摘要
Hemispheric asymmetries can be seen as one of the evolutionary adaptations that allowed the human brain to muster more complex cognitive processes than other primates.In this vein,the study published by Cheng et al.[1]presents a pivotal investigation of both the regional and connectional asymmetries within the inferior parietal lobule(IPL)in human,chimpanzee,and macaque.By investigating 4 sub-divisions of the IPL across the three species,Cheng and colleagues showed that the macroanatomical and connectional architecture of the IPL became more asymmetric throughout the primate lineage.While macaques show little to no structural asymmetries,chimpanzees display a more asymmetric architecture but with both leftward and rightward asymmetries in various connections.In contrast,the human IPL displayed the highest number of asymmetries among the three species with a clear tendency towards more lateralization.This evolutionary trend towards a more lateralized organization of the IPL may have accompanied an improved command of tool-use,stronger forelimb asymmetries,and the increasing complexity of communicative behavior.
