Featured Research

from universities, journals, and other organizations

Compromise Is Name Of The Game In How Brain Works, Say University Of Toronto Researchers

Date:
March 11, 2003
Source:
University Of Toronto
Summary:
The brain is constantly compromising as it pieces together information, often ignoring or downplaying small visual changes in the world that do not fit with its expectations. This process - far from being flawed - shows that the brain functions optimally, say University of Toronto researchers.

The brain is constantly compromising as it pieces together information, often ignoring or downplaying small visual changes in the world that do not fit with its expectations. This process - far from being flawed - shows that the brain functions optimally, say University of Toronto researchers.

Related Articles


"Our brains are very well designed," says Dr. Douglas Tweed, physiology professor at U of T and senior author on a paper in the March 6 issue of Nature. "The brain takes in raw data from its surroundings through sensors and interprets it, rejecting interpretations that it considers unlikely. The brain gauges the probabilities of things in real life and uses these estimates to guide our perceptions. But sometimes we can be fooled by bizarre things.

"This shouldn't be seen as a flaw in the system, however," Tweed argues. "This is the way the brain works. Sensors are always flawed; they simply do not provide enough information for us to reconstruct our world. The brain must use prior knowledge to interpret our surroundings and we found that it seems to do this optimally."

This research project, led by U of T post-doctoral fellow Matthias Niemeier, uses a theory presented in the 1800s by Hermann von Helmholtz, a German physiologist. Helmholtz, who stated that perception is a matter of unconscious inference, suggested that all of our senses are imperfect and those signals sent to the brain are flawed. With this flawed data, the brain is forced to guess - based on its sensor readings - what is happening in the environment. With small or unexpected changes it often guesses wrong, which is why people can be fooled by optical illusions or sleight of hand, Tweed explains. He and Niemeier conducted the research with Professor Douglas Crawford of York University.

The researchers tested whether the brain's perception processes are working optimally given the flawed data it receives. They programmed a computer-simulated brain to make optimal use of sensor data and prior knowledge, giving it realistic vision and quick eye movements (also known as saccades). The researchers then measured how well it perceived events in its simulated world.

The team compared these findings with those of human subjects. Subjects' heads were immobilized and a device shaped like a contact lens inserted into their eye to measure its motion and relay information back to a computer. Using a large screen, researchers conducted two experiments that tested participants' perceptions of distance and degree of change, using a white dot that "jumped" on the screen. They found that small jumps were invisible to participants; larger ones were seen but individuals underestimated how far the dot jumped.

"What we found was that, in simple situations, the simulated computer brain perceived things the same way and made the same kinds of errors that human brains do, even when we programmed the computer to function optimally," says Niemeier.

"When small changes occurred during a saccade, these changes were either ignored or downplayed by both the computer and the test subjects. So we concluded that the optimal solution when it comes to perceiving the outside environment is to ignore some changes."

The brain knows what can and cannot realistically occur based on probability and prior knowledge, say the researchers. Eyes have quite a narrow field of high-resolution vision, something in the area of two degrees, Niemeier explains. To obtain a complete picture, a person's eyes are constantly making quick movements. These saccades - about 100,000 a day - scan our surroundings and take about 30 milliseconds each. The brain knows that an event is unlikely to happen in 30 milliseconds and either ignores or downplays small changes (also known as saccadic suppression of displacement). Only when a change is large enough does the brain notice, he says.

"The brain makes the best possible use of the flawed data it gets from sensors like the eyes or ears, piecing together bits of information until a final picture is obtained, much like the process involved in solving a jigsaw puzzle," adds Tweed. "The sensors react even to unlikely or unexpected events but the brain disregards some of these signals to form one coherent picture. The brain is always compromising."

The research was supported by the Canadian Institutes of Health Research and the Canada Research Chairs program.


Story Source:

The above story is based on materials provided by University Of Toronto. Note: Materials may be edited for content and length.


Cite This Page:

University Of Toronto. "Compromise Is Name Of The Game In How Brain Works, Say University Of Toronto Researchers." ScienceDaily. ScienceDaily, 11 March 2003. <www.sciencedaily.com/releases/2003/03/030306075932.htm>.
University Of Toronto. (2003, March 11). Compromise Is Name Of The Game In How Brain Works, Say University Of Toronto Researchers. ScienceDaily. Retrieved March 28, 2015 from www.sciencedaily.com/releases/2003/03/030306075932.htm
University Of Toronto. "Compromise Is Name Of The Game In How Brain Works, Say University Of Toronto Researchers." ScienceDaily. www.sciencedaily.com/releases/2003/03/030306075932.htm (accessed March 28, 2015).

Share This


More From ScienceDaily



More Mind & Brain News

Saturday, March 28, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

AAA: Distracted Driving a Serious Teen Problem

AAA: Distracted Driving a Serious Teen Problem

AP (Mar. 25, 2015) While distracted driving is not a new problem for teens, new research from the AAA Foundation for Traffic Safety says it&apos;s much more serious than previously thought. (March 25) Video provided by AP
Powered by NewsLook.com
Smartphone Use Changing Our Brain and Thumb Interaction, Say Researchers

Smartphone Use Changing Our Brain and Thumb Interaction, Say Researchers

Reuters - Innovations Video Online (Mar. 25, 2015) European researchers say our smartphone use offers scientists an ideal testing ground for human brain plasticity. Dr Ako Ghosh&apos;s team discovered that the brains and thumbs of smartphone users interact differently from those who use old-fashioned handsets. Jim Drury went to meet him. Video provided by Reuters
Powered by NewsLook.com
Many Don't Know They Have Alzheimer's, But Their Doctors Do

Many Don't Know They Have Alzheimer's, But Their Doctors Do

Newsy (Mar. 24, 2015) According to a new study by the Alzheimer&apos;s Association, more than half of those who have the degenerative brain disease aren&apos;t told by their doctors. Video provided by Newsy
Powered by NewsLook.com
A Quick 45-Minute Nap Can Improve Your Memory

A Quick 45-Minute Nap Can Improve Your Memory

Newsy (Mar. 23, 2015) Researchers found those who napped for 45 minutes to an hour before being tested on information recalled it five times better than those who didn&apos;t. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins