How visual experience and task context modulate the use of internal and external spatial coordinate for perception...

Area of Science:

• Cognitive Neuroscience
• Human Perception and Action
• Sensory Substitution

Background:

• Previous research suggests potential differences in coordinate system use between blind and sighted individuals.
• Understanding how sensory and motor systems adapt to vision loss is crucial for rehabilitation and assistive technologies.

Purpose of the Study:

• To investigate the flexibility of internal (body-centered) and external (space-centered) coordinate systems in congenitally blind versus sighted individuals.
• To compare performance on tactile and auditory tasks under different instructional frames of reference (internal vs. external).

Main Methods:

• Participants: Congenitally blind and sighted adults.
• Tasks: Tactile temporal order judgment and auditory Simon task.
• Conditions: Hands uncrossed/crossed; internal/external frame of reference instructions.

Main Results:

• Tactile task: Hand crossing impaired sighted but not blind participants (internal frame). Both groups showed decreased performance with external frame instructions.
• Auditory task: Both groups showed a Simon effect regardless of hand position or frame of reference, suggesting default external frame activation.
• Overall: Both blind and sighted individuals can flexibly activate internal and external frames.

Conclusions:

• Congenitally blind individuals demonstrate significant cognitive flexibility in utilizing both internal and external frames of reference.
• The ability to switch between coordinate systems is not solely dependent on visual experience.
• Findings have implications for understanding spatial cognition and developing adaptive strategies for individuals with visual impairments.