Balancing Flexibility and Interference in Working Memory

Working memory is central to cognition, flexibly holding the variety of thoughts needed for complex behavior. Yet, despite its importance, working memory has a severely limited capacity, holding only three to four items at once. In this article, I review experimental and computational evidence that the flexibility and limited capacity of working memory reflect the same underlying neural mechanism. I argue that working memory relies on interactions between high-dimensional, integrative representations in the prefrontal cortex and structured representations in the sensory cortex. Together, these interactions allow working memory to flexibly maintain arbitrary representations. However, the distributed nature of working memory comes at the cost of causing interference between items in memory, resulting in a limited capacity. Finally, I discuss several mechanisms used by the brain to reduce interference and maximize the effective capacity of working memory.

Automated summary

Working memory is crucial for cognition, but has a limited capacity of only three to four items at once. It relies on interactions between the prefrontal cortex and sensory cortex to maintain arbitrary representations flexibly, while the distributed nature of working memory leads to interference and limits its capacity. To maximize effective capacity, the brain uses mechanisms to reduce interference.