The Chicken Head is a dance that was popularized by the video clip to Chingy's Right Thurr, which was a big hit back in 2003.

If you do the Chicken Head well, the flapping of your 'wings' makes you look a bit like a chicken. Another distinctly chicken-like aspect of the dance is that you need to keep your head more or less still, while swinging your body from side to side.

For this post I will elaborate a bit on this last point.

As you can see in the video above, chickens are remarkably good at keeping their head still while their body is moving. They are able to do this when someone else moves their body, as in the video, but also when they move themselves. This is why a chicken's head (or a pigeon's head, as in the video below) bobs back and forth during walking: The chicken keeps its head still with respect to the environment by moving it backwards to compensate for the forwards body movement. This continues until the head cannot move back any further, at which point it rapidly snaps forward, momentarily breaking the otherwise near perfect head stabilization (see note 1 below for a popular myth on head bobbing).

When you think of it, head stabilization is a remarkable feat: The gravitational (or vestibular) sense is required to keep the head up-right, regardless of the body's orientation. And you also need to take into account the position of the body parts relative …

I don't remember when I first saw a video of an octopus's amazing camouflaging abilities, but I know that I've been fascinated ever since.

Its not just the octopus that is a master of disguise, though. Pressured by the unique challenges of marine life, many marine animals have evolved elaborate forms of camouflage. Prime examples of this can be found in the twilight zone, the colloquial term for the oceanic zone that lies a few hundred meters beneath the surface. Because of the three-dimensional nature of their aquatic environment, it is extremely difficult for animals in the twilight zone to camouflage themselves properly: When viewed from below, they need to blend in with the (relatively) bright surface. When viewed from above, they must blend in with the dark ocean floor, or the equally dark depths. A singular form of camouflage will simply not do!

In response to this challenge, many "twilight fish" have evolved multiple, complementary forms of camouflage. To be hidden when viewed from above, they tend to have a darkly pigmented back that avoids standing out against the oceanic darkness below (a in the figure). Another, more ingenious form of camouflage is provided by silvery, reflective sides (b). These function as mirrors that reflect light from the surface, thus providing near invisibility when viewed from below at a slight angle. Obviously, having a dark back or reflective sides offers little protection when viewed from directly below. To be invisible from this angle as well, these fish employ a …

Over the past few months a lot of work has been done on OpenSesame, the graphical experiment builder. And, if all goes well, version 0.25 ("Dashy Darwin") will be released soon! For this release, the focus wasn't on new functionality, but on bug-fixes and adding polish to the user interface. Thanks to a large (and rapidly growing) amount of user feedback, 0.25 is looking to be a great release! Thanks to everybody who helped out, even if just in a small way by dropping a note and/ or giving some constructive comments.

At this point, the pre-release packages are pretty stable, but of course there's always the chance of bugs that have been overlooked. If you have some time to spare (or are starting a new experiment), I would encourage you to try the latest pre-release packages and let me know of your experiences (particularly bad ones). When 0.25 is officially released, you will receive a notification so you can immediately switch to the official, stable version.

Download (0.25-pre13 is the latest pre-release right now):

• [OpenSesame 0.25 has been released, pre-release builds are no longer available]
  

A few weeks ago it became known that Diederik Stapel, a Professor at the University of Tilburg, and one of Hollands most celebrated social psychologists, committed academic fraud. I didn't write anything about it before, because the details and the extent of the fraud were largely unknown. But after the publication of an interim rapport on Monday, I felt the urge to write a few words about it. After all, this case reflects very badly on psychological research, and perhaps on the whole of science.

So what happened? Basically, Stapel made up data. Lots of it. And some of it got published in prestigious academic journals such as Science. It appears that Stapel acted alone, and played an elaborate act to fool his co-workers. According to the interim rapport, the usual chain of events was as follows:

Together with a co-worker, which could be one of his PhD-students, a post-doc, or a fellow senior academic, Stapel came up with a research question and, together, they designed an experiment. All the details of the study were discussed and decided on, again, together. So far, so good. Next, Stapel went to a school to conduct the actual experiment (he often worked, or pretended to work, with schools). By himself, this time. Because, or so Stapel argued, the schools knew him. They trusted him. And it would be inappropriate and unnecessary for other researchers to accompany him on these visits.

In actuality, we now know, Stapel did not visit any schools at all …

Gnotero, the standalone sidekick to the Zotero reference manager, has gotten a major revamp, and has been renamed to Qnotero. The (slight) name change reflects a switch in the underlying graphical toolkit, from Gtk to Qt (for those who care about nerdy details). The functionality offered by Qnotero is basically the same: You can quickly search through your Zotero references, and open attached PDFs. So what's new?

Compared to Gnotero, Qnotero is 

• prettier
• themeable (right now there are a few different color and icon schemes)
• faster
• fully functional on Windows
• drag-and-droppable (you can drag PDFs from the search results onto, say, your desktop)

Get it here!