A major breakthrough in visual memory research
McGill University in Montreal announced this week that three researchers at the school have made a breakthrough in the study of the origins of visual memory.
The research answers the question “of how and where exactly in the brain the visual information coming from our eyes is first transformed into short-term memories,” the school said in a press release.
The researchers published their findings in the journal Nature Neuroscience.
“Humans and other primates can temporarily encode, store and keep within the focus of attention visual information unavailable to the eyes. This ability, known as working memory, allows past experiences to influence our current thoughts and behaviors, and is crucial to cognitive processes such as abstract thinking, decision-making and action planning,” they concluded after five years of research.
Professor Julio Martinez-Trujillo of McGill’s Department of Physiology, one of the article’s authors, explained the importance of the discovery in slightly more exciting language:
“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.”
The researchers studied the neuronal activity of two macaque monkeys, both tasked with repeatedly memorizing the motion direction of a visual stimulus—in this case a random sequence of dots moving across a computer screen.
After several experiments, the team concluded that there exists a “functional boundary” between the two contiguous areas of the brain responsible for short-term memory; one which encodes information about what the eyes are seeing in the present moment and the other that encodes the “abstract representations” produced by our short-term memory or imagination.
“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,” said McGill PhD student and article co-author Diego Mendoza-Halliday. “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, while enthusiastic about the findings, noted that they came as something of a surprise.
“It is rare to find this kind of sharp boundary in biological systems of any kind,” said 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.”