The Morphological Substrate of Cerebral Asymmetry: the Problem of Its Measurement

To the Editor.  —Albanese et al¹ analyzed the asymmetry of weight and cortical surface in the anterior speech region of the inferior frontal gyrus and its different parts. They found a left predominance in the posterior portion, which is concerned with language. Their results showed an excellent correlation between weight and surface values. The weight and surface ratio was the same for the portions related to language and different for the remainder of the inferior frontal gyrus. This was the most recent of a series of articles^2-11 trying to find a morphological substrate for functional asymmetries. All these articles have in common the fact that they used unsuitable methods to achieve their goal.The most reliable method to detect structural differences between brain regions is quantitative morphology or morphometry. These evaluation procedures have been applied to prove or disprove structural differences between the left and right hemisphere,¹²