Effects of stress on functional connectivity during verbal processing.

Area of Science:

• Neuroscience
• Cognitive Psychology
• Genetics

Background:

• Stress significantly impacts cognitive functions, including language processing.
• Understanding the neural mechanisms underlying stress effects on language is crucial.
• The role of genetic factors like serotonin transporter gene polymorphisms (5-HTTLPR) in stress susceptibility is increasingly recognized.

Purpose of the Study:

• To investigate the effects of acute stress on functional connectivity (FC) within language processing brain regions during verbal fluency tasks.
• To examine the influence of gender and serotonin transporter gene polymorphisms (5-HTTLPR) on stress-induced changes in FC.
• To explore the relationship between stress-induced alterations in FC and task performance.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to measure brain activity in 45 healthy volunteers (28 females).
• Participants completed letter and category verbal fluency tasks under induced stress (Montreal Imaging Stress Test) or control conditions.
• Genotyping for SLC6A4 gene polymorphisms (5-HTTLPR) was performed using buccal swabs.

Main Results:

• Significant variations in FC strength were observed between regions, including the left inferior frontal gyrus and left middle temporal gyrus.
• Males exhibited increased FC strength over both long and short distances during the task under stress.
• Individual differences in stress effects on task performance correlated with changes in FC.

Conclusions:

• Long-distance FC may strengthen to manage the cognitive load imposed by stressors.
• Short-distance functional connections might be enhanced in a gender-specific manner under stress.
• FC alterations could serve as a neuroimaging marker for the impact of stress on performance, with potential for therapeutic applications.