The Experts below are selected from a list of 130074 Experts worldwide ranked by ideXlab platform
Tom Theys - One of the best experts on this subject based on the ideXlab platform.
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single cell selectivity and Functional Architecture of human lateral occipital complex
PLOS Biology, 2019Co-Authors: Thomas Decramer, Elsie Premereur, Mats Uytterhoeven, Wim Van Paesschen, Johannes Van Loon, Peter Janssen, Tom TheysAbstract:The human lateral occipital complex (LOC) is more strongly activated by images of objects compared to scrambled controls, but detailed information at the neuronal level is currently lacking. We recorded with microelectrode arrays in the LOC of 2 patients and obtained highly selective single-unit, multi-unit, and high-gamma responses to images of objects. Contrary to predictions derived from Functional imaging studies, all neuronal properties indicated that the posterior subsector of LOC we recorded from occupies an unexpectedly high position in the hierarchy of visual areas. Notably, the response latencies of LOC neurons were long, the shape selectivity was spatially clustered, LOC receptive fields (RFs) were large and bilateral, and a number of LOC neurons exhibited three-dimensional (3D)-structure selectivity (a preference for convex or concave stimuli), which are all properties typical of end-stage ventral stream areas. Thus, our results challenge prevailing ideas about the position of the more posterior subsector of LOC in the hierarchy of visual areas.
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single cell selectivity and Functional Architecture of human lateral occipital complex
bioRxiv, 2019Co-Authors: Thomas Decramer, Elsie Premereur, Mats Uytterhoeven, Wim Van Paesschen, Johannes Van Loon, Peter Janssen, Tom TheysAbstract:Abstract The human lateral occipital complex (LOC) is more strongly activated by images of objects compared to scrambled controls, but detailed information at the neuronal level is currently lacking. We recorded with microelectrode arrays in the LOC of two patients, and obtained highly selective single-unit, multi-unit and high-gamma responses to images of objects. Contrary to predictions derived from Functional imaging studies, all neuronal properties indicated that the subsector of LOC we recorded from occupies an unexpectedly high position in the hierarchy of visual areas. Notably, the response latencies of LOC neurons were long, the shape selectivity was spatially clustered, LOC receptive fields were large and bilateral, and a number of LOC neurons exhibited 3D-structure selectivity (a preference for convex or concave stimuli), which are all properties typical of end-stage ventral stream areas. Thus, our results challenge prevailing ideas about the position of the LOC in the hierarchy of visual areas.
Gordon J Chelune - One of the best experts on this subject based on the ideXlab platform.
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Functional Architecture of the cortico basal ganglia circuitry during motor task execution correlations of strength of Functional connectivity with neuropsychological task performance among female subjects
Human Brain Mapping, 2013Co-Authors: William R. Marchand, Yana Suchy, Cheryl Garn, Susanna Johnson, Gordon J Chelune, Nicole WoodAbstract:The primary aim of this study was to enhance our understanding of the Functional Architecture of the cortico-basal ganglia circuitry during motor task execution. Twenty right-handed female subjects without any history of neuropsychiatric illness underwent fMRI at 3 T. The activation paradigm was a complex motor task completed with the nondominant hand. Analyses of Functional connectivity strength were conducted for pairs of structures in input, intrinsic, and output segments of the circuitry. Next, connectivity strengths were correlated with results of neurocognitive testing conducted outside of the scanner, which provided information about both motor and cognitive processes. For input pathways, results indicate that SMA–striatum interactions are particularly relevant for motor behavior and disruptions may impact both motor and cognitive functions. For intrinsic pathways, results indicate that thalamus (VA nucleus) to striatum feedback pathway appears to have an important role during task execution and carries information relevant for motor planning. Together, these findings add to accumulating evidence that the GPe may play a role in higher order basal ganglia processing. A potentially controversial finding was that strong Functional connectivity appears to occur across intrinsic inhibitory pathways. Finally, output (thalamus to cortex) feedback was only correlated with motor planning. This result suggests circuit processes may be more relevant for future behaviors than the execution of the current task. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
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age related changes of the Functional Architecture of the cortico basal ganglia circuitry during motor task execution
NeuroImage, 2011Co-Authors: William R. Marchand, Yana Suchy, Cheryl Garn, Susanna Johnson, Nicole Wood, Gordon J CheluneAbstract:Abstract Normal human aging is associated with declining motor control and function. It is thought that dysfunction of the cortico-basal ganglia circuitry may contribute to age-related sensorimotor impairment, however the underlying mechanisms are poorly characterized. The aim of this study was to enhance our understanding of age-related changes in the Functional Architecture of these circuits. Fifty-nine subjects, consisting of a young, middle and old group, were studied using Functional MRI and a motor activation paradigm. Functional connectivity analyses and examination of correlations of connectivity strength with performance on the activation task as well as neurocognitive tasks completed outside of magnet were conducted. Results indicated that increasing age is associated with changes in the Functional Architecture of the cortico-basal ganglia circuitry. Connectivity strength increased between subcortical nuclei and cortical motor and sensory regions but no changes were found between subcortical components of the circuitry. Further, increased connectivity was correlated with poorer performance on a neurocognitive task independently of age. This result suggests that increased connectivity reflects a decline in brain function rather than a compensatory process. These findings advance our understanding of the normal aging process. Further, the methods employed will likely be useful for future studies aimed at disambiguating age-related versus illness progression changes associated with neuropsychiatric disorders that involve the cortico-basal ganglia circuitry.
