(in German)

Multitasking requirements are a key feature of modern computer-aided workplaces. We examined whether two attention-intensive tasks can be processed at the same time in the brain.

Healthy participants performed a computer-based task (visual-manual flanker task) and an auditory-verbal semantic decision task simultaneously. The brain activity was assessed by parameters of the electroencephalogram (EEG).

Two key research questions were of particular interest:

1. Can multitasking-related behavioural changes in reaction time be proved on the neuronal level through indicators of bioelectrical brain activity?
2. Does simultaneously processed spoken information affect the error detection and evaluation?

To investigate age effects two age groups of employable population (20 to 35 and 50 to 60 years old, respectively) were studied. Behavioural data (reaction time, error rates and post-error slowing) and components of event-related potentials (ERPs) reflecting semantic analysis and error processing (Ne/ERN, Pe, N400) were examined.

Error rates increased and reaction times shortened in the flanker task, when semantic information had to be simultaneously processed. Errors in the flanker task were accompanied by prolonged responses in the semantic decision task and delayed the N400 peak latency for more than 400 ms. The post-error slowing in the flanker task was observed in the single task condition, but not in the dual task condition. The Ne/ERN and Pe amplitudes showed opposite changes in the dual task condition: while Ne/ERN amplitudes increased, Pe amplitudes decreased. The results confirm the interference between the tasks on the neuronal level. These mutual interferences impair not only the single task performance, but cause also changes in error processing.

Please download the complete report "Effects of multitasking on error" (in German only).