Sidestepping spatial confounds in object-based correspondence effects: The Bimanual Affordance Task (BMAT)

Area of Science:

• Cognitive Psychology
• Motor Control
• Perception

Background:

• Previous research indicated that object handle orientation influences response times, suggesting affordance perception activates motor systems.
• However, asymmetrical objects used in prior studies confounded spatial and affordance properties, raising questions about the true drivers of these effects.
• Existing attempts to isolate spatial compatibility from affordance effects have yielded inconsistent results.

Purpose of the Study:

• To investigate whether object affordances in symmetrical objects facilitate response times, independent of spatial confounds.
• To introduce a novel paradigm, the Bimanual Affordance Task (BMAT), to study affordance perception without spatial biases.

Main Methods:

• Developed the Bimanual Affordance Task (BMAT) using symmetrical objects with distinct unimanual (e.g., handbag) or bimanual (e.g., laundry hamper) grasp affordances.
• Participants (N=36) performed unimanual (left/right) or bimanual responses to indicate object color.
• Measured response times based on the compatibility between the object's afforded grasp and the participant's response type.

Main Results:

• Response times were significantly faster when the object's afforded grasp (unimanual or bimanual) matched the type of response executed (unimanual or bimanual).
• This facilitation occurred even with symmetrical objects, eliminating spatial compatibility as a confounding factor.

Conclusions:

• Object affordances can influence motor responses independently of spatial compatibility.
• The Bimanual Affordance Task (BMAT) provides a valid method for studying affordance perception in the absence of spatial confounds.
• Findings support the role of affordance perception in action planning and execution.