Time and numerosity estimation in peripersonal and extrapersonal space

Area of Science:

• Cognitive psychology
• Neuroscience
• Magnitude perception

Background:

• Action guidance is thought to rely on a common encoding system for space, time, and number.
• The benefit of this shared system is clear within peri-personal space but less so in extra-personal space.

Purpose of the Study:

• To investigate how stimulus distance affects the perception of duration and numerosity.
• To determine if magnitude perception differs between peri-personal and extra-personal space.

Main Methods:

• Replicated a duration reproduction task with stimuli in peri- vs. extra-personal space.
• Applied the same paradigm to a non-symbolic numerosity estimation task.
• Participants performed duration reproduction and numerosity estimation tasks with visual stimuli at varying distances.

Main Results:

• Duration estimates were overestimated for stimuli in extra-personal space, consistent with prior research.
• Numerosity perception also showed overestimation for distant stimuli, but this effect was smaller and explained by perceived size differences.
• Temporal information processing is robustly affected by stimulus position, while numerosity perception appears distance-independent.

Conclusions:

• Time and numerosity may share encoding systems in peri-personal space for action optimization.
• Separate mechanisms likely underlie time and numerosity representation in extra-personal space.
• Investigating magnitude perception across spatial planes reveals processing differences potentially missed otherwise.