Mechanisms of Emotions

Mechanisms of Emotions

Ben Kavalec

Over the past couple of decades, scientists have used a wide range of disciplines to advance our understanding of the mechanisms of emotion. In a review by Derryberry and Tucker, they attempt to condense all recent findings on the neural substrates of emotion into a single resource. Their paper, Neural Mechanisms of Emotion (1992) explores the neural mechanisms of emotion from an evolutionary perspective. The authors conclude that these mechanisms are distributed across four main regions: the brainstem, limbic, paralimbic, and neocortical regions. Within these regions, the authors discuss descending and ascending connections that are critical to peripheral effects on patterned bodily responses, central effects on cognitive processing, and subjective emotional experience.

            The most primitive brainstem structures regulate the autonomic, endocrine, and motor activities of the body. In this regard, these structures are fundamental to the function of emotion. As evolution progressed, additional structures differentiated, leading to the limbic system, which provided greater sensitivity to emotional signals in the environment. When cortical structures evolved, primitive paralimbic regions began to surround the limbic system, and eventually progressed towards modern neocortical fields. It is the authors’ conclusion that the brain’s architecture is best understood through an evolutionary light, with certain primitive control systems overlaid by more complex networks, as described above.

            An evolutionary analysis is required for an analysis of the human brain’s emotional control system. For example, the most recently differentiated neocortical networks work to control sensory and motor processes. In contrast, the paralimbic networks represent bodily states and motor dispositions. It is through these sensory fields, activated by signals or inputs from the body, that feelings of emotions arise.

            This paper explores in great detail how each region described has an effect on different bodily functions. However, the authors never focus on the actual mechanisms of evolution that new structures arose from, which would be of interest to an evolutionist. In this light, what general characteristics of brain structure do you think would be important to carry on through generations, eventually ending with humans?

Word count: 334

Derryberry, D., Tucker, D. (1992) Neural Mechanisms of Emotion. Journal of Consulting and Clinical Psychology, 60(3), 329-338.