Objective measures taken at each time point included salivary cortisol, the Digit-Symbol Substitution Test (DSST; (Wechsler, 1955), and the Grooved Pegboard (Lafeyette Industries, Lafeyette, Indiana). Salivary cortisol was obtained via a plain cotton swab (Sarstedt, Sarstedt, Germany) and later stored in a −80 °C freezer until assayed using a high sensitivity salivary cortisol enzyme immunoassay kit (Salimetrics, State College, PA). The DSST and Grooved Pegboard are psychomotor performance tasks that measure cognitive-motor processing speed and fine motor coordination, respectively, and were previously described in detail in (Brumback et al., 2007).
