Ruben Gur | University of Pennsylvania (original) (raw)

Papers by Ruben Gur

Research paper thumbnail of Gender differences in aging: cognition, emotions, and neuroimaging studies

Dialogues in Clinical Neuroscience, 2002

Gender and aging moderate brain-behavior relationships. Advances in neuroscience enable integrati... more Gender and aging moderate brain-behavior relationships. Advances in neuroscience enable integration of neurobehavioral, neuroanatomic, and neurophysiology measures. Here we present neurobehavioral studies thai examine cognitive and emotion processing in healthy men and women and highlight the effects of sex differences and aqinq. Neuroanatomic studies with maqnetic resonance imaging (MRI) indicate that the progressive decrease in brain volume affects froniotemporal brain regions in men more than in Vi/omen, Functional imaging methods suggest sex differences in rate of blood flow, pattern of glucose metabolism, and receptor activity. The role of ovarian hormones is important in elucidating the observed relationships. A life span perspective on gender differences through the integration of available methodologies will advance understanding healthy people and the effects of brain disorders.

Research paper thumbnail of Subcortical MRI Volumes in Neuroleptic-Naive and Treated Patients With Schizophrenia

American Journal of Psychiatry, 1998

Research paper thumbnail of “It’s not what you say, but how you say it”: a reciprocal temporo-frontal network for affective prosody

Frontiers in Human Neuroscience, 2010

Research paper thumbnail of Striatal intrinsic reinforcement signals during recognition memory: relationship to response bias and dysregulation in schizophrenia

Front. Behav. Neurosci., 2011

Research paper thumbnail of Dynamic evoked facial expressions of emotions in schizophrenia

Schizophrenia research, 2008

Impaired facial expressions of emotions have been described as characteristic symptoms of schizop... more Impaired facial expressions of emotions have been described as characteristic symptoms of schizophrenia. Previous investigations of dynamic facial expressions have reported on global assessment of positive and negative emotion expressions. In this study, we examined facial expression differences based on duration and frequencies of emotion expressions. 12 persons with stable schizophrenia and matched healthy controls underwent a standardized procedure for evoked facial expressions of five universal emotions, including happy, sad, anger, fear, and disgust expressions. Subjects completed self-ratings of their emotion experience. Reliable raters coded evoked facial expressions according to the Facial Expression Coding System. For each emotion, facial expressions were coded as target, non-target or neutral expressions. Logistic regression analyses examined group differences in duration and frequencies of facial expressions. Comparing overall duration of and frequencies of emotion expres...

Research paper thumbnail of Neural correlates of moral reasoning in autism spectrum disorder

Social Cognitive and Affective Neuroscience, 2012

Research paper thumbnail of Ventrolateral prefrontal cortex and the effects of task demand context on facial affect appraisal in schizophrenia

Social Cognitive and Affective Neuroscience, 2010

Research paper thumbnail of Flat Affect in Schizophrenia: Relation to Emotion Processing and Neurocognitive Measures

Schizophrenia Bulletin, 2006

Research paper thumbnail of Neurocognitive Performance Stability in a Multiplex Multigenerational Study of Schizophrenia

Schizophrenia Bulletin, 2012

Research paper thumbnail of Facial emotion discrimination: I. Task construction and behavioral findings in normal subjects

Psychiatry Research, 1992

Research paper thumbnail of Assessing declarative memory in schizophrenia using Wisconsin Card Sorting Test stimuli: the Paired Associate Recognition Test

Psychiatry Research, 1996

Research paper thumbnail of Being right is its own reward: Load and performance related ventral striatum activation to correct responses during a working memory task in youth

Research paper thumbnail of Exposure to herpes simplex virus, type 1 and reduced cognitive function

Journal of Psychiatric Research, 2013

Research paper thumbnail of Automated video-based facial expression analysis of neuropsychiatric disorders

Journal of Neuroscience Methods, 2008

Research paper thumbnail of Parallel psychometric and cognitive modeling analyses of the Penn Face Memory Test in the Army Study to Assess Risk and Resilience in Servicemembers

Journal of Clinical and Experimental Neuropsychology, 2013

Research paper thumbnail of The Reproducibility of the 133Xe Inhalation Technique in Resting Studies: Task Order and Sex Related Effects in Healthy Young Adults

