Summary: Have you ever felt your attention briefly slip during a dull or repetitive task, as if a small part of your brain “turned off” for an instant? New research shows these micro-lapses reflect sleep-like brain activity that can occur while we are awake. These so‑called “local sleep” events are common when people are tired, but they occur far more often in adults with attention‑deficit/hyperactivity disorder (ADHD). The study suggests these intrusions may be a core mechanism behind the inconsistent attention, slower responses, and daytime sleepiness often seen in ADHD.
Researchers led by Elaine Pinggal at Monash University analyzed how sleep-like slow waves present during wakefulness affect sustained attention. The study recorded electroencephalography (EEG) in adults performing a continuous attention task and compared 32 adults with ADHD (who were off medication) to 31 neurotypical adults. Results show higher rates of sleep-like slow waves in the ADHD group, and those waves were associated with more attention lapses, greater error rates, slower and more variable reaction times, and increased subjective sleepiness.
Key Facts
- Local sleep defined: Sleep-like slow waves are brief episodes of cortical slowing that can appear in localized brain regions during wakefulness. They effectively reduce processing in the affected area for a fraction of a second, producing a transient lapse in performance.
- Study sample: The comparison included 32 adults with ADHD (medication withdrawn) and 31 neurotypical adults, all performing a sustained attention task while EEG recorded brain activity.
- Performance associations: Higher density of sleep-like slow waves was linked to more omission and commission errors, slower mean reaction times, greater reaction-time variability, and higher ratings of sleepiness.
- Potential nonpharmacological approach: Prior work in neurotypical people shows that targeted auditory stimulation during sleep can boost deep slow waves and may reduce the occurrence of wake slow waves the next day. Researchers propose testing whether similar sleep-based interventions could reduce daytime local sleep and improve attention in people with ADHD.
The investigators measured slow-wave (SW) density across the scalp and related these neural markers to task performance, self-reported mental states (on-task, mind wandering, mind blanking), and subjective sleepiness. Adults with ADHD showed more SW density, particularly over parieto‑temporal regions, along with increased theta oscillations over fronto‑temporal electrodes. Higher SW density correlated with worse performance and more reports of mind wandering or blanking. Mediation analysis indicated that SW density statistically explained a substantial portion of the attention and vigilance differences observed between ADHD and control groups.
Pinggal and colleagues emphasize that local sleep is a normal brain phenomenon that emerges during demanding or monotonous tasks. However, in ADHD the transition between wakeful and sleep-like brain states appears more fragile, producing frequent micro‑sleep intrusions that impair sustained attention. The findings link sleep disturbances and daytime attention fluctuations and propose a mechanistic bridge between the two.
Key Questions Answered
Q: Does this mean people with ADHD are literally falling asleep while awake?
A: Not in the dramatic sense of nodding off. The phenomenon is “local sleep”: small cortical regions briefly exhibit slow-wave activity while the rest of the brain remains awake. If those regions support attention, a momentary lapse results.
Q: Why does this happen more in ADHD brains?
A: The study suggests the boundary between awake and sleep-like brain states is more permeable in ADHD. Under prolonged or repetitive demands, some brain circuits may “tire” faster and slip into short sleep-like episodes more readily.
Q: Can these brain flickers be reduced without medication?
A: The research points to sleep quality as a promising target. Techniques that strengthen deep slow-wave sleep—such as precisely timed auditory stimulation during sleep—have reduced wake slow waves in neurotypical samples. Testing whether improving true sleep can lower daytime local sleep and improve attention in ADHD is a plausible next step.
Editorial Notes
- This article was edited by a Neuroscience News editor.
- The journal paper was reviewed in full by our staff.
- Additional context and clarification were added to summarize methods and implications.
About this ADHD research news
Author: SfN Media
Source: SfN
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Original Research: Closed access. Title: “Sleep-like Slow Waves During Wakefulness Mediate Attention and Vigilance Difficulties in Adult Attention-Deficit/Hyperactivity Disorder” by Elaine Pinggal et al., Journal of Neuroscience. DOI: 10.1523/JNEUROSCI.1694-25.2025.
Abstract (condensed)
ADHD is characterized by variable behavior and frequent lapses in attention, often accompanied by sleep problems and excessive daytime sleepiness. EEG studies in sleep‑deprived neurotypical people link wake slow waves to inattention, but their role in ADHD was previously unclear. This study recorded EEG while adults with and without ADHD completed a sustained attention task with intermittent probes of mental state. Individuals with ADHD produced more slow waves during wakefulness, more mind wandering and mind blanking, more errors, slower and more variable reaction times, and higher sleepiness ratings. Slow-wave density correlated with these attentional measures and mediated the relationship between ADHD and attentional difficulty. The results suggest that wake slow waves may be a mechanistic link between sleep disturbances and the attentional variability observed in adult ADHD.