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Abstract:
Time production requires integration of incoming sensory
information with cognitive and motor processes. Prior
research implicates subcortical structures essential to precise
timing, noting potential contributions of cortical
interconnections. Cortical investigations of time
perception reveal a right hemisphere bias for temporal processing,
related to attention. The current study examined cortical
contributions during time reproduction. Performance
during the unpaced portion of synchronized finger tapping (300 and
600 ms inter-stimulus intervals (ISI)) was compared in patients
with unilateral right (RHD) or left (LHD) hemisphere damage and
normal individuals. Data were analyzed for accuracy, overall
variability, and variability related to hypothetical $E3clock$E4
and $E3motor$E4 processes (Wing and Kristofferson, 1973). Patients
were as accurate as normal controls in reproducing the ISIs, but
showed elevations in all variability measures, particularly around
the 600 ms ISI. Clock variability increased at both ISIs
when the 300 ms ISI was performed first, but only in the RHD group.
Lesion reconstructions comparing patients with impaired and
unimpaired timing variability suggested that middle frontal and
inferior parietal areas of both hemispheres were important for
timing variability, but not accuracy. Presentation order biases in
clock variability after RHD raise the possibility that sensitivity
to temporal context is greater in the right hemisphere
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