Section Summary

Five theories of emotion were presented that emphasized the idea of subjective feelings of emotions emerging from interactions between the environment or exteroceptive stimuli and internal physiological changes, that in turn influence how appraisal/cognitive processes in the brain generate different emotions. The collective theories agree on the essential nature of the three components for emotions to develop. However, they each propose a different sequence or order in which sensory and brain appraisal processes lead to an awareness of personal subjective feelings. The James-Lange theory stresses that the feeling component of emotion derives from the perceived pattern of bodily sensations following encounters with external events. Cannon-Bard on the other hand emphasizes that internal body changes associated with physiological arousal and the development of emotional attributes occur simultaneously, yet independently. Ideas proposed in the two-factor theory by Schachter-Singer model stress the importance of cognitive appraisals of context in the brain as a key factor in determining the category of emotions that will be attributed to any event as opposed to the intensity of physiological responses produced by the experience. This view was advanced by Magda Arnold, Richard Lazarus and other appraisal theorists who suggested a range or dimensions that are evaluated during the appraisal process to ultimately determine which emotions are generated from any given emotional encounter. The final Constructionists theories differ from each of the previous four through their emphasis on the brain in assessing stimuli from the immediate context while simultaneously comparing this input with past episodes saved in memory. These two sources of information are then used to construct a hypothesis or prediction of what an organism is experiencing to yield the category or labels we assign to emotions.

Paul Ekman’s research is most noted for revealing that all humans are endowed with an innate capacity to identify basic categories of different subjective emotions. He conducted an extensive number of experiments with participants from different countries to verify that these innate skills are not influenced by cultural norms. His research demonstrated that humans from a wide range of cultural backgrounds were fairly accurate in detecting the six core basic emotions from expressions viewed in test photographs. Robert Plutchik advanced Ekman’s views by noting the presence of eight basic emotions. Plutchik’s research was noteworthy for describing how complex emotions develop. His Wheel of Emotions diagram explains how one or more of the eight basic emotions are integrated with higher or lower intensity feelings to create the complex emotions one may encounter.

The three components essential for emotional awareness involves an evaluation of exteroceptive stimuli, their impact on interoceptive physiological changes and complicated appraisal processes that inform the body of which goal directed “agonistic or appetitive” responses to generate to stimuli within the immediate environment. The Papez circuit is critical to all of these components. Subcortical structures of the Papez circuit, like the hypothalamus and amygdala, operate in the background, out of conscious awareness, to control many of the mind/body interactions that permit organisms to detect the significance of a given circumstances and to select the appropriate adaptive responses to preserve a state of homeostasis and allostasis. The combination of appraisal, conceptual, decision-making and motor planning exercises performed within the cortical regions of the Papez circuit allows organisms to successfully meet the appetitive or agonistic challenges in the environment. Some caution must be exerted however, in translating findings from animal studies to direct applications in humans. One challenge for all of neuroscience research is to understand which neural circuits underlying emotions in animals are also found in humans.

Emotional disturbances associated with depression continue to baffle scientists, clinicians and mental health providers. These causes of depression-related disorders are challenging to dissect because they can result from dysregulation of any of the structures within the Papez circuit or interconnections between them. The two main causes of depression involve extreme negative reactions to environmental events or from an internal imbalance in neurotransmitter functioning. Although the latter cause is effectively treated in most cases by restoring deficiencies in brain neurochemicals, more resistant forms of depression may involve alterations in the activity of emotion circuits in the brain. Contemporary research and clinical findings reveal an important contribution of the ventromedial prefrontal cortex as possible generator of melancholic, morbid and depressive symptoms while the dorsolateral prefrontal cortex may protect against depression by inhibiting negative emotions through conceptual and reappraisal processing. Findings emerging from these types of investigations are affording the scientific community opportunities to narrow down the possible substrates underlying depression and to target specific neural circuits to unlock the mystery of this disease.