Christine Blume

University of Basel | UNIBAS · Centre for Chronobiology

For many studies, participants’ sleep-wake patterns are monitored and recorded prior to, during and following an experimental or clinical intervention using actigraphy, i.e. the recording of data generated by movements. Often, these data are merely inspected visually without computation of descriptive parameters, in part due to the lack of user-fri...

Objective: To investigate the relationship between the presence of a circadian body temperature rhythm and behaviorally assessed consciousness levels in patients with disorders of consciousness (DOC; i.e., vegetative state/unresponsive wakefulness syndrome or minimally conscious state). Methods: In a cross-sectional study, we investigated the pres...

While it is a well-established finding that subject's own names (SON) or familiar voices are salient during wakefulness, we here investigated processing of environmental stimuli during sleep including deep N3 and REM sleep. Besides the effects of sleep depth we investigated how sleep-specific EEG patterns (i.e. sleep spindles and slow oscillations...

Humans live in a 24-hour environment, in which light and darkness follow a diurnal pattern. Our circadian pacemaker, the suprachiasmatic nucleui (SCN) in the hypothalamus, is entrained to the 24-hour solar day via a pathway from the retina and synchronises our internal biological rhythms. Rhythmic variations in ambient illumination impact on behavi...

In modern societies, human rest–activity rhythms and sleep result from the tensions and dynamics between the conflicting poles of external social time (e.g., work hours and leisure activities) and an individual’s internal biological time. A mismatch between the two has been suggested to induce ‘social jetlag’ [1] and ‘social sleep restriction’, tha...

Recent research revealed a surprisingly large range of cognitive operations to be preserved during sleep in humans. The new challenge is therefore to understand functions and mechanisms of processes, which so far have been mainly investigated in awake subjects. The current study focuses on dynamic changes of brain oscillations and connectivity patt...

Study Objectives While light therapy has proven effective in re-entraining circadian rhythms, the potential of such an intervention has not been evaluated systematically in post-comatose patients with disorders of consciousness (DOC), who often have strongly altered circadian rhythms. Methods We recorded skin temperature over 7–8 days in patients...

The current study investigated heart rate (HR) and heart rate variability (HRV) across day and night in patients with disorders of consciousness (DOC). We recorded 24-h electrocardiography in 26 patients with DOC (i.e., unresponsive wakefulness syndrome (UWS; n = 16) and (exit) minimally conscious state ((E)MCS; n = 10)). To examine diurnal variati...

The current study investigated heart rate (HR) and heart rate variability (HRV) across day and night in patients with disorders of consciousness (DOC). We recorded 24-h ECG in 26 patients with DOC (i.e., unresponsive wakefulness syndrome [UWS; n=16] and (exit) minimally conscious state [(E)MCS; n=10]). To examine diurnal variations, HR and HRV indi...

The brain continues to respond selectively to environmental stimuli during sleep. However, the functional role of such responses, and whether they reflect information processing or rather sensory inhibition is not fully understood.Here, we present 17 human sleepers (14 females) with their own name and two unfamiliar first names, spoken by either a...

The brain continues to respond selectively to environmental stimuli even during sleep. However, the functional role of such responses, and whether they reflect information processing or rather sensory inhibition is not fully understood. Here, we presented 17 human sleepers (14 females) with their own name and two unfamiliar first names, spoken by e...

The human circadian system consists of the master clock in the suprachiasmatic nuclei of the hypothalamus as well as in peripheral molecular clocks located in organs throughout the body. This system plays a major role in the temporal organization of biological and physiological processes, such as body temperature, blood pressure, hormone secretion,...

Study objectives During infancy, adequate sleep is crucial for physical and neurocognitive development. In adults and children, night-time noise exposure is associated with sleep disturbances. However, whether and to what extent infants’ sleep is affected, is unknown. Thus, this study investigated the relationship between nocturnal transportation n...

Past research has demonstrated differential responses of the brain during sleep in response especially to variations in paralinguistic properties of auditory stimuli, suggesting they can still be processed “offline”. However, the nature of the underlying mechanisms remains unclear. Here, we therefore used multivariate pattern analyses to directly t...

