Explicit spatial compatibility is not critical to the object handle effect.

Area of Science:

• Cognitive Psychology
• Neuroscience
• Object Perception

Background:

• The handle effect shows a response advantage when an object's handle matches the responding hand.
• This effect is often explained by affordance theories, suggesting motor activation for grasping.
• An alternative view links the handle effect to the Simon effect, a spatial compatibility phenomenon.

Purpose of the Study:

• To investigate whether the handle effect occurs independently of spatial compatibility.
• To differentiate between affordance-based and spatial compatibility-based explanations of the handle effect.

Main Methods:

• Three experiments were conducted varying stimulus-response compatibility and task demands.
• Participants responded bimanually to object categories, colors, or orientations.
• Stimulus and response locations were manipulated vertically, and responses horizontally.

Main Results:

• The handle effect was observed in categorization and orientation tasks, alongside a vertical Simon effect.
• In a color judgment task (standard Simon effect paradigm), the handle effect vanished, while the Simon effect intensified.
• This dissociation highlights distinct mechanisms underlying the handle effect.

Conclusions:

• Affordance, not solely spatial compatibility, plays a crucial role in the handle effect.
• The findings support models integrating both affordance and spatial compatibility mechanisms in object representation.
• This research clarifies the interplay between object properties and motor responses in perception.