Impaired Error Processing and Semantic Processing During Multitasking

Abstract

Abstract. Neuronal mechanisms of error processing under multitasking and their impact on the processing of a concurrent task were examined. Twenty-one younger and twenty older healthy adults performed a visual-motor flanker task or an auditory-vocal semantic task or both tasks simultaneously. During task performance the electroencephalogram (EEG) was continuously recorded. The event-related potential (ERP) was derived from the EEG, and ERP components associated with error processing (Ne and Pe) and semantic processing (N400) were analyzed. Older participants responded more slowly than younger ones in the flanker task regardless of the multitasking condition, while accuracy was equal in both groups. In the flanker task, multitasking led to an increase of error rates, a reduction of reaction times, and a disappearance of post-error slowing (PES). Error detection (Ne) was delayed and error awareness (Pe) attenuated in the single flanker task relative to the multitasking condition. In the semantic task, multitasking led to an increase of reaction times and a delay of the N400 in particular when an error in the flanker task occurred. First, these results indicate that multitasking impaired error processing, in particular conscious error perception (Pe) and abolished post-error adjustments of performance (PES) which may have resulted in a more risky response tendency in the flanker task. Second, multitasking impaired semantic processing, in particular after an error in the concurrent flanker task. Hence, multitasking compromised error processing and error prevention in one of the tasks, and semantic processing in the other task. Consequently, multitasking should be avoided at workplaces with error-prone job assignments or where poor understanding of communication may have serious consequences.