Incidentally encoded temporal associations produce priming in implicit memory

A key assumption of some leading memory theories is that information about the relative order of events is automatically encoded whenever memories are formed and automatically retrieved whenever events are remembered. This information is often used to guide memory search: Remembering one event tends to trigger the retrieval of other events previously experienced nearby in time (temporal contiguity effect). The retrieved context framework attributes this temporal contiguity effect to automatic encoding and retrieval processes, predicting temporal contiguity even in incidental encoding and implicit retrieval. There is strong evidence of temporal contiguity following incidental encoding, but does the prediction hold for implicit retrieval? In this experiment, we tested the framework’s predictions for recall and repetition priming. Across 30 trials, undergraduates (n=603\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$n = 603$$\end{document}) read a series of words aloud as they appeared onscreen. In each trial, two words were repeated (cue and target), initially separated by |lag|=\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$| =$$\end{document} 1, 2, or 5. On their second presentation, the cue word was presented first, immediately followed by the target word. We found a strong temporal contiguity effect in a surprise free recall test, replicating previous work with explicit retrieval. For implicit retrieval, we compared repetition priming (how quickly subjects began reading a word on its first versus second presentation) for cue and target words. Repeating a cue word enhanced repetition priming for its associated target word, and this effect varied with the initial lag between the cue and target. These results support theories that assume temporal information is encoded and retrieved automatically.