Illusory visual-depth reversal can modulate sensations of contact surface

Area of Science:

• Neuroscience
• Psychology
• Sensory Perception

Background:

• Stable perception requires integrating continuous sensory information and prior knowledge.
• Visuo-tactile integration is crucial for understanding the external world.

Purpose of the Study:

• To introduce and investigate a novel visuo-tactile illusion using a visual-depth-reversal stimulus.
• To explore how the brain reconciles conflicting visual and tactile information during perception.

Main Methods:

• A building model stimulus was designed to create ambiguous visual depth perception (concave vs. convex).
• Participants observed and held the model, experiencing conflicting visual and tactile cues.
• Questionnaires and tactile estimation tasks were used to assess perception.

Main Results:

• Participants predominantly perceived the stimulus as a stable, convex cuboid, despite tactile information indicating otherwise.
• This visual dominance was particularly strong under monocular observation.
• Participants reported tactile sensations consistent with the visual appearance, ignoring veridical contact information.

Conclusions:

• Visual perception can override accurate tactile information, demonstrating the brain's flexible integration of senses.
• Object knowledge may play a role in resolving conflicting visuo-tactile inputs.
• The study highlights the complex interplay between vision, touch, and prior experience in shaping perception.