Oligodendroglioma Functional imaging demonstrated during the sentence completion a verb generation task, predominantly left hemispheric activity. In relationship to the lesion, there is activity along the median margin of lesion within the superior frontal gyrus, presumably activity within the pre-SMA (language SMA). During the motor task of toe tapping and finger tapping, there is bold response identified along the posterior medial margin of the lesion in keeping with activation in the SMA region.