A novel approach to validate the efficacy of single task ERP paradigms to measure cognitive workload

The present study examined the utility of a single-task paradigm to evaluate cognitive workload. The cognitive workload from twenty-five healthy participants was measured during a tilt-ball game while tones were presented in the background to generate event-related potentials (ERPs) in electroencephalographic (EEG) data. In the game, participants were instructed to move the ball to highlighted targets and avoid moving obstacles. The game's difficulty level was manipulated (easy, medium, hard) by adjusting the number and speed of the moving obstacles. The difficulty levels were presented in a random order during multiple short runs to minimize the effects of habituation, fatigue, and boredom. The behavioral results showed that greater task difficulty resulted in a significant decrease (p < 0.001) in game performance, i.e., participants achieved few targets with a high collision rate. To evaluate cognitive workload, we measured the amplitude of early ERP components (N1, P1, and P2) corresponding to the involuntary attention orienting response. The amplitude of the N1 component decreased significantly (p = 0.029) with an increase in cognitive workload. These findings suggest that the early ERP component, specifically the N1, corresponds to attention orienting response, and that the task difficulty modulates it. This study provided evidence that the inverse relationship between ERP components and cognitive workload can be reliably assessed by controlling for other factors such as habituation or boredom during a single task paradigm.