The detection of (NREM-REM) sleep cycles in human sleep data (i.e., polysomnographically assessed sleep stages) enables fine-grained analyses of ultradian variations in sleep microstructure (e.g., sleep spindles, and arousals), or other amplitude- and frequency-specific electroencephalographic features during sleep. While many laboratories have sof...

Background: "Open science" is an umbrella term describing various aspects of transparent and open science practices. The adoption of practices at different levels of the scientific process (e.g., individual researchers, laboratories, institutions) has been rapidly changing the scientific research landscape in the past years, but their uptake differ...

The detection of sleep cycles in human sleep data (i.e. polysomnographically assessed sleep stages) enables fine-grained analyses of ultradian variations in sleep microstructure (e.g. sleep spindles, and arousals), or other amplitude- and frequency-specific electroencephalographic features during sleep. While many laboratories have software that is...

Background:Better integrity of circadian rhythms has been shown to relate to a richer behavioral repertoire in patients with disorders of consciousness (DOC). As light exposure has proven successful in treating circadian rhythm disorders, we sought to investigate whether simulating natural daylight in a clinical setting can entrain circadian rhythm...

Background: "Open science" is an umbrella term describing various aspects of transparent and open science practices. The adoption of practices at different levels of the scientific process (e.g., individual researchers, laboratories, institutions) has been rapidly changing the scientific research landscape in the past years, but their uptake differ...

"Open science" is an umbrella term describing various aspects of transparent and open science principles. The adoption of open science principles at different levels of the scientific process (e.g., individual researchers, laboratories, institutions) has been rapidly changing the scientific research landscape in the past years, but uptake of these...

Background: Actigraphy has received increasing attention in classifying rest-activity cycles. However, in patients with disorders of consciousness (DOC), actigraphy data may be considerably confounded by passive movements, such as nursing activities and therapies. Consequently, this study verified whether circadian rhythmicity is (still) visible in...

As experts, scientists must inform the public and political actors about relevant topics by providing a well-balanced analysis and overview of existing as well as missing scientific evidence. Particularly in cases where evidence is not solid, they must remain objective and not fan fear. Maintaining good scientific practice can be challenging, espec...

During the past years, the prevalence of sleep problems has been increasing steadily in industrial societies and represents a major social and socioeconomic burden. The situation in Austria was last evaluated in 2007 by Zeitlhofer and colleagues in a representative sample of 1000 participants. In the current study, we sought to evaluate the sleep b...

In this commentary, we first respond to apparent misconceptions that became evident in a recent review by Roenneberg, Winnebeck, and Klerman (2019) in this journal. Beyond this, we elaborate on our understanding of the advisory role of scientists for society. We argue that, as experts, they should inform the public and political actors about releva...

Background Actigraphy has received increasing attention in classifying rest-activity cycles. However, in patients with disorders of consciousness (DOC), actigraphy data may be considerably confounded by passive movements, such as nursing activities and therapies. Consequently, this study verified whether circadian rhythmicity is (still) visible in...

Humans live in a 24-hour environment, in which light and darkness follow a diurnal pattern. Our circadian pacemaker, the suprachiasmatic nuclei (SCN) in the hypothalamus, is entrained to the 24-hour solar day via a pathway from the retina and synchronises our internal biological rhythms. Rhythmic variations in ambient illumination impact behaviours...

During the past years, the prevalence of sleep problems has been increasing steadily in industrial societies and represents a major social and socioeconomic burden. The situation in Austria has last been evaluated in 2007 by Zeitlhofer and colleagues in a representative sample of 1000 participants. To allow for an updated picture, we have been coll...

This letter to the editor does not have an abstract.

Introduction Healthy circadian rhythmicity has been suggested to relate to a better state of brain‐injured patients and to support the emergence of consciousness in patient groups characterised by a relative instability thereof such as patients with disorders of consciousness (DOC). Methods Going beyond earlier studies, we have adopted a systems‐l...

While it is a well-established finding that subject’s own names (SON) or familiar voices are salient during wakefulness, we here investigated processing of environmental stimuli during sleep including deep N3 and REM sleep. Besides the effects of sleep depth we investigated how sleep-specific EEG patterns (i.e. sleep spindles and slow oscillations...

