Although emotion is closely associated with motivation, and interacts with perception, cognition, and action, many conceptualizations still treat emotion as separate from these domains. Here, a comparative/evolutionary anatomy framework is presented to motivate the idea that long-range, distributed circuits involving the midbrain, thalamus, and forebrain are central to emotional processing. It is proposed that emotion can be understood in terms of large-scale network interactions spanning the neuroaxis that form “functionally integrated systems.” At the broadest level, the argument is made that (...) we need to move beyond a Newtonian view of causation to one involving complex systems where bidirectional influences and nonlinearities abound. Therefore, understanding interactions between subsystems and signal integration becomes central to unraveling the organization of the emotional brain. (shrink)

Cognitive and emotional processes are now known to be intertwined and thus the limbic system that underlies emotions is important for human brain evolution, including the evolution of circuits supporting language. The neural substrates of limbic functions, like motivation, attention, inhibition, evaluation, detection of emotional stimuli and others have changed over time. Even though no new, added structures are present in the human brain compared to nonhuman primates, evolution tweaks existing structural systems with possible functional implications. Empirical comparative neuroanatomical evidence (...) is presented here in support of such changes in the limbic system, including the amygdala and the orbitofrontal cortex. Given their possible functional significance, these alterations may further enable and enhance human interest and motivation to communicate beyond what is seen in other primates living in complex social groups. The argument here is that even though emotion processing is likely needed for increased social complexity independent of language, the reason why humans want to talk may be related in part to the enhancement of socioemotional processes resulting from the reorganization and rewiring of underlying neural systems some of which are interconnected to the language areas. Neurodevelopmental disorders in humans affecting both language and sociability fuel such arguments. (shrink)