Strategy-dependent changes in memory: effects on behavior and brain activity.
In the present study, an implicit strategy manipulation was used to explore the contribution of memory strategy to brain activation and behavioral performance. Participants were biased to use either a short-term (maintenance-focused) or long-term (retrieval-focused) memory strategy within a single memory task through manipulation of task context. In comparing directly matched trials across the different task contexts, we observed clear changes in both behavioral performance and brain activity across a network of regions located primarily within lateral and medial frontal cortex. These effects of the memory strategy manipulation suggest that when a retrieval-focused strategy is induced, mnemonic processes are preferentially engaged during the encoding period. In contrast, when a maintenance-focused strategy is induced, mnemonic processes are preferentially engaged during the delay and response periods. Taken together, the results imply that covert cognitive strategies play an important role in modulating brain activation and behavior during memory tasks.
Speer
Nicole K
NK
Washington University, St. Louis, Missouri 63130, USA.
Jacoby
Larry L
LL
Braver
Todd S
TS
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001519:Behavior / Q000502:physiology*; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000145:classification* / Q000502:physiology*; D008570:Memory, Short-Term / Q000502:physiology; D010775:Photic Stimulation; D011581:Psychological Tests; D011597:Psychomotor Performance; D011930:Reaction Time; D021641:Recognition, Psychology; D013997:Time Factors; D014055:Tomography, Emission-Computed; D014706:Verbal Learning