The relationship between changes in the RAI and changes in WM task performance (accounting for memory load) was investigated using a repeated-measures general linear model controlling for age, years of smoking, FTND, IQ, and head motion. Changes in WM task performance on the 4 task conditions (0-, 1-, 2-, and 3-back) were measured by median correct response time (ΔRTa − s) and d prime (Δd′a − s), a measurement of accuracy (z value of hit rate minus false alarm rate).36
