Thu, 15 Nov 2012 10:02 UTC
The team, headed by Dr. Ran Hassin, along with Dr. Anat Maril and graduate students Asael Sklar, Ariel Goldstein, Nir Levy and Roi Mandel, concluded that people can read and do math non-consciously. Their findings fly in the face of existing theories regarding unconscious processes. These previous theories state that reading and solving math problems, which are two prime examples of complex, rule-based operations, do, in fact, require consciousness.
The team was able to present sentences and equations unconsciously to their subject group of 270 university students. The technique they employed was Continuous Flash Suppression (CFS) which leaves one eye of the participant exposed to a series of rapidly changing images while the other eye is simultaneously exposed to a constant image. The rapidity of images to one eye dominates the consciousness of the participant. This allows the constant image to not be experienced consciously.
The first set of experiments to use CFS asked the participants to pronounce a number that appeared on a computer screen. The unconscious constant image was an arithmetic equation. What the team determined from this experiment was that participants could pronounce more quickly the conscious number if it had been the answer to the unconscious equation. As an example, when the non-conscious equation of 9 minus 5 minus 1 was shown, participants were able to pronounce 3 faster than 4, even though they had not consciously seen the equation.
A second set of experiments focused on verbal non-consciousness. In it, participants were non-consciously exposed to short verbal expressions that remained on screen until participants could acknowledge that they had seen them. The other eye was exposed to rapidly flashing images. Their results found that negative verbal expressions, like 'human trafficking', or unusual phrases, like 'the bench ate the zebra' were acknowledged faster than more positive expressions, like 'ironed shirt' or less unusual phrasing, like 'the lion ate the zebra'. The team claims this indicates a definite recognition by the unconscious of things that are more negative or out of the ordinary.
"These results show that the humans can perform complex, rule-based operations unconsciously, contrary to existing models of consciousness and the unconscious," say the researchers.
"Therefore," said Dr. Hassin, "current theories of the unconscious processes and human consciousness need to be revised. These revisions would bring us closer to solving one of the biggest scientific mysteries of the 21st century: What are the functions of human consciousness."
Dr. Hassin and his team at Hebrew University have published their findings this week in the journal Proceedings of the National Academy of Sciences (PNAS).