Perception’s vulnerability to emotion

Our brains can be blinded by emotions, says Vanderbilt University psychologist David Zald.

Zald and his colleagues trained twenty-one volunteers to spot a neutral target image — like a picture of a tree or a typical building — out of a series of other images flying by at 10 pictures per second. They asked the subjects to press a key when they spotted their image and indicate whether that image was rotated to the left or the right. He says the volunteers could do this correctly 90 percent of the time. But as he and his team reported in Psychonomic Bulletin and Review, if a gory or erotic image was presented before the target image the participants were far more likely to miss the target.

“When an emotional picture appears, it seems to short circuit that processing in the brain that will then help you construct a visual conscious perception,” says co-author Steven Most, a psychologist at Yale University.

According to the Discover article from which I’ve excepted, Zald believes that emotionally charged information can literally block the brain from perceiving subsequent information.

Another clue to the malleability of perception that I blogged about yesterday.

;-)

More on the malleability of perception

A Cornell University study examines the relationship between what we believe about people and our memory of events involving them.

To conduct the study, David Pizarro, assistant professor of psychology at Cornell, and three colleagues

gave 283 college students a story about a man who walked out on a restaurant bill, including what the man ate and drank and the amount of his bill. Half the participants read that the man walked out on the bill because he “was a jerk who liked to steal,” and half read that the man left without paying because he received an emergency phone call.

“One week later the people who were told he was a jerk remembered a higher bill — from 10 to 25 percent more than the bill actually was. Those who were told he had an emergency phone call remembered a slightly lower-than-actual bill,” said Pizarro.

The researchers appear focused on how these distortions may affect civic institutions (e.g. eyewitness testimony during criminal trials); they also characterize the distortions as stemming from observers’ ethical judgments. In Pizarro’s words: “[O]ur study shows that morally blaming a person can distort memory for the severity of his or her crime or misbehavior.”

But it seems to me that something broader is at work, here. It’s not morals, but motivation. When we witness events involving other people, and string those events together as a narrative, the narrative is shaped by our understanding of the players’ motivations.

At some point, we also “shade in” or heighten certain details within our memory of events in order to capture or express our understanding of it more accurately (as opposed to cataloguing what actually happened).

Kinda like writing fiction ;-)

The full study will be published in a forthcoming issue of the Memory and Cognition.

(Incidentally, the Cornell article I’ve quoted here implies that every single person in the study misremembered the bill. Hmmmmm. I suppose that’s possible . . .)

Bug guts matter

John Roach writes for National Geographic about research into the bacteria that lives in the guts of termites; the bacteria enable termites to digest wood by converting it to hydrogen.

So here’s what’s cool: researchers speculate that if we can understand how the bacteria do this, we may be able to use that information to create a new energy technology. One of the researchers, Daniel Kammen, director of the Renewable and Appropriate Energy Laboratory at the University of California at Berkeley

imagines a day when “little digesters” — a termite germ-derived technology — sit in people’s garages and process piles of woody waste to produce enough hydrogen to power cars and homes.

Off the grid and into the termite mound :-)

Mark your sundial

Scientists are predicting that the next bout of intense solar activity will come sooner, and be more intense, than the last one.

We may start to see some action as soon as this fall. Peak activity will hit about 2012.

As a practical matter, we’re even more dependent on technology than we were the last time this happened (around the turn of the millenium). So this is going to be . . . interesting.

Fortunately, we also have the aurora borealis. During the last period of peak solar activity, I saw northern lights all the time here in Upstate New York. I am really looking forward to seeing them again.

What’s in a face?

Lots, it turns out. Our hormonal levels influence facial shape, for starters. And when we eyeball members of the opposite sex, we interpret their face shapes as indicators of attractiveness. Women whose faces indicate higher levels of estrogen are rated, by men, as better-looking.

It goes the other way as well. This story in The Economist looks at research into how women react to the shape of men’s faces — high testosterone-y, “rugged” faces vs. lower testosterone, softer features.

And then there is our response when we’re around someone attractive. Some researchers speculate that humans evolved the ability to see color because doing so helped us detect each others’ blushes.

What fascinates me most about all this is how it unconscious it is. We walk around with our big brains, interpreting everything abstractly. Meanwhile so many of our choices are influenced, if not governed by chemical signals, tiny variations in the size of facial features, tiny changes in skin color or pupil size.

We live double lives, and we don’t even know it.

Yeah, but when was the first blond joke?

This Sunday Times article doesn’t say. But it does give an overview of a theory proposed by Canadian anthropologist Peter Frost about the provenance of blond hair itself. He figures women outnumbered men in northern Europe at the end of the Ice Age. Lighter hair helped women stand out in a crowded field. Get dates and stuff. And they didn’t have Clairol back then, apparently.

Extinctions of Yore

Well, the Permian extinction of yore. If you can’t recall it, that’s perhaps because it happened 250 million years ago, and you’re not a geologist, or both.

There’s a book on it out, now: Extinction, by Douglas H. Erwin, a Smithsonian paleobiologist. It’s been reviewed here in a Washington Post piece by Joshua Foer.

Spooky quantum stuff

A quantum computer that can calculate . . . while it’s not running.

“It is very bizarre that you know your computer has not run but you also know what the answer is,” says [University of Illinois at Urbana-Champaign research] team member Onur Hosten.

“Very bizarre.” Master of the understatement, Onur.

This scheme could have an advantage over straightforward quantum computing. “A non-running computer produces fewer errors,” says Hosten.

Let me guess: Microsoft operating system!

:-D