Evidence for a Compensatory Relationship between Left- and Right-Lateralized Brain Networks

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Brain Imaging

Background:

• Human brain exhibits functional asymmetry between hemispheres.
• Language networks are typically left-lateralized, but lateralization of other networks is less understood.
• The interplay between lateralization of different brain networks within individuals is largely unknown.

Approach:

• Quantified lateralization for 17 brain networks using relative cerebral hemisphere surface area.
• Validated the surface area measure for ecological, convergent, external validity, and test-retest reliability.
• Tested hypotheses across Human Connectome Project, Human Connectome Project-Development, and Natural Scenes datasets.

Key Points:

• Language, visuospatial attention, and executive control networks were hypothesized to be most lateralized.
• Language networks were significantly left-lateralized; attention and executive control networks were significantly right-lateralized.
• Found support for a dependent relationship: greater left-lateralization in one network correlated with greater right-lateralization in another, and vice versa.

Conclusions:

• Brain network lateralization is complex and shows systematic interdependencies.
• Understanding these lateralization patterns offers insights into brain organization at the macro-scale.
• Findings are relevant for neurodevelopmental conditions like autism and schizophrenia, which involve lateralization disruptions.