Poster C23, Sunday, March 26, 5:00 – 7:00 pm, Pacific Concourse
The Effects of Acute Psychosocial Stress on Oculomotor Saccadic Adaptation
Delia A. Gheorghe1, Muriel T.N. Panouillères2, Nicholas D. Walsh1; 1University of East Anglia, 2University of Oxford
Early-life stressors and stress-related psychopathology have been reported to affect cerebellar structure and function. However, the mechanism through which stress affects cerebellar function in healthy individuals is unknown. The aim of the current experiment was to test the effects of experimentally-induced stress on forward saccadic adaptation in 49 young healthy men and women. Saccadic adaptation is a form of motor learning, which facilitates error-driven adaptive changes in saccade size. Cerebellar integrity is necessary for successful sensorimotor adaptation in humans. Stress induction was achieved by employing the offline version of the Montreal Imaging Stress Task (MIST), shown to generate significant physiological responses. In the experiment, participants matched for gender and age were exposed to either an experimental or a control condition. Saliva for cortisol determination was collected before, immediately after, 10 or 30 minutes after the MIST. Saccadic adaptation was assessed 10 minutes after stress induction, when cortisol levels reached their peak. Participants in the experimental group reported significantly more stress symptoms than controls. Adaptation was elicited using the classic double-step target paradigm with a 30% target eccentricity. Previous data collected in our lab showed that this paradigm induces a strong adaptation effect, explaining 89% of gain variance in healthy volunteers. Similarly, behavioural analyses showed that control participants demonstrated a significant increase in gain. This effect was not present for men and women exposed to the stressor. Initial results indicate that acute stress reduces the ability to acquire saccadic adaptation, potentially via perturbations to cerebellar circuits.
Topic Area: EMOTION & SOCIAL: Emotion-cognition interactions