Identifying the Seat of Emotion in the Human Brain

While our understandings of life evolve through our rational thoughts as they are reflectively appended to our experiences, our direct human experiences are spotlights of awareness that are physically felt and emotionally hued and colored before they are rationally arrayed, and this immediate experience is irreducible as it rolls forward through time:

 “… emotion will present itself as an irreducible novelty in relation to the phenomena of attention, memory, perception…”

…yet if we wish to reflectively understand how our emotions operate,

“…You can, indeed, inspect these phenomena and the empirical notion of them we build following the psychologist…” (Sartre, 1948)

And placing our selves under the experimental lens of contemporary psychology we will see that our emotions developmentally arise and spread through our nervous systems and consciousness as-

“… a response of the whole organism, involving (1) physiological arousal, (2) expressive behaviors, and (3) conscious experience.” (David Myers, 2010)

Physiological arousal occurs when neural impulses travel into the central nervous system, impressing our unconsciousness awareness first through our brain’s limbic system.   The limbic system is the primitive ‘brain’ that developed long before our extensive cortical layers evolved with our rational thinking and it is too our primitive physiological/emotional ‘reactions’ via the limbic system that we owe our fundamental survival, what Sartre (1948) refers to as the “…essential structure…” of our “… reactions against the world”.

 (For illustrations of the brain and limbic system see figures 1, 2 & 3 endnote [i]). 

The limbic system initially generates our emotions and the ‘amygdala’ (with its own emotional memory banks) is fundamentally the central alarm system that scans incoming sensory information for trouble (Daniel Goleman, 1995).   

Incoming sensory information is constantly ‘tasted’ by the amygdala for emotional content that is commensurable with its emotional memories and is then physiologically routed for instant reactions…

“The amygdala takes in information both directly from the sense organs and via the sensory cortices, and connects to the cortex and also to the hypothalamus, creating a circuit.  When the amygdala is activated it sends signals around this circuit.  These trigger body changes as they pass through the hypothalamus, and create conscious recognition of the emotion as they pass through the frontal lobe.” (Rita Carter et al, 2010)

Yet despite our eventual cortical recognitions of emotions, initially the amygdala is capable of bypassing our cortex and reacting on its own to increase our heart-rate and blood pressure and prepare our muscles for the actions of our ‘Expressive behaviors’ such as ‘fight or flight’; the amygdala is capable of ‘hijacking’ our body by emotionally ‘reacting’ to stimulus and instructing our body to act prior to our rational participation (and constraint):

“… research has shown that sensory signals from eye or ear travel first in the brain to the thalamus, and then – across a single synapse- to the amygdala; a second signal from the thalamus is routed to the neocortex- the thinking brain.  This branching allows the amygdala to begin to respond ‘before’ the neocortex, which mulls information through several levels of brain circuits before it fully perceives and finally initiates it’s more finely tailored response.” (Daniel Goleman, 1995)

Our emotions are fundamentally unconscious survival tools, thoughtless ‘reactions’ to potential dangers, yet once their signals arrive in our human frontal lobes they cruise into our conscious awareness as our emotional ‘feelings’.  At this point our emotions are comingled with our rational thoughts and are the potent co-creators of our meanings and values- and the pleasures of the so called “reward circuit” as well (Carter, et al, 2010).

According to David Myers again, “… EEG recordings show that emotions… activate different areas of the brain’s cortex, with some tendency for negative emotions to be linked to the right hemisphere and positive emotions to the left… The left frontal lobes rich supply of dopamine receptors may help explain why a peppy left hemisphere predicts a perky personality.  A neural pathway that increases dopamine levels runs from the frontal lobes to a nearby cluster of neurons… this small region lights up when people experience natural or drug induced pleasures (When you’re happy and you know it, your brain will surely show it).”

Yet despite these [emotional] ‘brain circuitry’ distinctions it should be pointed out that while in their initial physiological phases emotions, generally speaking, still have little distinctions; for example, anger and joy produce the same physiological ‘motions’ of heart beat and other preparatory physical reactions and this lack of physiological distinction can cause what is referred to as the cognitive “spill-over effect”.

