N-Back Working Memory

PI Name: Cal Adler, MD

Email: adlercb@ucmail.uc.edu

Areas: dorso-lateral pre-frontal cortex

Program: MacStim, ePrime, Psyscope

Durations: 5min 30 sec. to 17 minutes

Special Equipment: Diamond shaped button box

Description: The n-back task is an established measure of “working memory”, the ability to maintain, update, and manipulate ongoing information in a short term memory store. It has been used in neuropsychological research across multiple clinical groups. The “n” in n-back refers to how many stimuli the test-taker must concurrently keep in mind and continuously update during the task. In the version of this task that has been tested at the CCHMC IRC, participants view numbers from one to four that consistently appear in one of four visual quadrants. In the “zero back” (control) condition, participants are asked to press one of four buttons to match each number as it is presented. In the “two back” (attention) condition, participants are asked to indicate the number that appeared two places prior to the number on the screen, requiring them to continuously monitor, maintain, update, and protect from interference a short-term store of previously-viewed information. Stimuli will be presented in a periodic block-design paradigm in which 30 second intervals of the two conditions are randomly interleaved until 5-15 sets of each condition has been presented. Within each block, 17 stimuli will appear without intervening time intervals; preceding each block there will be a 3 second warning of the change in task. Total task time (stimuli + warnings) will thus be 5 ½ min-16 ½ min. depending on how many sets of stimuli are used.