Cognitive Daily

Maps, directions, and video games: A model for how we perceive them

Thu, 18 Jun 2009 12:31:10 -0500

[Originally posted January, 2007]

Nearly all video games that offer a first-person perspective -- where the view on-screen simulates what a real person would see as she navigates through the virtual environment -- also include a virtual map to help in navigation. Even my favorite golf game has one. Such maps can be indispensable, but they also invite a question -- should the map rotate to align with the player's viewing angle, or should they remain at a constant orientation?

Aligning the map with the viewer's perspective makes it easier to find items, but constantly rotating the map might make it difficult for gamers to remember where those items are located when they move out of view -- when the object is needed, the map might be upside-down compared to when the object was first encountered.

Of course, maps aren't just useful for games -- more and more cars are equipped with GPS navigation systems, and hikers like myself like to use the old-fashioned paper type to help find campsites in the wilderness. Creating maps that are easy to compare to the first-person viewpoint, whether in a video game or an Air Force jet, can mean the difference between life and death.

Research on map orientation has found that mapreaders take locate items they see in a scene on the corresponding map at different rates. As you might expect, the more the map is rotated compared to the viewing angle of the scene, the longer an object takes to find, with upside-down maps taking the longest. But there is a secondary effect, which depends on the location of the object in the scene. Items directly in front of the viewer are located fastest, regardless of the orientation of the map. As the items move to the right/left and farther away, they take longer to find. But items that are farthest away, near the back of the scene, are found nearly as quickly as items directly in front of the viewer.

Take a look at this simple scene, made using the customizable video game Unreal Tournament:

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Self-refilling bowls: An idea whose time should never come

Wed, 17 Jun 2009 10:48:51 -0500

[Originally posted in April 2007]

One "trick" dieters often use is to put their food on a smaller plate. The idea is to fool yourself into thinking you're eating more food than you really are. But doesn't our stomach tell us how full we are?

Actually, it doesn't. Brian Wansink has devoted his career to studying how perception of food intake relates to actual eating behavior. Together with James Painter and Jill North, he's come up with a dramatic demonstration of how wrong our stomachs can be.

Volunteers were recruited to participate in a soup-only lunch in a room adjoining the school cafeteria. They filled out a form asking about color preferences, then were seated a table with four different-colored bowls. The colors were just a distraction: the real purpose of the study was to see how much people would eat when their soup bowls refilled automatically.

Two of the participants ate from self-refilling bowls; the other two had their bowls refilled by a server. Everyone was encouraged to eat as much as they wanted. The self-refilling bowls involved a fair bit of cooking technology -- plastic tubes connected a soup pot next to the table to the underside of each bowl. The refill rate of the bowls was adjusted so that the bowls could be filled completely in 20 minutes -- the duration of the study. Technically the bowls could be nearly empty by the end of the session, but each bowl held 18 ounces of soup, so this would have required consuming over a quart of soup!

Despite the fact that everyone's bowls were refilled, the people eating from self-refilling bowls ate 73 percent more soup. Even more surprising is that they didn't feel any different from people who ate from manually-refilled bowls:

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Test your boundaries -- then find out how you made them

Mon, 15 Jun 2009 10:21:04 -0500

[Originally posted in February, 2007]

When you look out the window and then look away, how do you remember what you saw? Do you hold a picture of the window in your head, frame and all? What about a photo? Do you remember the physical photo, or do you imagine the real scene it represents? If you remember the scene, and not the photo, then how do you form the boundaries of the scene? Does your memory end precisely where the photo does?

Here's a little test to see how accurate your short-term memory of a photo is. When you play the movie below, you'll have a second to get ready, then a photo will flash for just a half-second. It will be replaced by a random pattern for two seconds, and then the photo will reappear. It might be the same as the original, or it might have been cropped or enlarged slightly. Your job is to say if the area depicted in the second photo is the same, larger, or smaller than the original.

