1. Neural bases of recognition, priming and fluency Chris Berry UCL David Shanks UCL Rik Henson MRC-CBU

2. According to one view the MTL drives recognition, but not priming and fluency (Conroy, Hopkins, & Squire, 2005) –The anterior MTL/perirhinal cortex is sensitive to recognition judgments (an explicit memory-strength/familiarity signal?) Does activity in the perirhinal cortex (and/or hippocampus) correlate with identification time, regardless of recognition judgment, or with recognition judgment, regardless of identification time? Does activity in perceptual/lexical/semantic neocortical regions correlate with identification time, regardless of recognition judgment? Recognition, priming and fluency ID time Recognition BOLD signal

3. ECHO 500 msec 1000 msec Clarification procedure 1500 ms 1. When you can identify the word say it aloud and then press a button. +++ 500 msec Study Test Y / N ? 500 msec 1000 msec Clarification procedure 1500 ms 1. When you can identify the word say it in your head and then press a button 2. Make yes/no recognition judgment 400 msec 1600 msec +++ 100 studied 100 new ISI = 5s Event-related design Stimuli: 4-letter words Stimuli OldNew Judgment Old HitFalse alarm New MissCorrect rejection 100 trials ISI = 3.5s

4. Proposal 16 normal, healthy volunteers 200 studied, 200 new items ~= 50 mins EPI [2 x 25 min study-test sessions (6 min study-phase, 17 min test-phase)] Whole brain fMRI (TR = 3s, TE = 50 ms, 3 x 3 x 3 mm resolution) GLM in SPM - 5 regressors (RT & 4 trial types)