Functional neuroimaging of short-term memory: The neural mechanisms of mental storage
Bart Rypma a1andJohn D.E. Gabrieli a2 a1 University of California, Department of Psychology, Berkeley, CA 94720-1650
[email protected] a2 Department of Psychology, Stanford University, Stanford, CA 19001
Cowan argues that the true short-term memory (STM) capacity limit is about 4 items. Functional neuroimaging data converge with this conclusion, indicating distinct neural activity patterns depending on whether or not memory task-demands exceed this limit. STM for verbal information within that capacity invokes focal prefrontal cortical activation that increases with memory load. STM for verbal information exceeding that capacity invokes widespread prefrontal activation in regions associated with executive and attentional processes that may mediate chunking processes to accommodate STM capacity limits.