Dichotic listening performance and interhemispheric integration after stress exposure

Area of Science:

• Neuroscience
• Psychology
• Endocrinology

Background:

• Functional hemispheric asymmetries (FHAs) were traditionally considered stable but are now known to be plastic.
• Endocrinological processes, particularly cortisol from the hypothalamus-pituitary-adrenal axis, impact information processing and may alter FHAs.

Purpose of the Study:

• To investigate the impact of acute stress on FHAs.
• To determine if stress-induced cortisol and sympathetic activation influence cognitive tasks and hemispheric processing.

Main Methods:

• Sixty participants completed the Banich-Belger task and dichotic listening tasks under both stress (Trier Social Stress Test) and control conditions.
• Measurements included across-field advantages (AFAs) and lateralization quotients for reaction times and responses.
• Salivary alpha amylase was used to indicate sympathetic activation.

Main Results:

• No significant differences were observed in dichotic listening tasks between stress and control sessions.
• The Banich-Belger task showed evidence of cortisol and sympathetic activation influencing AFAs.
• Acute stress did not impair dichotic listening but affected interhemispheric information integration.

Conclusions:

• Acute stress and elevated cortisol levels do not appear to affect dichotic listening performance.
• Stress significantly impacts interhemispheric integration, as evidenced by changes in the Banich-Belger task.
• Further research with neuroimaging (EEG, fMRI) and pharmacological methods is recommended to explore the relationship between hemispheric asymmetries and acute stress.