Negative reinforcement impairs overnight memory consolidation

Abstract

Post-learning sleep is beneficial for human memory. However, it may be that not all memories benefit equally from sleep. Here, we manipulated a spatial learning task using monetary reward and performance feedback, asking whether enhancing the salience of the task would augment overnight memory consolidation and alter its incorporation into dreaming. Contrary to our hypothesis, we found that the addition of reward impaired overnight consolidation of spatial memory. Our findings seemingly contradict prior reports that enhancing the reward value of learned information augments sleep-dependent memory processing. Given that the reward followed a negative reinforcement paradigm, consolidation may have been impaired via a stress-related mechanism.

Sleep enhances a spatially mediated generalization of learned values

“…Conflicting evidence suggests that sleep might specifically alter representations of salient high-value objects (Hu et al 2006;Payne et al 2008;Fischer and Born 2009;Wilhelm et al 2011;Van Dongen et al 2012;Stamm et al 2014) or have no specific effect on salient objects Tucker et al 2011;Baran et al 2013). Our results support the view that sleep specifically affects memory for salient, motivationally relevant stimuli.…”

“…While the negative impact of sleep on memory is consistent with Stamm et al (2014), a number of differences in experimental design between our study and Stamm et al (2014) should be considered. Akin to our study, Stamm et al (2014) had participants learn to navigate to objects associated with value in a virtual town.…”

“…We argue that they may have failed to Cold Spring Harbor Laboratory Press on May 9, 2018 -Published by learnmem.cshlp.org Downloaded from notice any difference in estimation of value because participants responded to value question only when they were certain. While a number of studies have found sleep-related enhancement memory for salient stimuli (Hu et al 2006;Payne et al 2008;Fischer and Born 2009;Javadi et al 2011;Wilhelm et al 2011;Van Dongen et al 2012), in the case of spatial navigation sleep has been reported to impair memory for rewarded objects (Stamm et al 2014). In addition, memory for items seen again in the same context has also been found to be worse after sleep .…”

“…Several studies have shown the amount of value or reward associated with items does not necessarily modulate sleep-dependent memory consolidation Tucker et al 2011;Baran et al 2013). Indeed, when post-sleep task performance determines how much reward can be gained, sleep can impair memory performance (Stamm et al 2014).While research has begun to explore how different stimuli properties affect sleep-dependent memory such studies used discrete, sequentially presented stimuli, with fixed temporal durations. This stands in contrast to real-world settings, where stimuli such as objects exist embedded in a spatially organized context and items are often encountered on several different occasions as part of travel through the world.…”

“…Several studies have shown the amount of value or reward associated with items does not necessarily modulate sleep-dependent memory consolidation Tucker et al 2011;Baran et al 2013). Indeed, when post-sleep task performance determines how much reward can be gained, sleep can impair memory performance (Stamm et al 2014).…”