Prefrontal cortex and recognition memory. Functional-MRI evidence for context-dependent retrieval processes

Anthony D. Wagner, John E. Desmond, Gary H. Glover, John D.E. Gabrieli

Research output: Contribution to journalArticle

Abstract

Functional neuroimaging studies of episodic recognition memory consistently demonstrate retrieval-associated activation in right prefrontal regions, including the right anterior and right dorsolateral prefrontal cortices. In theory, these activations could reflect processes associated with retrieval success, retrieval effort or retrieval attempt; each of these hypotheses has some support from previous studies. In Experiment 1, we examined these functional interpretations using functional MRI to measure prefrontal activation across multiple levels of recognition performance. Results revealed similar patterns of right prefrontal activation across varying levels of retrieval success and retrieval effort, suggesting that these activations reflect retrieval attempt. Retrieval attempt may include initiation of retrieval search or evaluation of the products of retrieval, such as scrutiny of specific attributes of the test item in an effort to determine whether it was encountered previously. In Experiment 2, we examined whether engagement of retrieval attempt is context-dependent by varying the context in which retrieval was performed; this was done by changing test instructions. Importantly, study and test stimuli were held constant, with only the test instructions varying across conditions. Results revealed that the pattern of right prefrontal activation varied across retrieval contexts. Collectively, these experiments suggest that right prefrontal regions mediate processes associated with retrieval attempt, with the probability of engaging these regions depending upon the retrieval context. Conflicting results across previous studies may be reconciled if the influence of retrieval context on the adopted retrieval strategy is considered. Finally, these results suggest that right prefrontal regions activated during recognition are not critical for successful performance as similar magnitudes of activation were present across multiple levels of performance. These findings reconcile imaging results with the selective effects of prefrontal lesions on retrieval-intensive episodic memory tests.

Original languageEnglish (US)
Pages (from-to)1985-2002
Number of pages18
JournalBrain
Volume121
Issue number10
DOIs
StatePublished - Oct 15 1998
Externally publishedYes

Keywords

  • Episodic memory
  • Explicit memory
  • Functional MRI
  • Prefrontal cortex
  • Strategic processes

ASJC Scopus subject areas

  • Clinical Neurology

Fingerprint Dive into the research topics of 'Prefrontal cortex and recognition memory. Functional-MRI evidence for context-dependent retrieval processes'. Together they form a unique fingerprint.

  • Cite this