Word: braining
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...learn such primal skills as walking and eating as well as how to become social, ethical beings. The mystery of memory is being teased apart, exposing the way we store facts and experiences in addition to the emotional flavors associated with them. Magnetic resonance imaging is probing the brain as it operates, essentially--if crudely--reading our minds, and raising all the attendant ethical questions...
Second, even as it's kick-starting the body, the amygdala sends out a crackle of signals to the rest of the brain. Some of them put the senses on high alert, ready to deal with a threat. But these signals also tell the neurons that any memories recorded in the next few minutes need to be especially robust. One piece of evidence for this scenario: Lawrence Cahill, a colleague of McGaugh's at Irvine, showed subjects emotionally arousing film clips, simultaneously gauging the activity of their amygdalae using positron-emission tomography (PET) scans. Three weeks later, he gave...
What happens biochemically, says McGaugh, is that when faced with an emotion-charged situation, such as a threat, our bodies release the stress hormones adrenaline and cortisol. Among other things, these signal the amygdala, a tiny, neuron-rich structure nestled inside the brain's medial temporal lobes, which responds by releasing another hormone, called norepinephrine. Norepinephrine does two important things. First, it kicks the body's autonomic nervous system into overdrive: the heart beats faster, respiration quickens, and the muscles tense in anticipation of a burst of physical exertion...
This is an oversimplification, of course. Other neurotransmitters, and even plain glucose--the sugar the brain uses for energy--may also play a part. And then there's the peculiar case of a woman who contacted McGaugh because she remembers absolutely everything. The stress-hormone model does not appear to apply in her case. Says McGaugh: "At one point I asked if she knew who Bing Crosby was. She's 40, so Bing Crosby doesn't loom large in her life, but she knew he died on a golf course in Spain, and she gave me the date, just like...
...people haunted consciously or unconsciously by painful memories, there may be hope. Roger Pitman, a professor of psychiatry at Harvard medical school, is working to understand post-traumatic stress disorder (PTSD). The syndrome, he believes, is the result of brain chemicals reinforcing themselves in a cerebral vicious circle. "In the aftermath of a traumatic event," he says, "you tend to think more about it, and the more you think about it, the more likely you are to release further stress hormones, and the more likely they are to act to make the memory of that event even stronger...