Sleep has been proposed to indicate preserved residual brain functioning in patients suffering from disorders of consciousness (DOC) after awakening from coma. However, a reliable characterization of sleep patterns in this clinical population continues to be challenging given severely altered brain oscillations, frequent and extended artifacts in c...

Demographic data for patients. The analyzed patient sample 12 UWS and 11 MCS subjects. Abbreviations: M = male, F = female, TBI = Traumatic Brain Injury, CVA-Cerebrovascular Accident, SSPE = Subacute Sclerosing Panencephalitis, SD- = lower severe disability (3 points on Extended Glasgow Outcome Scale), eMCS = emergence from MCS; CRC-R = Coma Recove...

Introduction Numerous studies indicate memory consolidation during sleep and postulate that memories are less susceptible to interference after sleep. Griessenberger et al. (2013), moreover, found that susceptibility to interference is pronounced in insomniacs in the declarative memory domain only as compared to the procedural domain. However, it i...

Estimating cognitive abilities in patients suffering from Disorders of Consciousness remains challenging. One cognitive task to address this issue is the so-called own name paradigm, in which subjects are presented with first names including the own name. In the active condition, a specific target name has to be silently counted. We recorded EEG du...

Emotionally relevant stimuli and in particular anger are, due to their evolutionary relevance, often processed automatically and able to modulate attention independent of conscious access. Here, we tested whether attention allocation is enhanced when auditory stimuli are uttered by an angry voice. We recorded EEG and presented healthy individuals w...

Emotional and self-relevant stimuli are able to automatically attract attention and their use in patients suffering from disorders of consciousness (DOC) might help detecting otherwise hidden signs of cognition. We here recorded EEG in three Locked-in syndrome (LIS) and four Vegetative State/ Unresponsive Wakefulness Syndrome (VS/UWS) patients whil...

Information processing has been suggested to depend on the current state of the brain as well as stimulus characteristics (e.g. salience). We compared processing of salient stimuli (subject’s own names [SONs] and angry voice [AV] stimuli) to processing of unfamiliar names (UNs) and neutral voice (NV) stimuli across different vigilance stages (i.e....

Theoretically, stimuli can be related to the self as subject (“I”) or object (“ME”) of experience. This event-related brain potential (ERP) study investigated whether listening to personal and possessive pronouns elicits different modes of self-processing regarding time-course and neural sources. Going beyond previous research, first (1PP) and seco...

One of the strongest stimuli to automatically catch attention is a person’s own name (ON). Auditory presentation of the ON has been shown to evoke electrophysiological markers of attention-orienting that even persist in states of diminished consciousness such as sleep (Perrin et al., 1999). Likewise, the emotional content such as familiarity of voi...

The ability to attribute independent mental states (e.g. opinions, perceptions, beliefs) to oneself and others is termed Theory of Mind (ToM). Previous studies investigating ToM usually employed verbal paradigms and functional neuroimaging methods. Here, we studied oscillatory responses in the electroencephalogram (EEG) in a non-verbal social cogni...

Advances in the development of new paradigms as well as in neuroimaging techniques nowadays enable us to make inferences about the level of consciousness patients with disorders of consciousness (DOC) retain. They moreover allow predicting their probable development. Today, we know that certain brain responses (e.g. event-related potentials or osci...

The ability to attribute independent mental states to oneself and others for the prediction and explanation of behaviour is a typically human characteristic termed “Theory of Mind” (ToM). Castelli et al. [1] introduced a paradigm for the investigation of ToM in which simple geometric shapes move in a random (R), goal-directed (GD) or complex way (T...

Due to improvement in the medical treatment of severely brain-injured patients, we have seen an increase in the number of patients suffering from disorders of consciousness (DOC) during the last years. DOC comprises two different states: the unresponsive wakefulness syndrome (UWS) and the minimally conscious state (MCS). While the former is charact...

Self-related stimuli such as the own name have been used to investigate self-awareness. The present study investigates a novel paradigm employing personal and possessive self-referential and non-self-referential pronouns (SRPs and NSRPs). Going beyond previous research, the robustness of the previously demonstrated self-reference effect was investi...