Why can’t you tickle yourself?

When doctors examine a ticklish patient, they place the patient’s hand over theirs during the exam to prevent the tickling sensation. Why does this work? Because no matter how ticklish you may be, you can’t tickle yourself. Go ahead. Try it. The reason is that with every move you make, part of your brain is busy predicting the sensory consequences of that movement. This system keeps your senses focused on what’s happening in the world so important signals aren’t drowned out in the endless buzz of sensations caused by your own actions.

For instance, as we write, we are unaware of the feel of the chair and the texture of our socks. Yet we’d immediately notice a tap on the shoulder. If the only information your brain received was ……….. (snip)

The advantage of spread-out learning is large and reliable. Two study sessions with time between them can result in twice as much learning as a single study session of the same total length. Spaced training works with students of all ages and ability levels, across a variety of topics and teaching procedures. Unsurprisingly, it also works with other animals, so you’d do well to remember this principle when you’re trying to train your dog.

(snip)

http://today.msnbc.msn.com/id/28644401/?GT1=43001