The Biological and Neuophysiological Approach
The biological origins of emotion seem to have originated with the suggestion by the philosopher William James in 1884 that emotions are a function of sensory and motor areas of the neocortex. This theory was set aside by the work of (Cannon and Bard in 1929) showing that emotional reactions require the use of the hypothalamus. Then, on the basis of such observations, Papez in 1937 suggested a group theory involving the hypothalamus, anterior thalamus, cingulate gyrus, and hippocampus. Following this, MacLean in 1949 and 1952 then named the structures of the Papez circuitry the "limbic system." Despite the prominence of the MacLean nomenclature to the limbic system, new studies found that many more areas were involved in the emergence of emotions. Various studies then concluded that the amygdala was consistently implicated in emotional processes over a variety of situations, and is currently holding center stage as a prominent area of emotions. In a nutshell, the amygdala has been identified as a key structure in the assignment of reward value to stimuli; in the conditioning of fear to novel stimuli; in the self-administration of rewarding brain stimulation; and in the elicitation by brain stimulation of a host of behavioral and autonomic responses typical of emotional reactions. LeDoux, J.E., Phelps, E.A., Handbook of Emotions, 2nd Edition, p. 157. & 158.
But as studies advanced, evidence has pointed to many circuits involved in the processing of emotional response. This has lead to general assumptions regarding emotional hardware:
Panksepp, J. Handbook of Emotions, 2nd Edition, 2000, p. 137
In studying the biological emergence of emotions you must crystallize two concepts: That which emerged from the biological structures that were put in place by forces that necessitated their being; and understanding that emotions then stretched to a higher level when our ancestors found themselves in the social situations of hunter-gatherer clans utilizing our human ability to conceptualize important issues.
Just knowing the main physical areas in the brain responsible for emotional processes is only the beginning of our voyage. As we enlarge our sphere of knowledge matters are complicated when we must then consider the neuropepetides, noradrenial, oxytocian, and serotoneric factors that influence emotions; not to mention cultural social differences in emotional signaling. In attempting to overcome this difficulty, scientists are placing emotional activity under a single conceptual umbrella, that focus on shared psychoneurological properties of basic emotional systems that help define emotions which consists of the following attributes:
Panksepp, Jaak, Handbook of Emotions, 2nd Edition, 2000, p. 137 & 138.
At the beginning of your studies in psychology, I recommend that you stay away from this "umbrella concept" regarding emotional attributes as it may tend to confuse you, but keep it in the back of your mind. I must however impress upon you that the hardware you seek to identify where emotions emerge are not definable structures like your index finger or a hard drive disk but are fields of neurons and glia located in a general area. Think of these areas like a field of yellow daises on a hillside: you can observe them as a distinct unit in a general area, but you also know that they got there by random placement within that specific bounty.
To quote J. Panksepp:
The "limbic system" has never been anything more than a high-order conceptual entity that helps us designate and discuss the general location of the families of functional neural systems that contribute most heavily to dynamic processes commonly placed under the conceptual umbrella of "emotions." Handbook of Emotions, 2nd Edition. p. 139.
But we "educated humans" must be able to communicate our understandings into broader audience in which we want to reach, and as a result such terms as "amygdala," "habenula," and "hippocampus" have emerged and remain stable in our language lexicons. Our attempts to be accurate must also bend to our desire to reach a larger audience.
One of the major keys to understanding the flow of emotions from a biological perspective lies in the reason that emotions evolved in the first place; their purpose. Panksepp divides these purposes into three categories:
To help you in your quest of knowing the emotional structures, I want to include part of Planksepp's general summary chart of the key neuroanatomical factors in the "Blue-Ribbion" emotions listed above. I have not included the neuromodulators such as oxytocin, dopamine, corticotropin-releasing factors, etc., one must factor into the emotional mix. That is up to you in order to complete your studies. I suggest the purchase of the Handbook of Emotions, 2nd Edition, plus a good "coloring book" of the human brain.
Table 9.1. General summary of the Key Neuroanatomical and Neurochemical factors That Contribute to the construction of Basic emotions within the Mammalian Brain. Panksepp, Jaak, Handbook of Emotions, 2nd Edition, p. 144.
