Changes in slow and fast alpha bands in subjects submitted to different amounts of functional electrostimulation.
OBJECTIVE
To examine the changes in slow (8-10Hz) and fast (10-12Hz) alpha bands of EEG in three groups of subjects submitted to different amounts of functional electrostimulation (FES). Our hypothesis is that different amounts of electrostimulation may cause different patterns of activation in the sensorimotor cortex. In particular, we expect to see an increase in alpha power due to habituation effects. We examine the two bands comprised by alpha rhythm (i.e., slow and fast alpha), since these two sub-rhythms are related to distinct aspects: general energy demands and specific motor aspects, respectively.


METHODS
The sample was composed of 27 students, both sexes, aging between 25 and 40 years old. The subjects were randomly distributed in three groups: control (n=9), G24 (n=9) and G36 (n=9). A FES equipment (Neuro Compact-2462) was used to stimulate the right index finger extension. Simultaneously, the electroencephalographic signal was acquired. We investigated the absolute power in slow and fast alpha bands in the sensorimotor cortex.


RESULTS
The G36 indicated a significant increasing in absolute power values in lower and higher alpha components, respectively, when compared with the control group. Particularly, in the following regions: pre-motor cortex and primary motor cortex.


CONCLUSIONS
FES seems to promote cortical adaptations that are similar to those observed when someone learns a procedural task. FES application in the G36 was more effective in promoting such neural changes. The lower and higher components of alpha rhythms behave differently in their topographical distribution during FES application. These results suggest a somatotopic organization in primary motor cortex which can be represented by the fast alpha component.
Velasques
Bruna
B
Brain Mapping and Sensory Motor Integration, Institute of Psychiatry of the Federal University of Rio de Janeiro (IPUB/UFRJ), Brazil. bruna_velasques@yahoo.com.br
Cunha
Marlo
M
Machado
Sergio
S
Minc
Daniel
D
Abrumhosa
Alexandre
A
Silva
Andressa
A
Basile
Luis
L
Cagy
Maurício
M
Piedade
Roberto
R
Ribeiro
Pedro
P
D000328:Adult; D000513:Alpha Rhythm / Q000528:radiation effects*; D000704:Analysis of Variance; D001931:Brain Mapping; D004558:Electric Stimulation; D005260:Female; D005385:Fingers / Q000294:innervation / Q000528:radiation effects; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000502:physiology / Q000528:radiation effects*; D011601:Psychophysics; D013003:Somatosensory Cortex / Q000502:physiology / Q000528:radiation effects*