Memory Retrieval Task

PI Name: Jerzy Szaflarski, MD, PhD

Email: szaflaj@ucmail.uc.edu

Areas: ??????

Program: PsyScope 1.1 on Mac G3

Durations: 7 min 15 sec

Special Equipment: Visual Presentation System, Hand button press

Description: We used a word recognition task that was developed based on the studies by the Barrow Neurological Institute. Fifteen to 30 minutes prior to scanning a list of 10 unrelated words was presented to the subject one word at a time for three seconds each, and the list was repeated 10 times. The subjects were instructed to memorize all words. Immediately before entering the scanner subjects were asked to recall all 10 target words uncued. Subjects proceeded to the scanner only once they correctly recalled all 10 items. During the fMRI scan, the word recognition task was presented in a blocked design alternating with a control task. The paradigm, which lasted 7 min 15 sec, began with a 15 sec control block to allow for T2 equilibration and then alternated between 30 sec of the recognition task and 30 sec of the control task for the next 14 blocks. Seventy words were presented, 22 target words and 48 novel words. During each recognition task block 10 words were presented once every 3 sec for 2.5 sec on a white background followed by a blank screen for 0.5 seconds. Words were presented in pseudo-randomized order. Each target word appeared twice, except for two words that appeared three times. Subjects were instructed to respond to all target words with a dominant hand button press, and respond to all foils with a non-dominant hand button press. During control task blocks a single asterisk ("*") was presented once every three seconds for 2.5 sec followed by a blank screen for 0.5 sec. Subjects were instructed to press the dominant hand button in response to asterisk presentation. The control task thus accounted for stimulation, attention, and response elements and prevented the performance of unrelated tasks.