There are two experiments that you can participate in online, here at cogsci.nl. Both are cognitive psychology classics. Try it, it's kinda fun (for a little while)!

I just analyzed the data from the feature integration experiment, based on the classic study by Treisman and Gelade. In this experiment, you have to indicate whether a red “T” is present in the display. (Btw, you can still participate in the experiment.)

In the “color popout” condition the red “T” is presented among green “T”-s. In the “shape popout” condition, it is presented among red “X”-es. These conditions are relative easy, because the target differs from the other letters (the distractor stimuli) on a single feature. That is, the target is either the only “T” (easy) or the only red object (even easier). According to Treisman and Gelade, you do not need to search the display for the target in these trials—the red "T" just pops out! Therefore, it doesn't really matter how many distractors there are. In the graph, you can see that, indeed, the “search slopes” for the popout conditions are relative flat: People do not respond much slower or make many more errors, if the red “T” is presented among many green “T”-s (large display size), relative to only a few green “T”-s (and analogously for the shape popout).

The situation is radically different for the conjunction condition. In the conjunction condition, the red “T” was presented among green “T”-s, green “X …

Update Nov 16, 2010: If you have trouble getting Zotero/ OpenOffice to work on Linux, please see this post.

If you've ever written a paper or a thesis you will no doubt agree that reference management can be a daunting task. You have to make sure that every reference in the text appears in the reference list, and, conversely, that every item from the reference list actually appears in the text. There are also many style guidelines that you're supposed to adhere to.

For example, according to the publication manual of the American Psychological Association (APA), the first time that you cite a paper you have to list all authors (unless there are more than five authors), like “(Author1, Author2, & Author3, 2010)”. In subsequent citations, you should name only the first author, like “(Author1 et al., 2010)”. In itself, this is a sensible rule, but it means that you have to keep track of where in the text you cite a paper for the first time. This also means that you have to update your citations whenever you shuffle around paragraphs. These are precisely the types of trivialities that you do not want to bother with while writing a manuscript!

Fortunately, there are software packages available that help you manage your references. The most famous of these are BibTeX (which is actually a format used by multiple tools), EndNote (widely used, but proprietary) and Zotero. If you want to cite a paper, you simply tell the reference manager to insert …

In a recent study in Biology Letters, Vahed and colleagues measured the size of testes in a number of bushcricket species. They found that in species with slutty females (i.e., a high level of polyandry), the males have larger testes. Somewhat surprisingly, however, larger testes do not lead to larger ejaculations, but instead to more frequent ejaculations. Clearly, the males are quite promiscuous as well.

Source: Wikimedia Commons

However, the real reason for mentioning this study is that Vahed and colleagues found a particular species of bushcricket, in which the testes account for a whopping 13.8% of the males' total body weight! The most ballsy animal ever found.

References

Although most animals are bilaterally symmetric, there are numerous subtle differences between left and right. An obvious example is that most humans prefer one hand, usually the right, over the other. Another famous example is the lateralization of most language functions to the left hemisphere of the brain.

Our perception of the world is not perfectly symmetrical either. In general we pay more attention to what happens to our right, but this preference is heavily dependent on context. When it comes to social interactions, we prefer the left visual field. For example, we tend to hold babies so that the baby faces us from the left.

Beluga mother and calf (Source: Wikimedia Commons)

This left-side preference in social interactions is not limited to humans. Chicks, for example, prefer to view other familiar chicks with their left eye (they also peck more at other chicks if they approach from the left - a social interaction, but not a very friendly one). And in a recent paper in PLoS One, Karenina and colleagues show that baby Beluga whales prefer to swim on their mothers right side, presumably so the baby can view its mother with its left eye. You might wonder if it's not the other way around, so that the mothers prefer to view the babies with their right eye, but apparently this is not the case. The mother whales are pretty much just floating around, and the babies control most of the interactions. Call me soft, but I think this is …

A big problem in psychological experiments is that the stimulus material is generally not very realistic. (For example, what do smileys really tell us about processing of emotional expressions?) This problem plagues my experiments as much as anybody else's. Therefore, in an attempt to add some extra realism to my stimuli I created anaglyphs today. Anaglyphs are images that convey a sense of 3d when viewed with red/blue (or sometimes red/ green) glasses. I'm not entirely sure yet if anaglyphs are suitable stimulus material, because they can be a little hard to view (they tend to look out-of-focus). But I guess I'll find out!

Here is a short video of the set-up that I used for creating the anaglyphs.