision, but normal retention, of auditory sensory (Echoic) Memory information in schizophrenia
Journal of abnormal psychology, 1997Co-Authors: Daniel C Javitt, Rael D Strous, Walter Ritter, Sandra Grochowski, Nelson CowanAbstract:Working Memory is the type of Memory that allows one to hold information in mind while working on a task or problem. The present study investigated attention-independent auditory sensory ("Echoic") Memory in 18 schizophrenic participants and 17 controls. Schizophrenic participants showed impaired delayed tone matching performance in comparison with controls. However, when groups were matched for performance at 1 s by varying the difficulty of the task across groups, schizophrenic participants showed normal retention of information as reflected in normal tone matching performance. These findings demonstrate that schizophrenic may be in the sensitivity of the system rather than the duration for which Memory traces were retained.
-
auditory sensory Echoic Memory dysfunction in schizophrenia
American Journal of Psychiatry, 1995Co-Authors: Rael D Strous, Nelson Cowan, Walter Ritter, Daniel C JavittAbstract:Objective: Studies of working Memory dysfunction in schizophrenia have focused largely on prefrontal components. This study investigated the integrity ofauditory sensory (“Echoic “) Memory, a component that shows little dependence on prefrontal functioning. Method: Echoic Memory was investigated in 20 schizophrenic subjects and 20 age- and IQ-matched normal comparison subjects with the use of nondelayed and delayed tone matching. Results: Schizophrenic subjects were markedly impaired in their ability to match two tones after an extremely brief delay between them (300 msec) but were unimpaired when there was no delay between tones. Conclusions: Working Memory dysfunction in schizophrenia affects brain regions outside the prefrontal cortex as well as within. (AmJ Psychiatry 1995; 152:1517-1519)
Nelson Cowan - One of the best experts on this subject based on the ideXlab platform.
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normal time course of auditory recognition in schizophrenia despite impaired precision of the auditory sensory Echoic Memory code
Journal of Abnormal Psychology, 1999Co-Authors: Lucy March, Nelson Cowan, Walter Ritter, Angel Cienfuegos, Lyra Goldbloom, Daniel C JavittAbstract:Prior studies have demonstrated impaired precision of processing within the auditory sensory Memory (ASM) system in schizophrenia. This study used auditory backward masking to evaluate the degree to which such deficits resulted from impaired overall precision versus premature decay of information within the short-term auditory store. ASM performance was evaluated in 14 schizophrenic participants and 16 controls. Schizophrenic participants were severely impaired in their ability to match tones following delay. However, when no-mask performance was equated across participants, schizophrenic participants were no more susceptible to the effects of backward maskers than were controls. Thus, despite impaired precision of ASM performance, schizophrenic participants showed no deficits in the time course over which short-term representations could be used within the ASM system.
-
Impaired precision, but normal retention, of auditory sensory (Echoic) Memory information in schizophrenia
Journal of abnormal psychology, 1997Co-Authors: Daniel C Javitt, Rael D Strous, Walter Ritter, Sandra Grochowski, Nelson CowanAbstract:Working Memory is the type of Memory that allows one to hold information in mind while working on a task or problem. The present study investigated attention-independent auditory sensory ("Echoic") Memory in 18 schizophrenic participants and 17 controls. Schizophrenic participants showed impaired delayed tone matching performance in comparison with controls. However, when groups were matched for performance at 1 s by varying the difficulty of the task across groups, schizophrenic participants showed normal retention of information as reflected in normal tone matching performance. These findings demonstrate that schizophrenic may be in the sensitivity of the system rather than the duration for which Memory traces were retained.
-
auditory sensory Echoic Memory dysfunction in schizophrenia
American Journal of Psychiatry, 1995Co-Authors: Rael D Strous, Nelson Cowan, Walter Ritter, Daniel C JavittAbstract:Objective: Studies of working Memory dysfunction in schizophrenia have focused largely on prefrontal components. This study investigated the integrity ofauditory sensory (“Echoic “) Memory, a component that shows little dependence on prefrontal functioning. Method: Echoic Memory was investigated in 20 schizophrenic subjects and 20 age- and IQ-matched normal comparison subjects with the use of nondelayed and delayed tone matching. Results: Schizophrenic subjects were markedly impaired in their ability to match two tones after an extremely brief delay between them (300 msec) but were unimpaired when there was no delay between tones. Conclusions: Working Memory dysfunction in schizophrenia affects brain regions outside the prefrontal cortex as well as within. (AmJ Psychiatry 1995; 152:1517-1519)
