Verbal working memory and solvent exposure: a positron emission tomography study

Area of Science:

• Neuropsychology
• Neuroimaging
• Toxicology

Background:

• Neuropsychological studies indicate frontal lobe dysfunction in individuals with a history of organic solvent exposure.
• These deficits are often associated with impaired working memory (WM).

Purpose of the Study:

• To investigate the neural activation patterns during verbal working memory tasks in individuals with a history of organic solvent exposure.
• To compare brain activity between solvent-exposed individuals and healthy controls using [15O] water positron emission tomography (PET).

Main Methods:

• Utilized [15O] water positron emission tomography (PET) to measure brain activity.
• Assessed verbal working memory performance in two tasks.
• Compared brain activation patterns between six solvent-exposed individuals and six age- and education-matched controls.

Main Results:

• Participants with solvent exposure exhibited atypical frontal lobe activation peaks during verbal working memory tasks.
• Posterior brain regions showed typical activation patterns in the solvent-exposed group.
• Task performance was equivalent between the solvent-exposed group and controls.

Conclusions:

• The findings support the hypothesis of frontal lobe dysfunction in individuals with a history of organic solvent exposure.
• Evidence suggests compensatory neural activity within anterior regions of the working memory system in this population.