As stated earlier it is in the human cortex that our physiological emotions become palpable as experienced ‘feelings’ when they become enmeshed with our intellectual reasoning; and sometimes this reasoning of ours isn’t as reasonable as we might like to think when our ‘hyped-up’ emotions spill over from one experiential context into another: human physiological excitation and the resulting emotional experience are dependent upon the cognitive distinctions we apply to them and this has been replicated in dozens of experiments:

“Insult people who have just been aroused by pedaling a exercise bike or watching rock videos and they will find it easy to misattribute their arousal to the provocation,  Their anger will exceed that of people similarly provoked but not previously aroused,  Likewise, sexually aroused people react with more hostility in anger-provoking situations,  And, vice versa- the arousal that lingers after an intense argument or a frightening experience may intensify sexual passion (Palace, 1995)” (Myers, 2010)

Beginning in the brains limbic system our physiological arousals may spread out over our entire bodies fueling our emotions but it is our brain’s higher cognitive abilities which experience, label, understand and channel these emotions.

References:

1. Sartre, Jean-Paul (1948), ed. Wahl, J., (1993) Essays in Existentialism, Part III,

    ‘The Emotions: outline of a theory’, New York,   NY, Citadel Press, p. 193

2. Myers, D, (2010), ‘Psychology’, Holland, MI, Worth Publishers, p. 499

3. Goleman, Daniel, (1995), Emotional Intelligence, Bantam Books, New York, NY, pp. 16-18

4. Ibid., Sartre, p. 196

5. Rita Carter, Susan Aldridge, Martyn Page, Steve Parker, (2009).  The Human Brain Book, New York, NY,

    DK Books, p. 124

6. ibid., Myers, (2010), pp. 501-502

7. ibid., Myers, (2010), p. 502

8. ibid, Myers, (2010), p. 503       

Endnotes:

[i] Illustration #1- The brain

Available at:   http://www.willamette.edu/~gorr/classes/cs449/brain.html

Illustration #2- The brain with its Limbic System;

Available at:    http://en.wikipedia.org/wiki/File:Brain_limbicsystem.jpg

This work is in the public domain in the United States because it is a work of the United States Federal Government under the terms of Title 17, Chapter 1, Section 105 of the US Code.

Illustration #3- The ‘Limbic system’;

Available at:   http://www.google.com/imgres?imgurl=http://www.scottsdalecc.edu/ricker/psy101/readings/section_4/images/limbic.gif&imgrefurl=http://www.scottsdalecc.edu/ricker/psy101/readings/section_4/4-2.html&usg=__nFGleqal8ImYyYzPrycAtVh4n7g=&h=408&w=504&sz=72&hl=en&start=26&zoom=1&tbnid=IDagewfvszo1mM:&tbnh=104&tbnw=129&prev=/images%3Fq%3Dthe%2Blymbic%2Bsystem%26um%3D1%26hl%3Den%26sa%3DG%26rls%3Dcom.microsoft:en-us:IE-Address%26rlz%3D1I7ACAW_enUS402US402%26biw%3D863%26bih%3D398%26tbs%3Disch:10%2C747&um=1&itbs=1&iact=hc&vpx=106&vpy=102&dur=780&hovh=202&hovw=250&tx=141&ty=194&ei=aMwHTdn4F46WsgPEyuy0Dg&oei=XswHTf76G5D2swOKoM3LDQ&esq=4&page=4&ndsp=10&ved=1t:429,r:0,s:26&biw=863&bih=398

This work is in the public domain in the United States because it is a work of the United States Federal Government under the terms of Title 17, Chapter 1, Section 105 of the US Code.

For further images see: http://www.google.com/images?rls=com.microsoft:en-us:IE-Address&oe=UTF-8&rlz=1I7ACAW_enUS402US402&q=limbic+system&um=1&ie=UTF-8&source=univ&ei=QzIFTaDlIo-osAOh8q2PDQ&sa=X&oi=image_result_group&ct=title&resnum=3&ved=0CD4

QsAQwAg&biw=1253&bih=691

For further information see: 

http://www.google.com/images?rls=com.microsoft:en-us:IE-Address&oe=UTF-8&rlz=1I7ACAW_enUS402US402&q=limbic+system&um=1&ie=UTF-8&source=univ&ei=QzIFTaDlIo-osAOh8q2PDQ&sa=X&oi=image_result_group&ct=title&resnum=3&ved=0CD4QsAQwAg&biw=1253&bih=691

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