Impact of repeated morning bright white light exposures on attention in a simulated office environment.

Attention is essential to the work. This study investigated the effects of two different light pulses on a simple attention task. In addition, the effects of subsequent exposure to constant but different illuminance levels on the continuation of the simple attention task and a subsequent complex attention task were examined. A total of 56 subjects were assigned in random order to two white light interventions that were repeated five times during the morning. Each light intervention consisted of a brief light pulse followed by constant light exposure and differed in temporal dimming dynamics and corneal illuminance. Subjective and psychometric parameters were recorded several times during light exposure. Heart rate variability (HRV) was derived from continuous electrocardiograms. Subjects showed improved reaction speed in the simple attention task, accompanied by higher HRV under a brighter light pulse without habituation by repetition. This difference in simple attention performance disappeared when light exposure remained the same after the light pulse. In addition, higher reaction speed and HRV were observed in the complex attention task under constant bright light exposure. Intermittent bright light seems promising to acutely improve attentional performance in office workplaces. Future research is needed to investigate daytime light effects on other work-related cognitive functions.

Effects of dynamic bedroom lighting on measures of sleep and circadian rest-activity rhythm in inpatients with major depressive disorder.

Bright light therapy is an effective treatment option for seasonal and non-seasonal affective disorders. However up to now, no study has investigated effects of dynamic bedroom lighting in hospitalized patients with major depression. A bedroom lighting system, which automatically delivered artificial dawn and dusk and blue-depleted nighttime lighting (DD-N lighting) was installed in a psychiatric ward. Patients with moderate to severe depression were randomly assigned to stay in bedrooms with the new lighting or standard lighting system. Patients wore wrist actimeters during the first two treatment weeks. Additionally, hospitalization duration and daily psychotropic medication were retrieved from patients' medical charts. Data from thirty patients, recorded over a period of two weeks, were analyzed. Patients under DD-N lighting generally woke up earlier (+ 20 min), slept longer (week 1: + 11 min; week 2: + 27 min) and showed higher sleep efficiency (+ 2.4%) and shorter periods of nighttime awakenings (- 15 min). In the second treatment week, patients started sleep and the most active 10-h period earlier (- 33 min and - 64 min, respectively). This pilot study gives first evidence that depressed patients' sleep and circadian rest/activity system may benefit from bedroom lighting when starting inpatient treatment.

Light Intervention Effects on Circadian Activity Rhythm Parameters and Nighttime Sleep in Dementia Assessed by Wrist Actigraphy: A Systematic Review and Meta-Analysis.

BACKGROUND AND OBJECTIVES: Persons with dementia often show circadian rhythm disturbances and sleep problems. Timed light exposure seems to be a promising nonpharmacological treatment option. In this review, meta-analyses were run on light effects on circadian activity rhythm parameters in persons with dementia measured with wrist actimetry. Furthermore, we update a Cochrane review, published in 2014, on actigraphically measured light effects in nighttime sleep parameters in persons with dementia. RESEARCH DESIGN AND METHODS: Four electronic databases were searched for randomized controlled trials. Effects in meta-analyses were summarized by using mean differences and 95% confidence intervals. We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to assess the risk of bias and registered the review protocol (PROSPERO: CRD42020149001). RESULTS: Thirteen trials met inclusion criteria, and either utilized light therapy devices, ambient room lighting systems, or dawn-dusk interventions. Eleven of these studies were subjected to meta-analyses. They did not reveal significant light effects on circadian activity parameters: amplitude (p = .62; n = 313), acrophase (p = .34; n = 313), intradaily variability (p = .51; n = 354), and interdaily stability (p = .38; n = 354). Furthermore, no light effects were found on sleep parameters: total sleep duration (p = .53; n = 594), sleep efficiency (p = .63; n = 333), wake after sleep onset (p = .95; n = 212), and sleep onset latency (p = .26; n = 156). Subgroup analyses, pooling data from 3 studies including persons with Alzheimer's dementia, also did not show light effects on circadian activity and sleep parameters. The overall risk of bias of included studies was high. DISCUSSION AND IMPLICATIONS: There is insufficient evidence for actigraphically measured circadian light effects in persons with dementia. More high-quality research is needed to recommend the application of adjunctive light.

Functional coupling of brain networks during creative idea generation and elaboration in the figural domain.

