Chapter 10 Summary

Emotion is a complex set of regulatory and cognitive functions defined by related changes in physiology and behavior, accompanied by feelings that help humans and other animals respond flexibly to biologically significant stimuli. By focusing on aspects of emotion that are amenable to neurobiological investigation, researchers have begun to identify the neural circuits and systems involved in emotional evaluation, expression, and experience.
Some structures in the limbic forebrain, such as the amygdala, are critical for emotional information processing, in part because of their rich anatomical connections with both sensory and visceral motor regions.
The original limbic system theory put forward in the 1940s has been repeatedly revised to acknowledge the contributions of additional brain areas, along with the fact that some medial forebrain structures, such as the hippocampus, also participate in functions that are not primarily emotional. The involvement of some of these brain regions in emotion—including the amygdala, insula, orbitofrontal cortex, and ventral anterior cingulate gyrus—has been confirmed with modern techniques in humans and other species. Such studies have further identified hemispheric asymmetry in aspects of emotional processing, including a right-hemisphere dominance for affective prosody, and some evidence for prefrontal asymmetry in processing emotional valence.
The limbic and paralimbic regions implicated in emotional processing connect with cortical brain regions that mediate other cognitive functions, and these interactions guide goal-directed behavior.
Features of the environment that elicit emotional responses receive priority in perception and attention. The rapidity of such prioritization suggests subcortical as well as cortical processing.
In addition to facilitating the retention of information about emotional events, the amygdala detects regularities in the environment that predict aversive outcomes, as shown by fear conditioning. The association of conditioned fears with environmental contexts requires the hippocampus as well. The extinction of conditioned fear involves inhibitory interactions between the ventromedial prefrontal cortex and the amygdala.
Arousal enhances memory consolidation by way of the stress response systems, which interact with the amygdala and memory-processing regions of the medial temporal lobe, including the hippocampus.
Understanding the neural architecture and pharmacological substrates of emotion-cognition interactions provides potential targets for the treatment of affective disorders characterized by perceptual and attentional biases toward emotional stimuli, as well as intrusive traumatic and stressful memories.
The ability to regulate emotions is critical to mental and physical health. Decreasing negative emotions by reappraising the meaning of emotional stimuli—a core component of cognitive therapies—involves inhibitory interactions between executive control regions in the lateral prefrontal cortex and emotional processing regions in the limbic forebrain, including the amygdala.