Featured Research

from universities, journals, and other organizations

The 'Been There, Done That' Memory Response

Date:
September 6, 2005
Source:
Cell Press
Summary:
One of the neural oddities of "declarative" memory -- the recall of past things and events -- is that some experiments have shown that recognizing a familiar object is accompanied by a reduction in activity of the brain's memory centers in the medial temporal lobe. Such a reduction seems counterintuitive, since remembering seems to be a positive event.

One of the neural oddities of "declarative" memory--the recall of past things and events--is that some experiments have shown that recognizing a familiar object is accompanied by a reduction in activity of the brain's memory centers in the medial temporal lobe. Such a reduction seems counterintuitive, since remembering seems to be a positive event.

Now, researchers led by Anthony D. Wagner, Brian D. Gonsalves, and Itamar Kahn of Stanford University have documented this reduced activity in humans and have demonstrated that the magnitude of the dip corresponds with the familiarity of the objects.

In their experiments reported in the September 1, 2005, issue of Neuron, the researchers asked volunteers to look at series of faces as the subjects' brains were scanned using either of two techniques. One was functional magnetic resonance imaging (fMRI), which gives information on the location and amount of activation of brain regions, and the other was magnetoencephalography (MEG), which reports the precise timing of brain responses. The technique of fMRI uses harmless magnetic fields and radio waves to map blood flow in the brain, which reflects brain activity, and MEG detects the infinitesimal magnetic fields generated by brain electrical activity.

The researchers asked the subjects to rate their familiarity with each face as "remembering" if they strongly recalled the face, "knowing" if they had a feeling of recognizing the face, or "new" if they didn't recall seeing the face before.

The fMRI scans revealed that the decrease in medial temporal lobe activity tracked the level of perceived memory strength for the faces. What's more, the MEG studies revealed that this reduction began very rapidly during the recognition process.

Previous studies of the phenomenon have been done in monkeys and have measured only the electrical changes in individual neurons during memory tasks. Thus, wrote reviewers Chantel Stern and Michael Hasselmo in the same issue of Neuron, "Overall, the innovative use of multimodal techniques in this study reflects an important move toward a tighter integration of neuroimaging data with the vast wealth of data at the cellular and circuit level."

Gonsalves and his colleagues concluded that "medial temporal structures, in the service of declarative memory, support recognition of stimuli that were previously encountered, allowing organisms to discriminate between novel and familiar items. The marked convergence between the present fMRI and MEG correlates of perceived memory strength suggest that graded reductions in medial temporal cortical responses support graded perceptions of item familiarity, providing a basis for such discriminations. As such, medial temporal mechanisms appear to rapidly signal knowledge about an item's relation to one's past."

###

The researchers include Brian D. Gonsalves of Stanford University; Itamar Kahn of Stanford University and Massachusetts Institute of Technology; Tim Curran of University of Colorado, Boulder; Kenneth A. Norman of Princeton University; and Anthony D. Wagner of Stanford University and the Athinoula A. Martinos Center for Biomedical Imaging, MGH/MIT/HMS. This study was supported by the National Science Foundation, NIMH, McKnight Endowment Fund for Neuroscience, Ellison Medical Foundation, and Alfred P. Sloan Foundation.

Gonsalves et al.: "Memory Strength and Repetition Suppression: Multimodal Imaging of Medial Temporal Cortical Contributions to Recognition" Neuron, Vol. 47, 751-761, September 1, 2005, DOI 10.1016/j.neuron.2005.07.013 www.neuron.org


Story Source:

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


Cite This Page:

Cell Press. "The 'Been There, Done That' Memory Response." ScienceDaily. ScienceDaily, 6 September 2005. <www.sciencedaily.com/releases/2005/09/050906080147.htm>.
Cell Press. (2005, September 6). The 'Been There, Done That' Memory Response. ScienceDaily. Retrieved April 19, 2014 from www.sciencedaily.com/releases/2005/09/050906080147.htm
Cell Press. "The 'Been There, Done That' Memory Response." ScienceDaily. www.sciencedaily.com/releases/2005/09/050906080147.htm (accessed April 19, 2014).

Share This



More Mind & Brain News

Saturday, April 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Study On Artists' Brain Shows They're 'Structurally Unique'

Study On Artists' Brain Shows They're 'Structurally Unique'

Newsy (Apr. 17, 2014) The brains of artists aren't really left-brain or right-brain, but rather have extra neural matter in visual and motor control areas. Video provided by Newsy
Powered by NewsLook.com
Is Apathy A Sign Of A Shrinking Brain?

Is Apathy A Sign Of A Shrinking Brain?

Newsy (Apr. 17, 2014) A recent study links apathetic feelings to a smaller brain. Researchers say the results indicate a need for apathy screening for at-risk seniors. Video provided by Newsy
Powered by NewsLook.com
Are School Dress Codes Too Strict?

Are School Dress Codes Too Strict?

AP (Apr. 16, 2014) Pushing the limits on style and self-expression is a rite of passage for teens and even younger kids. How far should schools go with their dress codes? The courts have sided with schools in an era when school safety is paramount. (April 16) Video provided by AP
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. 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:
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