Document Detail

Working memory and amnesia: The role of stimulus novelty.
MedLine Citation:
PMID:  22044651     Owner:  NLM     Status:  Publisher    
Despite the traditional view that damage to the hippocampus and/or surrounding areas of the medial temporal lobe (MTL) does not impair short-term or working memory (WM), recent research has shown MTL amnesics to be impaired on WM tasks that require maintaining a small amount of information over brief retention intervals (e.g., maintenance of a single face for one second). However, the types of tasks that have demonstrated WM impairments in amnesia tend to have involved novel stimuli. We hypothesized that WM may be impaired in amnesia for tasks that require maintaining novel information, but may be preserved for more familiar material, particularly if the material can be easily rehearsed. To test this hypothesis, patient HC, a 22-year-old developmental amnesic with relatively preserved semantic memory and 20 age and education matched controls performed a delayed match-to-sample task that required maintaining a single famous or non-famous face for 1-8s, digit span and reading span tasks, and a modified Brown-Peterson task that required maintaining a single high- or low-frequency word or a non-word for 4-8s. HC's performance was impaired for non-famous faces but preserved for famous faces, impaired for the reading span task but preserved for digit span, and it was impaired for non-words and unfamiliar low-frequency words but preserved for familiar words. These results support the hypothesis that an intact hippocampus is necessary for maintaining a single novel stimulus in WM. However, stimulus familiarity and rehearsal support WM via cortical regions independent of the MTL.
Nathan S Rose; Rosanna K Olsen; Fergus I M Craik; R Shayna Rosenbaum
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2011-10-25
Journal Detail:
Title:  Neuropsychologia     Volume:  -     ISSN:  1873-3514     ISO Abbreviation:  -     Publication Date:  2011 Oct 
Date Detail:
Created Date:  2011-11-2     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0020713     Medline TA:  Neuropsychologia     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Copyright Information:
Copyright © 2011. Published by Elsevier Ltd.
Rotman Research Institute of Baycrest, Canada; University of Toronto, Canada.
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