[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#: 277.7/KK33
Topic: D.17.b. Cortical planning and execution
Title: Relationship between finger movement rate, effort and regional cerebral blood flow
Authors: A. A. FURUSAWA 1 , *H. NISHIJO 2,1 , H. ONISHI 1 ;
1 Dept of Physical Therapy, Sch. of Hlth. Sci., Niigata Univ. of Hlth. and Welfare, Niigata City,
Japan; 2 Syst. Emotional Sci, Grad Sch. Med., Univ. of Toyama, Toyama, Japan
Abstract: Objectives: the purpose of this study was to investigate the relations between cerebral
activation, and amplitude and frequency of finger movement by means of near infrared
spectroscopy (NIRS). The subjects were required to perform an index finger tapping (IFT) task
with five different conditions of finger extension.
Methods: The subjects sat in a comfortable chair in a semi-darkened shielded room with their
eyes closed and were instructed to be awake. The regional cerebral hemodynamics (oxy-, deoxy-,
and the total-Hb) were recorded using 24-channel NIRS from 6 neurologically health subjects
under five different EIFT tasks. These are 5 conditions: 100% of maximal amplitude (MA) with
maximal frequency of tapping (T1), 100% MA with minimum frequency (T2), 50% MA with
maximal frequency (T3), 50% MA with minimum frequency (T4) and a random free tapping
(T5). In the separate experiment, the maximal amplitude and frequency of tapping were
determined. The subject‟s wrist and fingers were immobilized by straps except the index finger.
Each flexion movement of the index finger was triggered by a beep sound and the amplitude of
the movement was kept constant so that the subjects were required to touch a ruler above the
finger. Five cycles were performed and each of tapping cycles lasted 20 s, followed by a 40 s rest
period. Electromyograms (EMGs) from the finger extensor muscle (extensor indicis muscle)
were recorded.
Results: the all subjects showed that activation in the motor-related areas was stronger in the
condition of 100% MA with maximal frequency than the others conditions, consistent with the
differences in EMG activities.
Conclusions: the main finding of the study was that oxy-Hb levels decreased progressively
(T1>T2>T3>T5>T4). These results indicated that brain activation in the motor-related areas
were dependent on both the movement frequencies and amplitudes. In the MA tapping, EMG
activity was correlated to oxy-Hb levels in the motor cortex.
Disclosures: A.A. Furusawa, None; H. Nishijo, None; H. Onishi, None.