Movement and exercise
dmunger | February 13, 2008Which of these two pictures is more memorable?
The shot on the left is interesting primarily because Nora's in it -- if it was just a picture of a muddy trail, it wouldn't be notable at all to most people. The shot on the right is a dramatic mountain scene that you might remember even though (or perhaps because) there's not a human in sight.
But a seasoned hiker might be more interested in the photo of the muddy trail, which gives more information about the difficulty of the hike than a panoramic shot. Just as expert chess players are good at remembering the position of chess pieces on the…
dmunger | January 14, 2008I was a little surprised by an offhand observation Thomas Schubert made in a recent research report. He claimed that while men will commonly make a fist to celebrate a goal in a soccer match or a home run in baseball, it's unusual for women to do so.
I'm sure I've seen both female athletes and fans celebrating with fist pumps. But maybe I only noticed these cases because they were exceptions. Let's see if we can verify Schubert's observation with a little poll.
Take the pollFree Poll by Blog Flux
But there are additional gender dynamics to making fists besides who celebrates that way at a…
dmunger | January 2, 2008You might think humans are equally good at estimating distances no matter which direction they're looking. After all, we use the same visual tools to make those estimates -- binocular disparity (the different views we see from each eye), occlusion (whether one object is in front of or behind another), and so on. But consider the situation depicted to the right. Nora is inching her way down a steep rock column, with near-vertical drops on either side of her. If she underestimates the distance to flat ground below, she might decide she doesn't need to worry about falling. Overestimating the…
dmunger | December 6, 2007When we are trying to understand what someone is saying, we rely a lot on the movement of their face. We pay attention to how their faces move, and that informs our understanding of what is said. The classic example of this is the McGurk effect, where the same sound accompanied by different facial movements gets interpreted differently.
Take a look at this short video clip (QuickTime required) of me talking, with my voice muffled by what sounds like cocktail party conversation:
Can you understand what I'm saying? What about after I stop moving? Can you understand me in the second part of…
dmunger | August 28, 2007
We can recognize the faces of our friends very quickly from just a snapshot. Within 150 milliseconds of being flashed a photo, brain signals respond differently to photos containing animals than photos with no animals. We can categorize scenes as "beach," "forest," or "city" when they are flashed for even shorter periods.
But we also get a great deal of information from the motion of people and animals. We can identify our friends and family members just from a point-light display of them walking. We can also detect the emotions of point-light faces, and even the species of point-light…
dmunger | July 31, 2007Take a look at this movie (QuickTime Required):
The moving object is exactly the same in each picture, but the background is different. If you're like most people, you'll see one object as an ice skater, and the other as a spinning top.
This puts the objects in two different classes -- animate (something that can move by itself: a human, animal, robot, and so on) and inanimate (something that requires an external force to move). Do we perceive the two objects differently?
Arguably, it's important that we do: if an object can move by itself, it's much more likely to be a threat to us than if…
cogdaily | June 18, 2007This is a guest post by David Kerns, one of Greta's top student writers for Spring 2007.
As movie special effects technology improves, more and more live-action shots are being replaced with computer animation. Harry Potter flies across the Quidditch field; Spider-Man swings from web to web through the cityscape of New York City, and miniaturized Hobbits fight the overpowering Orcs of Middle-earth. All of these are examples of human movements that have been reconstructed with computer animation. But sometimes this type of animation fails to come across as real. When Harry falls from his…
dmunger | May 15, 2007When Greta earned her Ph.D. 13 years ago, Jim was two and a half years old, and Nora was just 10 months old. Jim knew a few words, and Nora couldn't talk at all. You might think a baby as young as Nora wouldn't have an appreciation for music or dance. If you can't walk, what good is dancing?
But babies -- and Nora was no exception -- love to be bounced. Bouncing her on your knee would elicit peals of laughter. Is this love of rhythmic bouncing somehow related to an appreciation of music?
Jessica Phillips-Silver and Laurel Trainor developed an ingenious study to see if babies even younger than…
dmunger | May 1, 2007Kevin Granata, one of the authors of the work described here, was killed in in the shootings at Virginia Tech on April 16, 2007.
A back injury can destroy a person's life. The pain can be so excruciating that even "passive" activities like sitting up to read a book become intolerable. Whether you work in a steel mill or sit at a desk, a back injury can make it impossible for you to earn a living. Even worse, for many of those who suffer with chronic back injury, is that because it's difficult for others to see what's wrong, there's a tendency to not believe the problem is "real."
Yet there…
dmunger | April 26, 2007There is a considerable body of research showing that eye contact is a key component of social interaction. Not only are people more aroused when they are looked at directly, but if you consistently look at the person you speak to, you will have much more social influence over that person than you would if you averted your gaze.
The problem arises when you address a group of people. How do you pick who to engage visually? Most public speakers are encouraged to look around the room, alternating eye contact with individuals in the audience. But there's no way to look at everyone at once -- so…
dmunger | March 27, 2007When we see a familiar face, or even a photo of a favorite car or pet, we're often flooded with memories from our past. Sometimes just seeing a person or object that's similar to the ones in our memory will trigger recollections we never knew we had. Maybe you've had a memory triggered by a scent or the texture of an object. Sometimes emotions such as happiness or anger will spur vivid memories, too.
