Executive functions

The Colour-Word-Interference Test (based on the Stroop effect [71]) is a frequently used neuropsychological test to assess inhibitory control [72, 73]. Here, the participants have to read out loud and as fast as possible nine tables. These tables consist of three different consecutive tasks that are presented three times: (i) read colour names (printed in black ink), (ii) name the colour of colour bars, (iii) name ink colour of colour names (printed colour never matches the written colour name) [71, 73]. The (iii) task is the incongruent condition requiring to inhibit the more automated task (e.g. reading the colour name), which is called the Stroop effect [71, 73]. The required time is stopped individually for each table and the corrected and uncorrected errors are determined for condition (iii). Additionally, the time difference between (ii) and (iii) is calculated [74]. In this study the German paper-pencil version of the Colour-Word-Interference Test will be used (Farbe-Wort-Interferenztest, [75]).

The Trail Making Test (TMT) is a neuropsychological test of visual search, processing speed and cognitive flexibility [76]. It consists of two tasks A and B, each requiring to connect 25 consecutive targets as quickly and accurately as possible. In part A, numbers (1–25) presented randomly on a piece of paper have to be connected in ascending order as fast as possible. Part B requires mental shifting between presented numbers (1–13) and letters (A-L). They have to be connected in alternating order (1, A, 2, B…). The processing time for each part will be recorded.