Assignment

Life offers us choices, and what an older part of the forebrain, the limbic system, chooses is to feel better right away. The conscious forebrain, the cerebral cortex, knows that this can be short-sighted and plunge us into the pain of a fight, a disease, or buying too much, but the frontal lobe is often too slow to grab the steering wheel in time. That's to say that emotions make quick decisions possible and we have the stress response to deal with the consequences. Chronic stress just makes things worse.

Emotions are more than feelings. They have behavioral, autonomic, hormonal and cognitive components. Take fear for an example.

Fear is so familiar. (And that nifty website has everything about fear that an exam would require.) But in the 1940's and 1950's, about all that textbooks taught about emotion was the James-Lange vs. Cannon-Bard controversy. Today we can do better.

What is Fear?

Fear involves sympathetic arousal, eyelid retraction, and distress. Read this account to put yourself in the mood.

Fear is often defined as an emotional response to a real or immediate threat (and anxiety is what we call the response to an imaginary or remote threat)? Why does fear appear in newborns as the outcome of loud noises and falling? (How often are infants hurt by loud noises or falling?) It's associated with the startle reflex and the Moro reflex, respectively. Later it becomes a response to pain, abandonment, and, to some extent, novelty. For example, the stimulus chosen to evoke fear in Little Albert was a loud gong.

Children and adults pick up fear responses by observing. A parent who is upset by a bee in the house may communicate a fear of bees (apiphobia) to a child. To study fear in the lab, psychologists focus on fear conditioning, in which a sensory stimulus like a tone (or a gong) is paired with electric shock. This pairing will make a rat freeze and defecate when it hears the tone after just one or two trials of training. Yet with all the evidence of learned fear, a question remains about its prenatal or even genetic origins. Do we have a built-in tendency to fear snakes and spidersmore than guns and tasers, which are much more dangerous?

What is the Function of Fear?

Fear is a special type of learning and memory. It can be learned in a single conditioning trial and retained for a lifetime. Since it is a common element of stress, it is important to understand its management. It is obviously not all-or-none; it varies in strength. Some people engage in fear for recreation, in skydivingor mountain climbing or other extreme sports (click on Real Player or Windows Media). For some people, fear is immobilizing and overpowering.

Unpleasant emotions like fear and dread seem to be generated by activity in the amygdala. It has been known for many years that surgical removal of the amygdala tames wild monkeys. The so-called Klüver-Bucy syndrome has been identified in humans as well. It's worth noting that it involves more than just tameness. A failure to appreciate this led to atrocious psychosurgery on prisoners involving Drs. Mark, Ervin, and Sweet 40 years ago.)

The amygdala lies near the frontal end of the temporal lobes, just where pencils stuck into an eye and ear on the same side of the head would meet. Recent research has shown that it is amazingly well connected with other parts of the brain.

A threat will affect the brain in two ways. An immediate response follows alerting of the lateral region of the amygdala. This first reaction is not a logical response, as the amygdala is not wired that way. The other, slower response that considers logic comes from the prefrontal cortex, which can inhibit the behavior that the amygdala triggers. So we will start to back away from a snake when the amygdala is alerted, then relax and continue on our way when the cortex recognizes the snake as a stick. In The Emotional Brain, Ledoux labeled these two routes the low road and the high road.

Questions

Consider each of the following points and respond:

What are the components (biological, cognitive, behavioral) of a specific emotion like love or fear?

What are the advantages of an emotion like love or fear? Cockroaches may lack emotions yet they manage to reproduce and escape threats pretty well.