Effects of functional electro-stimulation in the theta-band coherence: a quantitative electroencephalograph study

Functional electrical stimulation (FES) is a technique used for rehabilitation of motor and sensory dysfunction and consisted in the application of neuromuscular electrical stimulation concurrently with a functional activity. Previous studies suggest that sensory motor processing during FES stimulation of hand is similar to that of voluntary hand movement.

To examine the changes in theta band (4-8 Hz) coherence in the centro-parietal and temporo-parietal junction during a FES task. Our hypothesis is that different conditions of electro-stimulation can produce changes in the theta band coherence in the sensory-motor and multisensory integration.

The sample was composed of 24 students, male (n =14) and female (n =10), between 25 and 40 years old. Subjects were randomly distributed in three groups: control group (n = 8), G24 (n = 8) and G36 (n = 8). The control group simulated four blocks without electrostimulation been applied. The G24 group was exposed to four blocks of electrostimulation. The G36 group was exposed to six blocks of electrostimulation. We employed FES equipment to stimulate the extension of the right index finger and the electroencephalographic signal was simultaneously recorded.

A main effect was found for the condition, block and electrode in the centro-parietal junction, although we only found a main effect for condition and electrode in the temporo-parietal junction. CONCLUSION. Our results suggest that the functional coupling between the central and parietal areas is directly connected to the priming memory function, although the coupling between temporal and parietal areas is related to the working memory.