# Results and Analyses # -------------------- ## Data Reduction Eprime data files from the Letter E task and MSIT task ([click here to download zip file of individual files][1]) were concatenated (into files LetterE_EData.txt and MSIT200_EData.txt) and then combined with participants' self-report data using the R analysis script. The analysis script created two output files: BDEC_Results_Full.csv and BDEC_Results_Lite.csv. A separate dataset containing the primary variables necessary for the analysis was then created containing only those participants who met the necessary inclusion criteria (EgoDepletion_Analysed Dataset.csv). ## Analysis The file EgoDepletion_Analysed Dataset.csv was analysed using the [statistical software package JASP 0.7][2] to test the research hypotheses outlined in the preregistration. ## Results ### Participant We recruited participants (N = 86, males = 27, females = 59, M age = 22.71 years, SD = 3.94) through local student job search websites and paper notices placed on local noticeboards around the Massey University campus in Palmerston North, NZ. Participants were given a NZD$10 grocery voucher in thanks for their participation. All participants satisfactorily followed the instructions and met the specified inclusion criteria having English as their first-spoken language and being between 18 and 30 years old. Eleven participants were excluded because their performance on the letter ‘e’ task and MSIT fell below 80% accuracy or had mean reaction time or mean reaction time variability values that fell outside two standard deviations of the sample mean on the MSIT. The final sample comprised 38 participants in the hard letter ‘e’ (ego-depletion) condition and 37 participants in the easy letter ‘e’ (control) condition. Natalie Nikora, Olivia Sievwright, Katie Knapp, Adam Burston, and Randi Nehls served as the experimenters. Experimenter blinding was achieved, in part, by having one experimenter administer the Letter E task and the other administer the MSIT task. The experimenter who administered the MSIT task remained unaware of which version of the Letter E task that had been administered to each participant. Experimenters were also blind to the focal dependent variable of the study. At the conclusion of data collection none of the experimenters guessed that the primary measure of the MSIT task was reaction time variability. We deviated from the procedures of our preregistered plan only in that some of our experimenters differed from those named in the preregistration. The other procedures were followed according to our preregistered plan. ### Critical analyses **1–> Incongruent RTV comparison** Independent samples t-test comparing the ex-Gaussian fitted mean overall response time variability (RTV) for the incongruent items on the MSIT [note this is the ExGauss.I.RTVar.MSIT column in the output file] across the ego-depletion and control conditions. - Ego-depletion: n = 38; M RTV= 0.309; SD = 0.076; SE = 0.012 - Control: n = 37; M RTV = 0.312; SD 0.074; SE = 0.012 - t(73) =-0.167, p = .868, d = -0.04 **2–> Incongurent RT comparison.** Independent samples t-test comparing the mean overall response time (RT) for the incongruent items on the MSIT [note this is the I_1_MeanRT.MSIT column in the output file] across the ego-depletion and control conditions. - Ego-depletion: n = 38; M RT= 0.95; SD = 0.16; SE = 0.027 - Control: n = 37; M RT = 0.97; SD = 0.13; SE = 0.022 - t(73) = -0.659, p = .512, d = -0.15 **3–> Manipulation check.** A series of independent samples t-tests comparing all participants’ mean ratings of effort, fatigue, difficulty, and frustration across the ego-depletion and control conditions (with positive t’s indicating larger rating in the ego-depletion group). **Ego-depletion** - Effort, M = 5.53; SD = 1.08; SE = 0.18; - Fatigue, M = 3.60; SD = 1.75; SE = 0.28; - Difficulty, M = 3.97; SD = 1.30; SE = 0.21; - Frustration, M = 3.37; SD = 1.60; SE = 0.26 **Control** - Effort, M = 4.29; SD = 1.78; SE = 0.29; - Fatigue, M = 3.27; SD = 1.73; SE = 0.28; - Difficulty, M = 2.22; SD = 1.11; SE = 0.18; - Frustration, M = 2.22; SD = 1.68; SE = 0.28 **t-tests** - An adjusted degrees of freedom was used for the Effort analysis due to a significant Levene’s test. - Effort (t(59.24) = 3.60, M difference = 1.23, p < .001,); - Fatigue (t(73) = 0.84, M difference = 0.34, p = .407,); - Difficulty (t(73) = 6.28, M difference = 1.76, p < .001,); - Frustration (t(73) = 3.04, M difference = 1.15, p < .001,) ### Supplemental analyses **Letter E task accuracy.** An independent samples t-test for differences in overall accuracy on the letter ‘e’ task [note this is the ‘Acc.Overall.LetE’ column in the output file] across the hard (ego-depletion) and easy (control) conditions: Ego-depletion: n = 38; M accuracy = .943; SD = .050; SE = .0080 Control: n = 37; M accuracy = .997; SD = .005; SE = .0008 An adjusted degrees of freedom was used due to a significant Levene’s test. t(37.72) = 6.71, p < .001, d = 2.18 [1]: https://osf.io/project/9yikn/files/osfstorage/55be7b2b8c5e4a21794f116a/ [2]: https://jasp-stats.org