Featured Research

from universities, journals, and other organizations

Storage Limits On Our Visual Hard Drive

Date:
April 15, 2004
Source:
Vanderbilt University
Summary:
The amount of information we can remember from a visual scene is extremely limited and the source of that limit may lie in the posterior parietal cortex, a region of the brain involved in visual short-term memory.

NASHVILLE, Tenn. -- Scientists have discovered the region of the brain responsible for the old adage, "out of sight, out of mind."

Related Articles


The amount of information we can remember from a visual scene is extremely limited and the source of that limit may lie in the posterior parietal cortex, a region of the brain involved in visual short-term memory, Vanderbilt psychologist Renι Marois and graduate student J. Jay Todd have found. Their results were published in the April 15 edition of Nature.

"Visual short-term memory is a key component of many perceptual and cognitive functions and is supported by a broad neural network, but it has a very limited storage capacity," Marois said. "Though we have the impression we are taking in a great deal of information from a visual scene, we are actually very poor at describing its contents in detail once it is gone from our sight."

Previous findings have determined that an extensive network of brain regions supports visual short-term memory. In their study, Todd and Marois showed that the severely limited storage capacity of visual short-term memory is primarily associated with just one of these regions, the posterior parietal cortex.

Todd and Marois used functional magnetic resonance imaging (fMRI), a technique that reveals the brain regions active in a given mental task by registering changes in blood flow and oxygenation in these regions, to identify where the capacity limit of visual short-term memory occurs.

The brains of research participants were scanned with fMRI while they were shown scenes containing one to eight colored objects. After a delay of just over a second, the subjects were queried about the scene they had just viewed.

While the subjects were good at remembering all of the objects in scenes containing four or fewer objects, they frequently made mistakes describing displays containing a larger number of objects, indicating that the storage capacity of visual short-term memory is about four.

The fMRI results revealed that activity in the posterior parietal cortex strongly correlated with the number of objects the subjects were able to remember. The magnitude of the neural response in this brain area increased with the number of objects viewed up to about four and leveled off after that, even when additional objects were presented.

Importantly, the posterior parietal cortex did not respond differently to the number of objects presented in a scene if the participants were not asked to remember what they had seen. In contrast, regions of the visual cortex in the occipital lobe did respond differently to the number of objects even in the absence of the memory task. Thus, it appears that, while some regions of the visual cortex register how much visual information we see, the posterior parietal cortex represents how much of that information we can hold in mind.

"The results suggest that the posterior parietal cortex is a key brain area associated with our impoverished ability to hold a representation of a visual scene in our mind once the scene is out of sight," Marois said.

Marois is a member of the Kennedy Center for Research on Human Development, Vanderbilt Vision Research Center and the Center for Integrative & Cognitive Neuroscience. The work was supported by a grant from the National Science Foundation.


Story Source:

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


Cite This Page:

Vanderbilt University. "Storage Limits On Our Visual Hard Drive." ScienceDaily. ScienceDaily, 15 April 2004. <www.sciencedaily.com/releases/2004/04/040415012259.htm>.
Vanderbilt University. (2004, April 15). Storage Limits On Our Visual Hard Drive. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2004/04/040415012259.htm
Vanderbilt University. "Storage Limits On Our Visual Hard Drive." ScienceDaily. www.sciencedaily.com/releases/2004/04/040415012259.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Mind & Brain News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Are Female Bosses More Likely To Be Depressed?

Are Female Bosses More Likely To Be Depressed?

Newsy (Nov. 24, 2014) — A new study links greater authority with increased depressive symptoms among women in the workplace. Video provided by Newsy
Powered by NewsLook.com
Winter Can Cause Depression — Here's How To Combat It

Winter Can Cause Depression — Here's How To Combat It

Newsy (Nov. 23, 2014) — Millions of American suffer from seasonal depression every year. It can lead to adverse health effects, but there are ways to ease symptoms. Video provided by Newsy
Powered by NewsLook.com
Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) — Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. Video provided by Newsy
Powered by NewsLook.com
Milestone Birthdays Can Bring Existential Crisis, Study Says

Milestone Birthdays Can Bring Existential Crisis, Study Says

Newsy (Nov. 21, 2014) — Researchers find that as people approach new decades in their lives they make bigger life decisions. 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