The prestige of an academic journal is determined largely by its impact factor. This is a somewhat odd measure of how often, on average, a paper in a journal is cited in other academic publications. To give you a rough idea: In 2010, Nature and Science, the two most famous academic journals, had impact factors of 36 and 31, respectively. A decent journal in the field of cognitive science would have an impact factor of, say, 3. And when a journal's impact factor drops below 1, things get dodgy.

Editors will try to boost their journals' impact factor, of course. This is good, for the most part, because it provides editors with an incentive to create a decent journal that publishes good science. But as Wilhite and Fong show in a recent edition of Science, there's a dark side as well: Coercive self-citation.

Wilhite and Fong distributed a survey under academics from various disciplines. In this survey, respondents indicated whether, when submitting a manuscript to a journal, they had ever been asked by the editor to include useless citations to other papers from that same journal. The motivation for the editor to do so is obvious: Additional self-citations raise the journal's impact factor. Wilhite and Fong give a strikingly blatant example of such a request made by an editor to an author:

"You cite Leukemia [once in 42 references]. Consequently, we kindly ask you to add references of articles published in Leukemia."

Clearly, this seemingly friendly question implies something that …

A recent paper in PLoS Biology has caused a minor stir. In this paper, Pasley and colleagues show that you can find out which word a person has just heard by decoding activity in a specific part of the human brain. This is mind reading, in a sense. And it's therefore not surprising that some are talking about the Orwellian implications of this study, or speculate about the possibility of decoding inner speech in the same way.

But what did they Pasley and colleagues actually do? It's quite a technical paper, so you will have to forgive me if I have missed a few details. But the general idea behind the study is straightforward.

Pasley and colleagues recorded directly from the brain of human participants. Normally this is not possible, because intra-cranial recordings are highly invasive. You have to open up the skull in order to attach recording equipment to the brain. Few participants will agree to this, and even fewer ethical commissions will condone it. But sometimes, when a willing participant is about to undergo brain surgery (usually for a severe form of epilepsy), scientists get the unique opportunity to do this kind of experiment with humans.

The brain area that Pasley and colleagues recorded from was the posterior superior temporal gyrus. This area is traditionally thought of as a midway station in the transformation from low-level acoustic information (sounds without meaning attached to them) to conceptual representations (the meaning of words, concepts, etc.).

The neurons in this brain …

I just came across an inspiring blog post by the mathematician Tim Gowers. In this post, which I invite you to read, he calls for a boycott of Elsevier. I share his discontent and so, I hope, will you.

Elsevier is one of the largest academic publishers, and is notorious for charging extremely high prices. This places a considerable financial burden on publicly funded academic institutions, who are, for various reasons, practically forced to buy Elsevier content. Elsevier has also engaged in other dubious practices, such as actively supporting a bill against open access publishing.

Elsevier is not alone in this. In fact, not too long ago there was a similar outrage over price increases by the Nature Publishing Group. But, as Gower points out and as you can read in the overview by White and Creaser, Elsevier is quite simply the worst.

There is now a website, The Cost of Knowledge, which calls on scientists to declare publicly that they will not support Elsevier by publishing in or reviewing/ editing for any of the Elsevier journals. I must admit that, at first, I was a little hesitant to sign this, because preventing myself from publishing in Elsevier journals is not necessarily a booster for my (very young) career. But I have decided that I will sign nevertheless: There are plenty of good, open access alternatives in my branch of research: any of the PLoS journals, Journal of Vision, BioMed central, Journal of Eye Movement Research, to name but a …

The Great Bowerbird is a curious bird. The males spend most of their time building bowers, which are elaborate structures, constructed solely for attracting females. These loveshacks are decorated with stones (and sticks, bones, etc.) in a very specific way: Small stones are put near the entrance of the bower; Larger stones are put further away. When looking out from the inside of the bower, which is were the females stand during courtship, this arrangement leads to a striking distortion of perspective. You can see this in the image below (compare b to c). In a sense, the size gradient of the stones flattens the image, reducing the subjective perception of depth.

Photos from Kelley & Endler (2012) and Anderson (2012)

The male bowerbird is quite picky about this arrangement. If the size gradient is disturbed (by a biologist, for example), the males immediately restore it. But why? Since the purpose of the bower is to seduce females, it is tempting to speculate that the distorted perspective is aesthetically pleasing to female bowerbirds. Who, as mentioned above, tend to stand inside the bower as they watch the male perform his dance of seduction.

But there could be numerous other explanations. For example, the males could simply be too lazy to carry big stones all the way to the bower. Or something like that.

But no, it appears that the distorted perspective really is what matters. In a recent issue of Science, Kelley and Endler investigated what the perfect size gradient is …

The following illusion is a variation on the boogie-woogie illusion, described by Patrick Cavanagh and (yes, again!) Stuart Anstis. If you play the video and track the moving dot with your eyes, you will see that the edges of the diamond shape come to life. Specifically, the dots that make up the edges appear to travel along the lines. Kind of like the steps of an escalator.

So what might be going on here? I have to admit that my degree of belief in the explanation that I will outline here is modest. But that being said, here we go: Essentially, this illusion could be an instance of the aperture problem.

Imagine that you are looking through a hole, as in a in the figure below. Through this hole, you can see part of a bar, but not all of it. Now imagine that the bar moves, as in b, c, or d. Can you tell, based on what you can see through the hole, what the exact movement of the bar has been? No! As long as you cannot see the ends of the bar, all three forms of movement look the same.

So what do people perceive when presented with this type of ambiguous motion? Well, they tend to perceive a motion that is orthogonal to the length of the object (d). Perhaps we are biased to perceive orthogonal motion, because that's how objects generally move (do they, though?). Or perhaps it's because orthogonal motion is, in a …