Place-value and physical size converge in automatic processing of multi-digit numbers

Area of Science:

• Cognitive Psychology
• Numerical Cognition
• Visual Perception

Background:

• Multi-digit number processing is influenced by digit place-value and physical size.
• The interplay between these two factors in automatic number processing remains unclear.

Purpose of the Study:

• To investigate whether place-value or physical size has a greater impact on automatic multi-digit number processing.
• To examine the interaction between digit size, unit-decade compatibility, and decade-value-frame-size congruity.

Main Methods:

• Three experiments presented participants with two-digit number pairs in frames.
• Participants selected the larger frame while ignoring the numbers.
• Manipulated digit physical size, unit-decade compatibility, and decade-value-frame-size congruity.

Main Results:

• A decade-value-frame-size congruity effect occurred with larger decade digits in compatible pairs.
• This effect persisted regardless of digit size in compatible pairs when incompatible pairs were introduced.
• In incompatible pairs, the congruity effect disappeared, suggesting opposing influences canceled out.

Conclusions:

• Place-value and physical size are not processed independently in the Hindu-Arabic numerical system.
• These attributes are intertwined and appear to be processed as a unified attribute.