Evaluation of the Tiller Switch Layout of a Tractor Using Eye-Fixation Related Potentials

Area of Science:

• Ergonomics
• Human-Computer Interaction
• Neuroscience

Background:

• Tractor human-machine interface (HMI) layouts often mismatch operator expectations, leading to errors.
• Previous research used event-related potentials (ERPs) to assess expectation gaps, but real-world operation involves eye movements.
• Eye-fixation related potentials (EFRPs), specifically the lambda response, may offer a more practical measure of attention during operation.

Purpose of the Study:

• To investigate if the lambda response amplitude reflects reduced operator attention when tractor HMI deviates from expectations.
• To evaluate the potential of lambda response as an index for optimizing HMI design.

Main Methods:

• Conducted an experiment during actual tractor operation with 13 experienced male operators.
• Manipulated the tractor tiller switch position to create discrepancies with operator expectations.
• Measured the amplitude of the lambda response, a component of EFRP, during operation.

Main Results:

• A reduced lambda wave amplitude was observed when the tiller switch position differed from operator expectations.
• This reduction in amplitude correlated with increased difficulty in operating the tiller.
• The findings suggest a decrease in operator attention due to the unexpected control layout.

Conclusions:

• The amplitude of the lambda response serves as a viable index for evaluating operator attention.
• This neurophysiological measure can be used to optimize tractor HMI design, particularly switch placement.
• Addressing expectation gaps in HMI design can enhance operator performance and reduce errors.