Overview of the two studies.

Demographic information for the two study iterations.

Summary of task procedure for Study 2. The top arrow shows the overall procedure with a simplified schematic of two Wheel Stopping task blocks shown underneath. Participants also rated subjective stress levels on similar slider rating scales (not shown here).

a) Parameter estimates across all participants. b) Correlation coefficients between predicted and actual control ratings for both studies. c) Control rating responses over the time course of the experiment predicted from the model (red) plotted against the actual ratings (blue) for 3 randomly selected participants per study, with the correlation coefficient (r) per participant shown in the top right of each subplot.

Negative association between subjective control and subjective stress during the Wheel Stopping task for both studies. Points represent raw data and lines represents the estimated relationship from the linear mixed effects models in Tables 3 and S11, showing the relationship between subjective control and subjective stress, after accounting for perceived task difficulty and random effects of participant and timepoint. Shaded regions represents 95% confidence intervals.

The unique contributions of subjective control and perceived task difficulty on subjective stress during the Wheel Stopping task.

Linear mixed effects models predicting subjective stress from two timepoints: before and after the stressor (stress induction, timepoints 1 and 2), and after the stressor and after the stressor debrief (stress relief, timepoints 2 and 3).

The change in subjective stress between the two respective timepoints: a) Stress Induction – from before to after the stressor, and b) Stress Relief – from after the stressor to after the stressor debrief. Data points show the difference between timepoints per participant. Black points show the mean estimate of the contrast between the two timepoints from the linear mixed effects models in Table 4 (with 95% confidence intervals as error bars). The comparison shows the difference between these contrasts.

Descriptive statistics across the 4 conditions from Study 1.

Descriptive statistics across the 6 conditions in Study 2. Given that the Study 2 analyses compared group differences, we assessed group differences in demographic and questionnaire measures using a one-way ANOVA for continuous variables or a Chi-squared test for categorical variables.

Methodological details for both studies.

Mean BIC (across all participants and both studies) for each of the 7 models with different regressors. They are ordered in descending order left to right. The model furthest right was selected as the ‘winning’ model as it has the lowest BIC, although this was not significantly lower than the previous model.

Associations between questionnaire scores and mean task-level subjective control in Study 1, with WS control condition included as a covariate in the linear model. Adjusted p values (padj.) are FDR corrected p values given we ran five different models.

Associations between questionnaire scores and mean task-level subjective control in Study 2. Control condition was not included as a covariate in the linear model because the WS task was only presented in High Control. Adjusted p values (padj.) are FDR corrected p values given we ran five different models.

Associations between mean subjective control and questionnaire measures in a) Study 1, and b) Study 2. Data points are the data per participant (mean values) and the line represents the estimated relationship from the linear mixed effects models in Tables S4 and S5.

Associations between questionnaire scores and estimated intercept parameter from the computational model predicting control from WS task parameters in Study 1, with WS task control condition included as a covariate in the linear model. Adjusted p values (padj.) are FDR corrected p values given we ran five different models.

Associations between questionnaire scores and estimated intercept parameter from the computational model predicting control from WS task parameters in Study 2. Adjusted p values (padj.) are FDR corrected p values given we ran five different models.

Associations between questionnaire scores and mean task-level stress ratings, with external stressor intensity condition included as a covariate in the linear model for Study 1. Adjusted p values (padj.) are FDR corrected p values given we ran five different models.

Associations between questionnaire scores and mean task-level stress ratings, with external stressor intensity condition included as a covariate in the linear model for Study 2. Adjusted p values (padj.) are FDR corrected p values given we ran five models.

Associations between mean subjective stress and questionnaire measures in a) Study 1, and b) Study 2. Data points are the data per participant (mean values) and the line represents the estimated relationship from the linear mixed effects models in Tables S8 and S9.

Excluding the final timepoint to investigate the effects of control, difficulty and stress during the WS Task for Study 1.

Relationship between subjective control, perceived difficulty and subjective stress during the WS Task in Study 2, also when removing the final WS timepoint and including Domain. Predicted values from the leftmost column (Subjective Stress) model are presented in Figure 3.

Subjective stress ratings across the entire experiment in the different experimental conditions. The point is the mean per group and error bar represents standard error of the mean. Timepoints labelled WS 3, After Stressor, and After Stressor Debrief are the three timepoints used in the stressor controllability analyses isolating the stress induction and stress debrief (coded as timepoints 1, 2, 3). Jitter added to avoid overlap.