Implicit preferences are malleable, but does that change last? We tested nine interventions (eight real and one sham) to reduce implicit racial preferences over time. In two studies with a total of 6,321 participants, all nine interventions immediately reduced implicit preferences. However, none were effective after a delay of several hours to several days. We also found that these interventions did not change explicit racial preferences and were not reliably moderated by motivations to respond without prejudice. Short-term malleability in implicit preferences does not necessarily lead to long-term change, raising new questions about the flexibility and stability of implicit preferences.Word Count: 100 Keywords: attitudes, racial prejudice, implicit social cognition, malleability, Implicit Association Test Full CitationLai, C. K., Skinner, A. L., Cooley, E., Murrar, S., Brauer, M., Devos, T., Calanchini, J., Xiao, Y. J., Pedram, C., Marshburn, C. K., Simon, S., Blanchar, J. C., Joy-Gaba, J. A., Conway, J., Redford, L., Klein, R. A., Roussos, G., Schellhaas, F. M. H., Burns, M., Hu, X., McLean, M. C., Axt, J. R., Asgari, S., Schmidt, K., Rubinstein., R, Marini, M., Rubichi, S., Shin,. J. L., & Nosek, B. A. (2016). Reducing implicit racial preferences: II. Intervention effectiveness across time. Journal of Experimental Psychology: General, 145, 1001-1016. REDUCING IMPLICIT RACIAL PREFERENCES 3 Reducing Implicit Racial Preferences: II. Intervention Effectiveness Across TimeEarly theories of implicit social cognition suggested that implicit associations were largely stable. These claims were supported by evidence that changes in conscious belief did not lead to corresponding changes in implicit associations (e.g., Devine, 1989;Wilson, Lindsey, & Schooler, 2000). The psychologist John Bargh referred to the stability of implicit cognitions as the "cognitive monster": "Once a stereotype is so entrenched that it becomes activated automatically, there is really little that can be done to control its influence" (p. 378, Bargh, 1999). This dominant view has changed over the past fifteen years to one of implicit malleability, with many studies finding that implicit associations are sensitive to lab-based interventions (for reviews, see Blair, 2002;Gawronski & Bodenhausen 2006;Lai, Hoffman, & Nosek, 2013). These interventions vary greatly in approach. In one, for example, participants are exposed to images of people who defy stereotypes (e.g., admired Black people / hated White people; Joy-Gaba & Nosek, 2010). In another, participants are given goals to override implicit biases (e.g., Mendoza, Gollwitzer, & Amodio, 2010;Stewart & Payne, 2008).In most of the research on implicit association change, the short-term malleability of associations is tested by administering an implicit measure immediately after the intervention. Studies examining long-term change in implicit associations are rare. In a meta-analysis on experiments to change implicit associations (Forscher, Lai, et al., 2016), only 22 (3.7%) of 585 studies ...

Targeted memory reactivation (TMR) is a methodology employed to manipulate memory processing during sleep. TMR studies have great potential to advance understanding of sleep-based memory consolidation and corresponding neural mechanisms. Research making use of TMR has developed rapidly, with over 70 articles published in the last decade, yet no quantitative analysis exists to evaluate the overall effects. Here we present the first meta-analysis of sleep TMR, compiled from 91 experiments with 212 effect sizes (N ϭ 2,004). Based on multilevel modeling, overall sleep TMR was highly effective (Hedges' g ϭ 0.29, 95% CI [0.21, 0.38]), with a significant effect for two stages of non-rapid-eyemovement (NREM) sleep (Stage NREM 2: Hedges' g ϭ 0.32, 95% CI [0.04, 0.60]; and slow-wave sleep: Hedges' g ϭ 0.27, 95% CI [0.20, 0.35]). In contrast, TMR was not effective during REM sleep nor during wakefulness in the present analyses. Several analysis strategies were used to address the potential relevance of publication bias. Additional analyses showed that TMR improved memory across multiple domains, including declarative memory and skill acquisition. Given that TMR can reinforce many types of memory, it could be useful for various educational and clinical applications. Overall, the present meta-analysis provides substantial support for the notion that TMR can influence memory storage during NREM sleep, and that this method can be useful for understanding neurocognitive mechanisms of memory consolidation. Public Significance StatementSensory cues can be used to reactivate associated memories during sleep and thus promote memory consolidation. This meta-analysis shows that targeted memory reactivation during sleep can improve memory performance with a small to moderate effect, and that this effect is most clearly evident when memories are reactivated during Stages 2 and 3 of non-rapid-eye-movement (NREM) sleep.

Although people may endorse egalitarianism and tolerance, social biases can remain operative and drive harmful actions in an unconscious manner. Here we investigated training to reduce implicit racial and gender bias. Forty participants processed counter-stereotype information paired with one sound for each type of bias. Biases were reduced immediately after training. During subsequent slow-wave sleep, one sound was unobtrusively presented to each participant, repeatedly, to reactivate one type of training. Corresponding bias reductions were fortified in comparison to the social bias not externally reactivated during sleep. This advantage remained one week later, the magnitude of which was associated with time in slow-wave and rapid-eye-movement sleep after training. We conclude that memory reactivation during sleep enhances counter-stereotype training, and that maintaining a bias reduction is sleep-dependent.

Implicit preferences are malleable, but does that change last? We tested nine interventions (eight real and one sham) to reduce implicit racial preferences over time. In two studies with a total of 6,321 participants, all nine interventions immediately reduced implicit preferences. However, none were effective after a delay of several hours to several days. We also found that these interventions did not change explicit racial preferences and were not reliably moderated by motivations to respond without prejudice. Short-term malleability in implicit preferences does not necessarily lead to long-term change, raising new questions about the flexibility and stability of implicit preferences.Word Count: 100