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Ok, now that you are totally lost, let me add to your confusion by including the next table. From the table above, you now have a general knowledge of the various equipment involved in the "blue-ribbon" emotions. Ok, well, what happens when that equipment is turned on? What happens is that biochemical reactions that do occur, create a reaction. Most of these reactions we can acknowledge from a conscious level as occurring, but we also must take into account that some physical emotional reactions are at an unconscious level that we humans sometime acknowledge as "gut" feelings, or underlying "sense."
And one of the most useful tables that addresses this is issue in the Handbook of Emotions, was the chart listing 22 studies comparing two or more physiological measures that were the outcome of two or more discrete emotions, (pp. 181 & 182). The chart progresses from the earliest studies done in 1953 to the most recent of 1997 - of course more are being done as you read these words, so it would be wise to update your studies with the proper science journals. (see science journal page listings).
The chart will help you frame your study pathways reconfirming what has come before and to help select new directions in your studies. For example, as we expand the list of emotions (those resulting from induction), we will want to know what dependent variables would result.
To wet your appetite and curiosity to acquire the Handbook, I will list just two of the 22 studies found on pp. 181 & 182.
In 1969, Averill studied 123 people aged 17-24 (most likely undergrads) for the emotion of Happiness and Sadness using a control film preceding the recording. The dependent variables recorded were: HR = Heart Rate; SBP = Systolic Blood Pressure; DBP = Diastolic Blood Pressure; FCT = Face Temperature; FT = Finger Temperature; SCL = Skin Conductance Level; FPV = Finger Pulse Volume; NNSCR = Number of Nonspecific Skin Conductance Responses; RR = Respiration Rate, and Respiration Irregularity.
Averill, J.R. (1969). Autonomic Response Patterns During Sadness and Mirth. Psychophysiology, 5, 399 - 414.
In 1992, Sinha, Lovallo, & Parsons conducted studies of 26 individuals, median ages 21- 35 for the emotions of Anger, Fear, Joy, Sadness, and a neutral state [Imagery]. The dependent variables recorded were: HR = Heart Rate; SBP = Systolic Blood Pressure; DBP = Diastolic Blood Pressure; SV = Stroke Volume; CO = Cardiac Output; TPR = Total Peripheral Resistance; PEP = Preejection Period, and LVET = Left Ventricular Ejection Time.
Sinha, R., Lovallo, W.R., & Parsons, O.A. (1992), Cardiovascular differentiation of emotions. Psychosomatic Medicine, 54, 422 - 435.
Other dependent variables listed in the chart that I have not attached to a particular study include the following: BV = Blood Volume; DFA = Directed Facial Action; EMG = Muscle Activity; EOG = Eyeblink Rate; EDR-Dur = Electrodermal Response Duration; FRC = Functional Residual Capacity; HRV = Heart Rate Variability; HT = Hand Temperature; II = Inspiratory Index; LVET = Left Ventricular Ejection Time; MVT = Movement; NMTP = Number of Muscle Tension Peaks; NNSCR = Number of Nonspecific Skin Conductance Responses; OS = Oxygen Saturation of the Blood; PEP = Preejection Period; PI= Postinspiratory pause; PTT = Pulse Transit Time; RD = Respiration Depth; PSP = Respiration; RI = Respiration Irregularity. RR = Respiration Rate;
As you can see from the listed dependent variables, the possibilities of biological changes in the body, and thus our behavior resulting from those emotions is extremely more complicated then one could have previously imagined. Imagine for a moment all this information in the Handbook on emotional variables coming into play when we consider human behavioral activity from an evolutionary perspective. Imagine yourself tens of thousands years ago in a clan group and observing a hierarchy transference struggle (if you are a male), or for the behaviors associated with being accessed as an estrous female ( if you are on the receiving end as a female). What do you observe and feel? Can you observe emotions being emitted from the individuals in this power play or sexual access mechanism, and can you feel the emotions stirring within your own body and mind when your brain creates the imagery? Can you feel your Respiration Irregularity? Can you observe MVT in others and their relationship within the group? What's your facial temperature? And what does the eyeblink rate of the person you face tell you?
And you thought you understood human behavior, right? Well, my friend, both you and I are in the dark ages (in 2001) and have been blinded by our successes. Do you have the sinking (emotional) feeling that you will have to start over again in your understandings of human behavior, or you do you feel encouraged by the knowledge laid before your feet as signposts along a lonely highway? I sense the latter. I hope that this introductory approached has helped.
Copyright, Evolution's Voyage, 1995 - 2010