The colors of the rainbow do not begin to reflect all of the infinite hues of reflected light. However, the myriad colors of the world are not separate things, but are in truth admixtures of three primary colors, red, yellow, and blue. This simple conceptual scheme provided the explanation of color that made the replication of color easy, to the delight no doubt of interior decorators the world over.
Deriving complex structure from elemental processes serves all the physical and biological sciences, and like the metaphors of disease and space and time, can encapsulate a world view in a phrase. However, feelings or affective states have not been so tractable, though an early psychologist would demur. He was the late 19th century psychologist Wilhelm Wundt, the founder of experimental psychology. Wundt wanted to know the rudiments of felt experience, or affect, and his aim was to see if affect, like color, can be derived from rudimentary components. Wundt believed that the affective components of of the human mind could be determined by rigorously objective introspection. That is, he thought that affect or feelings could be broken down (or reduced) to their basic elements without sacrificing any of the properties of the whole. Wundt’s introspection was not a casual affair, but a highly practiced form of self-examination. He trained his students to make observations that were free from the bias of personal interpretation or previous experience, and used the results to develop a theory of affect which derived from three bi-polar dimensions. According to Wundt: “In this manifold of feelings… it is nevertheless possible to distinguish certain different chief directions, including certain affective opposites of predominant character.” Wundt identified three bipolar dimensions whose permutations comprised moment to moment affective states: (i) pleasurable versus un-pleasurable, (ii) arousing versus subduing, and (iii) strain versus relaxation. An attentive reader would note that strain versus relaxation also reflect unpleasant and pleasant affective states, however these states differ from our workaday pleasures and pains because they are continuously rather than intermittently present. So, with this new perspective, Wundt in effect postulated one discrete and two continuous affective dimensions. For example, a delicious meal or touching a hot pan are pleasurable and un-pleasurable states that occur discretely, however the relative activity of the covert musculature is continuous, as is our moment-to-moment state of alertness, or attentive arousal. For Wundt, the affective modalities or pleasure and arousal and their respective intensity were features or qualities of the simple feelings that arise from internal bodily sensations. People are, wrote Wundt, never in a state entirely free from feeling.
What Wundt did not know and could not know at the time due to the rudimentary observational tools then available was the source of arousal and pleasure, which are respectively due to the activity of mid-brain dopaminergic and opioid systems. The neuromodulator dopamine elicits a feeling of alertness and energy, but not pleasure, and is induced through the experience and anticipation of novel positive events. On the other hand, opioids are responsible for pleasure, and are elicited in very small regions or ‘hot spots’ in the brain by exteroceptive (food, drink) and interoceptive stimuli (relaxation). Finally, arousal and pleasure are not just complementary but synergistic. In other words, pleasure stimulates arousal, and arousal stimulates pleasure. This reflects the fact that the neuronal assemblies or nuclei that induce dopaminergic and opioid activity abut each other in the midbrain, and when individually activated can have synergistic effects, or dopamine-opioid interactions. This can explain why high arousal and pleasure, or ecstatic, peak, or ‘flow’ experiences, correspond to novel and ‘meaningful’ experiences during relaxed states.
The Affective Circumplex
If we map the continuous affective dimensions of Wundt’s proposal to each other, when informed by affective neuroscience, Wundt’s color wheel can bloom, and account for and predict different affective states. The vertical axis would represent dopaminergic activity, from high to low, whereas the horizontal axis would represent the degree of covert neuro-muscular activation, or muscular tension, again from high to low. High arousal would be felt as a sense of energy or alertness, and low arousal would be felt as a sense of lethargy or depression. High tension would be felt as anxiety or nervousness, and low tension would be felt as a pleasurable state of calm or relaxation. Mapping these affective events to their physiological correlates gives us emergent subjective states that match the emotional labels of our affective wheel, or an ‘emotional circumplex’. Thus ‘elation’, or a state of pleasure and arousal would occur when arousal is high and tension is low, ‘frustration’ would reflect high arousal and high tension, ‘worry’ would reflect low arousal and high tension, and ‘relaxation’ would correspond to low arousal and low tension.
And so with a little tinkering of Wundt’s proposal, his observations are correct after all, and perhaps as the affective wheel turns can help psychologists arrange the colors of emotion in ways that would do interior decorators of the soul proud.
For a more detailed analysis of Wundt’s work and how accurate introspection can map to simple neurological truths, see pp. 47-56 in my little book linked below and on my website on the history and implications of the neuropsychology of incentive motivation.