The influence of intolerance of uncertainty on the vigor of eye movement in a healthy population

Details

Supervisors

Missal, Marcus

Faculty

Faculté des sciences de la motricité

Degree label

Master [60] en kinésithérapie et réadaptation

Abstract

Uncertainty pervades daily life, evident in weather decisions and professional interactions, prompting rapid choices and critical introspection. Despite discomfort, it shapes routines and actions, as the brain processes information but may struggle with predictive accuracy due to incomplete data. Therefore, uncertainty is pivotal, influencing navigation through various situations. In this thesis, the relationship between uncertainty, intolerance of uncertainty and movement will be studied. The aim of this work is to see if someone who suffer from intolerance of uncertainty will show less favorable outcomes with the movement and its application. Participants completed three questionnaires: the Intolerance of Uncertainty Scale (IUS-27), Barratt’s Impulsivity scale (BIS-11), and Generalised Anxiety Disorder score (GAD-7), providing insights into personality traits and responses to uncertainty. Eye tracking captured responses to stimuli displayed on a screen, following calibration for clear views. To analyse guided eye saccade movement under uncertainty, the foreperiod paradigm was used. Stimuli included three squares, a dot, and a warning signal (WS), followed by an imperative stimulus (IS) signaling an eye saccade towards a specific square. Low Uncertainty and High Uncertainty trials induced temporal uncertainty. High uncertainty corresponding as a variable foreperiod and low uncertainty as a constant one. Feedback on responses was provided, maintaining experimental balance across uncertainty conditions. Participants experienced both conditions, starting with either Low or High Uncertainty, encountering equal proportions of directed and undirected arrows. First, the results demonstrate that uncertainty significantly influences movement. When subjects encountered higher levels of surprise, they exhibited longer reaction times (RT) combined with greater amplitude of movement (AMP). This suggests that humans take more time to respond and are less precise when confronted with high levels of uncertainty. Secondly, the linear mixed model also revealed an influence of the WS on movement. Since WS can be either a left or right directed arrow or an undirected one, the results indicate that when subjects were presented with a directed arrow, it decreased RT, maximum velocity of eye movement (MVE), and vigor. In other words, when subjects were compelled to choose one side without free will, it resulted in quicker responses associated with slower eye movements. Finally, no evidence was found to support the hypothesis that individuals with intolerance of uncertainty would exhibit lower vigor scores. Results from this study do not strongly support the notion that intolerance of uncertainty predicts poorer movement outcomes. This project contributes to understanding the relationship between uncertainty and intolerance of uncertainty with movement. Further research is needed to fully elucidate the potential interactions between these concepts.