Fig. 11.2.

This figure demonstrates the classical double dissociation model. Left frontal lobe lesions (green-shaded area) are associated with impairments in speech production and not speech comprehension, whereas left temporoparietal lobe lesions (orange-shaded area) are associated with the opposite pattern, specifically, impairment in speech comprehension with relative sparing of speech production. This double dissociation lends confidence to the selectivity of brain structure–function relations, where a specific brain region is more relevant to a selective process than to another.