Prolonged adaptation to delayed sensory feedback to a simple motor act (such as pressing a key) seems to provoke a recalibration of sensory-motor synchronization, causing instantaneous feedback to appear to precede the motor act that caused it (Stetson et al., Neuron, 2006). We investigated whether a similar recalibration occurs in school-age children, when plasticity may be expected to be even greater than in adults. Subjects adapted to delayed feedback for 100 trials, intermittently pressing a key that caused a tone to sound after a 200 ms delay. During the test phase, subjects responded to a light cue by pressing a key, which was accompanied by a tone played at a variable interval before or after the keypress. Subjects judged whether the tone preceded or followed the keypress. The data were fit with cumulative gaussian psychometric functions, yielding estimates of the points of perceived synchrony (mean) and precision (width). In agreement with previous studies, adults showed a shift in perceived synchrony after adaptation, so the keypress appeared to trail the auditory feedback, implying sensory-motor recalibration. However, school children of all ages (7, 8, 10 & 12 years) showed no adaptation of perceived simultaneity, although their precision in the simultaneity task was comparable with that of adults. This suggests that school-age children do not recalibrate sensory-motor simultaneity after adaptation, implying that the neural mechanisms underlying recalibration require the maturity of both the motor and sensory systems.

Temporal Recalibration; Motor Sensory Synchrony; Development