How Predictable are "Spontaneous Decisions" and "Hidden Intentions"? Comparing Classification Results Based on Previous Responses with Multivariate Pattern Analysis of fMRI BOLD Signals.

In two replication studies we examined response bias and dependencies in voluntary decisions. We trained a linear classifier to predict "spontaneous decisions" and in the second study "hidden intentions" from responses in preceding trials and achieved comparable prediction accuracies as reported for multivariate pattern classification based on voxel activities in frontopolar cortex. We discuss implications of our findings and suggest ways to improve classification analyses of fMRI BOLD signals that may help to reduce effects of response dependencies between trials.