Table 1.
Reaction time data of both tasks and age groups.
Figure 1.
Error-related negativity (response-related) for both groups and tasks parameterized at FCz.
Red: Young subjects, black: older subjects. Zero indicates button press.
Figure 2.
Topographic distribution of the average number of principle components accounting for 90% of variance.
Estimation of the variability between trials in the Ne-time window for both tasks. Blue indicates less variability between trials; red indicates more variability between trials. Beside each topography a colour legend is provided indicating the number of principle components (PCs) explaining at least 90% of variance between trials. For example having a look at the topography of the young subjects in the flanker task, one can see that at FCz about three principle components explain at least 90% of variance between trials. In older participants (left) about five principle components explain at least 90% of variance between trials. Note that in general the signal is least variable at fronto-central positions and reflects the typical Ne-topography.
Figure 3.
Dipole localizations and contributions of the Ne-IC cluster to the grand average ERP.
Upper panel: Dipole localizations of the Ne-IC cluster of the young group [Tal(x,y,z) = 2,10, 19; residual variance = 7.11%] and older subjects [Tal(x,y,z) = −1,10, 26; residual variance = 7.1%].(young = green, old = blue). Lower panel: Contributions of the Ne-IC clusters of each group in the time-window from 0–150 ms following response. Flanker task: The Ne-IC of young subjects cluster accounted for about 51% of variation in the time window 0–150 ms following erroneous response. The Ne-IC of older participants accounted for about 11% of variation in the Ne time window. Rotation task: Here, Ne-IC cluster of older participants accounted for fewer percent of variation compared to younger subjects, too [39.8%<10.42%].