The effects of sleep on repetitive thinking: from mind wandering to perseverative cognition.
Repetitive thinking has been conceptualized as a continuum, ranging from mind wandering to perseverative cognition such as worry and rumination. According to the mind wandering-perseverative cognition continuum hypothesis, mind wandering may be considered as an adaptive brain function that turns into maladaptive (perseverative) when it becomes rigid and inflexible (associated with slower RTs in cognitive control tasks, more effort to inhibit the thought and intrusiveness). Interestingly, behavioral studies show detrimental effects of sleep loss on cognitive control processes. Accordingly, sleep may play a critical role in the pathway from mind wandering to perseverative cognition. Despite this evidence, research conducted so far mostly investigated the effects of repetitive thinking on sleep, and largely ignored the effects of sleep as modulator of repetitive thinking. The aim of this study is to explore the effects of sleep on mind wandering, worry and rumination, their cognitive features (RTs, effort to inhibit the thought and intrusiveness), and their psychophysiological correlates using an experimental sleep deprivation procedure in healthy human beings. 60 participants will be randomly assigned either to a sleep deprivation or a good sleep control condition. The morning after, they will perform a 20-min tracking task with a thought probe. Spontaneous occurrence of mind wandering, worry and rumination episodes during the task will be investigated. Furthermore, psychophysiological measures (electrocardiogram) will be collected during the session. It is hypothesized that participants in the sleep deprivation condition, as compared to those in the good sleep condition will show: 1) lower rates of mind wandering, 2) higher rates of worry and rumination, 3) slower RTs, 4) more effort to inhibit the thought and more intrusiveness of the thought, 5) autonomic rigidity (low heart rate variability).