Comparison of cerebral activation between motor execution and motor imagery of self-feeding activity

Motor imagery is defined as an act wherein an individual contemplates a mental action of motor execution without apparent action.Mental practice executed by repetitive motor imagery can improve motor performance without simultaneous sensory input or overt output.We aimed to investigate cerebral hemodynamics during motor imagery and motor execution of a self-feeding activity using chopsticks.This study included 21 healthy right-handed volunteers.The self-feeding activity task comprised either motor imagery or motor execution of eating sliced cucumber pickles with chopsticks to examine eight regions of interest:pre-supplementary motor area,supplementary motor area,bilateral prefrontal cortex,premotor area,and sensorimotor cortex.The mean oxyhemoglobin levels were detected using near-infrared spectroscopy to reflect cerebral activation.The mean oxyhemoglobin levels during motor execution were significantly higher in the left sensorimotor cortex than in the supplementary motor area and the left premotor area.Moreover,significantly higher oxyhemoglobin levels were detected in the supplementary motor area and the left premotor area during motor imagery,compared to motor execution.Supplementary motor area and premotor area had important roles in the motor imagery of self-feeding activity.Moreover,the activation levels of the supplementary motor area and the premotor area during motor execution and motor imagery are likely affected by intentional cognitive processes.Levels of cerebral activation differed in some areas during motor execution and motor imagery of a self-feeding activity.This study was approved by the Ethical Review Committee of Nagasaki University(approval No.18110801)on December 10,2018.

A method for using video presentation to increase the vividness and activity of cortical regions during motor imagery tasks

In recent years,mental practice(MP)using laterally inverted video of a subject’s non-paralyzed upper limb to improve the vividness of presented motor imagery(MI)has been shown to be effective for improving the function of a paralyzed upper limb.However,no studies have yet assessed the activity of cortical regions engaged during MI task performance using inverse video presentations and neurophysiological indicators.This study sought to investigate changes in MI vividness and hemodynamic changes in the cerebral cortex during MI performance under the following three conditions in near-infrared spectroscopy:MI-only without inverse video presentation(MI-only),MI with action observation(AO)of an inverse video presentation of another person’s hand(AO+MI(other hand)),and MI with AO of an inverse video presentation of a participant’s own hand(AO+MI(own hand)).Participants included 66 healthy right-handed adults(41 men and 25 women;mean age:26.3±4.3 years).There were 23 patients in the MI-only group(mean age:26.4±4.1 years),20 in the AO+MI(other hand)group(mean age:25.9±5.0 years),and 23 in the AO+MI(own hand)group(mean age:26.9±4.1 years).The MI task involved transferring 1 cm×1 cm blocks from one plate to another,once per second,using chopsticks held in the non-dominant hand.Based on a visual analog scale(VAS),MI vividness was significantly higher in the AO+MI(own hand)group than in the MI-only group and the AO+MI(other hand)group.A main effect of condition was revealed in terms of MI vividness,as well as regions of interest(ROIs)in certain brain areas associated with motor processing.The data suggest that inverse video presentation of a person’s own hand enhances the MI vividness and increases the activity of motor-related cortical areas during MI.This study was approved by the Institutional Ethics Committee of Nagasaki University Graduate School of Biomedical and Health Sciences(approval No.18121303)on January 18,2019.