Investigation of Recognition Memory in FMRI Using Optimal Stimulus Arrangement with Behavioral Information from Pilot Studies

Dietmar Cordes¹, Grit Herzmann², Rajesh Nandy³, Tim Curran²

In this study, a new method is proposed for optimization of contrast detection power by including probabilistic behavioral information, based on pilot data, in the genetic algorithm. As a particular application, a recognition memory task is studied and the design matrix optimized for contrasts involving the familiarity of individual items and the recollection of the items' qualitative information. Optimization of contrast efficiency is a complicated issue, especially for recognition memory tasks, because subjects responses are not deterministic but probabilistic. Contrast efficiencies are not predictable unless behavioral responses are included in the design optimization.