Does the Mind Wander When the Brain Takes a Break? Local Sleep in Wakefulness, Attentional Lapses and Mind-Wandering

Abstract

Sleep has been classically described as an all-or-nothing global phenomenon. However, recent research strongly suggests that this view requires tempering. Invasive and non-invasive recordings in animals and humans show that neural activity typically associated with sleep can locally occur during wakefulness. Although local sleep is defined neuronally, it has been associated with impaired performance during cognitive tasks. Comparatively, the phenomenology of local sleep (i.e., what it feels like when your brain is partially asleep) has been less explored. Taking into account the literature on the neuronal and behavioral profile of local sleep intrusions in wakefulness, we propose that occurrences of local sleep could represent the neural mechanism underlying many attentional lapses. In particular, we argue that a unique physiological event such as local sleep could account for a diversity of behavioral outcomes from sluggish to impulsive responses. We further propose that local sleep intrusions could impact individuals’ subjective experience. Specifically, we propose that the timing and anatomical sources of local sleep intrusions could be responsible for both the behavioral consequences and subjective content of attentional lapses and may underlie the difference between subjective experiences such as mind wandering and mind blanking. Our framework aims to build a parallel between spontaneous experiences in sleep and wakefulness by integrating evidence across neuronal, behavioral and experiential levels. We use the example of attention deficit hyperactivity disorder (ADHD) to illustrate how local sleep could explain complex cognitive profiles which include inattention, impulsivity, mind-wandering and mind-blanking.

Local build-up of sleep pressure could trigger mind wandering: evidence from sleep, circadian and mind wandering research

“…An interesting commonality between these specific factors is that they all suggest a relation between MW and "non-optimal" or "fatigued" brain states. As will be discussed more in detail below, this suggestion nicely fits a recent proposal that related MW to local "fatigued" brain areas involved in task performance (Andrillon et al, 2019).…”

“…The idea that MW is caused by a depletion of resources has previously been dispelled by arguing that MW itself requires the same attentional resources that are needed for the primary task (Smallwood, 2010;Smallwood & Schooler, 2006;Thomson et al, 2015). However, by considering resource depletion as a local rather than a global phenomenon and by specifying this local resource depletion as an increase in local sleep pressure (e.g., because of a need for cellular maintenance (Vyazovskiy & Harris, 2013), or the necessity to remove potentially neurotoxic waste (Xie et al, 2013)), we here argue that this idea should not be too readily discarded (see also Andrillon et al, 2019).…”

Predicting lapses of attention with sleep-like slow waves

“…during stimulus presentation) and in the right place (i.e. in the brain regions involved in the task) would be predictive of distinct behavioral and phenomenological aspects of attentional lapses 11 .…”

Neuromodulation of the mind-wandering brain state: the interaction between neuromodulatory tone, sharp wave-ripples and spontaneous thought

“…At the more extreme end of the low arousal/low tonic noradrenaline spectrum, thoughts may become increasingly disjointed and transient, with less awareness of thoughts, which at its extreme may be experienced as a mind-blanking state (i.e. thinking of 'nothing') [174][175][176]. By contrast, relatively higher levels of tonic noradrenaline and arousal that facilitate an exploratory mode of behaviour may also engender an exploratory mode of spontaneous thought.…”