Poster F77, Tuesday, March 28, 8:00 – 10:00 am, Pacific Concourse
Age differences in event-related potential effects associated with strong and weak recollection
Erin Horne1, Joshua Koen1, Nedra Hauck1, Michael Rugg1; 1University of Texas at Dallas
The present study investigated age differences in ERP correlates of strong and weak recollection. Young and older adults studied concrete nouns while answering one of two questions about each word (fit in a shoebox or manmade). During a subsequent recognition memory test, participants made item memory judgments to test words using the RKN procedure. For words receiving a ‘Remember’ (R) response, a source memory judgment (which study task?) was required. We contrasted ERPs elicited on R trials where source retrieval was correct (‘strong recollection’), on R trials with incorrect source retrieval or a ‘don’t know’ response (‘weak recollection’), and on correct rejection trials. Young, but not older adults, displayed mid-frontal (300-500ms) and left parietal (500-800ms) retrieval success effects. These were graded (strong > weak recollection) at the parietal, but not the mid-frontal, electrodes. Young adults also demonstrated a late (1000-2000ms) posterior negative effect graded in the opposite direction (weak > strong). The retrieval success effects in older adults were dominated by a large, posteriorly maximum, negative-going wave. Unlike in young adults, the amplitude of this wave did not vary with recollection strength. Both young and older adults showed a positive-going ungraded right frontal recollection effect. The young adults’ data replicate and extend prior reports that frontal and left parietal ERP retrieval effects are differentially sensitive to recollection strength. The findings also provide striking evidence for the differential engagement of mnemonic processes supporting recollection in young and older adults, particularly as no group differences were observed for source memory accuracy.
Topic Area: LONG-TERM MEMORY: Episodic