Top-down modulation of hippocampal encoding activity as measured by high-resolution functional MRI

NEUROPSYCHOLOGIA

卷:51

Article

Carr, Valerie A.^1,3  Engel, Stephen A.^2,3,4  Knowlton, Barbara J.^3,4 

[1] Stanford Univ, Dept Psychol, Stanford, CA 94305 USA

[2] Univ Minnesota, Dept Psychol, Minneapolis, MN 55455 USA

[3] Univ Calif Los Angeles, Interdepartmental Program Neurosci, Los Angeles, CA 90095 USA

[4] Univ Calif Los Angeles, Dept Psychol, Los Angeles, CA 90095 USA

关键词: Medial temporal lobe;    Hippocampus;    Functional MRI;    Memory;    Encoding;    Goal states;   

DOI  :  10.1016/j.neuropsychologia.2013.06.026

来源: Elsevier

【 摘 要 】

Memory formation is known to be critically dependent upon the medial temporal lobe (MTL). Despite this well-characterized role, it remains unclear whether and how win encoding processes are affected by top-down goal states. Here, we examined the manner in which task demands at encoding affect MTL activity and its relation to subsequent memory performance. Participants were scanned using high-resolution neuroimaging of the MTL while engaging in two incidental encoding tasks: one that directed participants' attention to stimulus distinctiveness, and the other requiring evaluation of similarities across stimuli. We hypothesized that attending to distinctiveness would lead to the formation of more detailed memories and would more effectively engage the hippocampal circuit than attending to similarity. In line with our hypotheses, higher rates of subsequent recollection were observed for stimuli studied under the Distinctiveness than Similarity task. Critically, within the hippocampus, CA1 and the subiculum demonstrated an interaction between memory performance and task such that a significant subsequent memory effect was found only when task goals required attention to stimulus distinctiveness. To this end, robust engagement of the hippocampal circuit may underlie the observed behavioral benefits of attending to distinctiveness. Taken together, these findings advance understanding of the effects of top-down intentional information on successful memory formation across subregions of the MTL. (C) 2013 Elsevier Ltd. All rights reserved.

【 授权许可】

Free