Cognitive and neural correlates of memory retrieval in young and older adults

(cont.) increased activity whenever recollection was attempted, independent of the level of recollection success. The results are consistent with the hypothesis that increased left-lateralized retrieval activity in older adults supports recollection attempt. Age deficits in semantic memory are more subtle than in episodic memory. However, older adults are impaired when automatic, data-driven processes are not sufficient to support the retrieval of conceptual knowledge. The fMRI study described in Chapter 3 used semantic repetition priming to test two theories of the role LIPC plays in semantic retrieval. Young adults exhibited repetition-related BOLD response reductions in LIPC that were specific to the particular semantic task engaged, consistent with the hypothesis that LIPC supports controlled semantic retrieval. Older adults, in contrast, exhibited repetition-related signal reductions even when the semantic judgment made about a word differed across the two exposures, consistent with the hypothesis that older adults fail to gate irrelevant semantic information from working memory during initial presentation of the word.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Brain and Cognitive Sciences.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2004

Author dc:creator

• O'Kane, Gail, 1965-

Advisor dc:contributor.advisor

• Suzanne Corkin.

• Brain and Cognitive Sciences.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/28852

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/28852