PT  - JOURNAL ARTICLE
AU  - Ronald van den Berg
AU  - Wei Ji Ma
TI  - A rational theory of the limitations of working memory and attention
AID  - 10.1101/151365
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 151365
4099  - http://biorxiv.org/content/early/2017/06/18/151365.short
4100  - http://biorxiv.org/content/early/2017/06/18/151365.full
AB  - The precision with which items are encoded in working memory and attention decreases with the number of encoded items 1–4. Current theories typically account for this “set size effect” by postulating a hard constraint on the allocated amount of encoding resource, commonly formalized as samples, spikes, slots, or bits. While these theories have produced models that are quantitatively successful, they offer no principled explanation for the very existence of set size effects: given their detrimental consequences for behavioral performance, why have these effects not been weeded out by evolutionary pressure, for example by scaling the amount of allocated encoding resource with set size? Here, we propose a theory that is based on an ecological notion of rationality: set size effects establish an optimal trade-off between behavioral performance and the neural costs associated with stimulus encoding. We derive models from this theory for four visual working memory and attention tasks and find that it accounts well for data in eleven different experiments. Our results suggest that set size effects have a rational basis and that ecological costs should be considered in models of human behavior.