This afternoon I was eating a sub in the Plymouth harbor, finally enjoying a bit of sun, which we haven't seen much of this summer. I was joined by a seagull chick. It was presumably hoping to score a piece of my sub.

So why share this wholly unremarkable footage with you? The bird sat there for something like 10 minutes (gulls are nothing if not patient and persistent) and after a while it struck me that it didn't appear to look at me (or my sub) much at all. It seemed to be continuously distracted by something to its right or left, even though there was nothing there, at least nothing as interesting as my sub (I imagine). Then it dawned on me that, in contrast to appearance, the gull must have been looking at me all the time, but with different parts of its eye!

As you probably know, we see only a small part of our surroundings with high resolution and in color. This is the part that falls onto our fovea, a small, extra dense part of the retina. Foveal vision corresponds to about the size of a thumb at arm's length.

Yet we feel as though we have a complete and full-color perception of our entire visual field. In large part, this is because our eyes are mobile: If we think about something, we immediately look at it (bring it into foveal vision) to get a crisp view of the object in question.

So what …

QuiEdit, a full-screen text editor, is the most recent addition to the cogsci software family. I initially developed it for personal use, to write blog posts and such. Like most people, I'm easily distracted when I'm behind a computer (checking email, visiting news sites, etc.). I find that a full-screen text editor really helps when you want to get some writing done. Plus it's kind of pretty, I think, and if you disagree you can easily create your own theme.

Get it here!

As you probably know, brains of humans and other vertebrates consist of two halves, called hemispheres. By and large, both hemispheres carry out the same functions, but they are not identical. The best known asymmetry between the two hemispheres is the lateralization of language: The left hemisphere is dominant when it comes to language. Another obvious example is handedness: The right hand is primarily controlled by the left hemisphere, and vice versa, so handedness reflects a hemispheric specialization in the control of hand movements. Again, the left hemisphere is usually dominant.

The list goes on and on. Everywhere you look there are differences between left and right, which can often be traced back to asymmetries between the left and right hemispheres. Some differences, such as handedness, are obvious, some are subtle. And some are rather cute.

A while back I read a paper by Giorgio Vallortigara, one of the experts on lateralization, in which he made "a stroll through animals' left and right perceptual worlds." One figure in particular stuck in my mind:

So what are we looking at here? Vallortigara and colleagues investigated the predatory behavior of toads using the "worm test". They suspended worms, which toads enjoy very much, from a thread, and slowly brought the worms into the toads' field of view. Sometimes the worms entered the toads' visual field from the left, and sometimes from the right.

What the graph shows is that the direction from which the worm enters the toad's visual field makes a …

I have launched a forum (forum.cogsci.nl). I hope that this will be a convenient way to handle support for the various software packages that are available here. Because of the steadily increasing number of comments and questions, mostly related to OpenSesame (which has been downloaded more than 7000 times now), it became a bit difficult for me to keep track of everything with the current commenting system.

But, of course, the forum is not limited to technical support, and anybody is free to talk about pretty much anything!

Skull measuring is all the rage these days. A while back I wrote about a study by Lewis and colleagues, in which they showed that the 19th century anthropologist Samuel George Morton was correct in his assertion that cranial capacity differs between racial groups. This was surprising, because Morton's research had previously been dismissed as a prime example of how racist assumptions can bias results. It was believed, in other words, that Morton had tampered with his data to make sure that Caucasians had the largest cranial capacity of all racial groups.

Lewis and colleagues were quick to distance themselves from Morton's distinctly racist views, and emphasized that differences in cranial capacity do not reflect differences in intelligence, as Morton had believed. But this, of course, begs the question: If not intelligence, what do differences in cranial capacity reflect?

A recent paper by Pearce and Dunbar in Biology Letters sheds new light on this issue. Pearce and Dunbar measured the size of eye sockets and brains in skulls of people from various parts of the world. Unlike Morton, they did not focus on racial groups, but on the latitude of people's habitat (how far up north people lived). Their finding is straightforward: People that live far up north have larger eyes and correspondingly larger brains. Why? Because near the poles the days are shorter and, more generally …