Winter 2015

Working Memory Capacity: Limits on the Bandwidth of Cognition

Earl K. Miller and Timothy J. Buschman

Why can your brain store a lifetime of experiences but process only a few thoughts at once? In this article we discuss “cognitive capacity” (the number of items that can be held “in mind” simultaneously) and suggest that the limit is inherent to processing based on oscillatory brain rhythms, or “brain waves,” which may regulate neural communication. Neurons that “hum” together temporarily “wire” together, allowing the brain to form and re-form networks on the fly, which may explain a hallmark of intelligence and cognition: mental flexibility. But this comes at a cost; only a small number of thoughts can fit into each wave. This explains why you should never talk on a mobile phone when driving.

EARL K. MILLER is the Picower Professor of Neuroscience at the Massachusetts Institute of Technology. His recent publications include articles in such journals as Science, Nature, Proceedings of the National Academy of Sciences, and Neuron.

TIMOTHY J. BUSCHMAN is an Assistant Professor in the Department of Psychology at Princeton University. He has published articles in such journals as Neuron, Proceedings of the National Academy of Sciences, and Science.

To read this essay or subscribe to Dædalus, visit the Dædalus access page
Access now