NOVELTY ASSESSMENT IN THE BRAIN AND LONG-TERM-MEMORY ENCODING

Recent positron emission tomography (PET) studies have identified neur onal components of widespread novelty-assessment networks in the brain . We propose that the efficacy of encoding on-line information into lo ng-term memory depends on the novelty of the information as determined by these networks, and report a test of this ''novelty/encoding'' hyp othesis. Subjects studied a list of words. Half of the words were ''fa miliar'' by virtue of their repeated presentation to the subjects befo re the study of the critical list; the other half were novel, in that they had not previously been encountered in the experiment. The result s conformed to the prediction of the novelty/encoding hypothesis: accu racy of explicit (episodic) recognition was higher for novel than for familiar words.