Probabilistic antecedents of voluntary action are essential components of decision processes.

When decision outcomes can be predicted above chance from neural activity before participants indicate the decision is made, some claim this must change our concepts of voluntary decision, while others dismiss such data as reflecting small biases from the legacy of previous trials or the participant's pre-decision thoughts. In an interactive competitive decision framework, the existence of such probabilistic pre-decision biases is not challenging, but taken for granted. But neither are they uninteresting. Their interaction with incoming evidence about response options is what decisions are made of, and thus, studying their nature is an essential component of volition research.