The effect of mental workload on the visual field size and shape

Area of Science:

• Visual perception
• Cognitive psychology
• Human factors

Background:

• Mental workload is known to reduce visual field area.
• The impact of mental workload on visual field shape remains largely unexplored.
• Understanding these changes is crucial for tasks relying on peripheral vision.

Purpose of the Study:

• To investigate the effects of varying mental workload levels on the shape of the human visual field.
• To quantify visual field shape distortions induced by cognitive load.
• To explore implications for visual performance and modeling.

Main Methods:

• Measured visual fields of 13 subjects using a Goldmann visual perimeter under three mental workload conditions.
• Utilized tone counting tasks to induce mental workload without visual interference.
• Applied multiple shape measurement and analysis techniques to assess visual field variations.

Main Results:

• Visual field area decreased significantly with increasing mental workload (92.2% at medium, 86.41% at heavy load).
• The reduction in visual field area was non-uniform, causing statistically significant shape distortions.
• 12 distinct shape indices confirmed significant variations in visual field geometry under mental load.

Conclusions:

• Mental workload not only reduces visual field size but also significantly alters its shape.
• These findings highlight the 'tunneling effect' and its complex impact on visual performance.
• The results provide valuable data for optimizing tasks sensitive to visual field changes and for developing visual search models.