• Schicke and Röder present new data on the "body schema" the dynamic mental representation you have in your head of the position of the parts of your body. This system can, of course, be fooled: phantom limbs, for one. Their introduction is fascinating, because some of this stuff is, while mystifying, eminently autoexperimentable (well, you need a friend). For example, earlier work has shown that a person can tell which of their two index fingers has been touched first even when the stimuli are as little as 50ms apart but we need a 2-3x longer gap if our arms are crossed. Even better, congenitally blind people do not hesitate under arms-crossed conditions, suggesting that the visual system is involved in the construction of some sort of 3D spatial model early in life onto which the brain maps the hands' locations and interprets all stimuli through. Moreover, this 3D-coordinate system is obligatorily imposed in non-visual spaces, as shown when sighted people's response times are slowed by arm-crossing relative to uncrossed arms even when their arms are behind their backs. That's the intro; the results are extensions of these tests to other limbs: they show that, regardless of limb, crossing makes it harder for the brain to process and so stimuli must be timed further apart to be correctly resolved. Cross one arm over your leg and you are less good at telling whether your toe or your index finger was tweaked first. Go on. You know you want to.

There were more goodies (see my Starred Items list via Google Reader) but I didn't have time to write them up this week.