Journal of Cerebral Blood Flow & Metabolism, 1987

Repeated applications of the 133Xe inhalation technique for measuring regional CBF (rCBF) were ma... more Repeated applications of the 133Xe inhalation technique for measuring regional CBF (rCBF) were made during consecutive resting conditions in a sample of young healthy subjects. Subjects were grouped by order and by sex [nine had resting studies as the initial two measurements in a series of four measurement (six men, three women) and six had these measurements later (two men, four women)]. Three flow parameters were examined: f1 (fast flow) and IS (initial slope) for gray matter CBF, and CBF-15 for mean CBF (gray and white matter over 15-min integration), as well as w1, the percentage of tissue with fast clearing characteristics. With all groups combined, there were no significant differences between the two resting measurements, and high test-retest correlations were obtained for the flow parameters and w1. Analyses by order and sex grouping revealed, for the flow parameters, significant interactions of test-retest difference with order. Repeated initial studies showed reduced CBF ...

Research paper thumbnail of Reliability of Regional Cerebral Blood Flow Activation to Cognitive Tasks in Elderly Normal Subjects

Journal of Cerebral Blood Flow & Metabolism, 1993

The assessment of cerebral blood flow (CBF) using noninvasive 133Xe techniques provides an indire... more The assessment of cerebral blood flow (CBF) using noninvasive 133Xe techniques provides an indirect measurement of cortical metabolic activity. The utility of this method in longitudinal clinical studies depends on the stability and reproducibility of resting and activated flow measures. We evaluated CBF in a sample of 16 elderly normal subjects (aged 54–73 years) at rest and during task performance in two sessions separated by an average of 9 weeks. Resting global CBF was lower in the second session, a finding consistent with the known effects of habituation previously reported. Regionally specific activated CBF did not change with repeated measurements. The results provide evidence that the 133Xe technique is reliable and of potential utility in evaluating the effect of the natural course of brain disease, as well as the effects of therapeutic interventions on brain activity.

Research paper thumbnail of The Effect of Anxiety on Cortical Cerebral Blood Flow and Metabolism

Journal of Cerebral Blood Flow & Metabolism, 1987

The relation between anxiety and cortical activity was compared in two samples of normal voluntee... more The relation between anxiety and cortical activity was compared in two samples of normal volunteers. One group was studied with the noninvasive xenon-133 inhalation technique for measuring cerebral blood flow (CBF) and the other with positron emission tomography (PET) using 18Flurodeoxyglucose (18FDG) for measuring cerebral metabolic rates (CMR) for glucose. The inhalation technique produced less anxiety than the PET procedure, and for low anxiety subjects, there was a linear increase in CBF with anxiety. For higher anxiety subjects, however, there was a linear decrease in CBF with increased anxiety. The PET group manifested a linear decrease in CMR with increased anxiety. The results indicate that anxiety can have systematic effects on cortical activity, and this should be taken into consideration when comparing data from different procedures. They also suggest a physiologic explanation of a fundamental behavioral law that stipulates a curvilinear, inverted-U relationship between a...

Research paper thumbnail of White matter microstructure in schizophrenia: effects of disorder, duration and medication

British Journal of Psychiatry, 2009

BackgroundDiffusion tensor magnetic resonance imaging studies in schizophrenia to date have been ... more BackgroundDiffusion tensor magnetic resonance imaging studies in schizophrenia to date have been largely inconsistent. This may reflect variation in methodology, and the use of small samples with differing illness duration and medication exposure.AimsTo determine the extent and location of white matter microstructural changes in schizophrenia, using optimised diffusion tensor imaging in a large patient sample, and to consider the effects of illness duration and medication exposure.MethodScans from 76 patients with schizophrenia and 76 matched controls were used to compare fractional anisotropy, a measure of white matter microstructural integrity, between the groups.ResultsWe found widespread clusters of reduced fractional anisotropy in patients, affecting most major white matter tracts. These reductions did not correlate with illness duration, and there was no difference between age-matched chronically and briefly medicated patients.ConclusionsThe finding of widespread fractional an...

