Scientists say that one need not have to pay attention to something in order to learn it. For now they have shown that the greed for reward can spark unconscious learning in humans.
The new study by researchers at Boston University demonstrated that stimulus-reward pairing could elicit visual learning in adults, even without awareness of the stimulus presentation or reward contingencies.
"Recent studies have raised the question of whether visual skill learning requires an active goal directed process or whether learning can occur automatically without any task, stimulus awareness, or goal directed behavior," said study author Dr. Aaron Seitz, from the Department of Psychology at the University of California, Riverside.
For the study, the researchers designed a novel experimental paradigm to take the "task" out of perceptual learning.
They asked the participants to view a computer monitor, maintain their gaze on a central spot and enjoy the occasional drop of water that was delivered to their mouths through a tube.
The drop of water was considered a reward because subjects were required to abstain from eating and drinking for five hours before the experimental session.
The visual stimuli that were paired with the liquid rewards were viewed with one eye, and were imperceptible to the subjects because contour rich patterns were continuously flashed to the other eye.
"The use of this procedure allowed us to examine the specific hypothesis that reward-related learning signals are sufficient to cause improvements in visual sensitivity for visual stimuli paired with rewards," said Seitz.
It was found that stimulus-reward pairing was sufficient to cause learning, even when the subjects were not aware of the learned stimuli or stimulus-reward conditions.
The learning effects were specific to the eye receiving the stimuli, a condition indicative of an early, monocular stage of visual processing.
The results suggested that it was the automatic reinforcement mechanisms (such as those released at times of reward), rather than directed attention, that determined improvements in sensory skills.
"Our findings support the suggestion that visual skill learning is generally an unconscious process and that goal-directed factors, such as directed attention, serve mostly to bias how learning takes place rather than actually gating the learning process," hypothesized Seitz.
The study has been published in the journal Neuron.