Age-related shifts in hemispheric dominance for syntactic processing

Area of Science:

• Neuroscience
• Psycholinguistics
• Cognitive Aging

Background:

• Right-handed young adults without left-handed relatives exhibit lateralized brain responses to syntactic anomalies.
• This lateralization differs based on familial sinistrality, influencing event-related potential (ERP) patterns (P600 and N400).
• Aging is associated with a shift from asymmetric to more bilateral cognitive function.

Purpose of the Study:

• To investigate the stability of asymmetric syntactic processing in older adults.
• To determine if the lateralization patterns observed in young adults persist into older age.

Main Methods:

• Event-related potentials (ERPs) were recorded from 24 older adults (age 60+).
• Participants without a history of familial sinistrality performed grammaticality judgments on simple phrases.
• Hemisphere-biased presentations were used to assess lateralization of syntactic anomaly responses.

Main Results:

• Older adults showed a shift from the strongly lateralized pattern seen in young adults.
• P600 responses in older adults were elicited by both left-hemisphere-biased and right-hemisphere-biased presentations.
• The asymmetric response to syntactic violations was less pronounced in older adults.

Conclusions:

• The asymmetric brain response to syntactic violations changes with age.
• Syntactic processing, like other cognitive functions, appears to become more bilateral in older age.
• Familial sinistrality may interact with age to influence language processing lateralization.