Can we actually read words and phrases and solve multi-step mathematical problems without our having consciously been aware of them? A team in the Psychology Department at the Hebrew University has conducted a series of experiments that give a positive answer: people can read and do math non-consciously.
The results constitute a challenge to existing theories of unconscious processes, that maintain that reading and solving math problems -- two prime examples of complex, rule-based operations – require consciousness.
The conclusions of the Hebrew University team were published this week in PNAS (Proceedings of the National Academy of Sciences) in the US. The research team, headed by Dr. Ran Hassin, included graduate students Asael Sklar, Ariel Goldstein, Nir Levy and Roi Mandel, as well as Dr. Anat Maril.
To present sentences and equations unconsciously, the researchers used a cutting-edge technique called Continuous Flash Suppression (CFS). In CFS, one eye is exposed to a series of rapidly changing images, while the other is simultaneously exposed to a constant image. The rapid changes in the one eye dominate consciousness, so that the image presented to the other eye is not experienced consciously. Using this technique, more than 270 students at the Hebrew University were exposed to sentences and arithmetic problems.
In one set of experiments using this technique, participants were asked to pronounce numbers that appeared on a computer's screen. These numbers were preceded with unconscious arithmetic equations. The results of the experiments showed that participants could more quickly pronounce the conscious number if it had been the result of the unconscious equation. For example, when 9-5-1 was shown non-consciously, the participants were faster in pronouncing 3 than 4, even though they did not consciously see the equation.
In another set of experiments reported in the PNAS paper, participants were non-consciously exposed to a number of short verbal expressions that remained on screen until participants could say that they saw them. (In the meantime, the other eye was exposed to the rapidly flashing images). The results showed that negative verbal expressions (e.g., human trafficking) or unusual phrases (e.g., the bench ate a zebra) became conscious to the viewers before more positive expressions (e.g., ironed shirt and more usual phrases (e.g., the lion ate a zebra), indicating a definite "pickup" by the unconscious of something negative and 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."
The Hebrew University of Jerusalem: http://www.huji.ac.il
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
Bumblebees can recall which flowers yield nectar, but like people they can get mixed up – leading them to home in on flowers they have no experience of
Brain cells that help us predict the intentions of others before they've actively made a decision have been discovered in monkeys
Experiments in mice suggest that treatment of haemophilia could be more successful if the baby's immune system is primed while in the womb
Scientists have recovered cultivated wheat DNA from an 8,000-year-old submerged site off the British coast. The finding suggests hunter-gatherers were trading for the grain long before they grew it.
An exciting fossil find in China points to a 525-million year old sea-dweller who used its new backbone to swim nimbly away from predators
Birds are dinosaurs. That’s a fact underscored by dozens upon dozens of discoveries in the last 30 years.
Eyelashes keep dust out and fend off drying breezes, a study finds. To do that they need to be a very precise length. Extra-long fake eyelashes hurt more than they help.
New research from UCL brings us closer to finding out what’s behind one of our biggest killers
The UK has now become the first country to approve laws to allow the creation of babies from three people.
Three people with paralysed arms had their hands amputated and replaced by prosthetic ones that they control with their mind