The neuroscientific investigation of creative cognition has advanced by considering the functional connectivity between brain regions and its dynamic changes over time, which are consistent with stages in the ideation process. Surprisingly, although the communication between neuronal networks takes place in a time-scale of milliseconds, EEG studies investigating a time-course in cortico-cortical communication during creative ideation are rare and findings are typically restricted to the verbal domain. Therefore, this study examined functional coupling using EEG (task-related phase-locking in the upper-alpha range) during creative thinking in the figural domain. Using an innovative computerized experimental paradigm, we specifically investigated the stage of idea generation and the stage of idea elaboration in an adapted picture completion task. The findings confirmed a hypothesized increase of functional coupling from idea generation to elaboration, which was most pronounced in frontal-central as well as frontal-temporal networks. The connectivity in the frontal-parietal/occipital network already increased during idea generation and remained constant during elaboration. Importantly, more original participants generally showed higher functional connectivity in all brain networks. This elevated functional coupling with frontal brain regions might reflect increased executive processes related to internal attention, motor planning, and semantic selection processes supporting highly original thought in the figural domain.

Actigraphy for Assessing Light Effects on Sleep and Circadian Activity Rhythm in Alzheimer's Dementia: A Narrative Review.

BACKGROUND: Alzheimer's Disease (AD) is often accompanied by severe sleep problems and circadian rhythm disturbances which may to some extent be attributed to a dysfunction in the biological clock. The 24-h light/dark cycle is the strongest Zeitgeber for the biological clock. People with AD, however, often live in environments with inappropriate photic Zeitgebers. Timed bright light exposure may help to consolidate sleep- and circadian rest/activity rhythm problems in AD, and may be a low-risk alternative to pharmacological treatment. OBJECTIVE & METHODS: In the present review, experts from several research disciplines summarized the results of twenty-seven light intervention studies which used wrist actigraphy to measure sleep and circadian activity in AD patients. RESULTS: Taken together, the findings remain inconclusive with regard to beneficial light effects. However, the considered studies varied substantially with respect to the utilized light intervention, study design, and usage of actigraphy. The paper provides a comprehensive critical discussion of these issues. CONCLUSION: Fusing knowledge across complementary research disciplines has the potential to critically advance our understanding of the biological input of light on health and may contribute to architectural lighting designs in hospitals, as well as our homes and work environments.

EEG alpha activity during imagining creative moves in soccer decision-making situations.

This study investigated task-related changes of EEG alpha power while participants were imagining creative moves in soccer decision-making situations. After presenting brief video clips of a soccer scene, participants had to imagine themselves as the acting player and to think either of a creative/original or an obvious/conventional move (control condition) that might lead to a goal. Performance of the soccer task generally elicited comparatively strong alpha power decreases at parietal and occipital sites, indicating high visuospatial processing demands. This power decrease was less pronounced in the creative vs. control condition, reflecting a more internally oriented state of information processing characterized by more imaginative mental simulation rather than stimulus-driven bottom-up processing. In addition, more creative task performance in the soccer task was associated with stronger alpha desynchronization at left cortical sites, most prominently over motor related areas. This finding suggests that individuals who generated more creative moves were more intensively engaged in processes related to movement imagery. Unlike the domain-specific creativity measure, individual's trait creative potential, as assessed by a psychometric creativity test, was globally positively associated with alpha power at all cortical sites. In investigating creative processes implicated in complex creative behavior involving more ecologically valid demands, this study showed that thinking creatively in soccer decision-making situations recruits specific brain networks supporting processes related to visuospatial attention and movement imagery, while the relative increase in alpha power in more creative conditions and in individuals with higher creative potential might reflect a pattern relevant across different creativity domains.

The creative brain in the figural domain: Distinct patterns of EEG alpha power during idea generation and idea elaboration.

This study investigated EEG activity in the upper alpha band during the well-known Picture Completion Task of the Torrance Test of Creative Thinking (TTCT), a widely used creative ideation task in the figural domain. The application of a sophisticated computerized version of the TTCT facilitating the online assessment and digitalizing of participant's drawings allowed to separate two central stages of the creative ideation process (i.e., idea generation and idea elaboration). During idea generation, the participants' task was to generate an initial draft of an original and creative completion of the presented abstract lines and figures of the TTCT. During idea elaboration, the participants were required to mentally improve the originality of the initially generated idea/draft. Creative ideation in this figural task was generally associated with comparatively strong desynchronization of upper alpha power over parietal and occipital sites, indicating high visual/figural processing demands. Interestingly, the stage of idea elaboration was accompanied by a relative increase of upper alpha power at parietal and occipital sites compared to the stage of idea generation, indicating heightened top-down processing demands. Furthermore, task performance was associated with relative increases of upper alpha power at frontal sites and relative decreases at centro-temporal sites from the stage of idea generation to idea elaboration. This association suggests the importance of increased inhibitory control over stimulus-based bottom-up information and motor imagery in order to achieve more creative outputs. Taken together these findings add to the relevant literature in that they a) extend research on the relationship between EEG alpha activity and creativity to the figural domain, and b) support a multistage view of creative ideation, involving cognitive control and mental imagery as important components of creativity.

