Premium
Working memory and long‐term memory for faces: Evidence from fMRI and global amnesia for involvement of the medial temporal lobes
Author(s) -
Nichols Elizabeth A.,
Kao YunChing,
Verfaellie Mieke,
Gabrieli John D.E.
Publication year - 2006
Publication title -
hippocampus
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.767
H-Index - 155
eISSN - 1098-1063
pISSN - 1050-9631
DOI - 10.1002/hipo.20190
Subject(s) - psychology , neuroscience , working memory , functional magnetic resonance imaging , hippocampal formation , amnesia , hippocampus , neuroimaging , temporal lobe , long term memory , task (project management) , cognitive psychology , audiology , cognition , epilepsy , medicine , management , economics
Behavioral studies with amnesic patients and imaging studies with healthy adults have suggested that medial temporal lobe (MTL) structures known to be essential for long‐term declarative memory (LTM) may also be involved in the maintenance of information in working memory (WM). To examine whether MTL structures are involved in WM maintenance for faces, and the nature of that involvement, WM and LTM for faces were examined in normal participants via functional magnetic resonance imaging (fMRI) and in amnesic patients behaviorally. In Experiment 1, participants were scanned while performing a WM task in which they determined if two novel faces, presented 7 s apart, were the same or different. Later, participants' LTM for the faces they saw during the WM task was measured in an unexpected recognition test. During WM maintenance, the hippocampus was activated bilaterally, and there was greater activation during maintenance for faces that were later remembered than faces later forgotten. A conjunction analysis revealed overlap in hippocampal activations across WM maintenance and LTM contrasts, which suggested that the same regions were recruited for WM maintenance and LTM encoding. In Experiment 2, amnesic and control participants were tested on similar WM and LTM tasks. Amnesic patients, as a group, had intact performance with a 1‐s maintenance period, but were impaired after a 7‐s WM maintenance period and on the LTM task. Thus, parallel neuroimaging and lesion designs suggest that the same hippocampal processes support WM maintenance, for intervals as short as 7 s, and LTM for faces. © 2006 Wiley‐Liss, Inc.