Nicole Wood - One of the best experts on this subject based on the ideXlab platform.
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Functional Architecture of the cortico basal ganglia circuitry during motor task execution correlations of strength of Functional connectivity with neuropsychological task performance among female subjects
Human Brain Mapping, 2013Co-Authors: William R. Marchand, Yana Suchy, Cheryl Garn, Susanna Johnson, Gordon J Chelune, Nicole WoodAbstract:The primary aim of this study was to enhance our understanding of the Functional Architecture of the cortico-basal ganglia circuitry during motor task execution. Twenty right-handed female subjects without any history of neuropsychiatric illness underwent fMRI at 3 T. The activation paradigm was a complex motor task completed with the nondominant hand. Analyses of Functional connectivity strength were conducted for pairs of structures in input, intrinsic, and output segments of the circuitry. Next, connectivity strengths were correlated with results of neurocognitive testing conducted outside of the scanner, which provided information about both motor and cognitive processes. For input pathways, results indicate that SMA–striatum interactions are particularly relevant for motor behavior and disruptions may impact both motor and cognitive functions. For intrinsic pathways, results indicate that thalamus (VA nucleus) to striatum feedback pathway appears to have an important role during task execution and carries information relevant for motor planning. Together, these findings add to accumulating evidence that the GPe may play a role in higher order basal ganglia processing. A potentially controversial finding was that strong Functional connectivity appears to occur across intrinsic inhibitory pathways. Finally, output (thalamus to cortex) feedback was only correlated with motor planning. This result suggests circuit processes may be more relevant for future behaviors than the execution of the current task. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
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age related changes of the Functional Architecture of the cortico basal ganglia circuitry during motor task execution
NeuroImage, 2011Co-Authors: William R. Marchand, Yana Suchy, Cheryl Garn, Susanna Johnson, Nicole Wood, Gordon J CheluneAbstract:Abstract Normal human aging is associated with declining motor control and function. It is thought that dysfunction of the cortico-basal ganglia circuitry may contribute to age-related sensorimotor impairment, however the underlying mechanisms are poorly characterized. The aim of this study was to enhance our understanding of age-related changes in the Functional Architecture of these circuits. Fifty-nine subjects, consisting of a young, middle and old group, were studied using Functional MRI and a motor activation paradigm. Functional connectivity analyses and examination of correlations of connectivity strength with performance on the activation task as well as neurocognitive tasks completed outside of magnet were conducted. Results indicated that increasing age is associated with changes in the Functional Architecture of the cortico-basal ganglia circuitry. Connectivity strength increased between subcortical nuclei and cortical motor and sensory regions but no changes were found between subcortical components of the circuitry. Further, increased connectivity was correlated with poorer performance on a neurocognitive task independently of age. This result suggests that increased connectivity reflects a decline in brain function rather than a compensatory process. These findings advance our understanding of the normal aging process. Further, the methods employed will likely be useful for future studies aimed at disambiguating age-related versus illness progression changes associated with neuropsychiatric disorders that involve the cortico-basal ganglia circuitry.
William R. Marchand - One of the best experts on this subject based on the ideXlab platform.
