Neural correlates of motor-sensory temporal recalibration.

The relative timing of a motor-sensory event can be recalibrated after exposure to delayed visual feedback. Here we examined the neural consequences of lag adaptation using event-related potentials (ERPs). Participants tapped their finger on a pad, which triggered a flash either after a short delay (0 ms/50 ms) or a long delay (100 ms/150 ms). Following the exposure phase, they judged the temporal order of a synchronous tap-flash test stimulus. The synchronous flash was more often perceived to occur before the tap after exposure to long than short delays, indicating that the temporal relation between the tap and the flash was realigned. ERPs evoked by the synchronous tap-flash test stimulus showed that adaptation to delayed flashes caused an early attenuation of the visual P1 (85 ms-150 ms), and a later negativity at central electrodes (N450). The P1-attenuation may reflect the unexpected earliness of the test flash, or a violation of "cause-before-consequence". The N450 may be due to realignment of the adapted and the actual timing of the tap-flash interval. We conclude that motor-visual temporal recalibration has consequences at early perceptual levels of visual processing and involves a high-level recalibration mechanism.