Enlarged limbic structures in the human brain: the anterior thalamus and medial mamillary body

Major paradigms about human evolution stress the increase of cognitive capabilities, while considering our emotional and limbic systems to be relatively unchanged. Morphometric analyses of two limbic structures, the anterior thalamic nuclei (AP) and the medial mamillary bodies (MB), in 27 primate species show, however, that: human nuclei are as large as MB or larger AP than differences in anthropoid brain sizes predict; and prosimians and anthropoid patterns differ.