Researchers uncover basis for perceptual learning

August 2, 2006

The artist's trained eye can detect distinctions others can't; musicians pick up subtle changes in tone lost on the nonmusical. Brain researchers call these abilities perceptual learning.

Following up on an accidental finding, MIT researchers at the Picower Institute for Learning and Memory and colleagues have uncovered a mechanism for this phenomenon. The study will appear in the Aug. 3 issue of Neuron.

The original idea was to look at how visual deprivation affects the brain. But before mice in the experiment were deprived of vision, researchers recorded baseline measurements by showing them a striped pattern on a video screen.

Unexpectedly, the researchers found that although no change showed up during the viewing session, as few as 12 hours later the mice were more visually "tuned" to the pattern they had seen. Over several sessions, the mice's brain responses to the stripes increased, with the biggest responses occurring to stripes the mice saw more often. The researchers dubbed this change "stimulus selective response potentiation" or SRP.

"The properties of SRP are strikingly similar to those described for some forms of human perceptual learning," said Mark Bear, Picower Professor of Neuroscience and co-author of the study. As a result, "understanding this type of perceptual learning is important because it can reveal mechanisms of implicit memory formation and might be exploited to promote rehabilitation after brain damage. Detailed knowledge of how practice changes brain chemistry is likely to suggest new pharmacological and behavioral therapies to facilitate these changes.

"Brain researchers have studied perceptual learning for a long time, but until now, there has never been any insight into the mechanism behind it," said Bear, who also holds an appointment in MIT's Department of Brain and Cognitive Sciences.

The researchers specifically discovered that new neurotransmitter receptors are delivered to synapses, the connections among neurons, in the brain's visual cortex, leading to SRP. Changes in the brain triggered by learning strengthen the synapses.

In the MIT study, perceptual learning occurred in both young and adult mice, implying that the ability to sharpen sensory perception is not lost with aging.

In addition to Bear, authors include Mikhail Y. Frenkel, Picower Institute postdoctoral associate; Nathaniel B. Sawtell of Oregon Health and Sciences University; Antonia Cinira M. Diogo of the Universidade Federal do Rio de Janeiro; Picower Institute postdoctoral associate Bongjune Yoon; and Rachael L. Neve of McLean Hospital.

Source: MIT

Explore further: What neuroscience can learn from computer science

Related Stories

What neuroscience can learn from computer science

August 10, 2015

What do computers and brains have in common? Computers are made to solve the same problems that brains solve. Computers, however, rely on a drastically different hardware, which makes them good at different kinds of problem ...

Songbirds have a thing for patterns

June 25, 2015

You might think that young children would first learn to recognize sounds and then learn how those categories of sounds fit together into words. But that isn't how it works. Rather, kids learn sounds and words at the same ...

Recommended for you

Interactive tool lifts veil on the cost of nuclear energy

August 24, 2015

Despite the ever-changing landscape of energy economics, subject to the influence of new technologies and geopolitics, a new tool promises to root discussions about the cost of nuclear energy in hard evidence rather than ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.