attention

In a wonderful post at Mind Hacks, Vaughn, writing on "The myth of the concentration oasis" makes an argument that rather challenges my resistance to it: The 'modern technology is hurting our brain' argument is widespread but it seems so short-sighted. It's based on the idea that before digital communication technology came along, people spent their time focusing on single tasks for hours on end and were rarely distracted. The trouble is, it's plainly rubbish, and you just have to spend time with some low tech communities to see this is the case. He's been doing just that -- spending time in…
How do you decide how dangerous a sex-offender is? Certainly all cases of sexual assault are appalling, but clearly some incidents are worse than others. In some places, teenagers who photograph themselves naked and send the pictures to their friends can be prosecuted as purveyors of child-pornography. While we may want to intervene in these cases, surely the action shouldn't be as drastic as when we're dealing with an adult who's a serial child rapist. There are miles of gray area between these two extremes, and psychologists are often called on to make the tough judgment of how dangerous a…
One of stand-up comic George Carlin's most famous routines was the seven words you can't say on TV (obviously, not safe for work). He repeated the words over and over, and it was hilarious -- especially back in the days before most people had cable. These days we've become desensitized to those words, and it's hardly surprising any more to see them laced into casual conversation. Or is it? One test of our ability to ignore words is rapid serial visual presentation, or RSVP. In RSVP, you're shown a rapid sequence of words or images -- one about every tenth of a second. Your job is to pick out…
Some of the things psychologists ask their research subjects to do are really rather annoying. I'm not talking about Milgram-esque studies where people confront their inner demons, I'm talking about much more pedestrian stuff. This movie, for example, gives you a small taste of the Sustained Attention to Response Test (SART). A series of numbers will flash by, about 1 per second. While you watch, tap your finger on your desk for each number except the number 4. Give it a whirl: In some ways, it's a completely mindless task, but you have to keep paying attention or you'll end up tapping when…
Take a look at this graph showing population distribution by county in a fictional U.S. state: How do you read such a graph? Is this the ideal way to depict this sort of information? If you wanted to know which part of the state was most populous, how would you go about figuring it out? Researchers have developed conflicting models to explain how it's done. One model suggests that people reading this kind of graph must cycle between the different parts in order to understand it. This makes some sense: to answer our question about population, you'd have to look back and forth between the…
Every year about this time, we start thinking about an exciting television event: the Super Bowl. I'm excited because it's the biggest football game of the year. The rest of the family just likes to watch the commercials. No doubt, some of those commercials are hilarious, and there's often more conversation about the commercials than the game itself. Companies spend millions buying advertising time, and millions more developing commercials that will stand out from the pack on Super Bowl Sunday. Other than watching your favorite team lose, there's nothing more disappointing than seeing an old…
Yesterday's post showed that our memory for objects depends on the background information available when we first see the object: If you see a toy in a room, you remember it better later if you see it again in the room. Being in the same position in a blank picture of the room doesn't help. So what about the scene is helping us remember the object? It could be things in the immediate area of the object: are we remembering the precise object/background relationship? In our example, maybe we're remembering exactly how the propeller and the gear interact with the background: In 2003,…
Change blindness is a truly remarkable phenomenon. There are so many ways that the human perceptual system can be tricked into missing a change that appears right before our eyes, that it's sometimes astonishing that we aren't constantly running into walls or misplacing the basics of life -- our car keys, wallet, our what were were planning on eating for dinner. If you've never seen a demonstration of change-blindness, I'd suggest checking out some of the posts we've written about it before (For example, here, here, and here). So why don't we notice these sorts of changes? This video, based…
We can quickly spot a face staring at us in a crowd. We can do this much quicker, for example, than we can determine that no one is staring at us, as this movie demonstrates. A grid of 100 pictures of Greta will be flashed for about 1/3 of a second. Can you spot the photos where she's looking at you? You'll see two different grids. Most people are able to detect the staring faces much faster than those looking to the side. But we can also sometimes be fooled by faces, something we discussed on one of the first-ever CogDaily posts: In this picture, the eyes for each face are exactly the…
Remember this video? A few weeks ago we used it to demonstrate that facial expressions can disrupt the perceptual system in fundamental ways. Actually, because we could only show a few short clips, we weren't able to duplicate the research results found by John Eastwood, Daniel Smilek, and Philip Merikle. But in their, more comprehensive study, although viewers were instructed only to count "upturned arcs" or "downturned arcs," when those arcs formed "faces" with negative expressions, people counted the arcs slower and less accurately. But how exactly do facial expressions disrupt the…
