Year: 2006
Type: dissertation
Abstract: Flexible goal-oriented behavior requires the ability to carry information across temporal delays.Neurally, this ability is associated with sustained neural firing.In cognitive terms, this ability has often been associated with the maintenance of sensory material on-line, as during short-term memory tasks, or with the retention of a motor code, as during movement preparation tasks.The general issue addressed in this paper is whether short-term storage of sensory information and preparation of motor responses rely on different anatomical substrates.We used fMRI to measure sustained and time-varying delay-related cerebral activity evoked during performance of a delay non-match to sample task, where task contingencies rather than explicit instructions ensured that either sensory or motor representations were used to cross the delay period on each trial.This approach allowed us to distinguish sensory from motor characteristics of delay-related activity evoked by task contingencies, rather than differences in the control of short-term storage driven by verbal instructions.Holding sensory material on-line evoked both sustained and timevarying delay-related activity in prefrontal regions, whereas movement preparation evoked delay-related responses in precentral areas.Sustained activity in the intraparietal sulcus was sensitive to the presence of memoranda, but indifferent to the type of information that was retained in memory.Our findings indicate that short-term storage of sensory information and preparation of motor responses rely on partially segregated cerebral circuits.In the frontal lobe, these circuits are organized along a rostro-caudal dimension, corresponding to the sensory or motor nature of the stored material.
Author: Rogier B. Mars
Language: English
Subfield: Cognitive Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W1599125629