Figure 3: Early coding of motor intentions in a simplified choice task.

A) Task. The subject was free to move the shoulder or attempt movement of the thumb or index whenever she felt the urge to do so. There was no task structure outside the brief (250ms) change of annulus color from grey to green immediately after the movement had been detected following movement onset. B) Histogram of intervals between voluntarily initiated movements. C) Behavior during the free-choice task. Top: Transition probabilities between actions. Bottom: Percent of trials each action was performed (mean ± sem computed across sessions.) D) Single unit examples aligned to the verbal report of current movement onset (mean ± sem). E) Accuracy decoding current and next action in the voluntary movement sequence split by interval duration (mean ± sem across six sessions.)