Assessing Perceptual Load and Cognitive Load by Fixation-Related Information of Eye Movements

Area of Science:

• Cognitive Psychology
• Human-Computer Interaction
• Neuroscience

Background:

• Accurate mental workload assessment is vital in safety-critical domains like driving and piloting.
• Eye movement metrics, particularly fixation parameters, have shown potential but inconsistent results for workload evaluation.
• Previous research often failed to distinguish between different types of mental workload.

Purpose of the Study:

• To investigate the distinct effects of perceptual load and cognitive load on eye movement fixation parameters.
• To resolve discrepancies in prior research regarding fixation-related measures and mental workload.
• To validate the use of fixation parameters for indexing different stages of mental processing.

Main Methods:

• A modified video game was employed to independently manipulate perceptual and cognitive load.
• Participants' eye movements were tracked while engaging with varying levels of these two distinct mental workload types.
• Fixation duration and the number of fixations were analyzed in relation to the manipulated load conditions.

Main Results:

• High perceptual load led to shorter fixation durations and increased fixation frequency.
• Conversely, high cognitive load resulted in longer fixation durations and decreased fixation frequency.
• These opposing effects align with established load theory principles.

Conclusions:

• Fixation-related parameters demonstrate differential sensitivity to perceptual versus cognitive load.
• Eye movement metrics can serve as reliable indicators for assessing mental workload at distinct perceptual and cognitive processing levels.
• This research provides a refined method for understanding mental workload through eye-tracking analysis.