time-series (Gitelman et al., 2003). The PPI interaction term was the product of the neuronal time-series and a contrast vector coding for main effect of task (1 for 2-back; −1 for 0-back). This term was convolved with the HRF; PPI model regressors consisted of the interaction term, contrast vector and extracted time-series plus motion regressors from the original design (Friston et al., 1997). Single subject contrasts for the first regressor (interaction term) were calculated and used for second-level two sample t-tests evaluating Low and High resiliency groups.
