Abstract
(1) DP phenomenon shows no direct relationship to a lesion in a particular part of a particular hemisphere, as previously reported by Hakas & Kornhuber. (2) The region of responsibility for the development of DP will be located in some parts level with the subcortical area or the brain-stem. (3) By the use of focused ultra-sound irradiation, pronounced DP to the side of the lesion could be observed from the lesions of the lateral portion of ponto-mesencephalic reticular formation in the rabbit.