2007 March » The Thinking Meat Project

More about selective amnesia in rats

Mar 312007

I just ran across this press release on EurekAlert, issued today, which sheds further light on a topic I covered a couple of weeks ago (Eternal sunshine of the spotless rodent mind). Rats were exposed to two different sounds that were associated with painful electric shocks. Then half of the rats were given a drug that causes selective amnesia, and all of the rats were reminded of only one of the sounds by hearing it played again. The next day, the rats who had received the drug were afraid only of the sound they had not been reminded of, while the other rats remembered and feared both sounds. What appears to be going on is that the reminder triggered a reprocessing of the original memory, and the rats who did this reprocessing while they were drugged lost the original memory. Thus they feared only the sound that they did not remember and reprocess under the drug’s influence. I wanted to point out that this is contrary what I said a couple of weeks ago, based on the Discovery story I linked to, which said that the rats feared only the tone they had been reminded of. Mea culpa for blogging it without fully understanding how the study worked. Today’s press release makes more sense, and it’s easier to see how this could conceivably apply, some day, to the removal of traumatic memories in humans.

Psychology of baseball

Psychology Comments Off

Mar 302007

Opening day is only a couple of days away, which is as good a sign as any, at least to baseball fans, that spring really is here. Mike Stadler, a psychologist at the University of Missouri, has a new book coming out just in time for the start of the baseball season: The Psychology of Baseball: Inside the Mental Game of the Major League Player. Stadler covers the limits of human perception and motor skills that make batting the ball and catching a fly ball seem impossible, and the unconscious but sophisticated processing that renders these feats possible after all. He also goes into some of the performance psychology involved in playing baseball in the Major Leagues and the statistics of clutch hitting, slumps, and streaks (which might not really exist except in the mind of the beholder). To get an idea of the sort of material in the book, see this press release from EurekAlert, which covers some of the research that various psychologists and statisticians have done on the noble sport of baseball. All I can say in conclusion is “Go Diamondbacks!”

Spring fever!

Brain and mind Comments Off

Mar 292007

We’ve had a wave of unusually warm weather here over the past couple of weeks; the early spring flowers are in full bloom and the trees are starting to show their first green. It’s safe to say that spring has arrived. (Time to see if my wireless signal is strong enough out on the patio to work out there…) This article from Scientific American Mind talks about a possible biochemical basis for the physical manifestations of springtime in humans known collectively as spring fever. Although the phenomenon is not as obvious now as it was in earlier centuries, the number of human births shows a peaks in March, hinting at a peak of sexual activity in June (which is when luteinizing hormone production, linked to reproductive functioning in both sexes, also peaks). It’s not clear yet what causes this in humans; in other mammals, similar changes are triggered by the changing length of daylight.

There’s a little bit in the article about SAD (seasonal affective disorder) and how day length affects that. (Incidentally, I wrote this essay a year and a half ago that covers some research into the possible adaptive value of SAD.) I hadn’t realized that it’s the increase in morning daylight that is most important for driving off the winter blues; someone’s found that on the western edges of time zones, where the sun rises later, there’s more depression. Indiana is on the western edge of a time zone, and it’s always a big deal to me when, in late January, the sun here starts rising before 8am. The difference is mostly symbolic, but it matters to me to turn that particular corner. (This is one reason, by the way, that Daylight Saving Time (DST) makes less sense in Indiana; we tend to have darker mornings and lighter evenings anyway. There’s also a fundamental lunacy to DST that I will not go into here, but I’m generally willing to expound on the subject indefinitely for anyone who cares to listen.) Going clear back to an 8am sunrise when DST started in March this year was disheartening, to say the least. (See this article from the Los Angeles Times for more about DST and SAD.)

The evolutionary value of the squick response

Human origins and evolution, Psychology Comments Off

Mar 282007

I don’t know if anyone still uses the word “squick”, but I used to see it in some Usenet communities I used to frequent, back in the day. Something squicked you if it grossed you out. An anthropologist at UCLA has studied the emotion of disgust to try to get an idea of what its evolutionary roots might be. Through a series of studies, he’s been able to figure out that disgust seems to be triggered by situations where there is (or maybe is perceived to be) a threat of contamination by pathogens, and thus might well have protected early humans from dangerous situations.