Click to play movie (QuickTime Required)

What do you think? Let's collect the answers in a poll (don't repeat the movie until you've responded):

Even playing the movie repeatedly it might be difficult to tell, so I'll display both photos side-by-side at the end of the post. What we're exploring here is a phenomenon that's been investigated for several years by Helene Intraub and her colleagues:

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Musical SNARC: Do we have a musical scale in our heads?

Thu, 11 Jun 2009 17:15:44 -0500

There's lots of research suggesting that we may have something like a "number line" in our head: The SNARC effect says that if you normally read numbers from left to right, you're faster to react to small numbers with your left hand, and big numbers with your right hand. Similar research has also found a SNARC effect for letters (a SLARC effect?).

So it might make sense that there would be a similar effect for musical notes. You might call it a SMARC effect, but if you only hear one note at a time it's not really "music." Undaunted, a team led by Pascale Lidji has conducted several experiments on what they call the SPARC effect (spatial pitch association of response codes). In many languages, "low" and "high" are used to describe both musical pitches and physical position. Low notes on a piano are played with the left hand, while high notes are played with the right.

Lidji's team's basic experiment is simple. Sixteen students listened to musical notes, and were told to press a button to the left if the note was played on a piano, and to the right if it was played on a violin (the button assignments were switched halfway through). They heard almost 200 notes, but they were selected from just four pitches: C3 (one octave below middle C on a piano), G3, E5, and B5. The students were all non-musicians, and their results were compared to the results for 16 musicians (some students, some professionals, all with over 8 years of musical training). Here are the results:

This graph shows the difference in right-hand versus left-hand reaction times -- so if the right hand was slower to react, you see positive number, and if the left hand was slower, the number is negative. For non-musicians, there is no SPARC effect: there was no systematic difference in reaction time based on musical pitch. But for musicians, the right hand was slower to react to low notes and faster to react to high notes: that's a bona-fide SPARC effect.

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Babies as young as six months prefer different toys based on sex

Wed, 10 Jun 2009 15:37:41 -0500

When Nora was born, Jim was just 19 months old, and still unable to communicate other than with the most basic words (ba-ba, da-da, na-na). But we could tell right away that while he liked his new sister, he was a little jealous when our attention was focused on her needs, instead of his, as they had been his entire life. So we decided to get him a little baby doll, a boy, which he called "Seth." When we fed Nora, Jim fed Seth. When we changed her diapers, he changed Seth, and so on.

This was an effective distraction for a few months, but eventually Jim decided it was too much work caring for Seth and went on to other distractions, like emptying all the kitchen cupboards or running around the apartment like a mad banshee. He kept Seth for many years, but when he was around ten years old he must have decided that it was embarrassing to own a doll because we found it hidden in the deepest recess of his closet.

Psychologists have wondered for decades whether boys preferred "boy toys" because of a natural inclination to like hard, mechanically-oriented things, or simply because those around them encouraged them to play with the toys they felt were appropriate for boys. Similarly, do girls "naturally" like to play with dolls, or are they encouraged to do so by their parents? While researchers have found that kids around 18 months and older do prefer the traditional gender-specific toys, research for younger kids (presumably less-influenced by their parents) is less clear-cut.

A 2000 study showed babies between 3 and 18 months old pictures of toys traditionally preferred by each gender and measured how long boys and girls looked at the pictures. The boys as young as 9 months old seemed to prefer toys like balls, blocks, and cars to dolls, dustpans, and ovens. However, even the 18-month-old girls showed no apparent preference for any type of toy based on how long they looked at them.

One problem with this sort of study is that it's not very precise: is the baby really focusing on a particular toy, or just pointing its head in that general direction?

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iCephalon 2009 Keynote address (AKA Encephalon 72)

Mon, 08 Jun 2009 15:31:56 -0500

Here at Encephalon's temporary North Carolina headquarters, we were miffed to learn that our long-scheduled Keynote address has been upstaged by some upstart computer company's manufactured "event" in California.

Not to be outdone, we're giving Encephalon an upgrade of our own. Encephalon is now iCephalon. And boy, do we have an exciting lineup of products for you!

