Stronger left-hemisphere lateralization in older versus younger adults while processing conventional metaphors

Area of Science:

• Neuroscience
• Cognitive Psychology
• Linguistics

Background:

• Language comprehension involves semantic processing.
• Hemispheric lateralization of cognitive functions is a key area of neuroscience research.
• Aging can impact cognitive functions, including language processing and brain lateralization.

Purpose of the Study:

• To investigate age-related differences in hemispheric lateralization during semantic processing of literal words and conventional metaphors.
• To explore the role of accumulated knowledge in language comprehension lateralization in older adults.

Main Methods:

• A divided visual field paradigm was used with right-handed Hebrew speakers.
• Participants included younger (20-30 years) and older (69-85 years) adults.
• Tasks included semantic judgment and lexical decision, with analysis of visual field/hemisphere responses.

Main Results:

• Older adults demonstrated enhanced accuracy for conventional metaphors in the right visual field/left hemisphere compared to the left visual field/right hemisphere.
• Younger adults did not show significant hemispheric lateralization for metaphor processing.
• Vocabulary scores did not account for the observed group differences in lateralization.

Conclusions:

• Accumulated knowledge may lead to increased left-hemisphere lateralization for language comprehension in older adults.
• Hemispheric processing of semantic information, particularly metaphors, may shift with age.
• These findings contribute to understanding cognitive aging and language processing in the brain.