Perception
dmunger | September 27, 2005All this talk about stereotypes can get you thinking. Perhaps some stereotypes reflect actual differences. Take color vision, for example: men often refer to themselves as "color-impaired," letting the women in their lives make home design decisions and even asking them to match clothing for them. Maybe they're just behaving in accordance with traditional stereotypes ... but maybe there's something more to it.
In the 1980s, vision researchers began to find some real physical differences between the eyes of many women and those of most men. "Normal" color vision is possible because we have…
dmunger | September 22, 2005There is considerable evidence that using a cell phone impairs driving ability. The research has even reached the popular consciousness: hosts of radio call-in shows ask cell-phone callers to pull over before making their comments; drivers give wide berths to people who are obviously talking while they drive.
All this knowledge begs the question: If drivers are aware of the dangers of cell phone use, can they compensate for their weaknesses and effectively negate any problems from driving with a phone? Mary Lesch and Peter Hancock had been part of a 2003 team that had found drivers reacted…
dmunger | September 21, 2005We know that "average" faces are judged to be more attractive than the faces of the individuals making up the average. But this doesn't tell us what the mechanism for judging attractiveness is. Do we judge faces to be attractive because they are potential mates, or is there some other reason for perceiving attractiveness?
Jamin Halberstadt and Gillian Rhodes came up with a novel way to try to answer that question: instead of faces, they asked participants to rate other things. If we rate average birds as more attractive than actual examples of birds, then this could suggest that we have a…
dmunger | September 13, 2005Click on the image below to be taken to a quicktime movie showing 9 different faces. When the movie is finished playing, drag the slider back and forth to pick the face you think is the most attractive.
The faces are composite images—"average" faces made by morphing together 48 different photos. Previous research has shown that people typically perceive average faces as more beautiful than unusual faces (and here we've written about how easy it is to change our conception of "average"). But what about people from different racial groups? Would a Caucasian perceive an "average" South Asian…
dmunger | September 9, 2005Taste is a notoriously difficult sense to study. My son Jim can't stand baked potatoes, but I can't get enough of them. I don't like watermelon, but the rest of my family gobbles it up. Even more perplexingly, I do like watermelon candy. With all the individual differences in taste, how can scientists learn anything specific about how the sense works?
The difficulties in taste study are compounded by the fact that taste is intimately associated with the sense of smell. Every kid knows to plug his nose when trying a food he or she doesn't like. Researchers must be constantly aware that…
dmunger | August 25, 2005The human brain is incredibly specialized. There are individual neurons for recognizing faces, edges of objects, and specific sounds. One fruitful area of research recently has been to determine precisely how specialized the brain really is. Here's one example. The image below links to an animated movie. Click on it and see how quickly you can determine which direction the rectangles are moving:
If you're like most adults, you're able to determine the correct direction very quickly.
Now, take a look at this animation and try it again:
This one should have taken somewhat longer, even…
dmunger | August 23, 2005Perceiving motion creates a fascinating problem for psychologists. Physicists for centuries have devised a whole set of rules describing how objects actually move. These rules are so precise and accurate that it's tempting to say that the human perceptual system simply integrates them into motion we see, so that our mental representation of what we see is identical to what's actually going on in the world.
Some research, such as this article we reported on last month, supports that notion. Since we expect objects to keep on moving (the physical principle of momentum), then our representation…
dmunger | August 15, 2005One of Jean Piaget's most famous observations is the phenomenon of "object permanence"—the idea that babies younger than eight months old have no conception of an object once it's hidden from view. It's easy to see how he came to this conclusion. Click on the picture of my daughter Nora at six months of age to see a video of her spectacularly failing the object permanence test. Once the object is hidden under a napkin, she seems to lose all interest in it.
But does she really not understand that the object is still there, or is she simply interested in other things? A team of researchers…
dmunger | August 4, 2005Rummaging through your bag in search of keys, it's clear that you can recognize objects using just your fingers. But is it easier to recognize the keys if you feel them as if you were going to open to door, or if you encounter the key's teeth in some odd orientation--like pointed straight up? Consider the following pictures. Which object looks more familiar?
Indeed, it is easier to recognize objects visually when you see them in familiar orientations. Could this orientation effect extend to objects we touch? Fiona Newell and her colleagues used little LEGO towers to ask this question,…
dmunger | July 28, 2005Imagine sitting in a coffee shop, having a nice conversation with your friend Dave. If Dave looks at something, your eyes will reflexively move to look at the same item. This is actually quite convenient, because it may help you figure out what Dave is talking about, or what he might comment on next. How much of this joint attention reflex depends on Dave's face? You'll do this even if he only moves his eyes, without turning his head, so it might be that what you're reacting to isn't so much his face, but the movement of his pupils.