Psychophysiological Effects of a Single, Short, and Moderately Bright Room Light Exposure on Mildly Depressed Geriatric Inpatients: A Pilot Study.

BACKGROUND: Light interventions typically exert their mood-related effects during morning bright light exposures over several weeks. Evidence about immediate ambient room light effects on depressed individuals is still sparse. OBJECTIVE: The present study aimed at examining the acute effects of a single moderately bright room light exposure on mood, and behavioural and cardiac stress reactions of mildly depressed geriatric inpatients during a short cognitive stimulation and while resting. METHODS: Twenty-one inpatients were tested in a balanced cross-over design on 2 consecutive days under either conventional room light (standard light) or artificial sunlight conditions for 30 min. Room illumination was implemented with an artificial skylight, which perfectly imitated solar indoor illumination (e.g., cloudless sky and bright artificial sun). Light-induced changes of mood, heart rate, and heart rate variability were recorded while performing a perseveration test (acted as cognitive stimulation) twice. Additionally, light-related behaviour was observed during a resting period between the cognitive tests and various subjective ratings were obtained. RESULTS: Compared to standard light, exposure to artificial sunlight had a subjective calming effect over time (p = 0.029) as well as decreased heart rate and increased vagal tone (root mean squared of successive inter-beat intervals), both under cognitive workload and in resting conditions. Effect sizes of reported cardiac reactions were large. Cognitive variables were not influenced by light. Additionally, under the higher corneal illuminance of the artificial sunlight, patients perceived stronger glare (p = 0.030) and kept their eyes closed for longer times (p = 0.033) during the resting period. However, patients did not avoid bright light exposure while resting but voluntarily stayed within the area directly lit by the artificial sun nearly all the time (97%). CONCLUSION: To our knowledge, this study for the first time demonstrated immediate psychophysiological effects of a single, short room light exposure in mildly depressed geriatric inpatients during a short cognitive stimulation and while resting. The findings complement reported evidence on immediate alerting and mood-related effects of bright light exposures.

Carriers of the COMT Met/Met allele have higher degrees of hypnotizability, provided that they have good attentional control: a case of gene-trait interaction.

Genetic factors may explain part of the interindividual variability in hypnotizability. A new avenue that may provide more comprehensive understanding of the phenotypic effects of genetic variations is the study of gene-trait interaction. In this study, the authors investigate the relationship of the dopamine-related COMT and the serotonin-related 5-HTTLPR polymorphisms to hypnotizability by taking individual differences in executive attention into account. Homozygosity for the COMT Met allele, putatively linked to the capability or proneness to dissociate from reality, was associated with high hypnotizability only if paired with high-attention ability. The finding can be integrated into hypnosis theory and represents a case of gene-trait interaction suggesting that investigating the effects of a gene in the context of relevant psychological traits may further elucidate gene-brain-behavior relationships.

[The current state of research in bright light therapy]. / Lichttherapie: Zum Stand der aktuellen Forschung.

The significance of light for the human organism and especially for the mental health is well-established for a long time. Therefore, the impact of light on mood and the use of bright light as a treatment-option for affective disorders have been studied extensively by scientists. Today bright light therapy is the treatment of choice for saisonal affective disorders. In the last years several clinical trials could demonstrate the therapeutic efficacy of bright light therapy for different neurological and psychiatric disorders such as sleep disorders, non-seasonal affective disorders or dementia. This article will give an overview about the neurobiological basis for light therapy and discuss different disorders responsive to light therapy. Finally a short overview about technical aspects of light therapy and new developments in light engineering will be presented.

[Creativity in cannabis-users and in drug addicts in maintenance treatment and in rehabilitation]. / Kreativität bei Drogenkonsumierenden, Drogenabhängigen und Drogenentwöhnten.

