Cognitive performance
mistakes
After the beginning and before the end of the 4-h workplace examination subjects performed a math and a spelling test to examine possible effects of mask wearing on cognitive performance. The duration of each test, which ran automatically on a computer, was 11 min and the spelling test was administered after the math test.After the instruction, which was shown for 5 s, each of the 93 tasks was visible for 7 s. The elapsed time was displayed in the form of a progress bar below the task. Subjects were asked to answer as quickly and correctly as possible. In the math test, the subjects had to perform simple mental arithmetic. The tasks consisted of multiplying two numbers between 1 and 10 and subtracting a one or two-digit number from this product (e.g. (9 × 5) − 17 = 28). The subjects had to decide, if the correct calculation result was smaller, larger or equal compared with the given solution number. In the spelling test, subjects had to recognize misspelled words. These words had one or two mistakes or were correctly spelled.If subjects did not respond within the allotted time, the next task was automatically presented, and the task was scored as error (omission). The number of correct and false answers, omissions, and the mean response time were counted.