Processing concrete words: fMRI evidence against a specific right-hemisphere involvement

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psycholinguistics

Background:

• Previous research suggested abstract words are processed in the left hemisphere, while concrete words engage both left and right hemispheres.
• The dual-coding theory posits that concrete words access an imaginal representational system, potentially involving right-hemispheric areas.

Purpose of the Study:

• To investigate the neuroanatomical basis of concrete and abstract word processing using event-related functional magnetic resonance imaging (fMRI).
• To test the hypothesis of right-hemispheric involvement in concrete word processing.

Main Methods:

• Event-related fMRI was employed during a lexical decision task involving concrete and abstract words.
• Analysis focused on identifying brain regions differentially activated by word type.

Main Results:

• Abstract words showed greater activation in a subregion of the left inferior frontal gyrus (BA 45) compared to concrete words.
• Concrete words elicited specific activation in the left basal temporal cortex.
• No significant right-hemispheric activation specific to concrete words was observed.

Conclusions:

• The findings challenge the notion of specific right-hemispheric involvement for concrete word processing.
• The results suggest a revised understanding of the neuroanatomical underpinnings of the imaginal representational system in word recognition.
• Left-hemisphere regions play a crucial role in processing both abstract and concrete words.