General Principles

The visual scene is captured by the eye as a poor quality, two-dimensional representation

What is perceived is determined by:

‘Bottom-up’ processes. The percept of a stimulus is determined by features of the stimulus as processed by the visual cortex

‘Top-down’ processes. The interpretation (consciously or not) of a stimulus can be determined by our experience and knowledge

Important distinction!

Featureless surfaces, or those with textures of unknown sizes, can produce inaccurate judgements of size.

• Featureless surfaces, or those with textures of unknown sizes, can produce inaccurate judgements of size.

• Sea.
• Beehives for caravans.

• Can produce an inaccurate mental model of the situation which overrides the correct perception of the instruments.

• Top-down influences.
• Exacerbated by fatigue and workload.
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