emotion

EMOTION

The point for us is that even the simplest act of comparison involves emotional factors. --J. Z. Young (Programs of the Brain [1978:194])

The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. --Albert Einstein

Neuro term. 1. A pleasant or unpleasant mental state organized in the limbic system of the mammalian brain. 2. Specifically, feelings of agreement, anger, certainty, control, disagreement, disgust, disliking, embarrassment, fear, happiness, hate, interest, liking, love, sadness, shame, surprise, and uncertainty--as expressed nonverbally, apart from words.

Meaning: Emotions are mammalian elaborations of vertebrate arousal patterns, in which neurochemicals (e.g., dopamine, noradrenaline, and serotonin) step-up or step-down the brain's activity level, as visible in body movements, gestures, and postures. In mammals, primates, and human beings, feelings are displayed as emotion cues.

Anatomy. Before the mammalian brain, life in Nonverbal World was automatic, preconscious, and predictable. Reptilian motor centers reacted to vision, sound, touch, chemical, gravity, and motion-sensory cues with preset body movements and programmed postures. With the arrival of night-active mammals 180 m.y.a., smell replaced sight as the dominant sense, and a newer, more flexible way of responding--based on emotions and emotional memory--arose from the olfactory sense. In the Jurassic period, the mammalian brain invested heavily in aroma circuits designed to succeed at night as reptiles slept. These odor pathways gradually formed the neural blueprint for what was later to become our limbic brain.

Media. 1. "'Throughout most of the 20th century, emotion was not trusted in the laboratory,' writes noted University of Iowa neurologist Antonio R. Damasio, in his new book, 'The Feeling of What Happens'" (San Diego Union-Tribune, Oct. 27, 1999, E-1, E-4). 2. "Emotions are the ultimate in cerebral software" (San Diego Union-Tribune, Oct. 27, 1999, E-1). 3. "'The point of art is not to copy but to amplify,' he said, 'to create an emotional response in the viewer'" (San Diego Union-Tribune interview with UC-San Diego neuroscientist, Vilayanur Ramachandran [May 7, 1999, A1, A-19]).

Physiology. "Heart rate is a convenient and sensitive indicator of emotional tension" (Cherkovich and Tatoyan 1973:265).

RESEARCH REPORTS: Though our fingers, hands, and arms also telegraph feelings, academic research on emotion has focused almost entirely on facial expression. 1. In The Face of Emotion, Izard (1971:185) proposed nine major emotions: interest, enjoyment, surprise, distress, disgust, anger, shame, fear, and contempt. 2. From research on the face, six basic emotions--surprise, happiness, fear, anger, disgust, and sadness--have been proposed by Ekman (1984). 3. Primary (i.e., innate) emotions, such as fear, "depend on limbic system circuitry," with the amygdala and anterior cingulate gyrus being "key players" (Damasio 1994:133). 4. Secondary emotions (i.e., feelings attached to objects [e.g., to dental drills], events, and situations through learning) require additional input from the prefrontal and somatosensory cortices (Damasio 1994:134; viz. "The stimulus may still be processed directly via the amygdala but is now also analyzed in the thought process . . ." [Damasio 1994:137].). 5. "Thoughts and emotions are interwoven: every thought, however bland, almost always carries with it some emotional undertone, however subtle" (Restak 1995:21).

Neuro-notes I. 1. Smell carries directly to limbic areas of the mammalian brain via nerves running from the olfactory bulbs to the septum, amygdala, and hippocampus. In the aquatic brain, olfaction was critical for detecting food, foes, and mates from a distance in murky waters. 2. Like an emotional feeling, aroma has a volatile or "thin-skinned" quality because sensory cells lie on the exposed exterior of the olfactory epithelium (i.e., on the bodily surface itself). 3. Like a whiff of smelling salts, a sudden feeling may jolt the mind. The force of a mood is reminiscent of a smell's intensity (e.g., soft and gentle, pungent, or overpowering), and similarly permeates and fades. The design of emotion cues, in tandem with the forebrain's olfactory prehistory, suggests that the sense of smell is the neurological model for our emotions.

Neuro-notes II. Like aromas, emotions are either positive or negative (i.e., pleasant or unpleasant)--and rarely neutral. Like odors, feelings come and go, defy logic, and clearly show upon our face in mood signs. It is likely that many emotions evolved from aroma paleocircuits a. in subcortical nuclei (e.g., the paleocortex of the amygdala), and b. in layers of nerve cells within the forebrain's outer covering of neocortex. (N.B.: The latter's stratified architecture resembles that of the olfactory bulb, which is similarly organized in layers.)

Neuro-notes III. Ironically, the feeling that something is real, true, and right comes not from the reasonable neocortex, according to neuroanatomist Paul MacLean, but from evolutionary older, emotion centers of the limbic cortex (MacLean 1990:17).

Neuro-notes IV. From PET studies, Antonio Damasio notes, sadness activates the bilateral insular cortex and partially activates the cingulate gyrus. Happiness activates the insular cortex, posterior cingulate, and secondary somatosensory cortex. Fear deactivates secondary somatosensory regions, according to Damasio.

See also AROMA CUE, ENTERIC BRAIN.