Altered executive function in the lead-exposed brain: A functional magnetic resonance imaging study

Area of Science:

• Neuroscience
• Cognitive Science
• Environmental Health

Background:

• Lead exposure is a known neurotoxin, impacting cognitive functions like executive function.
• Few studies have utilized fMRI to directly investigate the neural basis of executive function deficits in individuals with prior lead exposure.

Purpose of the Study:

• To explore alterations in the neural correlates of executive function in the brains of individuals with a history of lead exposure.
• To compare brain activity during executive function tasks between lead-exposed individuals and healthy controls.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was employed.
• Participants included 43 individuals with past lead exposure and 41 healthy controls.
• Modified Wisconsin Card Sorting Task (WCST) versions of varying cognitive demand and a high-level baseline (HLB) task were administered.

Main Results:

• Healthy controls exhibited greater left dorsolateral prefrontal cortex activation than lead-exposed participants during a challenging WCST condition compared to HLB.
• Cortical activation showed an inverse relationship with blood lead concentration, even after accounting for other factors.

Conclusions:

• Lead exposure can lead to persistent functional disruptions in the brain networks essential for executive function.
• Neurotoxic effects of lead on cognitive processing appear to be long-lasting.