Biology subjects

van der Heijden, A. C.

Publications and source records attributed to van der Heijden, A. C..

3 recordsLinked to original sources

bioRxiv2025

Deepening sleep using an EEG wearable featuring modeling-based closed-loop neurostimulation

ObjectiveClosed-loop neurostimulation (CLNS) during slow-wave sleep (SWS) has been shown to enhance slow-wave activity, predominantly using laboratory equipment. To further advance CLNS research and its potential applications, there is a need for user-friendly EEG wearable equipment featuring CLNS that can support long-term CLNS studies in both clinical and home settings. ApproachHere we evaluate whether modeling-based CLNS (M-CLNS) with acoustic stimulation of slow oscillations (SOs) can be effectively implemented using a self-applicable EEG headband with forehead electrodes. We assess the performance of M-CLNS stimulus targeting over the EEG headband together with short-term, stimulus-locked, and more enduring enhancement of SWS. We validate our results against simultaneous recordings obtained using gold-standard laboratory PSG equipment. Main resultsOur findings demonstrate that the SO phase can be reliably assessed and accurately targeted using M-CLNS with the EEG headband. We show an immediate enhancement of SO dynamics in the short-term, as well as an enduring increase in power spectral density across SO and delta frequencies (0.75 - 5 Hz) across SWS. These results are in line with previous studies using M-CLNS with laboratory equipment. SignificanceThese findings demonstrate that M-CLNS with acoustic stimulation can successfully be applied using an EEG headband on the forehead to target SOs, leading to both immediate and enduring enhancements of SWS. In conclusion, M-CLNS in a self-applicable EEG headband may offer a promising tool for portable and non-invasive enhancement of SWS, with future potential for clinical and home-based applications.

neuroscience↗

bioRxiv2025

Precisely phase-locked acoustic stimuli globally enhance slow oscillations, but depress fast spindles

IntroductionSeveral studies have shown manipulation of slow oscillations (SO) and sigma power through auditory stimulation during sleep. Most of the evidence, however, regards effects immediately following stimulation rather than enduring effects. Moreover, effects on discrete fast and slow spindles have as yet not been assessed. Materials and MethodsHere we use a modeling-based approach to predict upcoming oscillatory activity in the EEG and precisely phase-lock subtle acoustic stimuli to the start of the SO positive deflection. We assess the effects of stimulation on discrete slow oscillations, fast and slow spindles in the seconds after stimulation and on the longer term. We relate our findings to observations at the level of spectral measures and stimulus evoked responses. ResultsOur observations show that slow wave measures were consistently increased, as apparent in measures of discrete SOs, SO and delta power and deflections in the ERP. On the other hand, fast spindle measures showed a temporally localized increase during a stimulus-induced SO positive deflection around 1 second after stimulation, but were globally decreased, both on the short and long term. The latter was apparent in measures of discrete fast spindles and PSD across longer periods of sleep. ConclusionsAcoustic stimuli, precisely phase locked to the SO onset, increase SOs and delta power globally, therewith deepening sleep. On the other hand, fast sleep spindles are globally depressed. This appears to be due, in part, to interruption of ongoing spindles by the stimulus and may furthermore reflect a depressing influence of slow oscillations on fast spindle dynamics. Future studies could evaluate the therapeutic potential of sleep deepening with acoustic stimulation in clinical populations who suffer from reduced deep sleep, such as in insomnia or post-traumatic stress disorder.

neuroscience↗

bioRxiv2021

Sleep spindle dynamics suggest over-consolidation in post-traumatic stress disorder

Devastating and persisting traumatic memories are a central symptom of post-traumatic stress disorder (PTSD). Sleep problems are highly co-occurrent with PTSD and intertwined with its etiology. Notably, sleep hosts memory consolidation processes, supported by sleep spindles (11-16 Hz). Here we assess the hypothesis that intrusive memory symptoms in PTSD may arise from excessive memory consolidation, reflected in exaggerated spindling. We use a newly developed spindle detection method, entailing minimal assumptions regarding spindle phenotype, to assess spindle activity in PTSD patients and traumatized controls (n=2x14, matched on gender). Our results show increased spindle activity in PTSD, which positively correlates with daytime intrusive memory symptoms. Together, these findings provide a putative mechanism through which profound sleep disturbance in PTSD may contribute to memory problems. Due to its uniform and unbiased approach, the new, minimal assumption spindle detection method seems a promising tool to detect aberrant spindling in psychiatric disorders.

neuroscience↗