Featured Research

from universities, journals, and other organizations

New Theory Of Visual Computation Reveals How Brain Makes Sense Of Natural Scenes

Date:
November 20, 2008
Source:
Carnegie Mellon University
Summary:
Computational neuroscientists have developed a computational model that provides insight into the function of the brain's visual cortex and the information processing that enables people to perceive contours and surfaces, and understand what they see in the world around them.

Computational neuroscientists at Carnegie Mellon University have developed a computational model that provides insight into the function of the brain's visual cortex and the information processing that enables people to perceive contours and surfaces, and understand what they see in the world around them.

A type of visual neuron known as simple cells can detect lines, or edges, but the computation they perform is insufficient to make sense of natural scenes, said Michael S. Lewicki, associate professor in Carnegie Mellon's Computer Science Department and the Center for the Neural Basis of Cognition. Edges often are obscured by variations in the foreground and background surfaces within the scene, he said, so more sophisticated processing is necessary to understand the complete picture. But little is known about how the visual system accomplishes this feat.

In a paper published online by the journal Nature, Lewicki and his graduate student, Yan Karklin, outline their computational model of this visual processing. The model employs an algorithm that analyzes the myriad patterns that compose natural scenes and statistically characterizes those patterns to determine which patterns are most likely associated with each other.

The bark of a tree, for instance, is composed of a multitude of different local image patterns, but the computational model can determine that all these local images represent bark and are all part of the same tree, as well as determining that those same patches are not part of a bush in the foreground or the hill behind it.

"Our model takes a statistical approach to making these generalizations about each patch in the image," said Lewicki, who currently is on sabbatical at the Institute for Advanced Study in Berlin. "We don't know if the visual system computes exactly in this way, but it is behaving as if it is."

Lewicki and Karklin report that the response of their model neurons to images used in physiological experiments matches well with the response of neurons in higher visual stages. These "complex cells," so-called for their more complex response properties, have been extensively studied, but the role they play in visual processing has been elusive. "We were astonished that the model reproduced so many of the properties of these cells just as a result of solving this computational problem," Lewicki said.

The human brain makes these interpretations of visual stimuli effortlessly, but computer scientists have long struggled to program computers to do the same. "We don't have computer vision algorithms that function as well as the brain," Lewicki said, so computers often have trouble recognizing objects, understanding their three-dimensional nature and appreciating how the objects they see are juxtaposed across a landscape. A deeper understanding of how the brain perceives the world could translate into improved computer vision systems.

In the meantime, the functional explanation of complex cells suggested by the computer model will enable scientists to develop new ways of investigating the visual system and other brain areas. "It's still a theory, after all, so naturally you want to test it further," Lewicki noted. But if the model is confirmed, it could establish a new paradigm for how we derive the general from the specific.

Karklin, who earned his Ph.D. in computational neuroscience, machine learning and computer science in 2007, is now a post-doctoral fellow at New York University.


Story Source:

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


Cite This Page:

Carnegie Mellon University. "New Theory Of Visual Computation Reveals How Brain Makes Sense Of Natural Scenes." ScienceDaily. ScienceDaily, 20 November 2008. <www.sciencedaily.com/releases/2008/11/081119140714.htm>.
Carnegie Mellon University. (2008, November 20). New Theory Of Visual Computation Reveals How Brain Makes Sense Of Natural Scenes. ScienceDaily. Retrieved September 20, 2014 from www.sciencedaily.com/releases/2008/11/081119140714.htm
Carnegie Mellon University. "New Theory Of Visual Computation Reveals How Brain Makes Sense Of Natural Scenes." ScienceDaily. www.sciencedaily.com/releases/2008/11/081119140714.htm (accessed September 20, 2014).

Share This



More Computers & Math News

Saturday, September 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

What This MIT Sensor Could Mean For The Future Of Robotics

What This MIT Sensor Could Mean For The Future Of Robotics

Newsy (Sep. 20, 2014) MIT researchers developed a light-based sensor that gives robots 100 times the sensitivity of a human finger, allowing for "unprecedented dexterity." Video provided by Newsy
Powered by NewsLook.com
How To Protect Your Data In The Still-Vulnerable iOS 8

How To Protect Your Data In The Still-Vulnerable iOS 8

Newsy (Sep. 20, 2014) One security researcher says despite Apple's efforts to increase security in iOS 8, it's still vulnerable to law enforcement data-transfer techniques. Video provided by Newsy
Powered by NewsLook.com
How Much Privacy Protection Will Google's Android L Provide?

How Much Privacy Protection Will Google's Android L Provide?

Newsy (Sep. 19, 2014) Google's local encryption will make it harder for law enforcement or malicious actors to access the contents of devices running Android L. Video provided by Newsy
Powered by NewsLook.com
Virtual Reality Headsets Unveiled at Tokyo Game Show

Virtual Reality Headsets Unveiled at Tokyo Game Show

AFP (Sep. 18, 2014) Several companies unveiled virtual reality headsets at the Tokyo Game Show, Asia's largest digital entertainment exhibition. Duration: 00:48 Video provided by AFP
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:
from the past week

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