A new cognitive psychology article nearly every day
Cognitive Daily reports nearly every day on fascinating peer-reviewed developments in cognition from the most respected scientists in the field.
Greta Munger is Associate Professor of Psychology at Davidson College whose works include The History of Psychology: Fundamental Questions. Dave Munger is a writer whose works include Researching Online and The Pocket Reader. And yes, he is married to Greta.
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May 18, 2006
Category: Face perception • Research • Social
Take a look at this photo:
What emotion would you say I'm expressing here? Let's make this one a poll (make sure you answer before you read any farther):
Posted by Dave Munger at 12:46 PM • Comments (37)
April 11, 2006
Category: Attention • Face perception • Learning and testing • Research • Social
Yesterday's post brings up an interesting question: How can you be unaware of having even seen an image, and yet be able to make reliable judgments about that image? That article is just one example of a variety of situations in which people can be unaware of seeing something, even immediately after being given a quick glimpse of it, yet behave as if they have seen it.
We discussed how visual images can be "masked" -- flashed quickly and then followed by another image which is displayed for a longer period. Though observers had no conscious recollection of seeing faces, they still could make accurate judgments about the attractiveness of the faces they had seen. Earlier experiments have found that the ability of the skin to conduct electricity as well as responses in the amygdala region of the brain can be affected by these masked images, again, with no conscious knowledge on the part of the viewer of having seen the image.
So how can our skin and brain respond to the image without our being conscious of seeing it? A team led by J.S. Morris developed a procedure to find out. Since the amygdala is activated during a fear response, they first conditioned volunteers to be afraid of a black and white photo of man with an angry facial expression. They used photos of four different men, two angry, and two neutral. These photos flashed randomly on the screen at intervals of around 20 seconds. When one (and only one) of the angry photos was displayed, a 1-second burst of white noise was played at a level of 100 decibels (loud enough to make you jump, but not to hurt your ears). Each face was shown six times.
Posted by Dave Munger at 04:18 PM • Comments (8)
April 10, 2006
Category: Face perception • Research • Social
How long does it take to decide if someone's attractive? It might be before you even know you looked.
Researchers can use a masking technique to show an image of a human face subliminally -- without the observer being aware of seeing it. To do it, they first show a scrambled face (39 milliseconds). Next, the face itself (13 milliseconds), a blank screen (13 milliseconds), and a cartoon face (39 milliseconds). I've tried to duplicate the technique using an animated GIF file, but I think it's beyond the capability of an ordinary web browser.
Did you see a human face? I had no trouble recognizing my son Jim in the animation, but you might be less aware of the image.
But Ingrid Olson and Christy Marsheutz were able to effectively mask images in the laboratory to try to measure how quickly humans can judge attractiveness. How did they do it?
Posted by Dave Munger at 02:42 PM • Comments (10)
April 06, 2006
Category: Attention • Face perception • Research • Social
Standup comics have long made vice president Dick Cheney the butt of their jokes, suggesting that he's never seen in public with the President because he inhabits some fortified underground bunker so as to avoid terrorists or some other unidentified threat, or that he's actually a cyborg, secretly controlling the government from his dark, hidden lair. But recent research in visual attention suggests that there might be another reason Cheney wouldn't want to be seen near the President. It may be that by standing next to a more famous person, your own appeal is diminished.
I'm actually only half-joking about this. Several studies, including one we've analyzed on Cognitive Daily, have taken a look at the relationship between attention and emotion: we respond quicker to emotional faces than neutral faces. Fewer studies have been conducted on the reverse phenomenon: when we search for an object, how do we react to it emotionally?
Take a look at this grid of colorized black-and-white photos: A team led by Jane Raymond showed volunteers similar grids and asked them to search for yellow males.
Posted by Dave Munger at 03:55 PM • Comments (5)
April 03, 2006
Category: Attention • Face perception • Research • Social
Babies as young as three months old will follow the eyes of an adult to look at the same thing the adult is looking at. This behavior makes sense from an evolutionary perspective: if a predator or other danger looms, we can learn from the actions of others (though it's unclear exactly what a three-month old would do to escape a ravenous bear).
But if the gaze-following behavior is really a survival adaptation, wouldn't we be more likely to follow someone's gaze if they also had a fearful facial expression? After all, if someone's glancing to the side with a cheerful smile, we don't expect they're looking at a jaguar ready to pounce. There's some evidence to support this notion. Several researchers have found that in photos of crowds, people are quicker to spot angry faces than happy faces.
A team led by Andrew Mathews showed volunteers photos of faces looking either to the left of the right, and with fearful or happy expressions. Then a letter appeared to one side of the face. While participants were faster at identifying the letter when it was on the side the face was looking at, they weren't any faster when the face had a fearful expression. So does this mean people never pay attention to the facial expression when following someone's gaze?
Posted by Dave Munger at 02:54 PM • Comments (0)
January 25, 2006
Category: Face perception • Perception • Research • Social
Disney's purchase of Pixar makes it clear that computer-generated (CGI) animation appears to be the wave of the future in movies. But one difficulty with CGI animation is conveying realistic emotions. While film animators (whether they use computers or not) can use artistic license to achieve the desired effects, when "emotions" are generated exclusively by computer, it can be difficult to identify the key factors in conveying that emotion.
We've discussed avatars, for example, as one way that computers can automate human interaction. Artificial intelligence -- lifelike simulators of human responses -- will also need to mimick emotions convincingly in order to interact effectively with real people. Harold Hill, Nikolaus Troje, and Alan Johnston have investigated two aspects of how CGI animations can effectively express emotion.
Posted by Dave Munger at 03:08 PM • Comments (1) • TrackBacks (1)
July 22, 2005
Category: Face perception • Memory • Research • Social
I've created a quick animation of distorted pictures of my son Jim, together with some normal ones. Take a minute or so to watch the animation, then decide if the last picture you're shown looks "normal" to you. Click on the normal (but pre-eyeglasses and braces) photo of Jim below to begin:
I'll let you know whether or not the final picture was distorted in the comments.
A large body of research has found that we perceive faces that are closer to the average as more beautiful than distinctive faces. We've written about one such study here, but even more surprisingly other experiments have found that the pictures rated most beautiful are computer composites of several different faces, a true "average" face. But an average face in Bangkok is different from one in Nairobi, which is again different from the average face in Kansas City. There is no one "average" face—it depends on what faces you're averaging together. Perhaps we actually arrive at a conception of beauty simply by averaging together the faces we see around us—maybe we don't have an innate sense of beauty, but instead learn it from our environment.
That's what the animation of Jim's face above was supposed to do: change your idea of a "normal" face. I made the animation after reading a study by a team led by Gillian Rhodes and published in Psychological Science. I showed you distorted images, but they were distorted only in one direction—they made Jim's face more and more spherical. I could also have distorted them in the opposite direction, making the face more and more bowl-like, but I wanted to affect your concept of normal, so I only showed you different degrees of spherical faces.
In Rhodes et al.'s study, their method was a bit more complex. First they showed participants a set of faces distorted in both directions—spherical and bowl-like—and at different levels of distortion, ranging from 10 to 50 percent. Participants rated each image on a scale of 1 to 7 for both normality and attractiveness. Next, for five minutes they were shown a sequence of images much like the animation of Jim above—this set was only distorted in one direction for each participant. Finally, they were shown the whole range of images once again and asked to rate them. This time, the faces that had been distorted as much as 30 or 40 percent were rated as more attractive than any of the other faces. Here's the graph of normality ratings for a group who had seen the positive (spherical) distortion:
In just five minutes, the perception of attractiveness and normality was changed. Whether the distortion was positive or negative, researchers could easily manipulate participants' perceptions of beauty.
So where is this adaptation made? Is it done by the eyes themselves, or some early level of vision processing like where we process shapes and edges? Or is it a higher cognitive function, like how we distinguish different species of animal or read a book? Rhodes and her colleagues devised a new experiment to help isolate where it's taking place. In this experiment, they rotated faces by 45 degrees, so that you'd have to lean your head on its side to make them look right. They devised an even more dramatic distortion, where the eyes were moved apart or together and the nose appropriately narrowed or widened. For the pre-test, the faces were all rotated in one direction, but for the post-test, they were rotated the opposite direction. The results were the same.
Since rotating an image is a relatively high-level cognitive task, the team reasoned that perception of beauty and normality must be an even higher task, something that takes place after images have been rotated.
What's the use of having our conception of beauty so easily manipulated? Rhodes et al. argue that it's essential for this trait to be easily changed based on circumstances. After all, if we find ourselves among members of a different race, we may still need to decide who will make the best mate. Typically, those closed to the average will be the healthiest members of a group. This research might also explain how styles can change so rapidly. I wince when I see 1980s pictures of myself wearing thin pink ties and white jackets with the collars up. But clearly back then, I wasn't seen by others as particularly abnormal or unattractive—if I had been, I wouldn't have a wife and two kids to show for myself today.
Rhodes, G., Jeffery, L., Watson, T. L., Clifford, C., & Nakayama, K. (2003). Fitting the Mind to the World: Face Adaptation and Attractiveness Aftereffects. Psychological Science, 14(6), 558-566.
Posted by Dave Munger at 08:07 AM • Comments (12)
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