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. Author manuscript; available in PMC: 2015 Jun 1.
Published in final edited form as: Psychol Sci. 2014 Apr 22;25(6):1227–1234. doi: 10.1177/0956797614526415

Figure 3. Effects of Methylphenidate and Prior Regulation on Reaction Time Variability.

Figure 3

A. With placebo pretreatment, engaging in prior sustained regulation increased reaction time variability—thought to reflect diminished control over attentional distractions and ‘mind wandering’—during trials requiring regulatory control in a second task. This effect was abolished with methylphenidate pretreatment. B. The effects of prior regulation and methylphenidate were quite similar in the sigma (Gaussian variability) and tau (exponential variability) parameters. C. Histogram showing the reaction time profile for the average subject in the Placebo/Post-Regulation condition versus the Methylphenidate/Post-Regulation condition. Relative to the Methylphenidate-Post-Regulation profile, the Placebo-Post-Regulation profile has a similar mean, but greater mass to the right of the mean and a longer tail. @=p<0.1. Error bars represent standard error of the mean.