Effects of partial sleep deprivation on within-format and cross-format priming

Abstract

Study Objectives: The purpose of this study was to examine the effects of sleep on long-term priming. We report the results of a preliminary experiment that enabled us to verify that priming can last for 4 hours, and we also report the results of a study of partial sleep-deprivation. Design: Subjects performed 2 tasks: within-format and cross-format priming. Settings: Sleep laboratory. Participants: Ninety-eight healthy young subjects participated in the 2 studies reported here: 48 in the preliminary experiment and 50 in the sleep-deprivation study. Intervention: Testing after a 4-hour diurnal retention interval (Experiment 1) or after an equivalent interval filled with early or late sleep, or corresponding periods of wakefulness (Experiment 2). Measurements and Results: A tachistoscopic identification paradigm, consisting of naming aloud briefly flashed drawings, was used to assess 2 priming conditions: a same-format or within-format condition (in which items were drawings in the study and test phases) and a different- or cross-format condition (in which the symbolic format of the items differed between the 2 phases: words/drawings). In Experiment 1, we revealed significant priming effects in both conditions after a 4-hour interval. In Experiment 2, only same-format priming effects were observed, but their magnitude was smaller than in Experiment 1. There was no significant difference in priming scores between the sleep and wake groups. Conclusions: Sleep does not appear to have a strong effect on priming. Instead, priming appears to be affected by circadian influences.