Don't I know you? Research sheds light on memorial retrieval

Dec 07, 2009

We have all had the embarrassing experience of seeing an acquaintance in an unfamiliar setting. We know we know them but can't recall who they are. But with the correct cues from conversation or context, something seems to click and we can readily access very rich and vivid memories about the individual.

A team of researchers from the University of Toronto and the Krembil Neuroscience Centre at the University Health Network have shed some light on this mysterious process, discovering that the hippocampus, a brain region in the temporal lobe, is only involved when cues enable us to recall these rich memories.

"We used a technique called (fMRI) that allows us to identify brain regions engaged during specific types of mental processes," says Melanie Cohn, a postdoctoral fellow in and lead author of the paper published online today by the at www.pnas.org

In the first stage of the study, healthy young adults were exposed to pairings of oddly unrelated words, such as "alligator" and "chair", and invited to learn them by putting them in the same sentence and so on. Next, while being scanned in the fMRI, participants were shown a series of single words - some of which had been studied in the word pairings and some of which had not. Participants were asked to rate their memory for each word in terms of how confident they were that it was a word that they had studied earlier or not.

After each decision, participants were given a cue: the word was presented along with the word it was initially paired with. For about half of the familiar words, ie those that subjects recalled learning earlier, the pairing triggered rich detailed memories of the context -- such as the sentence they had made up to include both words -- in which the original pairing was learned. The fMRI scan showed hippocampus activity only when cues were used to retrieve memories.

"This study is important because it resolves a current debate on the role of the hippocampus in retrieving memories. Some have argued it is the strength of the memory that matters most in retrieval. We have shown it is actually context that activates the hippocampus," explains Cohn. The findings also have direct relevance to understanding the type of memory problems found in Epilepsy or Alzheimer's, diseases in which patients have suffered damage to the "Being able to characterize specific types of loss will lead to development of better clinical measures for diagnosis and monitoring of temporal-lobe dysfunction," she says.

Source: University of Toronto (news : web)

Explore further: Omega-3 fatty acids and vitamin D may control brain serotonin

add to favorites email to friend print save as pdf

Related Stories

Memory trick shows brain organization

Aug 28, 2008

A simple memory trick has helped show UC Davis researchers how an area of the brain called the perirhinal cortex can contribute to forming memories. The finding expands our understanding of how those brain areas that form ...

Stress-related disorders affect brain's processing of memory

Dec 03, 2008

Researchers using functional MRI (fMRI) have determined that the circuitry in the area of the brain responsible for suppressing memory is dysfunctional in patients suffering from stress-related psychiatric disorders. Results ...

Recommended for you

Omega-3 fatty acids and vitamin D may control brain serotonin

14 hours ago

Although essential marine omega-3 fatty acids and vitamin D have been shown to improve cognitive function and behavior in the context of certain brain disorders, the underlying mechanism has been unclear. In a new paper published ...

Researchers develop method for mapping neuron clusters

17 hours ago

A team of scientists has developed a method for identifying clusters of neurons that work in concert to guide the behavior. Their findings, which appear in the journal Neuron, address a long-standing mystery about the or ...

One brain area, two planning strategies

21 hours ago

Ready to strike, the spear fisherman holds his spear above the water surface. He aims at the fish. But he is misled by the view: Due to the refraction of light on the surface, he does not see the actual location ...

Study maps extroversion types in the brain's anatomy

Feb 26, 2015

Everyday experience and psychological studies alike tell us that there are two different types of extroverts: The gregarious "people-persons" who find reward in sharing affection and affiliation with others, ...

User comments : 0

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.