Prosencephalic asymmetries in Lemuridae.

This study was undertaken to determine if regional volumetric asymmetries are a function of sulcal complexity and/or brain size. A complete series of coronal sections of cerebra from six species of Lemuridae, a family of strepsirhines, was digitized. Regional volumes were integrated and indices of asymmetry were calculated. The most significant asymmetries were found in retrocalcarine cortex, suggesting that striate and extrastriate asymmetries emerged early in primate evolution. Results further indicated that the degree of regional volumetric asymmetries, as measured by our indices, does not vary with sulcal complexity and/or brain size.