Researchers have widely accepted that what sets humans apart from nonhuman primates are prefrontal cortex–driven behaviors such as decision-making, reasoning, planning, and attention. In a new JNeurosci paper, research led by Rogier Mars, at University of Oxford, and Katherine Bryant, at Aix-Marseille University, provides a better picture of the cortical evolution that distinguishes human brains from other primates.
The researchers compared cortical organization not only between humans and macaques, which is a standard for human and nonhuman primate comparisons in research, but also between humans and chimpanzees, humans' closest living relative. Notably, the chimpanzee brain scans used in this study were obtained from a publicly accessible research archive prior to the 2015 U.S. Fish and Wildlife Service and National Institutes of Health regulations governing research with chimpanzees. In addition to unique prefrontal cortex organization, connections between brain regions associated with emotional regulation, social cognition, and language processing seem distinctly human. The researchers found that this was especially true for chimpanzee comparisons. According to the authors, their study suggests that emotional and social behaviors may distinguish human abilities from other species in addition to behaviors driven by prefrontal cortex.
