Loss of Brain Synchrony May Explain Working Memory Limits

Summary: Trying to retain too much information in our working memory can lead to a breakdown in communication between areas of the brain responsible for maintaining it, researchers say.

Source: City University London.

A new study from City, University of London and MIT may have revealed the reasons behind our memory limitations. The researchers found that trying to retain too much information in our working memory leads to a communication breakdown between parts of the brain responsible for maintaining it.


Read more: http://neurosciencenews.com/brain-synchrony-working-memory-8887/


Abstract

Working Memory Load Modulates Neuronal Coupling

There is a severe limitation in the number of items that can be held in working memory. However, the neurophysiological limits remain unknown. We asked whether the capacity limit might be explained by differences in neuronal coupling. We developed a theoretical model based on Predictive Coding and used it to analyze Cross Spectral Density data from the prefrontal cortex (PFC), frontal eye fields (FEF), and lateral intraparietal area (LIP). Monkeys performed a change detection task. The number of objects that had to be remembered (memory load) was varied (1–3 objects in the same visual hemifield). Changes in memory load changed the connectivity in the PFC–FEF–LIP network. Feedback (top-down) coupling broke down when the number of objects exceeded cognitive capacity. Thus, impaired behavioral performance coincided with a break-down of Prediction signals. This provides new insights into the neuronal underpinnings of cognitive capacity and how coupling in a distributed working memory network is affected by memory load.


Source: George Wigmore – City University London Publisher: Organized by NeuroscienceNews.com. Image Source: NeuroscienceNews.com image is adapted from the City University London news release. Original Research: Open access research for “Working Memory Load Modulates Neuronal Coupling” by Dimitris A Pinotsis, Timothy J Buschman, and Earl K Miller in Cerbreal Cortex. Published March 28 2018. doi:10.1093/cercor/bhy065