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- Nilsonne, Gustav, et al.
(författare)
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A multimodal brain imaging dataset on sleep deprivation in young and old humans
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The Stockholm Sleepy Brain Study I is a functional brain imaging study of 48 younger (20-30 years) and 36 older (65-75 years) healthy participants, with magnetic resonance imaging after normal sleep and partial sleep deprivation in a crossover design. We performed experiments investigating emotional mimicry, empathy for pain, and cognitive reappraisal, as well as resting state functional magnetic resonance imaging (fMRI). We also acquired T1- and T2-weighted structural images and diffusion tensor images (DTI). On the night before imaging, participants were monitored with ambulatory polysomnography and were instructed to sleep either as usual or only three hours. Participants came to the scanner the following evening. Besides MRI scanning, participants underwent behavioral tests and contributed blood samples, which have been stored in a biobank and used for DNA analyses. Participants also completed a variety of self-report measures. The resulting multimodal dataset may be useful for hypothesis generation or independent validation of effects of sleep deprivation and aging, as well as investigation of cross-sectional associations between the different outcomes. V. 2 of this manuscript published 2017-10-12. Changes: new co-author (Claus Lamm), changed affiliations for Kristoffer Månsson, minor changes in the abstract, and revisions of the main text and figures.
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| 5. |
- Nilsonne, Gustav, et al.
(författare)
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Intrinsic brain connectivity after partial sleep deprivation in young and older adults
- 2017
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Konferensbidrag (refereegranskat)abstract
- Introduction: Sleep deprivation has been reported to affect intrinsic brain connectivity, notably in the default mode network, but studies to date have shown inconsistent effects and have largely included young participants. We therefore aimed to investigate effects of partial sleep deprivation on intrinsic brain connectivity in young and older participants. Methods: Participants aged 20-30 (n = 30) and 65-75 (n = 23) years underwent partial sleep deprivation (3 h sleep) in a cross-over design, with two eyes-open resting state functional magnetic resonance imaging (fMRI) runs in each session. We assessed intrinsic brain connectivity using independent components analysis (ICA) as well as seed-region analyses of functional connectivity, and also analysed global signal variability, regional homogeneity, and the amplitude of low-frequency fluctuations. Participants were monitored with eye-tracking to ensure they did not fall asleep during scanning. Results: Sleep deprivation caused increased global signal variability, defined as log-transformed standard deviation of average gray matter signal (0.16 [0.07, 0.24], p = 0.0004). In contrast to previous studies, sleep deprivation did not cause major changes in investigated resting state networks, nor did it cause changes in regional homogeneity. Younger participants had higher functional connectivity in most examined resting state networks, as well as higher regional homogeneity in brain areas including anterior and posterior cingulate cortex. Conclusions: We show for the first time that partial sleep deprivation caused increased global signal variability. This outcome should be examined as a potential biomarker for sleepiness using independent data. Unlike a few earlier studies, we did not find less default mode connectivity in the sleep deprived state, possibly because of stricter monitoring of participants' wakefulness.
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| 6. |
- Nilsonne, Gustav, et al.
(författare)
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Intrinsic brain connectivity after partial sleep deprivation in young and older adults : results from the Stockholm Sleepy Brain study
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Sleep deprivation has been reported to affect intrinsic brain connectivity, notably reducing connectivity in the default mode network. Studies to date have however shown inconsistent effects, in many cases lacked monitoring of wakefulness, and largely included young participants. We investigated effects of sleep deprivation on intrinsic brain connectivity in young and older participants. Participants aged 20–30 (final n = 30) and 65–75 (final n = 23) years underwent partial sleep deprivation (3 h sleep) in a cross-over design, with two 8-minutes eyes-open resting state functional magnetic resonance imaging (fMRI) runs in each session, monitored by eye-tracking. We assessed intrinsic brain connectivity using independent components analysis (ICA) as well as seed-region analyses of functional connectivity, and also analysed global signal variability, regional homogeneity, and the amplitude of low-frequency fluctuations. Sleep deprivation caused increased global signal variability. Changes in investigated resting state networks and in regional homogeneity were not statistically significant. Younger participants had higher connectivity in most examined networks, as well as higher regional homogeneity in areas including anterior and posterior cingulate cortex. In conclusion, we found that sleep deprivation caused increased global signal variability, and we speculate that this may be caused by wake-state instability.
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| 7. |
- Radun, Igor, et al.
(författare)
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Company employees as experimental participants in traffic safety research : Prevalence and implications
- 2019
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Ingår i: Transportation Research Part F. - Stockholm : Elsevier BV. - 1369-8478 .- 1873-5517. ; 60, s. 81-92
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Tidskriftsartikel (refereegranskat)abstract
- The use of company employees as experimental participants when testing products, technology or paradigms developed by the same company raises questions about bias in results and research ethics. We aimed to investigate the prevalence of studies authored by car company researchers with car company employees as participants, to assess the risk of bias in such studies, to investigate journal editors’ opinions in the field of traffic safety regarding these procedures, and to offer a general discussion about ethical and methodological implications. Three types of data were collected. We (i) examined guidelines and recommendations for authors in eleven selected peer-reviewed journals in the area of traffic safety; (ii) surveyed editors of these journals; and (iii) reviewed articles authored by researchers from a selected group of car manufacturers and published in these journals during 2011–2015. Guidelines and recommendations for authors in the included journals did not mention whether and under what circumstances company employees can be research participants, nor did publishers’ general guidelines. However, three out of the four editors who responded to our survey believed that this issue of private company researchers using participants from the same company deserves to be explicitly addressed in their journal’s guide for authors. The total number of regular articles and conference papers during 2011–2015 in the eleven journals reviewed was 6763; 95 (1.4%) listed at least one car manufacturer in the authors’ affiliations; and out of these, nine included company employees as participants. In summary, company employees are seldom (0.13%) used as research participants in traffic safety research. Nevertheless, the use of company employees as research participants raises questions about bias in results as well as about incursions into the participants’ autonomy.
