Recalibration of the convergence system

Area of Science:

• Vision science
• Perceptual psychology
• Neuroscience

Background:

• Prism adaptation is a model for studying sensory recalibration.
• Convergence, the inward turning of the eyes, provides depth cues.

Purpose of the Study:

• To investigate adaptation to altered convergence stimuli.
• To determine how prism spectacles affect distance perception.

Main Methods:

• Participants trained with convergence-increasing or -decreasing prisms for 8 minutes.
• Distance to a binocular target was estimated before and after prism exposure.
• The relationship between convergence and perceived distance was analyzed.

Main Results:

• A linear relationship was found between the reciprocal of estimated distance and convergence.
• Consistent directional changes in adaptation were observed post-training.
• These changes suggest a recalibration of the absolute convergence level.

Conclusions:

• The visual system adapts to altered convergence inputs.
• Distance perception recalibrates based on changes in eye alignment.
• This adaptation involves adjusting the brain's interpretation of convergence cues.