Research paper thumbnail of Levels-of-Processing Effect on Frontotemporal Function in Schizophrenia During Word Encoding and Recognition

American Journal of Psychiatry, 2005

Research paper thumbnail of Gender differences in aging: cognition, emotions, and neuroimaging studies

Dialogues in Clinical Neuroscience, 2002

Gender and aging moderate brain-behavior relationships. Advances in neuroscience enable integrati... more Gender and aging moderate brain-behavior relationships. Advances in neuroscience enable integration of neurobehavioral, neuroanatomic, and neurophysiology measures. Here we present neurobehavioral studies thai examine cognitive and emotion processing in healthy men and women and highlight the effects of sex differences and aqinq. Neuroanatomic studies with maqnetic resonance imaging (MRI) indicate that the progressive decrease in brain volume affects froniotemporal brain regions in men more than in Vi/omen, Functional imaging methods suggest sex differences in rate of blood flow, pattern of glucose metabolism, and receptor activity. The role of ovarian hormones is important in elucidating the observed relationships. A life span perspective on gender differences through the integration of available methodologies will advance understanding healthy people and the effects of brain disorders.

Research paper thumbnail of Subcortical MRI Volumes in Neuroleptic-Naive and Treated Patients With Schizophrenia

American Journal of Psychiatry, 1998

Research paper thumbnail of “It’s not what you say, but how you say it”: a reciprocal temporo-frontal network for affective prosody

Frontiers in Human Neuroscience, 2010

Research paper thumbnail of Striatal intrinsic reinforcement signals during recognition memory: relationship to response bias and dysregulation in schizophrenia

Front. Behav. Neurosci., 2011

Research paper thumbnail of Dynamic evoked facial expressions of emotions in schizophrenia

Schizophrenia research, 2008

Impaired facial expressions of emotions have been described as characteristic symptoms of schizop... more Impaired facial expressions of emotions have been described as characteristic symptoms of schizophrenia. Previous investigations of dynamic facial expressions have reported on global assessment of positive and negative emotion expressions. In this study, we examined facial expression differences based on duration and frequencies of emotion expressions. 12 persons with stable schizophrenia and matched healthy controls underwent a standardized procedure for evoked facial expressions of five universal emotions, including happy, sad, anger, fear, and disgust expressions. Subjects completed self-ratings of their emotion experience. Reliable raters coded evoked facial expressions according to the Facial Expression Coding System. For each emotion, facial expressions were coded as target, non-target or neutral expressions. Logistic regression analyses examined group differences in duration and frequencies of facial expressions. Comparing overall duration of and frequencies of emotion expres...

Research paper thumbnail of Neural correlates of moral reasoning in autism spectrum disorder

Social Cognitive and Affective Neuroscience, 2012

Research paper thumbnail of Ventrolateral prefrontal cortex and the effects of task demand context on facial affect appraisal in schizophrenia

Social Cognitive and Affective Neuroscience, 2010

Research paper thumbnail of Flat Affect in Schizophrenia: Relation to Emotion Processing and Neurocognitive Measures

Schizophrenia Bulletin, 2006

Research paper thumbnail of Neurocognitive Performance Stability in a Multiplex Multigenerational Study of Schizophrenia

Schizophrenia Bulletin, 2012

Research paper thumbnail of Facial emotion discrimination: I. Task construction and behavioral findings in normal subjects

Psychiatry Research, 1992

Research paper thumbnail of Assessing declarative memory in schizophrenia using Wisconsin Card Sorting Test stimuli: the Paired Associate Recognition Test

Psychiatry Research, 1996

Research paper thumbnail of Being right is its own reward: Load and performance related ventral striatum activation to correct responses during a working memory task in youth

Research paper thumbnail of Exposure to herpes simplex virus, type 1 and reduced cognitive function

Journal of Psychiatric Research, 2013

Research paper thumbnail of Automated video-based facial expression analysis of neuropsychiatric disorders

Journal of Neuroscience Methods, 2008

Research paper thumbnail of Parallel psychometric and cognitive modeling analyses of the Penn Face Memory Test in the Army Study to Assess Risk and Resilience in Servicemembers

Journal of Clinical and Experimental Neuropsychology, 2013

Research paper thumbnail of The Reproducibility of the 133Xe Inhalation Technique in Resting Studies: Task Order and Sex Related Effects in Healthy Young Adults

