Study indicates how we maintain visual details in short-term memory

February 20, 2009

Working memory (also known as short term memory) is our ability to keep a small amount of information active in our mind. This is useful for information we need to know on-the-fly, such as a phone number or the few items we need to pick up from the grocery store. We hang on to the information for a brief period of time, just long enough to make a phone call or get through the checkout line, and then we forget it forever.

We receive much of our information through our visual system, but it was unknown how much of this visual information is actively involved in short term memory. Psychologists John T. Serences from the University of California, San Diego, along with Edward F. Ester, Edward K. Vogel and Edward Awh from the University of Oregon wanted to examine which neural systems enable the maintenance of these visual details in short term memory.

While undergoing functional magnetic resonance imaging (fMRI) scans, volunteers were shown an image for one second and were instructed to remember either the color or the orientation of the image. Following the image, volunteers saw a blank screen for 10 seconds, then were shown another image and had to indicate if it was the identical color or orientation (depending on which they were told to remember) as the first image. The researchers analyzed brain activity during the 10 second delay (when short term memory is active) in the primary visual cortex, the main region of the brain which handles visual information.

The results, described in Psychological Science, a journal of the Association for Psychological Science, revealed that during the 10 second delay, there was very specific activation in the visual cortex, specifically in areas normally involved in processing color and orientation. Moreover, close examination of the patterns of activity in the visual cortex allowed the authors to "decode" the specific color or orientation value that volunteers were holding in mind. This suggests that during short term memory the visual area of the brain is actively "thinking" about a specific feature of an object (e.g. color or orientation), to ensure that the information will be maintained and not forgotten.

The authors note that these findings "suggest that observers have top-down control over which features are stored" because the activity in the visual cortex represented only the voluntarily stored aspects of the image. In this way, we can ensure that only the most relevant details of the world around us are maintained in this online mental workspace.

Source: Association for Psychological Science

Explore further: Methylene blue shows promise for improving short-term memory

Related Stories

Smartphones won't make your kids dumb. We think.

June 7, 2016

Like many parents, Sandy is concerned about how much time her 18-month-old spends in front of screens. Weighing up the available evidence, Olivia Solon explains that she might be worrying too much. Jessica's tiny fingers ...

Decoding short-term memory with fMRI

February 21, 2009

People voluntarily pick what information they store in short-term memory. Now, using functional magnetic resonance imaging (fMRI), researchers can see just what information people are holding in memory based only on patterns ...

Brain's code for visual working memory deciphered in monkeys

November 2, 2012

The brain holds in mind what has just been seen by synchronizing brain waves in a working memory circuit, an animal study supported by the National Institutes of Health suggests. The more in-sync such electrical signals of ...

Recommended for you

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Cow embryos reveal new type of chromosome chimera

May 27, 2016

I've often wondered what happens between the time an egg is fertilized and the time the ball of cells that it becomes nestles into the uterine lining. It's a period that we know very little about, a black box of developmental ...

Shaving time to test antidotes for nerve agents

February 29, 2016

Imagine you wanted to know how much energy it took to bike up a mountain, but couldn't finish the ride to the peak yourself. So, to get the total energy required, you and a team of friends strap energy meters to your bikes ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.