A few months back I bought an e-reader. An IRex (DR800S) to be specific. This is my second e-reader, to be even more specific, because the Sony (PRS600) that I used before had an unfortunate accident. Although I occasionally use the e-reader to read books (not too often, though, I promised myself that I would not let it stand in the way of having pretentiously well-stocked bookshelves), my main use for it is to read academic papers. I thought my experiences might be of some use to anyone who is thinking of buying an e-reader for the same purpose.

Initially, I wanted to buy an e-reader with a small display, which are considerably cheaper than the large ones, and just scroll through the pdfs like you would on a regular computer. Luckily I didn't, because e-readers are way to sluggish to comfortably scroll through a document. This is because e-ink displays have a very low refresh rate (i.e., it takes quite some time for the image to change). Most e-readers have the option to reformat (reflow) text, which means that the reader tries to increase the font size while maintaining a reasonable layout. For books, which tend to have a fairly straightforward layout, this works fine, but for multicolumn .pdfs (i.e., most academic papers) the results are disastrous. So basically, if you want to read academic papers, you will want an e-reader with a sizable display. The IRex has an 8 inch display, which is just large enough …

OpenSesame 0.17 is available! In addition to bug-fixes and numerous refinements to the graphical interface, there are a few noteworthy new features:

• There is now a debug window, which is invaluable when creating Python inline code. You can print to the debug window using the standard Python 'print' statement. The debug window also includes a simple Python interpreter.
• Added a timeout option to response items.
• Added an auto response mode, in which OpenSesame simulates responses. This can be very handy when you want to give your experiment a test run, but rather not spend an hour sitting behind your computer pressing keys.
• Added plugins! You can (relatively) easily extend OpenSesame's functionality through plug-ins. Four plug-ins are already included:
  • fixation_dot: a convenience plugin for displaying central fixation dots.
  • text_display: a convenience plugin for presenting text displays.
  • text_input: a response collection plugin which provides a text input field.
  • advanced_delay: a timing plugin which waits for a random interval with a specified mean and standard deviation.
• Another tutorial. This is not really a feature, of course, but it is nevertheless a very useful addition. You can download the tutorial here (PDF format).

Get it here!

Today I would like to highlight a study by Jan Theeuwes (my PhD supervisor) and myself, to celebrate that the paper is now officially available. (It's still in press, but Psychological Science provides “online first” access to articles. If you do not have access to Psychological Science, you can find an unofficial postprint here.)

In this paper we focus on the “problem” of eye movements. This may seem strange. Clearly, the ability to make eye movements is very adaptive, because it allows us to quickly scan the environment without having to make head (or body) movements, which are costly in terms of time as well as energy. So what's the problem?

The “problem” that I'm referring to is that with every eye movement, the retinal image of the world changes enormously. Therefore, if we were to take changes in the retinal image as evidence for changes in the world around us, we would perceive a dizzyingly unstable world. Which, clearly, we don't. We may be vaguely aware of the fact that we make eye movements, but subjectively it does not feel as though eye movements interfere with our sense of “visual stability”. Apparently, the visual system somehow compensates very effectively for eye movements.

Another phenomenon on which we focus in the paper is “inhibition of return” (IOR). IOR refers to the fact that after we have attended to some location, either covertly (i.e., from the corner of our eye) or by looking at that location, we ignore that location …

I'm pleased to announce that development on OpenSesame has started. OpenSesame is a graphical experiment builder. Compared to existing software for creating psychological experiments, OpenSesame has a number of cool extra tricks up its sleeve.

OpenSesame is ...

• … free and open-source.
• … cross-platform. Windows and Linux packages will be provided, but if the required libraries are installed, OpenSesame should also run on Mac OS.
• … an extremely easy way to build experiments using a graphical user interface. You can even draw your stimulus displays using the built-in sketchpad!
• … compatible with Python. This means that you can combine the ease of the graphical interface with the full power of Python scripting.

You can expect a first version of OpenSesame to land in the software section of cogsci.nl in the near future. For now I have a couple of screenshots. So let's take a look! (Click on the screenshots to see the full size images.)

The screenshot below shows a “sequence” item. A sequence runs a number of other items in sequence (obviously). In the example below, the sequence consists of a fixation display, a cue display, a target display, a keyboard response collector, and, finally, a logger item (which logs the response to file). A typical experimental trial, in other words. One of the cool things of the sequence item is that you can use conditional statements. For example, depending on the value of the “cue” variable, either the “cue_left …

A colleague of mine just installed Zotero and he reminded me of a particularly nasty issue that affects Zotero on most modern Linux distributions. I believe it affects at least all recent versions of Ubuntu, Fedora and OpenSUSE. The problem stems from the fact that the Sun implementation of Java has been replaced with the open source OpenJDK kit, which does not play nice with Zotero. The symptoms are confusing error messages when you try to use Zotero from within OpenOffice.

The solution is to remove all OpenJDK packages and install Sun java. In Ubuntu you can do this by opening the Synaptic package manager under System → Administration → Synaptic package manager, searching for openjdk and icedtea and removing all matching packages that you have installed. Next you search for sun and install the following packages: sun-java6-bin, sun-java6-jre and sun-java6-plugin. Next, restart Firefox and OpenOffice and you should be good to go!

Update Jan 3 2011: In order to install Sun java you need to enable the Canonical partner repository in Ubuntu. If it isn't enabled already, you can do so by opening the Synaptic package manager (Menu → System → Administration → Synaptic Package Manager), opening the Software Sources (Menu → Settings → Repositories) and enabling the Canonical Partners repository (Other Software → Canonical Partners).