First up, iPeople. Our Neurocritic division discusses the exciting discovery touted as the "people person brain area." Really? That almost sounds too good to be true! If you're skeptical, all we ask is that you follow the link. The Neurocritic division also offers an analysis of the new TV show iMental. Sure, it might offer typecast, stereotyped views of psychiatrists and their patients, but I hear the star has absolutely dreamy eyes.

Over at the SharpBrains division, be sure to check out iFitBib an amazing resource that will revolutionize the way you look at comprehensive bibliographic references about brain fitness.

If that sounds impressive to you, just wait till you see what's available at our BrainImplant division. This video explains the most exciting product since the invention of the wheel-shaped brick of cheese, known, of course, as the iPlant!!!! How do you get people to do pretty much anything you want? Just implant an electrode in their brain that makes the most humdrum activities feel as great as sexual intercourse. Dull physical exercise, hard labor, even filling out mindless tax forms can now be the most mind-blowing events of the day! Side effects include becoming government controlled zombies and a complete lack of interest in actual sexual intercourse, but if you're having this much fun, who cares? BrainImplant also had a couple other interesting announcements, which I'm sure you'll check out while you're waiting for your iPlant to arrive in the mail.

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Encephalon, miscellaneous site news

Fri, 05 Jun 2009 13:53:16 -0500

We'll be hosting Encephalon here at CogDaily on Monday -- it's a bimonthly festival of the best cognitive / neuroscience blog posts on the web. If you've got a post you'd like to see included, send an email to encephalon -- . -- host -- @ -- gmail -- . -- com (remove dashes).

In other site news, this week we're moving to our summer schedule, which means, due to our travel schedule, Casual Fridays are on hiatus until the fall. Also, you might see a few more repeat posts than usual. We'll try to stay on top of things, but in general, you should expect to see posts a little less frequently. Don't worry, things will ramp back up in the fall. Enjoy your summer (or winter, depending on where you live)!

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How we learn to judge the size of faraway objects

Thu, 04 Jun 2009 16:12:44 -0500

It's pretty obvious to most people that the two shoes in this picture are the same size:

But if you actually took a ruler to your computer display it would show that the image of my right shoe is nearly twice as wide as the image of my left shoe. Young children will mistakenly say that the real left shoe is smaller than the right shoe; it's only gradually that we learn to take the context of the photo into account and conclude that the shoes are the same size: the shoes appear to be a matched set; the left shoe is a bit out of focus, the railing to the left shows that the left shoe is farther away than the right shoe; we know more distant objects tend to appear smaller, and so we determine that they are the same size. Of course, it's also relatively easy to fool the perceptual system:

In an Ames room, the height of the walls, the pattern on the floor, and the size of the doors is varied so that our usual visual cues don't work. We're fooled into thinking the person on the left is a giant, while the person on the right seems tiny (in fact she's simply farther away than she appears).

If we can be so easily fooled, it might make you wonder: What, exactly, are we learning about the sizes of distant objects as we grow older? The prevailing notion for decades has been that we gradually learn cues to the size of objects and how far away they are. By the time they are ten, most kids are about as good at judging the size of distant objects as adults -- they are said to have achieved "size constancy." But recently Carl Granrud has begun to challenge that notion. Even in normal perceptual circumstances (in an open field, say, rather than an Ames room), adults make systematic errors, overestimating the size of distant objects. Granrud believes that the perceptual system simply doesn't give us enough information to accurately judge the size of distant objects, and so we develop a system of compensation. While young kids undercompensate, adults often overcompensate.

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Cognitive Monthly: June issue now available

Mon, 01 Jun 2009 13:43:07 -0500

The second edition of Cognitive Monthly is now available. "Duke Nukem Comes to Dinner: Do Violent Games Make Violent Kids?" synthesizes and expands on our coverage of the impact of violent video games.

