Developmental changes in the neural influence of sublexical information on semantic processing

Area of Science:

• Neuroscience
• Developmental Psychology
• Cognitive Science

Background:

• Semantic processing involves understanding word meanings.
• Lexical and sublexical information interact during word recognition.
• Developmental changes in semantic processing are not fully understood.

Purpose of the Study:

• To investigate developmental changes in semantic processing in children and adolescents.
• To explore the interaction between lexical and sublexical semantic information.
• To examine how association strength and visual similarity of Chinese characters affect semantic judgments.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to study brain activity.
• Participants (8-16 years old) performed a semantic judgment task on Chinese character pairs.
• Stimuli varied in association strength (global unit) and visual similarity (sublexical unit).

Main Results:

• Increased activation in the left angular gyrus (BA 39) for visually similar pairs with strong associations in older children.
• Greater age-related increases in the angular gyrus for strong associations in visually similar pairs.
• Increased activation in the left posterior middle temporal gyrus (BA 21) for visually dissimilar pairs with weak associations in older children.

Conclusions:

• Shared sublexical semantics facilitate lexical integration in older children.
• Conflicting sublexical information increases demands on lexical access in older children.
• Older children demonstrate increased sensitivity to sublexical information during lexical processing.