Why do we make bad choices, when we "know better?" We see rain clouds in the sky but we don't take an umbrella to work. More seriously, we marry someone who's an alcoholic or drug addict, even though we know it's a mistake. Acknowledged killers who have murdered their wives and are on death row get large numbers of marriage proposals from lonely women. Neurobiologists say that the brain remembers, even if we don't. But aren't our brains really us?
Researcher Adam Messinger compares it to subliminal knowledge, which is there, even the information doesn't enter our consciousness. An example? "You know you?ve met the wife of your work colleague but you can't recall her face."
Part of this problem is that the "filing system" of our brain gets more crowded as we get older, so it's harder to find things. Human memory relies mostly on association; when we try to retrieve information, one thing reminds us of another, which reminds us of yet another, and so on. Neurobiologists are trying to get a better idea of how associative memory works.
Messinger worked with Thomas D. Albright, and together they studied the associative memory of rhesus monkeys. After being shown the first symbol (i.e. dark clouds) they were presented with two symbols, from which they had to pick the one that was associated with the initial cue (i.e. umbrella). The reward was a sip of their favorite fruit juice. Albright says, "For the first time, we can a look at the brain activity of a rhesus monkey and infer what the animal knows. We want the monkeys to behave perfectly on these tests, but one of them made a lot of errors. We wondered what happened in the brain when the monkeys made the wrong choice, although they had apparently learned the right pairing of the symbols."
While the monkeys tried to remember the associations, the scientists observed signals from the nerve cells in a special area of the brain called the "inferior temporal cortex" (ITC). This area is used for visual pattern recognition and for storage of this type of memory. When Albright and his team analyzed the activity patterns of brain cells in the ITC, they could trace about a quarter of the activity to the monkey's behavioral choice. But more than 50% of active nerve cells (neurons) were of a very special type, which the researchers believe are responsible for the correct pairing of a cue and an associated symbol. Surprisingly, these brain cells kept firing even when the monkeys picked the wrong symbol. Albright says, "In this sense, the cells 'knew' more than the monkeys let on in their behavior."
This type of research will teach us how to use our brains to their fullest capacity, as well as how to beat off the effects of elderly dementia and even Alzheimer's. Albright and Messinger say, "Behavior may vary, but knowledge endures." In other words, the information you're looking for is in your brain somewhere, you just need to learn how to access it.
Scientists are studying what information our brains take in from peripheral vision (the images that come in from the corners of our visual field) and they are also seriously studying our intuition--when we "know" something but can't prove it.
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