NUS researchers have uncovered new insights into the brain’s ability to retain working memory despite distractions, such as when we are interrupted mid-task or when we receive new information. Their findings paint a picture contrary to conventional understanding of how the brain works, suggesting a mechanism for small populations of neurons to flexibly store different types of information, instead of remaining unchanged by disruptions. The research was published online in Nature Neuroscience on 9 October.
Working memory is a type of short-term memory that stores and manages information required for everyday cognitive tasks such as reasoning and language comprehension. It operates over a short time-frame, enabling us to focus despite distractions. Working memory is maintained by the prefrontal cortex of the brain, and is used when we engage in tasks such as recalling a phone number to dial or doing mental sums.
Previously, it was thought that neural activity in the prefrontal cortex is unchanged and unaffected by distractions, allowing for information to be retained.
The NUS study – led by Assistant Professor Yen Shih-Cheng from NUS Electrical and Computer Engineering, and Assistant Professor Camilo Libedinsky from NUS Psychology – showed that it is quite the opposite. Their findings suggest that distractions in fact alter the activity of the neurons, but the brain is able to retain information by reorganising the information within the same population of neurons. The “code” by which the neurons use to maintain memory information morphs into a different one in the presence of a distraction.
The implications and potential from the findings are wide-ranging, from applications in artificial intelligence to neuropsychiatric research that tackles cognitive conditions.
“Our study could potentially 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 Asst Prof Yen.
Asst Prof Libedinsky also considered the results of the study within the context of abnormal brain function, where the neurons fail to reorganise when memory is disturbed. “Patients with Parkinson’s disease, schizophrenia and dementia show declines in working memory. We could like to explore whether the mechanisms we uncovered could help explain these memory deficits,” he said.
Next, the team plans to investigate the conditions that trigger neurons to reorganise the information in the prefrontal cortex, how the information is reorganised and how this may affect other parts of the brain.
See press release.