Fig. 3

Results of a PC-based cognitive test applied in the PFIFF study for the four participants groups (solid black: old assembly line, dotted black: old non-assembly line, solid gray: young assembly line, dotted gray: young non-assembly line). The test consisted of a long sequence of simple numerical categorization tasks. The participants memorized the task sequence in advance and switched among these tasks. Reaction times indicate the time elapsed from the presentation of a test stimulus on the screen and the button press after a correct stimulus categorization. Error rates indicate the mean number of erroneous responses. As can be seen in the bar graphs, the older assembly-line participants showed the longest reaction times and clearly higher error rates than the other three groups due to loss of the correct task sequence. This suggests lower working memory performance that was also visible in the ERPs by reduced P3b amplitude (bottom left). The impaired error monitoring is reflected by the selective reduced amplitude of the error negativity in this group (Ne; bottom right). See Gajewski et al. (2010b) for further details