Abstract
Many different factors can temporarily or permanently impair movement and impairs cortical organization, e.g. hand immobilization. Such changes have been widely studied using electroencephalography. Within this context, we have investigated the immobilization effects through the theta band coherence analysis, in order to find out whether the immobilization period causes any changes in the inter and intra-hemispheric coherence within the cerebral cortex, as well as to observe whether the theta band provides any information about the neural mechanisms involved during the motor act. We analyzed the cortical changes that occurred after 48 hours of hand immobilization. The theta band coherence was study through electroencephalography in 30 healthy subjects, divided into two groups (control and experimental). Within both groups, the subjects executed a task involving flexion and extension of the index finger, before and after 48 hours. The experimental group, however, was actually submitted to hand immobilization. We were able to observe an increase in the coupling within the experimental group in the frontal, parietal and temporal regions, and a decrease in the motor area. In order to execute manual tasks after some time of movement restriction, greater coherence is present in areas related to attention, movement preparation and sensorimotor integration processes. These results may contribute to a detailed assessment of involved neurophysiological mechanism in motor act execution.
Highlights
Sensorimotor integration mechanisms can be affected by many factors, among which are hand-immobilizing lesions that can temporarily or permanently impair movement and bring about changes to the cortical organization [1,2] in addition to provoking a reduction of neuromuscular activity [3]
A main effect was found for the experimental group, with a decrease in coherence for the P3/Pz [F (1.114) = 39.903; Figure 1 Cortical changes during motor tasks. a) Effects for factor group observed in the frontal inter-hemisphere (F3/F4) derivations by mean and SD (p < .001); b) Main effects for factor treatment observed in the left frontal cortex (F3/Fz) derivation by mean and SD (p < .001); c) Effects for factor treatment observed in the F7/Fz derivations by mean and SD (p = .017)
Other studies have demonstrated that the pre-motor and pre-frontal cortexes are related to action creation and voluntary control and to executive functions [28,31], and that theta activity occurs during that behavior which demands planning updating for the motor act, according to the received sensory information [5,35]. This way, due to the fact of the coherence analysis presenting evidence of the coupling between cortical areas during motor task execution [21,22], our findings demonstrate that, in order for the individual to execute the task, greater coupling between these areas was needed for the planning and motor response to the stimulus, which demanded greater joint action of such cortical regions [36]
Summary
Sensorimotor integration mechanisms can be affected by many factors, among which are hand-immobilizing lesions that can temporarily or permanently impair movement and bring about changes to the cortical organization [1,2] in addition to provoking a reduction of neuromuscular activity [3]. This has been observed in the study by Gondin [4] after submitting subjects to a two-week immobilization. Researches have demonstrated the theta band involvement in studies about coherence in cognitive, sensory and motor tasks [17,20], little is known about its activity when related to movement restriction
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
