*3.8. n-Back Test Scoring*

For each trial (i.e., each morning, afternoon, evening per study day), the participants' response time and the correctness/incorrectness of responses were recorded. We calculated four different scores for the n-back tests: median reaction time and percent correct, stratified by congruent vs. incongruent items. We treated all reaction times the same and did not segment or weigh based on items that the participants got correct vs. incorrect. Each participant was then given a cognitive score based on a self-created scoring function (Equation (1)) of the reaction time, degree of difficulty of question, and correctness. The metric accounts for variation across multiple elements of the n-back results leading to a greater representation of performance. The formula for the metric is

$$\frac{\sum\left(1 - \frac{\text{Racation Time}}{\text{Max Racation Time}}\right) \* \text{Answer Correct} \* \frac{\text{Step Rack}}{2}}{n} \tag{1}$$