Whenever kids are involved in a violent crime, speculation about their upbringing inevitably takes center stage. Were they abused or neglected? Is there something their parents could have done to prevent the tragedy? Most recently, video games have been targeted as the possible root of the problem. But are video games really to blame for horrific massacres like the shootings at Columbine and Virginia Tech?

This month's report considers the growing role video games play in our kids' lives -- and whether the playing violent games might really cause kids to be violent themselves. We assess the latest research on violent games and how it impacts kids. Researchers have found that playing some violent games does result at least temporarily in aggressive behavior, but games themselves are complex, and sorting out how they affect kids can be difficult.

Aggression and violence clearly aren't the only ways games affect kids, so we also discuss research demonstrating how gaming can be beneficial. Do the benefits of gaming outweigh the many potential harms? We also describe how we've managed video games in our family, and offer some guidelines on how parents can approach gaming in their own homes.

PDF / iPhone version (full-color) $2
Amazon Kindle version (black and white) $2
Length: 9,295 words, 33 pages

Cover photo: Casey Fleser

Cognitive Monthly is an in-depth mini e-book that you can download and read on your computer, iPod, iPhone, e-reader, or any device that can handle a PDF. Each month we cover a different cognitive psychology issue. Although based on posts that have appeared in Cognitive Daily, it goes beyond what's in the blog, synthesizing and incorporating interviews and other insights.

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Casual Fridays: What does an emoticon do?

Fri, 29 May 2009 16:16:21 -0500

Last week we asked readers to rate a set of statements they might see on Twitter. The premise of our study was that sometimes it's difficult to decide whether someone is insulting you or complimenting you. But we were actually examining a slightly different question: what effect does an emoticon have on a statement? Can you make a negative comment seem "nice" just by adding a smiley or a wink afterwards?

Everyone saw the same 13 statements, presented in random order:

That's the most incisive comment I've ever seen
You are just so *interesting*
Yawn
You're as brilliant as you are attractive
I agree
That is teh roxxors
A statement like that seems like it should be obvious. Why has no one figured that out before?
Some people just don't understand what a wonderful person you are
Oh, sure. People who share your political view are *always* right
Wow. Just wow. That is the most amazing thing I have ever seen
That's absolutely ridiculous. Only a complete idiot would agree with that statement
Thank God you and your big mouth only have 140 characters to express your dull platitudes
Please, tell me more

However, the emoticons each viewer saw were different. Three of the statements were followed by a smiley -- :-), three were followed by a wink -- ;-), three had an exclamation mark, and three had no extra punctuation at all. The last statement ("Please, tell me more") was followed by one of four less common emoticons: ;-P :-( :-/ :-0.

We had over 1,100 respondents, so over 250 people rated each statement with paired with each emoticon. Did the type of emoticon affect the perception of the intended meaning of the statement? Here are the results:

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Can we tell who's speaking based only on body movements? Depends on their emotion

Thu, 28 May 2009 16:34:42 -0500

Take a look at this video. Your job: decide which person speaks first:

Click to view Video 1 (QuickTime required)

Let's make this a poll:

Now, try another one. Once again, decide which person speaks first:

Click to view Video 2 (QuickTime required)

Make your response here:

David Rose and Tanya Clark showed videos like this to 17 student volunteers, and asked the same question: who spoke first in each video? The videos are point-light displays, which show movements of particular points on an actor's body, but not the nuances of facial movements and expressions.

The videos were used in an earlier experiment about identifying emotion (which we've discussed on Cognitive Daily). That study showed that people are accurate in identifying emotions in point-light displays. Now they wanted to find out if people can determine who's talking in the same videos. Here are the results:

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Does faking amnesia permanently distort your memory?

Wed, 27 May 2009 14:15:36 -0500

A common defense in murder cases is "focal retrograde amnesia": the defendant claims to have simply forgotten what occurred around the time of the crime (perhaps due having consumed too much alcohol or other drugs). In fact, "amnesia" is claimed in as many as 45 percent of murders. Psychologists know that this sort of amnesia is actually quite rare, so it's very likely that most, if not all of these defendants are faking amnesia.

