Assessing the Relationship between Cognitive Load and Cervicobrachial Muscle Response during a Typing Task

Abstract

Workers in office environments often have to deal with high cognitive workload due to the coordination of multiple work tasks. The objective of this research was to use a dual-task paradigm to examine the impact of cognitive load in office-type tasks on the cervicobrachial muscle activity response and performance. Cognitive load was manipulated by presenting subjects with examples of the three different types of cognitive tasks described in Rasmussen's (1983) taxonomy, including skill-, rule-, and knowledge-based tasks while they performed a secondary typing task. Performance in the secondary task, cervicobrachial muscle activity, and subjective measures of perceived stress and mental workload were the dependent measures. Results showed a significant effect of the different cognitive tasks. The cognitive task causing the highest level of subjective workload also produced 66.67% higher muscle activity in the right trapezius, and 8.33% and 10.53% higher activity in the left and right cervical erector spinae, respectively, in comparison to muscle activity associated with the cognitive task causing the lowest perceived workload. With respect to performance, a 29.8% decrease was observed in typing productivity when the rule-based task was completed as compared to typing with no additional cognitive load.