The main aim of this study was to investigate potential differences between different groups of drug addicts (patients in maintenance treatment, n = 14; patients in rehabilitation, n = 12) and Cannabis-Users (n = 13), along with a healthy control group (n = 18), with respect to verbal and figural creativity and general cognitive ability. Participants worked on different measures for the assessment of different facets of creativity, intelligence and experienced psychiatric symptoms. The results indicated that patients in maintenance and, to some extent Cannabis-Users scored higher regarding verbal creativity than patients in rehabilitation. With respect to figural creativity we observed no differences between the experimental groups. Concerning the Big Five personality traits, patients in maintenance treatment scored highest on Neuroticism while on a purely descriptive level Cannabis-Users achieved the highest scores with respect to openness to experience and extraversion.

State-dependent changes of prefrontal-posterior coupling in the context of affective processing: susceptibility to humor.

The aim of the present study was to examine whether interindividual differences in the coupling or decoupling of prefrontal and posterior cortices during the exposure to social-emotional information may predict an individual's positive emotional responsiveness. Susceptibility to humor was assessed in a behavioral paradigm several weeks after the EEG recordings. State-dependent changes of prefrontal-posterior EEG beta coherence were recorded during stimulation with other people's auditory expressions of cheerfulness and sadness. Greater decreases of coherence during the stimulation with positive affect expressions prospectively predicted greater positive emotional responsiveness, indicated by higher amusement ratings in response to cartoons and higher scores in a questionnaire measure of exhilarability. Greater increases of coherence during the stimulation with negative affect expressions did not predict perceived funniness but were related to shorter response latencies to the amusement ratings. The results further support the notion that a more loose prefrontal-posterior coupling may be related to loosening of control of the prefrontal cortex over incoming emotional information and, thus, to a propensity to deeper emotional involvement and a greater impact of perceptual input, whereas increased prefrontal-posterior coupling may be related to strong control and the propensity to protect oneself from becoming emotionally affected.

[Dementia and music]. / Demenz und Musik.

Patients suffering from dementia are nevertheless still able to render exceptional musical performances. For example, they can recognize music from childhood and reproduce lyrics and melodies of songs with four verses. Furthermore, behavioural symptoms such as psycho- motor agitation and crying, but also aggressive behaviour can be positively influenced by music and motivation and positive emotions can be increased. A variety of physiological and psychological changes occur when patients are listening to music. Previous research could show that music activated different parts of the brain especially in the temporal cortex, but also motoric areas in the frontal cortex, thalamus and cerebellum were essential for rhythm, melody and harmony perception and processing. Music therapy is an interpersonal process in which music is used within a therapeutic relationship to address physical, emotional, cognitive, and social needs of individuals with various psychiatric or medical conditions. However, until now only little research has been directed towards non-pharmacological treatments like music therapy in dementia patients. Further research is warranted to investigate the long term influence of music therapy on patients suffering from dementia.

No deterioration of cognitive performance in an aggressive unilateral and bilateral antidepressant rTMS add-on trial.

BACKGROUND: Cognitive functions were assessed before and following a course of repetitive transcranial magnetic stimulation (rTMS) in patients with depression participating in a sham-controlled, randomized trial of rTMS as adjunct to antidepressant treatment. METHOD: Forty-one medicated inpatients with a DSM-IV diagnosis of a depressive episode were consecutively randomly assigned to 1 of 3 groups comparing 2 active rTMS conditions with sham stimulation. The rTMS was applied either at high frequency over the left dorsolateral-prefrontal cortex (DLPFC) (10 sessions x 10 trains x 10 seconds 20 Hz at 100% motor threshold [MT], 90-second intertrain interval) or in a combined high- and low-frequency manner to the left and right DLPFC, respectively (10 sessions x 1 train x 10 minutes at 120% MT). Thirty-eight patients completed a neuropsychological test battery at baseline and following day 14. The cognitive assessment focused on motor skills, attention, executive functions, learning, and memory. Data were collected from November 1999 to August 2002. RESULTS: Active treatment groups did not differ with respect to assessed cognitive measures and thus were pooled. A comparison of short-term changes (baseline-day 14) in neuropsychological performance revealed a more favorable time course of the actively treated patients for encoding in the verbal memory test compared with the sham-stimulated patients. CONCLUSIONS: Unilateral rTMS as well as bilateral combined rTMS revealed no detrimental effects on cognition, as compared with the sham group. Moreover, neither the add-on design nor the used aggressive parameters had a negative impact on cognitive measures in comparison with sham. Repetitive transcranial magnetic stimulation might have mild beneficial cognitive effects partly independent of its antidepressant efficacy.