Reward Processing Deficits During a Spatial Attention Task in Patients With ADHD: An fMRI Study

Area of Science:

• Neuroscience
• Developmental Psychology
• Cognitive Science

Background:

• Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by difficulties in attention, hyperactivity, and impulsivity.
• Reward processing is crucial for learning and behavior, and its dysregulation is implicated in ADHD.

Purpose of the Study:

• To investigate neural processing of reward-predicting cues and reward feedback in children with ADHD compared to typically developing controls.
• To explore how brain activity in specific regions differs between groups during a reward-based attention task.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to scan 16 healthy children and 19 children diagnosed with ADHD.
• Participants completed a spatial attention paradigm involving reward cues and feedback on earned rewards.

Main Results:

• In the ventral anterior thalamus, controls showed greater activation to reward cues, while ADHD participants showed the opposite pattern (nonreward > reward).
• For reward feedback, controls exhibited greater activation in the left caudate and frontal eye field when rewards were absent, whereas ADHD participants showed the reverse (reward > nonreward).

Conclusions:

• ADHD is associated with atypical processing of reward-predicting cues and feedback.
• These findings suggest difficulties in integrating reward contingency information with attentional processes in ADHD.