Attenuated hemispheric asymmetry in metaphor processing among adults with ADHD

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psychiatry

Background:

• Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by inattention and hyperactivity.
• Understanding the neural underpinnings of cognitive differences in ADHD is crucial for developing targeted interventions.
• Metaphor comprehension involves complex cognitive processes that may be differentially affected in ADHD.

Purpose of the Study:

• To investigate hemispheric processing of metaphors in adults with ADHD compared to neurotypical controls.
• To explore the relationship between metaphor processing asymmetry and sustained attention in ADHD symptoms.

Main Methods:

• A divided visual field paradigm was employed to assess hemispheric processing.
• Participants included 24 adults with ADHD and 24 control participants.
• Metaphorical, literal, and unrelated word pairs were presented to the left and right visual fields, corresponding to the right and left cerebral hemispheres.

Main Results:

• Control participants showed greater efficiency in processing metaphors in the left hemisphere (via the right visual field).
• Adults with ADHD exhibited reduced hemispheric asymmetry in metaphor processing.
• Reduced lateralization of metaphor processing and deficits in sustained attention significantly predicted ADHD symptom severity.

Conclusions:

• Adults with ADHD demonstrate less lateralized hemispheric processing of metaphors compared to controls.
• Diminished metaphor processing lateralization, coupled with attention deficits, suggests distinct cognitive mechanisms in ADHD.
• These findings support multiple pathway models of ADHD, highlighting the heterogeneity of cognitive deficits in the disorder.