Table 1.
Participant characteristics.
Fig 1.
Participants completed implicit bias assessments both before and after a computerized counter-bias training procedure. TMR was then conducted during a 90min nap, and implicit bias was assessed again immediately following the nap. A final IAT and exit questionnaire were administered one week later. Times on right represent minutes elapsed. Green and blue sound icons represent the two distinct auditory cues associated with racial and gender counter-bias training, only one of which was presented during the nap TMR procedure.
Fig 2.
Participants sorted a stimulus (word or picture) in the center of the screen into either the category in the top left or the category in the top right of the screen. For example, in this figure, the correct response would be to sort the word “Chemistry” to the left, as chemistry belongs in the “Science” category. Critically, categories at the top of the screen were comprised of one group (e.g. male or female) paired with one attribute (e.g. science or art). Implicit bias was measured by comparing the speed of sorting stimuli into bias-congruent categories (such as those pictured, where science is associated with male and art is associated with female) with the speed of sorting stimuli into bias-incongruent categories (such as male/arts and female/science).
Fig 3.
Average D600 scores at each IAT timepoint.
Both cued and uncued bias significantly decreased from the baseline to the prenap IATs, with a non-significant increase in cued bias and decrease in uncued bias from the prenap to postnap IATs. Both cued and uncued bias non-significantly increased from the postnap to delayed IATs. The crucial Cueing (cued vs. uncued) x Time (prenap vs. postnap) interaction effect was not significant. Error bars ±SEM.
Table 2.
Race and gender implicit bias levels.
Fig 4.
Change in implicit bias levels at the immediate and one-week delay tests.
Cued and uncued bias did not change differentially from the prenap test to the postnap or 1-week delayed tests. Furthermore, cued bias increased numerically (though non-significantly) at both points and relative to uncued bias.
Table 3.
Implicit bias levels by condition.
Fig 5.
No association between minutes in SWS x minutes in REM and differential bias change.
Table 4.
Sound cue reporting.
Fig 6.
95% CIs for the immediate postnap effect of cueing in Hu et al. [6] and in our replication attempt.
The confidence intervals do not overlap, suggesting that the two studies are not estimates of the same effect. However, our confidence interval overlaps with 0, allowing the possibility of a small effect (Hedges’ g = -0.18) in the direction observed by Hu et al. [6].