What we know about certain brain mechanisms makes this…
dmunger | July 19, 2005We've posted on boundary extension before, here, here, and here, but we've never written about boundary extension and kids. Boundary extension is when we remember more of a picture than was actually shown to us, as if our mind is actively creating a portion of the image we didn't see, beyond its boundaries. A 2002 team led by John Seamon found that people of all ages experience boundary extension.
Some research has found evidence that boundary extension doesn't work for all images. We reported on a study by Andrew Mathews and Bundy Mackintosh suggesting that for emotional, arousing images,…
dmunger | July 18, 2005Baby rats, only 5 days old and still very much reliant on their mothers for food, can be artificially dehydrated by injecting them with a saline hypertonic solution. If a source of water is placed very close to the rat's snout, it will drink. But 21-day-old rats who have just been weaned from their mothers and who readily eat and drink on their own can be injected with the same saline hypertonic and won't drink any more than non-dehydrated rats the same age. The difference is that the older rats still have to decide to drink—the water is available in their cages, but they still must actively…
dmunger | July 13, 2005Take a look at this picture I took last year when we went to Venice. Look at it fairly closely, because there will be a "test" at the end of this post.
We have posted on boundary extension before: it's a simple phenomenon where our memory for a picture is consistently different from the actual picture we saw before. We remember a larger frame, or boundary for the picture, than was actually present. This effect can be measured in many different ways—for example, by asking people to sketch the picture they saw, or draw the frame on a larger picture, or, as was done in today's experiment, by…
dmunger | July 11, 2005There's something about kids and dogs. The phrase "A boy and his dog" brings up quite a range of images: from the sweetness of Norman Rockwell to what sounds like a truly bizarre movie from 1975. Despite not being a dog-person myself (okay, not being a pet-person at all), I find the results from a study that looked at kids and dogs amazing. Marina Pavlova and her colleagues at the University of Tüebingen were curious about how well kids would understand point-light displays. Imagine placing little lights on the major joints of someone's body (hips, elbows, etc) and then watching them move…
dmunger | July 8, 2005Are attractiveness and distinctiveness related? Are we more likely to remember a pretty face than an ordinary one? This data suggests not:
When people are asked to rate faces for attractiveness and deviation from an average face, there's a clear correlation: the more attractive the face, the less it deviates from average. Average faces are more beautiful, it seems. But now consider this data:
Here, people were asked to rate faces on the same scale of attractiveness, but instead of rating whether a face deviated from the average, they were asked whether a face would stand out in a crowd.…
dmunger | July 1, 2005Take a look at the following two movies. Your job is to determine whether the yellow square is moving faster in the first movie or the second movie.
If you're like me, you're probably cynical enough to guess that they were moving at the same speed. But if you're honest and you just go with your initial impression of what you're seeing, it's hard not to perceive the second movie as much slower than the first one. What you're witnessing is Michotte's launching effect paradigm, first observed in 1946 by Albert Michotte: when two objects collide, we ascribe the motion of the second object to…
dmunger | June 17, 2005There's been a great deal of research on appetite and satiation, both on animals and humans. For humans, of course, the motivation is often focused on how we can lose weight. Almost everyone believes they would look better if they could just lose a few pounds. Most of the research has focused on the taste of food and the physical sensation of fullness, and the results—as you might have suspected—have been inconclusive.
There is some evidence that if you leave the remnants of a meal around (used candy wrappers, for example), then people will eat less than if the evidence of the food is…
dmunger | June 13, 2005Adults have been found cross-culturally to prefer blue to other colors. It's a nearly universal preference. But does this preference occur naturally, or do children and infants have different preferences? Prior to 2001, there wasn't a definitive answer to this question. In that year, Marcel Zentner of the University of Geneva conducted a study that not only answered that question, but also sought to explore the relationship between color and emotion ("Preferences for colours and Colour-Emotion Combinations in Early Childhood," Developmental Science, 2001).
Zentner's study showed 3- and 4-year…
dmunger | June 10, 2005When I was about twelve years old, I came up with an idea for a massive practical joke to play on an unsuspecting baby. For its entire childhood, everyone around the baby would conspire to convince it that the sky was green. Then at some point in the future, perhaps in front of the entire sixth grade class at Whitworth Elementary School, the truth would be revealed, and one poor kid's world would be turned upside-down.
Somehow I was never able to recruit enough people to pull this ruse off, but it does beg the question: would such a joke even be possible, or would our natural perceptual…
dmunger | May 26, 2005Heinz's green ketchup nothwithstanding, we generally like our foods to be predictable colors: milk, white; bananas, yellow; oranges—well, you get the idea. But when foods are the "right" color, do they actually taste any different? We all know that food coloring is tasteless, so what happens when we dye foods different colors?
The results so far have been difficult to pin down. A study in 1960 found that green pear nectar tasted less sweet than colorless pear nectar. A study in 1962 found no such result. A 1982 study revealed red dye made strawberry juice sweeter; a 1989 study found it did…