In Part 7 of the series, I looked briefly at the James-Lange Theory of Emotional Regulation which states that emotions occur secondary to the physiological response to a stimulus. A contrasting theory of emotions is the Cannon-Bard theory which states that our emotional and physiological responses to a stimulus occur simultaneously. One specific variation of this theory is the Cannon-Bard Thalamic Theory of Emotions. In this theory it is assumed that the Thalamus is inhibited from sending activating signals to the Autonomic Nervous System by inhibitory signals from the Cerebral Cortex. The Theory states that an appropriate stimulus can activate the Cerebral Cortex and remove the inhibitory control on the Thalamus. Subsequently there is both cortical activity and autonomic activity – emotional and physiological responses to the stimulus. A schematic for this theory is shown in the diagram above.
There is some experimental data to support this theory which I won’t cover here. If we consider this theory it helps us to think about emotions differently. If we start to look at the Thalamus as an area which regulates emotional responses then we can examine relevant data to further explore this. For instance this small case series looks at the treatment of Tourette’s Syndrome using Deep Brain Thalamic Stimulation. In one case the researchers report a decrease in Depression but an increase in aggression. The caveat is that case series are generally good at posing hypotheses for further exploration. A case of pathological laughter subsequent to a gamma knife Thalamotomy was treated with Sertraline in this paper. By generating explicit neuroanatomical models of emotional regulation we can begin to examine the literature in a more systematic way. Even if we start off with an innaccurate model, we may after many iterations arrive at a better understanding of these phenomenon.
Insular Cortex Resources on this Site
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