Mean response rate indicating the velocity of illusory movement, Run 1 and Run 2 combined data (N = 12).

<p>Data points represent standardized mean rate of keypress for the preceding 30-seconds period. Error bars represent 95% confidence intervals of the mean. We only show the results from time periods with a probability of responding of more than 0.5 across the two runs. <i>Circles</i>: Means were computed from the responses indicating illusory movement to the left (positive sign) and the right (negative sign), as well as no movement (zeros). The velocity computed this way steadily decreases throughout the vibration period. <i>Triangles</i>: Means were computed only for periods in which movement was perceived (i.e., zeros were excluded) separately for illusory extension (positive sign) and flexion (negative sign). Perceived speed measured this way remains relatively constant. <i>Thick grey line:</i> results from the control condition in which the participants attempted to press one key at a constant rate for six minutes.