AsianScientist (Nov. 9, 2017) – In a study published in Nature Neuroscience, researchers from the National University of Singapore (NUS) have discovered a mechanism that could explain how the brain retains working memory when faced with distractions.
Working memory is a form of short-term memory responsible for storing and managing the information required to carry out everyday cognitive tasks, such as reasoning and language comprehension. It operates over short time scales and allows us to focus our attention, resist distractions and guide our decision-making.
The prefrontal cortex plays a central role in maintaining of working memory and suppressing distractors. Past studies have shown that working memory is stored in the activity of populations of neurons in the prefrontal cortex through unchanging neural activity. Such findings suggest that the activity of the neurons is unaffected by distractions, allowing for information to be retained.
In this study, a team of researchers led by Assistant Professor Yen Shih-Cheng from the Department of Electrical and Computer Engineering at NUS discovered that although distractions change the activity of the neurons, those neurons are able to retain information by reorganizing the way they process information.
In other words, the code used by the neurons to maintain memory information takes on a different configuration after a distractor is presented. This unexpected finding has strong implications for our understanding of how the brain processes information, which in turn may lead to inspiration for research in artificial intelligence, as well as neuropsychiatric research, where deficits in memory and attention are common.
“Our study could provide inspiration for new types of computer architectures and learning rules used in artificial neural networks modelled after the brain. This could potentially enhance the neural network’s ability to store information flexibly using fewer resources, and to exhibit greater resilience in retaining information in these networks—for instance, in the presence of new incoming information or disruption to the activity,” said Yen.
The researchers also found that when memory is disturbed, the code failed to reorganize the neurons appropriately. Since patients with Parkinson’s disease, schizophrenia and dementia show declines in working memory, this research could lead to a better understanding of such disease states.
Moving forward, the team plans to conduct further studies to understand the conditions that trigger the reorganization of information in the populations of neurons in the prefrontal cortex. The team is also interested to study how the information is reorganized, and whether this affects activity in other parts of the brain. Furthermore, the researchers hope to use the findings of the study to develop novel neural network architectures.
The article can be found at: Parthasarathy et al. (2017) Mixed selectivity morphs population codes in prefrontal cortex.
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Source: National University of Singapore; Photo: Shutterstock.
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