Electrophysiological analysis of a sensorimotor integration task

• Published in: Neuroscience letters Vol. 426; no. 3; pp. 155 - 159
• Main Authors: Velasques, Bruna, Machado, Sergio, Portella, Cláudio Elidio, Silva, Julio Guilherme, Basile, Luis F.H., Cagy, Mauricio, Piedade, Roberto, Ribeiro, Pedro
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 22.10.2007; Elsevier
• Subjects: Adult; Asymmetry; Biological and medical sciences; Brain Mapping; Electrophysiology; Female; Frontal Lobe - physiology; Functional Laterality; Fundamental and applied biological sciences. Psychology; Humans; Male; Motor control; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Motor Skills - physiology; qEEG; Sensorymotor integration; Somatosensory Cortex - physiology; Vertebrates: nervous system and sense organs; qEEG; Sensorymotor integration; Asymmetry; Motor control; Electrophysiology; Sensorimotor coordination
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/j.neulet.2007.08.061

The present experiment aimed at investigating electrophysiologic changes observed as beta band asymmetry, by Quantitative Electroencephalography (qEEG), when individuals performed a reaching motor task (catching a ball in free fall). The sample was composed of 23 healthy individuals, of both sexes, with ages varying between 25 and 40 years old. All the subjects were right handed. A two-way ANOVA was applied for the statistical analysis, to verify the interaction between task moment (i.e., 2 s before and 2 s after ball's fall) and electrode (i.e., frontal, central and temporal regions). The first analysis compared electrodes placed over the somatosensory cortex. Central sites (C3–C4) were compared with temporal regions (T3–T4). The results showed a main effect for moment and position. The second analysis was focused over the premotor cortex, which was represented by the electrodes placed on the frontal sites (F3–F4 versus F7–F8), and a main effect was observed for position. Taken together, these results show a pattern of asymmetry in the somatosensory cortex, associated with a preparatory mechanism when individuals have to catch an object during free fall. With respect to task moment, after the ball's fall, the asymmetry was reduced. Moreover, the difference in asymmetry between the observed regions were related to a supposed specialization of areas (i.e., temporal and central). The temporal region was associated with cognitive processes involved in the motor action (i.e., explicit knowledge). On the other hand, the central sites were related to the motor control mechanisms per se (i.e., implicit knowledge). The premotor cortex, represented by two frontal regions (i.e., F3–F4 versus F7–F8), showed a decrease on neural activity in the contralateral hemisphere (i.e., to the right hand). This result is in agreement with other experiments suggesting a participation of the frontal cortex in the planning of the apprehension task. This sensorimotor paradigm may contribute to the repertoire of tasks used to study clinical conditions such as depression, alzheimer and Parkinson diseases.