A Tradeoff in the Neural Code across Regions and Species

Abstract

Summary Many evolutionary years separate humans and macaques, and whereas the amygdala and cingulate-cortex evolved to enable emotion and cognition in both, an evident functional gap exists. Although it was traditionally attributed to differential neuroanatomy, functional differences might also arise from coding mechanisms. Here, we find that human neurons better utilize information capacity (efficient coding) than macaque neurons, in both regions; and that cingulate neurons are more efficient than amygdala neurons, in both species. In contrast, we find more overlap in the neural vocabulary and more synchronized activity (robustness coding) in monkeys in both regions, and in the amygdala of both species. Our findings demonstrate a tradeoff between robustness and efficiency across species and regions. We suggest that this tradeoff can contribute to differential cognitive functions between species, and underlie the complementary roles of the amygdala and the cingulate-cortex. In turn, it can contribute to fragility underlying human psychopathologies.

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