For example, he looked at pregnant women and found that morning sickness enhances the disgust response in food-related situations, which might protect women from food-borne diseases at a time when their immune system is not as active (during the first trimester of pregnancy, the immune system has to relax a little to let the baby develop). He also had people evaluate various hypothetical transplant scenarios to identify which organs made for the most disgusting transplants (turns out it was appendages, which are most exposed to the outside world and possible contamination). For more information, check out the press release from EurekAlert.

Free will: Who’s driving the car?

Being human, Books, Brain and mind, Thought and consciousness Comments Off

Mar 272007

This article from the Financial Times reviews three recent books that discuss free will, specifically the ways that neuroscientific findings about our behavior affect our concept of free will. The reviewer goes way overboard, in my opinion, in suggesting that we face the possibility that no one can be blamed for anything because we’re bound by causality. The books he reviewed are all recent; a 2003 book by Daniel Dennett, Freedom Evolves, cuts through a lot of the agonizing over whether to hold people responsible for their actions by suggesting that although we are indeed subject to causality, just like the rest of the physical universe, we have enough control over our lives that we do have all the free will we need. To quote from the Wikipedia article about the book:

Free will, seen this way, is about freedom to make decisions without duress, as opposed to an impossible and unnecessary freedom from causality itself. To clarify this distinction, he coins the term ‘evitability’ as the opposite of ‘inevitability’, defining it as the ability of an agent to anticipate likely consequences and act to avoid undesirable ones. Evitability is entirely compatible with, and actually requires, that human action be deterministic.

I’m pretty much with Dennett on this, but the Financial Times review still makes for interesting reading.

Young children learn how to behave from watching others’ emotions

Psychology Comments Off

Mar 262007

One of my brothers uses a quote in his email signature that says something like “Learn from the mistakes of others. You’ll never have time to make them all yourself.” Children as young as 18 months can evidently learn from watching an emotional interaction between two adults. In a study in which toddlers watched two adults, one of who was playing with a toy while the other one either watched neutrally or got angry, the children avoided the behavior that provoked the angry response, in effect apparently learning from another person’s “mistake” not to get into the same trouble themselves. (Interestingly, the child behaved differently only if the angry adult was still in the room and looking at the child, not if s/he left or was not watching.) You can read more about this “emotional eavesdropping” in this article from Science Daily.

Ape-like Homo rudolfensis

Human origins and evolution 2 Responses »

Mar 252007

Homo rudolfensis is the earliest species in the genus Homo, and a recent reconstruction of a 1.9 million-year-old skull shows this earliest human ancestor as distinctly more ape-like than was previously believed. Richard Leakey originally found the skull in Kenya and reconstructed it by hand; he described H. rudolfensis as relatively large-brained with a more human facial profile (vertical rather than sloping back from a protruding jaw). However, Timothy Bromage of the New York University College of Dentistry has made a new reconstruction of the same skull based on biological principles about the architecture of the face; these principles describe the relationships between eyes, ears, and mouth in mammals. His reconstruction reveals a smaller cranial cavity and a protruding jaw, resembling pre-human hominids more than modern humans. Bromage says that Leakey’s reconstruction was based on mistaken preconceptions. EurekAlert has a press release, and if you feel so inclined, you can read the abstract from the International Association for Dental Research meeting where the new reconstruction was presented.

Roots of human morality in other primates

Animal behavior Comments Off

Mar 242007

Nicholas Wade of the New York Times has written another interesting article, this time about the seeds of human moral behavior that can be observed in other primates. He discusses the social order that are established among other kinds of primates and the social rules and behaviors that help keep groups functioning, and how humans might have elaborated on these to derive our own complicated moral systems. He includes some interesting quotes from primatologist Frans de Waal and covers some of the debate between moral philosophers and biologists on where morals come from.

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