Poster D78, Monday, March 27, 8:00 – 10:00 am, Pacific Concourse
The neural correlates of successful source encoding and recognition
Louis Renoult1, Carolin Sievers1, Matthew Spriggs1, Andrew P. Bayliss1; 1University of East Anglia, UK
Few studies using the recognition-source paradigm have compared the neural correlates of correct (hits+), incorrect source (hits-) and forgotten trials (misses) at study and test. In the present event-related potential (ERP) study, twenty participants completed four blocks of an indoors/outdoors categorization task in which stimuli were presented as words, pictures or in both modalities in alternation (multi-modal condition). In a subsequent surprise recognition test, participants performed an old-new recognition task followed by a source judgment. Overall, results showed that source memory effects were much more robust at test than at study (respective max effect sizes of 1.5 versus 0.2). At study, two putative familiarity effects were identified, whereby hits- differed from misses at fronto-central sites bilaterally and later on at right centro-parietal sites. In addition, a linear increase in amplitude across repeated stimulus encoding predicted subsequent recollection at frontal and centro-parietal sites. At test, putative recollection effects were observed mainly at centro-parietal sites, where hits+ systematically differed from both hits- and misses. These effects peaked around 600ms after stimulus onset, typical of the LPC component associated with recollection. Interestingly, the amplitude of a late posterior negativity was found to predict subsequent memory performance for the multi-modal source (pictures & words) at study and to show maximal amplitudes for correct recollection of this modality at test. Further studies using the recognition-source paradigm will be useful to investigate whether the neural correlates of familiarity and recollection can be more robustly differentiated at study when using a voluntary encoding task.
Topic Area: LONG-TERM MEMORY: Episodic