HIGHER-ORDER ASSOCIATIVE LEARNING IN AMNESIA - EVIDENCE FROM THE SERIAL REACTION-TIME-TASK

Patients with anterograde amnesia are commonly believed to exhibit nor mal implicit learning. Research with the serial reaction time (SRT) ta sk suggests that normal subjects can implicitly learn visuospatial seq uences through a process that is sensitive to higher-order information that is more complex than pairwise associations between adjacent stim uli. The present research reexamined SRT learning in a group of amnesi c patients with a design intended to specifically address the learning of higher-order information. Despite seemingly normal learning effect s on average, the results suggest that amnesic patients do not learn h igher-order information as well as control subjects. These results sug gest that amnesic patients have an associative learning impairment, ev en when learning is implicit, and that the medial temporal lobe and/or diencephalic brain areas typically damaged in cases of amnesia normal ly contribute to implicit sequence learning.