People process lots of information about the environment while adapting as this information changes—without high energy use. Neuroscientists researching the brain's efficiency in processing information in the environment are split: Some believe that the brain saves energy by sharpening and refining its representations of expected events, while others believe it prioritizes unexpected events, which carry new information. In a new paper from JNeurosci, Reuben Rideaux and colleagues, from the University of Sydney, ultimately discovered that the brain may use both strategies at different times.
The researchers manipulated participants' expectations as they made predictions about where visual targets would move. The participants responded quicker to expected events but remembered these events with less precision than unexpected events. Responses to expected events were even faster when study volunteers were motivated to track the location of visuals, but recall remained poor in these instances. Individual differences in how well participants remembered events were linked to how sharply events were represented in the brain. Says Rideaux, "This study suggests both camps are partly right and partly wrong—the brain uses both strategies, but at different stages and in service of different goals. Expected events get a prestimulus motor head start; unexpected events get poststimulus sensory priority. This reframes the debate from 'Which account is correct?' to 'How do these complementary mechanisms interact?'"
Rideaux provides a real-world example of playing tennis to further elaborate: "A returner who has read her opponent's pattern knows the next serve is probably going wide to the forehand. She moves toward that spot before the ball is struck and gets her racket on it cleanly—the expectation buys her precious milliseconds, and the more she's focused on the match, the bigger the gain. But ask her, frame by frame, exactly where the ball bounced inside the service box, and her memory is fuzzier than for the rare surprise serve down the T, which she'll remember with vivid spatial precision. Her brain prepared a motor response for the likely location and then, having committed to acting, didn't bother encoding the precise location of the ball that confirmed what the brain already predicted."
