Reduced prefrontal efficiency for visuospatial working memory in attention-deficit/hyperactivity disorder

Area of Science:

• Neuroscience
• Cognitive Psychology
• Developmental Psychology

Background:

• Attention-deficit/hyperactivity disorder (ADHD) is associated with visuospatial working memory deficits.
• Previous research on ADHD has primarily focused on nonspatial memory neural correlates.
• Understanding the neural basis of visuospatial working memory in ADHD is crucial for targeted interventions.

Purpose of the Study:

• To investigate brain activation and functional connectivity during visuospatial working memory in youth with and without ADHD.
• To compare neural responses to varying working memory loads between ADHD and control groups.
• To identify specific brain regions and networks involved in visuospatial working memory deficits in ADHD.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used in 24 youth with ADHD and 21 healthy controls.
• Participants performed an N-back task assessing visuospatial working memory at different load levels (0-back, 1-back, 2-back).
• Block-design analyses examined brain activation and functional connectivity, contrasting high and low working memory loads.

Main Results:

• Both groups performed comparably, showing similar frontoparietal activation patterns.
• Youth with ADHD exhibited greater left dorsolateral prefrontal cortex (DLPFC) and posterior cingulate cortex (PCC) activation under high load.
• ADHD group showed altered functional connectivity, including increased DLPFC-intraparietal sulcus and decreased DLPFC-midcingulate/PCC connectivity.

Conclusions:

• Youth with ADHD demonstrate reduced DLPFC efficiency for high-load visuospatial working memory.
• Individuals with ADHD may rely more on posterior spatial attention circuits for spatial memory.
• Larger sample replication is recommended to validate these findings.