Take a look at this quick movie. You'll be shown a "ready" screen, followed by a quick flash of eight letters arranged in a circle. Your job is to spot either a "Z" or a "K" in that circle of letters, while ignoring other letters appearing outside of the circle. You'll see two different circles of letters in the movie. Each circle will either contain a Z or a K. Again, ignore the letters appearing outside of the circle. Go ahead, give it a shot. Just watch the video once! What order did you see the Z and the K in? Let's make this a poll. What letters did you see? ( surveys) I don't…
Take a look at these pictures. Each picture depicts four shapes -- irregular vertical columns spanning the height of the picture. It's easy to tell which letter is on a column and which is not, right? If our readers are typical, over 90 percent would agree that a is on a column and b is not. But why? The space defined by the irregular vertical lines is equal in both cases. The only difference between the two figures is which direction the "pointy" curves face and which direction the convex, "smooth" curves face. Yet nearly everyone agrees that areas defined by the convex curves (like those…
[Originally posted in May, 2007] "I just didn't see him" is a claim that's repeated over and over in accident reports. Drivers earnestly claim that they simply didn't notice the bicycle/pedestrian/motorcycle they crashed into. The claim is made so frequently that certainly there must be a grain of truth to it. Yet it certainly isn't the case that car drivers can't see such obstacles -- after all, they can see traffic signals that are much smaller than a bike or a motorcycle. What they mean to say is that their attention was otherwise engaged -- perhaps by a phone conversation, perhaps by…
When we're in a crowded space, making visual judgments becomes more difficult. But it doesn't take much to trigger a crowding effect. Clicking on the picture below will take you to a quick movie (QuickTime required) that should demonstrate the effect. Focus on the cross to the left, then start the movie (it may start automatically, depending on your browser). In two seconds, a "T" will flash briefly on the right side of the screen. Your job is to determine whether the T is upright or inverted (upside-down). After another two seconds, three Ts will appear. This time, you must judge only the…
Do you multitask? I'm not talking about literally doing two things at once, like emailing while talking on the phone, or playing the trombone while washing the dishes. I'm talking about the more common phenomenon of starting one project before you're finished with another. For example, after I read the journal article I'll be discussing in this post, I caught up on some email correspondence, ordered a new phone for my office, and ate lunch. Now I'm finally getting around to actually writing the post itself. Why didn't I just read the article and then write my post while it was fresh in my…
Take a look at the short movie I've linked below (Click on the picture to play. QuickTime required). The movie shows a virtual gripping device (two red balls) lifting rectangular objects and placing them on a conveyor belt. Do you notice anything unusual happening as the objects are being moved? This is a recording of the image seen by a volunteer using a virtual-reality headset and two force-feedback devices to simulate moving objects by picking them up with a thumb and index finger. The force-feedback devices offer resistance so that the volunteer feels as if he is lifting real objects…
Imagine yourself walking on a treadmill that starts at a reasonable pace: say, two and a half miles per hour. Every two minutes, the treadmill increases its speed by 0.2 mph: 2.7 mph, 2.9 mph, 3.1 mph, and so on. If you're in good physical condition, at some point -- usually between about 3.0 and 4.5 mph -- you'll find it more comfortable to start running instead of walking. Different individuals have different thresholds based on their fitness level and other factors, but even taking these things into account, it's difficult to explain exactly why people start running when they do. Do…
[This article was originally published in January of 2007] Many 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…
It shouldn't take you long to notice what's wrong with this picture: Obviously Nora is defying gravity in this shot -- you can't help but notice it. But in your first glance at the photo, how quickly do you notice what's wrong? Do you spot the oddity faster than you'd notice Nora in the original, unaltered picture? A 1978 study by Geoffrey Loftus and Norman Mackworth found that people respond quicker to unusual or inappropriate objects in line drawings, such as an octopus instead of a tractor in a farm scene. They moved their eyes an average of 7 degrees to fixate on the unusual objects.…
Take a look at this short video clip (QuickTime required). It's called an RSVP (rapid serial visual presentation), meaning that it's a quick sequence of still images. In this case, it's a random sequence of letters. Your job is to look for a number among the letters. At some point during the clip, you should also see a dot flash in one corner of the video. You also need to take note of the corner in which the dot appears. A rectangle will flash shortly before the dot, possibly giving a clue to where the dot will appear: It's actually not a very difficult task (especially when I tell you that…