Total activation change of visual and motor area due to various disturbances.

Brain activation is affected by gradient acoustic noise and various disturbances as well as by other primary tasks. Therefore, we have studied the effects of various disturbances of two different levels of difficulty, that is, weak and strong difficulty levels for primary visual and motor tasks. In the case of visual task with motor and mental disturbances, we found it decreased as motor and mental disturbance difficulty-level increased, compared with the case of without motor and mental disturbances. To the contrary, in the case of motor activity, the total activation of motor cortex with weak and with strong mental disturbance increased as mental disturbance difficulty-levels increased. Therefore, one can conclude that when mental disturbance is added, the visual cortex and motor cortex have an opposite result and when the difficulty-level of the disturbance is increased, the primary tasks are affected more significantly. Although the current observation is preliminary and requires more careful experimental study, it appears that various disturbance effects on brain functions (such as motor and visual cortical responses) produce significant differences in data observations.