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- Tamm, Sandra, et al.
(författare)
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A combined fMRI and EMG study of emotional contagion following partial sleep deprivation in young and older humans
- 2020
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Sleep deprivation is proposed to inhibit top-down-control in emotion processing, but it is unclear whether sleep deprivation affects emotional mimicry and contagion. Here, we aimed to investigate effects of partial sleep deprivation on emotional contagion and mimicry in young and older humans. Participants underwent partial sleep deprivation (3 h sleep opportunity at the end of night), crossed-over with a full sleep condition in a balanced order, followed by a functional magnetic resonance imaging and electromyography (EMG) experiment with viewing of emotional and neutral faces and ratings of emotional responses. The final sample for main analyses was n = 69 (n = 36 aged 20–30 years, n = 33 aged 65–75 years). Partial sleep deprivation caused decreased activation in fusiform gyri for angry faces and decreased ratings of happiness for all stimuli, but no significant effect on the amygdala. Older participants reported more anger compared to younger participants, but no age differences were seen in brain responses to emotional faces or sensitivity to partial sleep deprivation. No effect of the sleep manipulation was seen on EMG. In conclusion, emotional contagion, but not mimicry, was affected by sleep deprivation. Our results are consistent with the previously reported increased negativity bias after insufficient sleep.The Stockholm sleepy brain study: effects of sleep deprivation on cognitive and emotional processing in young and old. https://clinicaltrials.gov/ct2/show/NCT02000076.
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| 9. |
- Tamm, Sandra, et al.
(författare)
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It hurts me too – an fMRI study of the effects of sleep restriction and age on empathy for pain
- 2016
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: Many emotional processes are affected by sleep restriction (Beattie et al. 2015). Whether this is likewise true for social emotions, such as empathy, is not known. Empathy for pain has previously been studied using paradigms where subjects are presented with pain in others or pictures of pain in others. These paradigms consistently activated areas in the anterior cingulate cortex and anterior insula. Aging affects both sleep (Vitiello 2012) and emotional functions (Mather 2012), but whether the role of sleep in emotional functioning is stable across age is not known. This study aims to investigate how neural and behavioral responses to pain in others are affected by sleep restriction and age, and whether age modulates the role of sleep in responses to pain in others.Methods: In a randomized cross-over experimental design, 47 healthy younger (age: 20-30) and 39 older (age: 65-75) volunteers underwent fMRI twice, after either normal sleep or sleep restricted to 3 hours. In an event-related fMRI task, participants viewed pictures of needles pricking a hand (pain condition) or Q-tips touching a hand (control condition), and reported their vicarious unpleasantness. Preprocessing and analyses were performed in SPM12 and included slice time correction, realignment, DARTEL normalization and smoothing with an 8x8x8 FWHM kernel. First level analyses included fixed effects for events, motion parameters and button presses. At second level a full factorial design was applied. Additional region of interest analyses were performed in anterior insula and anterior cingulate cortex.Results: The contrast pain > control robustly activated anterior cingulate cortex and anterior insula (FWE p < 0.05, fig 1) as well as other areas previously proposed as the core empathy for pain network (Lamm et al. 2011). Older participants generally experienced more unpleasantness in response to pictures of pain compared to younger participants (p < 0.001), and this was accompanied by higher activity in bilateral angular gyrus (FWE p < 0.05). Age and sleep interacted so that sleep restriction caused decreased unpleasantness in young and increased unpleasantness in old to pain stimuli (p < 0.01), even though there was no significant simple main effect of sleep restriction in any age group. In clusters in bilateral insula, old participants showed more activity and young less activity in response to pain after sleep restriction (p < 0.001 uncorrected).Conclusions: Compared to younger participants, older subjects generally responded more to pain in others, shown as subjective experience as well as brain responses. With sleep restriction, empathic responses in young and old changed in opposite directions, so that empathic responses increased in older and decreased in younger participants. Given that empathy is crucial in effective interaction with others, our findings imply possible age-related changes in prosocial behavior, amplified by short sleep.
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| 10. |
- Tamm, Sandra, et al.
(författare)
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Sleep restriction caused impaired emotional regulation without detectable brain activation changes—a functional magnetic resonance imaging study
- 2019
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Ingår i: Royal Society Open Science. - : The Royal Society. - 2054-5703. ; 6:3
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Tidskriftsartikel (refereegranskat)abstract
- Sleep restriction has been proposed to cause impaired emotional processing and emotional regulation by inhibiting top-down control from prefrontal cortex to amygdala. Intentional emotional regulation after sleep restriction has, however, never been studied using brain imaging. We aimed here to investigate the effect of partial sleep restriction on emotional regulation through cognitive reappraisal. Forty-seven young (age 20–30) and 33 older (age 65–75) participants (38/23 with complete data and successful sleep intervention) performed a cognitive reappraisal task during fMRI after a night of normal sleep and after restricted sleep (3 h). Emotional downregulation was associated with significantly increased activity in the dorsolateral prefrontal cortex (pFWE < 0.05) and lateral orbital cortex (pFWE < 0.05) in young, but not in older subjects. Sleep restriction was associated with a decrease in self-reported regulation success to negative stimuli (p< 0.01) and a trend towards perceiving all stimuli as less negative (p = 0.07) in young participants. No effects of sleep restriction on brain activity nor connectivity were found in either age group. In conclusion, our data do not support the idea of a prefrontal-amygdala disconnect after sleep restriction, and neural mechanisms underlying behavioural effects on emotional regulation after insufficient sleep require further investigation.
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