A UC Davis neuroscience team has found that when people become experts in recognizing a visual object, they use the part of the brain that increases the amount of information you can keep in mind at a given time.
The more expertise a person has, the more activity is found in that part of the brain that looks for patterns and rules -- in a region of the frontal lobe, report UC Davis graduate students Christopher Moore and Michael Cohen and associate professor of psychology Charan Ranganath in the Oct. 25 issue of Journal of Neuroscience.
"When you become an expert, you exploit your knowledge of what is both common and what is distinctive in a category," Ranganath says. "Our data showed that people with expertise are not just 'seeing better' but that they know what to look for. By using this knowledge, experts are better at recognizing and remembering items from the expert category."
The finding has implications for the elderly, as well as others with an inability to activate the frontal lobe, such as those with heart disease and hardened arteries.
"This area is hit hard by aging," Ranganath says. "We think memory-skills training can improve the ability to activate this brain area."
In the past, scientists have generally assumed that visual expertise causes changes in parts of the brain that process sight.
"We expected that when people with an expertise saw an object they recognized, it would create a tuning of the visual cortex -- areas of brain that allow you to recognize visual objects," Ranganath said. And, indeed, his team did see activity in that part of the brain.
The team's research shows that when people are calling up a visual memory, their brain creates a division of labor, also relying on the frontal lobe where learning takes place. In that area, the brain relies on more abstract skills to look for and remember the distinctive characteristics of the objects.
Training allows people to use their knowledge of the rules of any particular object to guide understanding of category relationships, Ranganath said. The more training, the more the brain is able to remember, his team found.
In the experiment, participants trained for 11 hours in recognizing and remembering objects from a category of visual objects created explicitly for the exercise. After training, participants developed significant advantages at recognizing and remembering objects from the trained category.
The researchers then scanned participants' brains, while they were trying to remember objects from the expert category and objects from another unknown category.
Their results showed that, even long after the training sessions, participants showed significant advantages at recognizing and remembering objects from the trained category.
Ranganath's team also found that experts can become confused when the specific relationships they have learned are violated.
"For instance, when the visual objects were turned upside down, our experts couldn't distinguish the objects from the expert category any better than objects from an unfamiliar category," Ranganath said.
Although the experiment focused on visual recognition, Ranganath believes the same principle can be applied to other forms of expertise.
"It is likely that training in any kind of memory skill will induce changes in the frontal lobe that may allow you to improve your memory."