PT  - JOURNAL ARTICLE
AU  - Mark W. Schurgin
AU  - John T. Wixted
AU  - Timothy F. Brady
TI  - Psychophysical Scaling Reveals a Unified Theory of Visual Memory Strength
AID  - 10.1101/325472
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 325472
4099  - http://biorxiv.org/content/early/2018/11/16/325472.short
4100  - http://biorxiv.org/content/early/2018/11/16/325472.full
AB  - Models of visual memory have operated on the assumption that memory representations can be explained in physical stimulus space, leading to proposals that we have fixed limits on visual working memory capacity and there is a strong distinction between working memory and longterm memory representations. Here we show that perception and memory are not based on physical stimulus space, and instead rely on a transformed representation that is non-linearly related to the physical stimulus space. This result calls into question the fundamental basis of nearly all extant models. We show that when psychophysical distance rather than physical distance is considered, aspects of memory that have required fundamentally different models -- across different stimuli, tasks, and even the distinction between working and long-term memory -- can be explained with a unitary signal detection framework. These results lead to a substantial reinterpretation of the relationship between perception, working memory and longterm memory.