Nonconscious Information Processing
At any given moment our five senses are taking in more than 11,000,000 pieces of information. Scientists have determined this by counting the receptor cells each sense organ has and the nerves that go from these cells to the brain. Our eyes alone receive and send over 10,000,000 signals to our brains each second. Scientists have also tried to determine how many of these signals can be processed consciously at any given point in time, by looking at such things as how quickly people can read, consciously detect different flashes of light, and tell apart different smells. The most liberal estimate is that people can process consciously about 40 pieces of information a second.
In a study by Pawel Lewicki, Thomas Hill, and Elizabeth Bizot, the participant’s task was to watch a computer screen divided into four quadrants. On each trial, the letter X appeared in a quadrant, and the participant pressed one of four buttons to indicate which one. Unbeknownst to the participant, the presentations of the X’s were divided into blocks of 12 that followed a complex rule. For example, the X never appeared in the same square two times in a row; the third location depended on the location of the 2nd; the 4th location depended on the location of the preceding two trials; and an X never “returned” to its original location until it had appeared in a least two of the other squares. Although the exact rules were complicated, the participants appeared to learn them. As time went by their performance steadily improved, and they became faster and faster at pressing the correct button when the X appeared on the screen. Non of the participants, however, could verbalize what the rules were or even that they had learned anything.
The researchers suddenly changed the rules so that the clues predicting where the X would appear were no longer valid, and the participants’ performance deteriorated. Participants noticed that they could no longer do the task very well but none of them knew why.
Strangers to Ourselves — Discovering the Adaptive Unconscious by Timothy D. Wilson