title: Capacity-speed relationships in prefrontal cortex.
abstract: Working memory (WM) capacity and WM processing speed are simple cognitive measures that underlie human performance in complex processes such as reasoning and language comprehension. These cognitive measures have shown to be interrelated in behavioral studies, yet the neural mechanism behind this interdependence has not been elucidated. We have carried out two functional MRI studies to separately identify brain regions involved in capacity and speed. Experiment 1, using a block-design WM verbal task, identified increased WM capacity with increased activity in right prefrontal regions, and Experiment 2, using a single-trial WM verbal task, identified increased WM processing speed with increased activity in similar regions. Our results suggest that right prefrontal areas may be a common region interlinking these two cognitive measures. Moreover, an overlap analysis with regions associated with binding or chunking suggest that this strategic memory consolidation process may be the mechanism interlinking WM capacity and WM speed.
authors: Radiology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America. vprabhakaran@uwhealth.org
authors: Vivek
authors: V
authors: Prabhakaran
authors: Bart
authors: B
authors: Rypma
authors: Nandakumar S
authors: NS
authors: Narayanan
authors: Timothy B
authors: TB
authors: Meier
authors: Benjamin P
authors: BP
authors: Austin
authors: Veena A
authors: VA
authors: Nair
authors: Lin
authors: L
authors: Naing
authors: Lisa E
authors: LE
authors: Thomas
authors: John D E
authors: JD
authors: Gabrieli
mesh_terms: D001519:Behavior / Q000502:physiology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult