Study reveals how the brain organizes memories?

In a scientific precedent, researchers at the University of California, Irvine, have discovered basic mechanisms by which the hippocampus in the brain organizes memories into a series of segments, a discovery that may constitute an important early step towards understanding the manifestations of memory failure in cognitive disorders such as Alzheimer's disease and other forms of dementia. .

The researchers, according to what was reported in the journal Nature Communications and reported by Science Daily , by integrating electrical recording techniques in rodents with statistical machine learning analysis of a huge set of data, revealed evidence indicating that the hippocampal network , encodes and maintains the progress stages of experiments to aid decision making.

Norbert Forten, professor of neurobiology and behavior at the University of California, Berkeley, points out that "the human brain keeps a very good record of when certain experiences or events occur. It is an ability that helps us make decisions in our daily lives, but before this study we did not have a clear idea of ​​the mechanisms The nervous system is behind these operations.

Neurological disorders

"What matters here is that this type of memory is severely impaired in a variety of neurological disorders, or simply with aging, so we really need to know how this brain function works."

The research project, which took more than 3 years to complete, included experimental and data analysis phases, in which the researchers monitored the firing of neurons in the brains of mice while they were subjected to a series of smell recognition tests. By presenting 5 different scents in different sequences, the scientists were able to measure the animals' memory of the correct sequence, and discover how their brains were able to remember these sequence relationships.

Fortin describes this process: "The analogy I'm going to think of is computing. If I were to stick electrodes in your brain - which we can't do, so we use mice - I could at any moment see which cells were firing and which weren't (activated or not)," This gives us some insight into how the brain represents and computes information. When we record patterns of activity in a structure, it's as if we're seeing zeros and ones in a computer."

A dynamic picture of how the brain works

Measurements of neural activity and inactivity, obtained in millisecond intervals over minutes, provide a dynamic picture of how the brain works.

Fortin asserts, he and his colleagues were sometimes able to "read the minds" of the test organisms, by watching the cells "encode" (which signals and which don't) in rapid succession.

Fortin and his co-authors knew early on that readings of hippocampal activity would lead to massive amounts of raw data, so from the early stages of the project he enlisted the participation of statisticians from the University of California's Donald Breen School of Information and Computer Science.

Babak Shahbaba, professor of statistics at the university and senior author of the study, said, "Emerging neuroscience studies rely on data science methods because of the complexity of their data. Brain activities are recorded on a millisecond scale, and these experiments last for more than an hour, so you can imagine how quickly the amount of data grows."

He noted that when neurons encode information such as memories, scientists can get a glimpse into this process, by examining the pattern of escalating activity across all neurons.

Dealing with neural patterns as images

“We found that we could treat these neural patterns as images, and this unlocked our ability to apply deep machine learning methods,” Shahbaba said. “We analyzed the data using a convolutional neural network, a methodology frequently used in image processing applications such as facial recognition.” .

In this way, the researchers were able to decode the firing of neurons to retrieve the information.

Shahbaba said the tools and methodologies developed during this project can be applied to a wide range of problems, and Fortin may expand his line of investigation to include other areas of the brain.