Developmental Changes in Neural Lateralization for Visual-Spatial Function? Evidence From a Line-Bisection Task

Area of Science:

• Neuroscience
• Developmental Psychology
• Cognitive Science

Background:

• Hemispheric specialization traditionally assigns language to the left and spatial functions to the right hemisphere.
• Evidence largely stems from adult studies and lesion patients, leaving developmental origins of lateralization less understood.
• Language processing in young children (4-6 years) shows bilateral activation, shifting to left-hemisphere dominance later in childhood.

Purpose of the Study:

• To investigate the developmental trajectory of lateralization for a spatial task in children.
• To determine if spatial tasks exhibit a similar developmental shift in lateralization as observed in language.
• To examine functional magnetic resonance imaging (fMRI) activation during a line bisection task in children aged 5-12 years.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was employed to measure brain activity.
• Participants were children aged 5-12 years.
• The task involved judging the longer end of a bisected vertical line, a spatial judgment task.

Main Results:

• Children consistently demonstrated right-lateralized activation in parietal and posterior temporal regions.
• These activation patterns mirrored those observed in adult studies of the line bisection task.
• No significant age-related changes in the degree of right-lateralization were found within the 5-12 year age range.

Conclusions:

• Spatial processing, specifically for the line bisection task, appears to be stably lateralized to the right hemisphere from early childhood.
• This contrasts with the developing bilateral representation and subsequent left-lateralization observed for language functions.
• Understanding developmental trajectories of lateralization is crucial for comprehending general principles of brain organization.