The brain patterns that drive this behavior are not well-understood, but a new study from MIT’s McGovern Institute for Brain Research shows that habit formation appears to be an innate ability that is fine-tuned by experience — specifically, the costs and rewards of certain choices.
Neuroscientists led by Institute Professor Ann Graybiel found that untrained monkeys performing a simple visual scanning task gradually developed efficient patterns that allowed them to minimize the time it took to receive their reward.
The task was designed to mimic natural scenarios — a nearly infinite number of choices for the monkeys to make and an unpredictable reward structure. “We wanted to create an environment that would be similar to the world we walk around in every day — an environment where there are lots of choices the animal can make,” says Theresa Desrochers, an MIT graduate student and lead author of a paper describing the work in the Proceedings of the National Academy of Sciences the week of Oct. 25.
The findings not only help reveal how the brain forms habits, but also could shed light on neurological disorders where amplified habit-formation results in highly repetitive behavior, such as Tourette’s syndrome, obsessive-compulsive disorder and schizophrenia, says Graybiel.
Graybiel and Desrochers took an unusual approach to their study. In most behavioral studies of monkeys, the researchers first train the animals to perform a task, then begin experiments. In this case, Graybiel and Desrochers wanted to see if the monkeys could learn a simple visual free-scanning task with no training at all.
The researchers measured the monkeys’ eye movements and brain activity as they looked at a grid of either four or nine dots. In each trial, after a period of time when the monkey just looked around, a different dot was randomly chosen to be “baited,” meaning that the monkey succeeded in the trial when its gaze landed on that dot. After a successful trial ended, the monkey received a food reward.
While the task itself is simple, it is capable of generating a rich variety of behavior, due to the number of choices available to the animals. The monkeys performed such trials about 1,000 times a day, and over several months, they developed ways to look at all of the different dots in sequences that were more and more cost-effective — meaning that they reached the target dot faster.
The changes were gradual: The animals would use one pattern for five to 10 days, then shift to a slightly different pattern. When looking at the entire mass of data, the researchers couldn’t tell what was driving these changes. However, a trial-by-trial analysis revealed that very small variations in the scanning patterns could reduce the overall time to receive the reward, which would then reinforce that behavior and lead the monkey to adopt the new pattern.
“The upshot was that tiny little changes in cost — how far they moved the eyes — seemed to be driving these shifts until they did it as optimally as they could, despite the fact that they had never been instructed,” says Graybiel.
This suggests that primates have an “inborn tendency to maximize reward and minimize cost,” says Graybiel. She and Desrochers believe the same kind of phenomenon, known as reinforcement learning, may also guide human habit formation.
“When you drive to work, it’s never going to take exactly the same amount of time. You might try one different street to avoid a stoplight, or some other subtle variation. At some point, you may completely shift,” says Desrochers.
Desrochers and Graybiel plan to design studies that will test whether humans show the same kind of habit-forming behavior in an eye-scanning task similar to the one the monkeys learned. They also hope to discover which parts of the brain control habit formation. They believe that the basal ganglia, which play a role in learning, and the prefrontal cortex, which is involved in planning, are likely candidates.
Funding: National Eye Institute Grant, the Office of Naval Research Grant, National Defense Science and Engineering Graduate Fellowship, Friends of the McGovern Fellowship and a Sloan Research Fellowship
Source: “Optimal habits can develop spontaneously through sensitivity to local cost” by, Theresa M. Desrochers, Dezhe Z. Jin, Noah D. Goodman, and Ann M. Graybiel. Proceedings of the National Academy of Sciences, 25 October, 2010.
Julie Pryor | Newswise Science News
Further reports about: > Brain > Brain Research > Eating Habits > Proceedings of the National Academy of Sciences > Science TV > Tourette’s syndrome > eye movement > fine-tuned by experience > habit-formation results > neurological disorders > obsessive-compulsive disorder > schizophrenia > visual scanning task
Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung
High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences