Discovery sheds light on where visual memories are born

August 11, 2014
Important advance in brain mapping and memory

"When a tiger starts to move towards you, you need to know whether it is something you are actually seeing or whether it's just something that you remember or have imagined," says Prof. Julio Martinez-Trujillo of McGill's Department of Physiology. The researcher and his team have discovered that there is a clear frontier in the brain between the area that encodes information about what is immediately before the eyes and the area that encodes the abstract representations that are the product of our short-term memory or imagination. It is an important advance in brain mapping and opens the doors to further research in the area of short-term memory.

These finding, which are described in an article just published in Nature Neuroscience, resolve a question that has occupied neuroscientists for years. Namely that of how and where exactly in the the coming from our eyes is first transformed into short-term memories.  "We found that while one area in the brain processes information about what we are currently seeing, an area right beside it stores the information in short-term memory," says McGill PhD student Diego Mendoza-Halliday, first author of the article.  "What is so exciting about this finding is that until now, no one knew the place where visual information first gets transformed into short-term memory."

The researchers arrived at this conclusion by measuring the in these two areas in the brains of macaques as they first looked at, and then after a short time (1.2 - 2 seconds) remembered, a random sequence of dots moving across a computer screen like rainfall. What surprised Martinez-Trujillo and his team was how clearly demarcated the divide was between the activities and functions of the two brain areas, and this despite the fact that they lie side-by-side.

"It is rare to find this kind of sharp boundary in of any kind," says Martinez-Trujillo. "Most of the time, when you look at the function of different brain areas, there is more of a transitional zone, more grey and not such a clear border between black and white. I think the evolutionary reason for this clear frontier is that it helped us to survive in dangerous situations."

The discovery comes after five years spent by Martinez-Trujillo and his team doing research in the area. Despite this fact, he acknowledges that there was a certain amount of serendipity, and a lot of technological help involved in being able to capture a signal that travels for 3 milliseconds and fires synapses in neurons that lie right beside one another.

Martinez-Trujillo and his team continue to work on mapping the receptors and connectivity between these two areas of the brain. But what is most important for him is to try and relate this discovery to schizophrenia and other diseases that involve hallucinations, and in order to do so he is working with a psychiatrist at Montreal's Douglas Hospital.

Explore further: How do we split our attention?

More information: "Sharp emergence of feature-selective sustained activity along the dorsal visual pathway"  by Mendoza-Halliday et al in Nature Neuroscience: dx.doi.org/10.1038/nn.3785

Related Stories

How do we split our attention?

December 21, 2011
McGill's Cognitive Neurophysiology Lab team finds that we are natural-born multi-taskers.

Short-term memory of crows relies on different neural mechanisms than humans

June 5, 2014
German researchers discover neurons allowing crows to remember short-term – although their brains are different from ours.

Filters that reduce 'brain clutter' identified

April 14, 2011
(PhysOrg.com) -- McGill researchers suggest malfunctions in neurons that filter visual information may be responsible for diseases such as ADHD and schizophrenia.

Do not disturb: How the brain filters out distractions

July 4, 2014
You know the feeling? You are trying to dial a phone number from memory… you have to concentrate…. then someone starts shouting out other numbers nearby. In a situation like that, your brain must ignore the distraction ...

Short-term memory is based on synchronized brain oscillations

January 31, 2012
Scientists have now discovered how different brain regions cooperate during short-term memory.

How chronic pain disrupts short term memory

February 7, 2013
A group of Portuguese researchers from IBMC and FMUP at the University of Porto has found the reason why patients with chronic pain often suffer from impaired short –term memory. The study, to be published in the Journal ...

Recommended for you

Cognitive cross-training enhances learning, study finds

July 25, 2017
Just as athletes cross-train to improve physical skills, those wanting to enhance cognitive skills can benefit from multiple ways of exercising the brain, according to a comprehensive new study from University of Illinois ...

Brain disease seen in most football players in large report

July 25, 2017
Research on 202 former football players found evidence of a brain disease linked to repeated head blows in nearly all of them, from athletes in the National Football League, college and even high school.

Lutein may counter cognitive aging, study finds

July 25, 2017
Spinach and kale are favorites of those looking to stay physically fit, but they also could keep consumers cognitively fit, according to a new study from University of Illinois researchers.

Zebrafish study reveals clues to healing spinal cord injuries

July 25, 2017
Fresh insights into how zebrafish repair their nerve connections could hold clues to new therapies for people with spinal cord injuries.

Brain stimulation may improve cognitive performance in people with schizophrenia

July 24, 2017
Brain stimulation could be used to treat cognitive deficits frequently associated with schizophrenia, according to a new study from King's College London.

New map may lead to drug development for complex brain disorders, researcher says

July 24, 2017
Just as parents are not the root of all their children's problems, a single gene mutation can't be blamed for complex brain disorders like autism, according to a Keck School of Medicine of USC neuroscientist.

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.