| Abstract | Studies of phase correction in sensorimotor synchronization often
introduce timing perturbations that are unpredictable with regard
to direction, magnitude, and position in the stimulus sequence. If
participants knew any or all of these parameters in advance, would
they be able to anticipate perturbations and thus regain synchrony
more quickly? In Experiment 1, we asked musically trained participants
to tap in synchrony with short isochronous tone sequences
containing a phase shift (PS) of 100, 40, 40, or 100 ms and
provided advance information about its direction, position, or both
(but not about its magnitude). The first two conditions had little
effect, but in the third condition participants shifted their tap in
anticipation of the PS, though only by about ±40 ms on average.
The phase correction response to the residual PS was also enhanced.
In Experiment 2, we provided complete advance information about
PSs of various magnitudes either at the time of the immediately
preceding tone (‘‘late’’) or at the time of the tone one position back
(‘‘early’’) while also varying sequence tempo. Anticipatory phase
correction was generally conservative and was impeded by fast
tempo in the ‘‘late’’ condition. At fast tempi in both conditions,
advancing a tap was more difficult than delaying a tap. The results
indicate that temporal constraints on anticipatory phase correction
resemble those on reactive phase correction. While the latter is
usually automatic, this study shows that phase correction can also
be controlled consciously for anticipatory purposes. |