Journal of Cerebral Blood Flow & Metabolism, 1987

Repeated applications of the 133Xe inhalation technique for measuring regional CBF (rCBF) were ma... more Repeated applications of the 133Xe inhalation technique for measuring regional CBF (rCBF) were made during consecutive resting conditions in a sample of young healthy subjects. Subjects were grouped by order and by sex [nine had resting studies as the initial two measurements in a series of four measurement (six men, three women) and six had these measurements later (two men, four women)]. Three flow parameters were examined: f1 (fast flow) and IS (initial slope) for gray matter CBF, and CBF-15 for mean CBF (gray and white matter over 15-min integration), as well as w1, the percentage of tissue with fast clearing characteristics. With all groups combined, there were no significant differences between the two resting measurements, and high test-retest correlations were obtained for the flow parameters and w1. Analyses by order and sex grouping revealed, for the flow parameters, significant interactions of test-retest difference with order. Repeated initial studies showed reduced CBF ...

Research paper thumbnail of Reliability of Regional Cerebral Blood Flow Activation to Cognitive Tasks in Elderly Normal Subjects

Journal of Cerebral Blood Flow & Metabolism, 1993

The assessment of cerebral blood flow (CBF) using noninvasive 133Xe techniques provides an indire... more The assessment of cerebral blood flow (CBF) using noninvasive 133Xe techniques provides an indirect measurement of cortical metabolic activity. The utility of this method in longitudinal clinical studies depends on the stability and reproducibility of resting and activated flow measures. We evaluated CBF in a sample of 16 elderly normal subjects (aged 54–73 years) at rest and during task performance in two sessions separated by an average of 9 weeks. Resting global CBF was lower in the second session, a finding consistent with the known effects of habituation previously reported. Regionally specific activated CBF did not change with repeated measurements. The results provide evidence that the 133Xe technique is reliable and of potential utility in evaluating the effect of the natural course of brain disease, as well as the effects of therapeutic interventions on brain activity.

Research paper thumbnail of The Effect of Anxiety on Cortical Cerebral Blood Flow and Metabolism

Journal of Cerebral Blood Flow & Metabolism, 1987

The relation between anxiety and cortical activity was compared in two samples of normal voluntee... more The relation between anxiety and cortical activity was compared in two samples of normal volunteers. One group was studied with the noninvasive xenon-133 inhalation technique for measuring cerebral blood flow (CBF) and the other with positron emission tomography (PET) using 18Flurodeoxyglucose (18FDG) for measuring cerebral metabolic rates (CMR) for glucose. The inhalation technique produced less anxiety than the PET procedure, and for low anxiety subjects, there was a linear increase in CBF with anxiety. For higher anxiety subjects, however, there was a linear decrease in CBF with increased anxiety. The PET group manifested a linear decrease in CMR with increased anxiety. The results indicate that anxiety can have systematic effects on cortical activity, and this should be taken into consideration when comparing data from different procedures. They also suggest a physiologic explanation of a fundamental behavioral law that stipulates a curvilinear, inverted-U relationship between a...

Research paper thumbnail of White matter microstructure in schizophrenia: effects of disorder, duration and medication

British Journal of Psychiatry, 2009

BackgroundDiffusion tensor magnetic resonance imaging studies in schizophrenia to date have been ... more BackgroundDiffusion tensor magnetic resonance imaging studies in schizophrenia to date have been largely inconsistent. This may reflect variation in methodology, and the use of small samples with differing illness duration and medication exposure.AimsTo determine the extent and location of white matter microstructural changes in schizophrenia, using optimised diffusion tensor imaging in a large patient sample, and to consider the effects of illness duration and medication exposure.MethodScans from 76 patients with schizophrenia and 76 matched controls were used to compare fractional anisotropy, a measure of white matter microstructural integrity, between the groups.ResultsWe found widespread clusters of reduced fractional anisotropy in patients, affecting most major white matter tracts. These reductions did not correlate with illness duration, and there was no difference between age-matched chronically and briefly medicated patients.ConclusionsThe finding of widespread fractional an...

Research paper thumbnail of Levels-of-Processing Effect on Frontotemporal Function in Schizophrenia During Word Encoding and Recognition

American Journal of Psychiatry, 2005