The significance of the Speech-sounds Perception Test for cerebral functions

Results on the Speech-sounds Perception Test have been related in the literature to damage of the left temporal lobe in human adults, but these reports have been based on clinical impressions rather than controlled experimental studies. We compared Speech-sounds Perception Test scores and Verbal IQ for groups with left, right, and diffuse cerebral lesions in categories of cerebral vascular damage and traumatic brain injury. The only significant finding was a lower Verbal IQ in the group with left cerebral vascular lesions. The Speech-sounds Perception Test, being dependent upon attention and sustained concentration (in spite of its exclusively verbal content), was not found to be a reliable indicator of left cerebral damage. Caution should be exercised in adoption of clinical observations without having checked their generality by using controlled experimental comparisons.