Neuroscience
Ardesheer Talati and Joy Hirsch. Functional Specialization within the Medial Frontal Gyrus for Perceptual Go/No-Go Decisions Based on "What," "When," and "Where" Related Information: An fMRI Study. Journal of Cognitive Neuroscience. 2005; 17: 981-993.
fMRI Research Center, Department of Radiology, Center for Neurobiology and Behavior, Columbia University, Neurological Institute, Box B-41, 710 West 168th Street, New York, NY 10032.
Cortical systems engaged during executive and volitional functions receive and integrate input from multiple systems. However, these integration processes are not well understood. In particular, it is not known whether these input pathways converge or remain segregated at the executive levels of cortical information processing. If unilateral information streams are conserved within structures that serve high-level executive functions, then the functional organization within these structures would predictably be similarly organized. If, however, unilateral input information streams are integrated within executive-related structures, then activity patterns will not necessarily reflect lower organizations. In this study, subjects were imaged during the performance of a "perceptual go/no-go" task for which instructions were based on spatial ("where"), temporal ("when"), or object ("what") stimulus features known to engage unilateral processing streams, and the expected hemispheric biases were observed for early processing areas. For example, activity within the inferior and middle occipital gyri, and the middle temporal gyrus, during the what and when tasks, was biased toward the left hemisphere, and toward the right hemisphere during the "where" task. We discover a similar lateralization within the medial frontal gyrus, a region associated with high-level executive functions and decision-related processes. This lateralization was observed regardless of whether the response was executed or imagined, and was demonstrated in multiple sensory modalities. Although active during the go/no-go task, the cingulate gyrus did not show a similar lateralization. These findings further differentiate the organizations and functions of the medial frontal and cingulate executive regions, and suggest that the executive mechanisms operative within the medial frontal gyrus preserve fundamental aspects of input processing streams.
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Anthony H. Risser | neuroscience | neuropsychology | brain
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The following paper is available as an open full-download from PLoS. It provides an interesting example of the use of stop-signal tasks in pursuing a better understanding of executive functioning and its neuroanatomical correlates: Full publication Rule-guided...
Neuroscience
Abstract of the Day: Frontal Lobe Functioning
Ardesheer Talati and Joy Hirsch. Functional Specialization within the Medial Frontal Gyrus for Perceptual Go/No-Go Decisions Based on "What," "When," and "Where" Related Information: An fMRI Study. Journal of Cognitive Neuroscience. 2005; 17: 981-993.
fMRI Research Center, Department of Radiology, Center for Neurobiology and Behavior, Columbia University, Neurological Institute, Box B-41, 710 West 168th Street, New York, NY 10032.
Cortical systems engaged during executive and volitional functions receive and integrate input from multiple systems. However, these integration processes are not well understood. In particular, it is not known whether these input pathways converge or remain segregated at the executive levels of cortical information processing. If unilateral information streams are conserved within structures that serve high-level executive functions, then the functional organization within these structures would predictably be similarly organized. If, however, unilateral input information streams are integrated within executive-related structures, then activity patterns will not necessarily reflect lower organizations. In this study, subjects were imaged during the performance of a "perceptual go/no-go" task for which instructions were based on spatial ("where"), temporal ("when"), or object ("what") stimulus features known to engage unilateral processing streams, and the expected hemispheric biases were observed for early processing areas. For example, activity within the inferior and middle occipital gyri, and the middle temporal gyrus, during the what and when tasks, was biased toward the left hemisphere, and toward the right hemisphere during the "where" task. We discover a similar lateralization within the medial frontal gyrus, a region associated with high-level executive functions and decision-related processes. This lateralization was observed regardless of whether the response was executed or imagined, and was demonstrated in multiple sensory modalities. Although active during the go/no-go task, the cingulate gyrus did not show a similar lateralization. These findings further differentiate the organizations and functions of the medial frontal and cingulate executive regions, and suggest that the executive mechanisms operative within the medial frontal gyrus preserve fundamental aspects of input processing streams.
-
Anthony H. Risser | neuroscience | neuropsychology | brain
- Lose Yourself
You better lose yourself in the music, the moment You own it, you better never let it go You only get one shot, do not miss your chance to blow This opportunity comes once in a lifetime yo --Eminem, Lose Yourself When the Brain Loses Its Self: Prefrontal...
- Brain Scans And Lie Detection: True Or False?
Now this is a rapidly expanding area of research (and one that's quite well-funded by the DOD). Wired did a piece on this recently (Don't Even Think About Lying), and there's an AP story that appeared in papers around the country (e.g., the...
- Neuropsychology Abstract Of The Day: Route Navigation And Route Knowledge
Landmark sequencing and route knowledge: An fMRI study Cortex. 2011 Dec 16; Nemmi F, Piras F, Péran P, Incoccia C, Sabatini U, Guariglia C Abstract INTRODUCTION: The ability to navigate in a familiar environment mainly relies on route knowledge, that...
- Neuropsychology Abstract Of The Day: Fmri Protocol For Intrinsic Alertness
Revealing the Functional Neuroanatomy of Intrinsic Alertness Using fMRI: Methodological Peculiarities PLoS One. 2011; 6(9): e25453 Clemens B, Zvyagintsev M, Sack A, Heinecke A, Willmes K, Sturm W Abstract Clinical observations and neuroimaging data revealed...
- Stop-signal Task
The following paper is available as an open full-download from PLoS. It provides an interesting example of the use of stop-signal tasks in pursuing a better understanding of executive functioning and its neuroanatomical correlates: Full publication Rule-guided...