A new study adds an unexpected method to the list of ways to spur memories about our past: body position. That's right: just holding your body in the right position means you'll have faster, more…
dmunger | January 24, 2007Many many studies have repeatedly shown the dangers of driving while using a cell phone. Yesterday, while discussing a new law in Britain imposing heavy penalties not only for driving using a handheld phone, but also while using phones with hands-free kits, commenter Jan claimed that talking to a passenger was less dangerous than talking on a phone. I replied that I hadn't seen a study demonstrating that talking with passengers was any different from talking on a phone, and Jan provided a link to one such study.
Greta and I have both read over the study, and while we can't say from these…
dmunger | January 17, 2007Here in North Carolina, for many sports fans, it's considered common knowledge that basketball referees don't call fouls against Duke. The reasons for the supposed bias vary from racism, to payoffs from wealthy alums, to the intimidating atmosphere at Duke's legendary Cameron Indoor Stadium, but nearly everyone in the state who's not a Duke fan seems to believe that the rich northerners at Duke University get all sorts of unfair advantages.
That said, accusations of bias in sports officials aren't limited to the Atlantic Coast Conference. Studies on home field advantage in Major League…
dmunger | January 4, 2007This year's collegiate national football championship will be held in Phoenix, Arizona, at the usual home of the Arizona Cardinals. Neither competitor, Florida or Ohio State, is playing on its home field, so in principle the game should be an even match. Indeed, neither team has lost a home game this year, with Florida's lone loss coming at an away game in Auburn.
How big is the home field advantage? In the English Premier Football League (the other football), the home team wins 66 percent of the time. The home field advantage has been attributed to everything from understanding the local…
dmunger | August 15, 2006When Jim and Nora talk about the social groups in their school, they matter-of-factly categorize almost every fellow student into stereotyped pigeonholes. There are the nerds, the rockers, the cools, the goths, and of course, the jocks.
The assumption, naturally, is that none of these groups intersect. Jocks are dumb, nerds are smart, and cools could be smart if they cared about grades. But what of this "dumb jock" stereotype? Does it actually pan out in real life?
Herbert Marsh and Sabina Kleitman have conducted an exhaustive study of the records of over 12,000 American students, following…
dmunger | August 11, 2006What in the world is this thing?
It's called an optokinetic drum, and it's one of the many implements of torture you'll find in a spatial orientation lab. In an optokinetic drum, you sit or stand inside while the entire drum rotates around you. By changing the pattern on the inside of the drum, or by changing the way the drum rotates, a researcher can easily make you lose your lunch, breakfast, or even last night's dinner.
I got the picture of the drum from the Ashton Graybill Spatial Orientation Lab, where you'll find plenty of other devices that I sincerely hope the U.S. military doesn't…
dmunger | August 8, 2006Take a look at this short video clip. Can you tell which dot is blue and which is yellow?
Click here to play
Unless you have a rare vision impairment, this task should be easy for you. But read on, and we'll show you how you can become blind to this difference in as little as 40 minutes.
The human visual system is amazingly adaptive to eye movements. Consider this: if you film a video from a moving car, the resulting image is so jiggly that it's unwatchable. But if you're riding in the car, even on a bumpy road, the outside world appears stable and smooth.
Or take a camcorder and move it…
dmunger | July 5, 2006"Keep your eye on the ball" is a mantra I've heard applied to several sports: baseball, for hitting, football, for receiving, and golf, for teeing it up. It wasn't surprising to me when I read recently that cricketers also use this platitude to teach batsmen how to hit effectively.
The sum total of my experience with cricket is watching multi-ethic games in Van Cortland Park through our Bronx apartment window while Greta and I were finishing graduate school about 12 years ago. I didn't pick up on many of the rules, but I was stunned to see that cricketers, unlike baseball players, actually…
dmunger | June 12, 2006Experiments on change blindness have revealed striking limitations in visual memory. Take a look at the video below, for example (click to play -- and note that the video is contained in a java applet that may take a while to load -- but it's worth it!).
The woman is giving directions to one "construction worker," when two other "workers" carry a door in between them. A new worker (all of them are actually actors hired by the experimenters) is substituted during the hubbub, and the woman continues giving directions as if no change has occurred. This work has been duplicated in a variety of…
dmunger | June 5, 2006I've been an avid skier for over 25 years -- but I didn't start using goggles until very recently. Under the overcast Washington State skies, they didn't seem to be necessary. But now that I live in North Carolina, skiing is usually done under sunny skies on artificial snow; goggles are a must. As a person who also wears glasses, however, the experience can be frustrating -- any time I stop for more than a few seconds, my goggles, glasses, or both will usually fog up -- the goggles rely on airflow to keep from getting foggy. In this situation, I'm left with two choices: proceed with impaired…