During my bachelors in cognitive neuropsychology, we often looked at case studies in class. We might be given descriptions of patients with particular symptoms, and be asked to diagnose these patients. During these classes, our professor would often refer to Oliver Sacks' famous compilation of case studies, The Man Who Mistook His Wife for a Hat. From this moment on, Sacks was, to me, the face of neuropsychology. (Our professor often implied that he and 'Oliver' were close friends. I've always wondered whether this was true; our professor was a boastful man, and he's not mentioned anywhere in On the Move.)

But aside from a few extracts from Hat (Sacks has a one-word title for all of his books), I never read anything by Sacks until midway through my PhD, when I picked up The Island of the Colorblind. In the first story of Island (there are two), Sacks describes his visit to an isolated island where about 10% of the inhabitants are fully colorblind. Sacks set out to investigate this peculiar prevalence of full colorblindness, which, unlike red-green colorblindness, is very rare. In the second story of Island, Sacks describes another isolated island community, this time with a more serious problem: many people in this community develop a neurodegenerative disease that leads to Parkinson-like symptoms and crippling disability. Again, Sacks tries to get to the bottom of this medical mystery. (Spoiler alert: Neither story is solved.)

While reading Island, I fell in love with Sacks' writing. The way he …

The Best Illusion of the Year Contest took place last week. As always, there were some cool, new illusions among the finalists—a feast for illusion-afficionados like myself. I particularly like the Honeycomb Illusion by Marco Bertamini and Nicola Bruno. Take a moment to watch (my rendition of) their illusion in its beautiful simplicity (important: for best effect, watch in full screen and HD quality):

This illusion is nothing but a honeycomb grid with little stars (or barbs) at each node. You can see this in close-up on the right.

The stars are clearly visible when you look directly at them. But, and this is where things get interesting, you don't see any stars in the parts of the grid that you don't directly look at. In other words, you get the impression that the little stars follow your eyes around, as you scan the grid with your eyes. I personally find this very compelling.

So what's going on here?

The key to this illusion is that, at any one moment, you only have a clear view of a very small part of the world: the part that falls onto the central part of your retina (the fovea). This part is about the size of your thumb at arm's length. Your peripheral vision, the things that you see from the corner of your eye, is much less sharp, and color blind. This, among other things, is why you move your eyes: You successively direct your central vision at things that …

Ok, stop procrastinating for a moment, and spend your time on something useful. Like finding Boerke in this image:

Boerke, shown at the bottom left, is hiding among his comic-strip buddies. (Source: Stripmuseum Brussels)

While searching for Boerke, you probably scanned the picture in a particular way: You scrutinized small parts of the picture one by one, looking at things that you wouldn't normally look at. Maybe Boerke is behind the ticket counter? (And where's the ticket counter?) No ... Maybe Boerke is climbing the stairs then? No, that's Bobette ... And so on, until you spotted Boerke. (Assuming you have. If not: keep looking!)

But this is not how you usually look at pictures. If you weren't searching for Boerke, you would probably let your eyes wander across the picture, focusing mostly on conspicuous things, like the dinosaur and the rocket.

So, broadly speaking, there are two modes of looking that differ in the amount of effort that you invest: An 'effortful' mode, in which you actively control where your eyes are going, and a 'lazy' mode, in which you let your eyes wander and be drawn to conspicuous things. And, as my colleagues and I have shown in a recent paper (public PDF), it is possible to determine how much effort you invest in your eye movements, simply by monitoring the size of your pupils.

Our experiments were similar to a search-for-Boerke game: Participants searched for a small letter that was hidden somewhere in an image. This was a difficult …

Last week, six contestants in a cycling race in Norway were poisoned after drinking laundry detergent. Drinking detergent seems like an exceedingly idiotic thing to do. So how come that six people did this? Well ...

(Source: Twitter)

... Omo Aktiv & Sport really looks like a sports drink.

In the beginning of 2006, there were almost one hundred reports of people being poisoned after drinking Fabuloso, a surface cleaner that promises to make dirty floors shine again. Why? Well ...

... Fabuloso really looks like a soft drink.

The reason that manufacturers make their cleaning products look like food is obvious. People like eating better than cleaning, so a cleaning product is more attractive if it looks edible.

Non-foods that look like foods, and non-drinks that look like drinks, are called food-imitating products. They are recognized as a public health risk by the European Union. If a detergent looks like a drink, someone will drink it. The result is a nasty case of poisoning, which, in rare cases, can be deadly. It's a problem.

The issue of food-imitating products was studied in an interesting, if somewhat quirky, study by Basso and colleagues. This study is not new, but I think it's worth mentioning again after the cycling-race incident in Norway. First, Basso and colleagues reviewed real-life cases of poisoning by food-imitating products. Surprisingly, at least to me, poisoning was not limited to children or elderly, groups that you might expect to make these kinds of mistakes more easily. Rather, there were several reports of …

I'm writing this on my way back from London, where I attended a workshop on publication bias that was organized by the NC3Rs (the British National Center for the Replacement, Refinement, and Reduction of Animals in Research). Publication bias arises when not all scientific studies are published, and when the chance of whether a study is published depends on its outcome. More specifically, studies that show a 'positive' result (e.g. a treatment effect, or something that supports a researcher's hypothesis) are published more often than studies that show a 'negative' result (e.g. no treatment effect, or something that doesn't support a researcher's hypothesis). Publication bias distorts scientific evidence. In most cases, it makes treatments (drugs, therapies, etc.) seem more effective than they are, simply because we only see studies that show positive treatment effects.

Publication bias is increasingly recognized as a severe problem that affects all areas of science. It's not new. It's just that until recently little was done about it. It was therefore great to see this workshop bring researchers, funders, publishers, and people from industry together with the aim of discussing concrete ways of reducing publication bias. In this post I would like to tell you about some of the things that were discussed.

There were many excellent speakers, but I will first highlight the opening talk by Emily Sena. Her talk was partly based on a meta-analysis in which she investigated publication bias in animal research on stroke treatment. Her work nicely shows how …