We can confirm that many of these cases are faked: when defendants are given multiple-choice questions about the crime, they get the answers wrong too often. Think about it this way: if you are given a ten-item true/false test and you know none of the answers, you should get five of the answers right just by guessing. But if you actually know the answers and are just pretending not to know, you might get every single answer wrong. Unfortunately, this sort of test can't tell us who's faking and who's not, because some honest respondents might legitimately have an especially "bad" performance, purely based on chance. On a large scale, we know there's a lot of cheating going on, but there's no way to reliably pick out the cheaters.

But in testing for faking amnesia, a secondary phenomenon seemed to be appearing. Several studies found that people who were asked to pretend to have amnesia were later unable to recall as much as people who told the truth from the start.

The studies worked like this: Volunteers were told a story -- or actually acted out a story -- where they were the primary character: "you" robbed someone, or beat a man to death with a pool cue, or killed a girl in a car accident. Then half these participants were told to pretend not to remember the key details of the crime in an effort to avoid punishment, while the other half was told to remember as many as possible of the details. They were tested on their memory (or their false reconstruction) immediately after the story, and then returned to the laboratory a week later, and this time everyone was asked to try to recall the details of the crime accurately. The volunteers who told the truth the first time around did better on the second test. Does this mean that faking amnesia impairs your memory later on? Not necessarily.

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Encephalon is up at Neuroanthropology

Mon, 25 May 2009 16:47:03 -0500

Encephalon, the biweekly collection of the best psychology and neuroscience posts on the web, is now available at Neuroanthropology.

In addition to great science, there's a collection of clips from a classic movie about Italian food, "Big Night." Here's my favorite:

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Why my mom didn't buy me a slot car track for Christmas in 1978, even though I told her that's what I wanted

Mon, 25 May 2009 08:28:56 -0500

[This article was originally posted in December, 2006]

I'm not bitter about this, honest I'm not, but it does often seem that people who know you very well end up buying really lousy gifts. What I really want to find out is this: why do they do that? It turns out, market researchers want to know, too. How can they have a prayer of selling people things they don't want when people can't even convince their loved ones to buy them things they do want?

Davy Lerouge and Luk Warlop have designed a clever study to examine this very issue. They wanted to know whether couples who've been together for at least six months were any better at predicting each other's preferences than they were predicting preferences for strangers. They decided to study furniture preferences, because it's something couples generally have to agree on together. Also, since people don't buy furniture very often, most couples probably wouldn't have a specific purchase to use as a reference, and instead would be relying on general knowledge of each others' preferences.

Lerouge and Warlop recruited 35 couples to participate in the study. Each partner was placed in a separate cubicle for the duration of the study, and had no contact with his or her mate. They then were shown pictures of 30 different sets of bedroom furniture and asked to indicate their impression of it (positive or negative). The next part was the key to the study:

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Casual Fridays: Twinsult or Twompliment?

Fri, 22 May 2009 15:43:41 -0500

It's never been easy to communicate clearly online (or in person, for that matter). Often a statement meant as a compliment can be taken the wrong way. Or someone can mistake a statement made in jest for a serious statement. Now with tools like Twitter and texting limiting the total number of characters in a message, it may be even more difficult to convey nuance. Does everyone read these messages the same way? Or are some of us better-prepared to understand the nuances of online communication?

I think I may have come up with a (non-scientific) way to shed some light on those questions. You'll see a series of short statements you should imagine were sent to you on Twitter (or via email, if you're not familiar with Twitter). Your job is to decide whether you think the sender was complimenting or insulting you. Some of the statements should be quite obvious, but others may be more subtle -- your job is to cut through the rhetoric and guess what the sender was really thinking.

Click here to participate

As usual, the survey is brief, with just 13 short statements and a few additional questions. It should only take a few minutes to complete. You have until Thursday, May 28 to respond. There is no limit on the number of responses. Don't forget to come back next Friday for the results!

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