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Functional Architecture of the cortico basal ganglia circuitry during motor task execution correlations of strength of Functional connectivity with neuropsychological task performance among female subjects
Human Brain Mapping, 2013Co-Authors: William R. Marchand, Yana Suchy, Cheryl Garn, Susanna Johnson, Gordon J Chelune, Nicole WoodAbstract:The primary aim of this study was to enhance our understanding of the Functional Architecture of the cortico-basal ganglia circuitry during motor task execution. Twenty right-handed female subjects without any history of neuropsychiatric illness underwent fMRI at 3 T. The activation paradigm was a complex motor task completed with the nondominant hand. Analyses of Functional connectivity strength were conducted for pairs of structures in input, intrinsic, and output segments of the circuitry. Next, connectivity strengths were correlated with results of neurocognitive testing conducted outside of the scanner, which provided information about both motor and cognitive processes. For input pathways, results indicate that SMA–striatum interactions are particularly relevant for motor behavior and disruptions may impact both motor and cognitive functions. For intrinsic pathways, results indicate that thalamus (VA nucleus) to striatum feedback pathway appears to have an important role during task execution and carries information relevant for motor planning. Together, these findings add to accumulating evidence that the GPe may play a role in higher order basal ganglia processing. A potentially controversial finding was that strong Functional connectivity appears to occur across intrinsic inhibitory pathways. Finally, output (thalamus to cortex) feedback was only correlated with motor planning. This result suggests circuit processes may be more relevant for future behaviors than the execution of the current task. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
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age related changes of the Functional Architecture of the cortico basal ganglia circuitry during motor task execution
NeuroImage, 2011Co-Authors: William R. Marchand, Yana Suchy, Cheryl Garn, Susanna Johnson, Nicole Wood, Gordon J CheluneAbstract:Abstract Normal human aging is associated with declining motor control and function. It is thought that dysfunction of the cortico-basal ganglia circuitry may contribute to age-related sensorimotor impairment, however the underlying mechanisms are poorly characterized. The aim of this study was to enhance our understanding of age-related changes in the Functional Architecture of these circuits. Fifty-nine subjects, consisting of a young, middle and old group, were studied using Functional MRI and a motor activation paradigm. Functional connectivity analyses and examination of correlations of connectivity strength with performance on the activation task as well as neurocognitive tasks completed outside of magnet were conducted. Results indicated that increasing age is associated with changes in the Functional Architecture of the cortico-basal ganglia circuitry. Connectivity strength increased between subcortical nuclei and cortical motor and sensory regions but no changes were found between subcortical components of the circuitry. Further, increased connectivity was correlated with poorer performance on a neurocognitive task independently of age. This result suggests that increased connectivity reflects a decline in brain function rather than a compensatory process. These findings advance our understanding of the normal aging process. Further, the methods employed will likely be useful for future studies aimed at disambiguating age-related versus illness progression changes associated with neuropsychiatric disorders that involve the cortico-basal ganglia circuitry.
Thomas Decramer - One of the best experts on this subject based on the ideXlab platform.
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single cell selectivity and Functional Architecture of human lateral occipital complex
PLOS Biology, 2019Co-Authors: Thomas Decramer, Elsie Premereur, Mats Uytterhoeven, Wim Van Paesschen, Johannes Van Loon, Peter Janssen, Tom TheysAbstract:The human lateral occipital complex (LOC) is more strongly activated by images of objects compared to scrambled controls, but detailed information at the neuronal level is currently lacking. We recorded with microelectrode arrays in the LOC of 2 patients and obtained highly selective single-unit, multi-unit, and high-gamma responses to images of objects. Contrary to predictions derived from Functional imaging studies, all neuronal properties indicated that the posterior subsector of LOC we recorded from occupies an unexpectedly high position in the hierarchy of visual areas. Notably, the response latencies of LOC neurons were long, the shape selectivity was spatially clustered, LOC receptive fields (RFs) were large and bilateral, and a number of LOC neurons exhibited three-dimensional (3D)-structure selectivity (a preference for convex or concave stimuli), which are all properties typical of end-stage ventral stream areas. Thus, our results challenge prevailing ideas about the position of the more posterior subsector of LOC in the hierarchy of visual areas.
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single cell selectivity and Functional Architecture of human lateral occipital complex
bioRxiv, 2019Co-Authors: Thomas Decramer, Elsie Premereur, Mats Uytterhoeven, Wim Van Paesschen, Johannes Van Loon, Peter Janssen, Tom TheysAbstract:Abstract The human lateral occipital complex (LOC) is more strongly activated by images of objects compared to scrambled controls, but detailed information at the neuronal level is currently lacking. We recorded with microelectrode arrays in the LOC of two patients, and obtained highly selective single-unit, multi-unit and high-gamma responses to images of objects. Contrary to predictions derived from Functional imaging studies, all neuronal properties indicated that the subsector of LOC we recorded from occupies an unexpectedly high position in the hierarchy of visual areas. Notably, the response latencies of LOC neurons were long, the shape selectivity was spatially clustered, LOC receptive fields were large and bilateral, and a number of LOC neurons exhibited 3D-structure selectivity (a preference for convex or concave stimuli), which are all properties typical of end-stage ventral stream areas. Thus, our results challenge prevailing ideas about the position of the LOC in the hierarchy of visual areas.
