[Abstract Title]. - Society for Neuroscience

Poster
277. Voluntary Movement: Cortical Planning and Execution II
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 277.26/LL18
Topic: D.17.b. Cortical planning and execution
Support: Department of Defense, Army Research Office, W911NF0510538
Title: Electrocortical dynamics during competitive psychomotor performance
Authors: *J. C. RIETSCHEL 1 , M. E. COSTANZO 1 , R. N. GOODMAN 1 , A. J. HAUFLER 1 ,
L.-C. LO 1 , C. G. MCDONALD 2 , M. SAFFER 1 , B. D. HATFIELD 1 ;
1 Neurosci. and Cognitive Sci., Univ. of Maryland, College Park, MD; 2 Dept. of Psychology,
George Mason Univ., Fairfax, VA
Abstract: Placing individuals in a competitive situation induces variability of their motor
performance; while some „rise to the occasion‟ others may respond by „choking.‟ Despite this
robust behavioral phenomenon, the neurobiological changes that underlie this performance
variability are unclear. The psychomotor efficiency hypothesis posits that superior performance
occurs through a reduction of task-irrelevant cerebral cortical processing (Hatfield and Hillman,
2001). Specifically, this reduction has been inferred through increases in alpha power which is
thought to reflect cortical „idling‟ in areas not essential for task execution. However,
investigation of this hypothesis has been limited to novice-expert contrasts and motor learning
studies. Thus, the purpose of this study was to examine the changes in cerebral cortical dynamics
and kinematics during competition in an effort to explain performance variability during a
precision aiming task. Nineteen participants from the U. Maryland Reserve Officers' Training
Corps (ROTC) program completed a pistol shooting task under both performance alone (PA) and
competitive (C) conditions. EEG, autonomic measures and subjective self report were recorded
from subjects while they completed the PA condition independently. These same measures were
assessed during the C condition where the two participants were monitored simultaneously. The
EEG montage consisted of 30 electrodes and was sampled at 1000Hz. Further, spectral averages
in the alpha band (8-13Hz) were calculated for one-second bins in the 4 seconds preceding
trigger pull. Alpha power was subjected to a 2 (Order) X 2 (Condition) X 2 (Hemisphere) X 5
(Region) X 4 Second) ANOVA. Changes in Spielberger State Anxiety Inventory (STAI), heart
rate, cortisol and skin conductance provide evidence of a systematic difference in the
psychological state between conditions, specifically, increased state anxiety during the C
condition. Further, performance (i.e. aiming trajectories) was more variable during the
competition along with a significant decrease in alpha power. These results provide support for
generalizing the psychomotor efficiency hypothesis to a competitive situation. Beyond the
spectral assessment of EEG alpha power, an addition principal component analysis was
employed to further elucidate the temporal dynamics and spatial specificity of the event-related
alpha power.