The brain lateralization and development of math functions: progress since Sperry, 1974

Area of Science:

• Neuroscience
• Cognitive Psychology
• Mathematics Cognition

Background:

• Early research (Sperry, 1974) suggested left-hemisphere dominance for mathematical functions, with limited right-hemisphere capacity for simple addition.
• Studies on focal lesions indicated a role for the right hemisphere in complex calculations requiring spatial processing.
• Fifty years of research using advanced tools reveal a more intricate picture of brain lateralization in mathematical cognition.

Purpose of the Study:

• To review the current understanding of brain hemisphere involvement in mathematical processing.
• To explore the specific contributions of the right hemisphere beyond generic spatial processing.
• To clarify the developmental trajectory of mathematical function lateralization.

Main Methods:

• Review of existing theoretical frameworks and instrumental findings in neuroscience.
• Analysis of studies on lateralized focal lesions and split-brain conditions.
• Synthesis of developmental data on numerical cognition and brain lateralization.

Main Results:

• Left-hemisphere dominance for most mathematical functions in right-handed individuals is confirmed, but the right hemisphere plays specific, crucial roles.
• The right parietal lobe is implicated in storing spatial layouts for complex arithmetic, and the right insula is vital for processing numbers with zero.
• Developmental data indicate right-hemisphere dominance for basic numerical processes, shifting to a bilateral pattern by school age with greater right-hemisphere involvement in non-symbolic tasks.

Conclusions:

• Mathematical processing involves a complex interplay between both hemispheres, with each contributing specific functions even in simple tasks.
• The right hemisphere's role in mathematical cognition is more specialized than previously thought, extending to specific spatial and numerical processing.
• Brain lateralization for mathematical functions evolves, with early right-hemisphere dominance for basic processes and a shift towards bilateral engagement during development.