Evaluation of Decision-Making Fatigue After Traumatic Brain Injury

The COGED task consists of the classic N-back task of working memory-based decision making, followed by a valuation phase. The N-back phase of the task allows calculation of cognitive performance of a working memory task. During valuation, participants receive titrating offers of differing amounts of money to perform different difficulty levels of the N-back. The result is an effort discounting curve used to measure the individual effort cost. Effort discounting curves show the perceived cognitive effort required to complete each level of the task relative to another (typically the 1-back).

Participants are presented with three targets (decks of cards) on the screen, which they select with a mouse movement. Each of the three targets is associated with a hidden probability of reward, which drifts unpredictably and independently across trials. This encourages participants to "exploit" good options when they are available, but also occasionally to "explore "other targets, which could become better at any time. Eye Tracking is done at each visit while the participant completes the Restless Bandit tasks.