[Abstract Title]. - Society for Neuroscience

motor task and motor-cognitive task. On average, coherence at 25 - 26.5 Hz decreased from
0.095 during unilateral motor task to 0.063 during bilateral motor task and 0.058 during motorcognitive
task. The coefficient of variation of force (1.6% - 1.9%) and rectified EMG (13.2% -
13.6%) were constant across tasks. Although dual task did not influence motor output variability,
there was a tendency for decrease in cognitive performance with dual tasks. On average,
cognitive performance (accuracy of arithmetic and memory) decreased from 86.5% during
cognitive task to 74.0% during motor-cognitive task due to a decline in 5 out of 6 subjects. These
results suggest beta band coherence decreases when attention is divided during dual tasks
irrespective of the type of additional task, but there is no association between corticomuscular
coherence and motor output variability in a hand muscle during these tasks.
Disclosures: A.N. Johnson, None; M. Shinohara, None; S. Vohra, None.
Poster
277. Voluntary Movement: Cortical Planning and Execution II
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 277.29/LL21
Topic: D.17.b. Cortical planning and execution
Support: FNRS research Grant 1.5.047.06
Title: Neural correlates of automatic motor control: an event-related fMRI study
Authors: *G. GARRAUX 1 , P. PEIGNEUX 3 , K. D'OSTILIO 2 ;
1 Cyclotron Res. Ctr., 2 Univ. of Liège, Liège, Belgium; 3 Fac. of Psychological and Educational
Sci., Free Univ. of Brussels, Brussels, Belgium
Abstract: The neural correlates of automatic motor control in humans is poorly known. To
investigate this issue, we used event-related BOLD fMRI at 3T to record brain activity in 10
healthy volunteers (5F/5M; age range: 20-26) as they performed a subliminal priming task (1).
Arrows pointing to the left or to the right were used as prime and target stimuli. Primes were
rendered invisible to the subjects using short presentation duration and visual backward masking.
The target stimulus, which cued a response with the left or the right hand, was displayed at the
same time as the random pattern mask. As expected, the group mean reaction time was shorter
when the prime and target pointed to the same direction than when they pointed to opposite
directions (mean ± sd: 413 ± 119,4 ms vs. 428 ± 119,3 ms; paired t-test, p=0.02). In a prime
identification task, subjects‟ performance was at chance level for primes presented for 17 ms as
in the main experiment. Brain activity was stronger in several areas including caudal medial
frontal regions (i.e., medial premotor and anterior cingulate areas) and striatum (p