Memory updating in dreams

Dreaming is influenced by the activation of newly formed memory traces in the sleeping brain, but how this happens is still being investigated. In a study testing whether people dream of recent experiences that overlap with well-established semantic networks, participants received new information about a favorite celebrity. Their dream content was tracked across three consecutive nights, and they were asked about recent and remote memory sources of their dreams. The celebrity manipulation did not affect dream content. However, the dataset offers rich descriptive information about how recent and remote memory fragments are incorporated into dreams and how multiple memory sources combine to create bizarre, imaginative scenarios. These observations are discussed in light of the proposed memory updating function of sleep-dependent memory consolidation and the NEXTUP model of dreaming.

Study at a glance

Abstract

Robert Stickgold's research was among the earliest to rigorously quantify the effect of learning on dream content. As a result, we learned that dreaming is influenced by the activation of newly formed memory traces in the sleeping brain. Exactly how this happens is an ongoing area of investigation. Here, we test the hypothesis that participants are especially likely to dream of recent experiences, which overlap with well-established semantic networks. We created an artificial situation in which participants encountered new information about a person with which they have extensive past experience-a favorite celebrity. We tracked the effect of novel information about a favorite celebrity on participants' dream content across 3 consecutive nights and queried participants about other recent and remote memory sources of their dreams. While the celebrity manipulation failed to affect dream content, this dataset provides rich descriptive information about how recent and remote memory fragments are incorporated into dreams, and how multiple memory sources combine to create bizarre, imaginative scenarios. We discuss these observations in light of the proposed "memory updating" function of sleep-dependent memory consolidation, as well as Stickgold and Zadra's NEXTUP (Network Exploration to Understand Possibilities) model of dreaming. This paper is part of the Festschrift in honor of Dr Robert Stickgold.