Visual memories are stored along a compressed timeline

In continuous recognition the recency effect manifests as a decrease in accuracy and a sublinear increase in response time (RT) with the lag of a repeated stimulus. The recency effect could result from the gradual weakening of mnemonic traces. Alternatively, the recency effect could result from a search through a compressed timeline of recent experience. These two hypotheses make very different predictions about the shape of response time distributions. Using highly-memorable pictures to mitigate changes in accuracy enabled a detailed examination of the effect of recency on retrieval dynamics. The recency at which pictures were repeated ranged over two orders of magnitude across three experiments. Analysis of the RT distributions showed that the time at which memories became accessible changed with the recency of the probe, as predicted by a serial search model suggesting that visual memories can be accessed by sequentially scanning along a compressed representation of the past. In recognition memory experiments participants must determine whether a probe stimulus has been previously experienced or not. As the recency of a repeated probe decreases, the accuracy of the judgment decreases and response time (RT) increases (Donkin & Nosofsky, 2012; Hockley, 1982; Monsell, 1978; Murdock & Anderson, 1975; Shepard & The complete set of images can be downloaded from http://cvcl.mit.edu/MM/stimuli.html. Address correspondence to Marc Howard, Center for Memory and Brain, Department of Psychological and Brain Sciences, 2 Cummington Mall, Boston, MA 02215, [email protected]. Supported by NSF IIS 1631460 and PHY 1444389 (MWH and IS) and a Google award (AO). peer-reviewed) is the author/funder. All rights reserved. No reuse allowed without permission. The copyright holder for this preprint (which was not . http://dx.doi.org/10.1101/101295 doi: bioRxiv preprint first posted online Jan. 18, 2017;