1,183 research outputs found
Giulia Veronica Varisco
No full textThe headword explains the biography and the contribution of the author Giulia Varisco to the children's literatur
Is sleep essential for neural plasticity in humans, and how does it affect motor and cognitive recovery?
No full textThere is a general consensus that sleep is strictly linked to memory, learning, and, in general, to the mechanisms of neural plasticity, and that this link may directly affect recovery processes. In fact, a coherent pattern of empirical findings points to beneficial effect of sleep on learning and plastic processes, and changes in synaptic plasticity during wakefulness induce coherent modifications in EEG slow wave cortical topography during subsequent sleep. However, the specific nature of the relation between sleep and synaptic plasticity is not clear yet. We reported findings in line with two models conflicting with respect to the underlying mechanisms, that is, the "synaptic homeostasis hypothesis" and the "consolidation" hypothesis, and some recent results that may reconcile them. Independently from the specific mechanisms involved, sleep loss is associated with detrimental effects on plastic processes at a molecular and electrophysiological level. Finally, we reviewed growing evidence supporting the notion that plasticity-dependent recovery could be improved managing sleep quality, while monitoring EEG during sleep may help to explain how specific rehabilitative paradigms work. We conclude that a better understanding of the sleep-plasticity link could be crucial from a rehabilitative point of view
Poor sleep quality, insomnia, and short sleep duration before infection predict long-term symptoms after COVID-19
No full textBackground: Millions of COVID-19 survivors experience a wide range of long-term symptoms after acute infection, giving rise to serious public health concerns. To date, few risk factors for post-COVID-19 conditions have been determined. This study evaluated the role of pre-infection sleep quality/duration and insomnia severity in the incidence of long-term symptoms after COVID-19. Material and methods: This prospective study involved two assessments (April 2020 and 2022). At the baseline (April 2020), sleep quality/duration and insomnia symptoms in participants without current/prior SARS-CoV-2 infection were measured using the Pittsburgh Sleep Quality Index (PSQI) and the Insomnia Severity Index (ISI). At the follow-up (April 2022), we asked a group of COVID-19 survivors to retrospectively evaluate the presence of twenty-one symptoms (psychiatric, neurological, cognitive, bodily, and respiratory) that have been experienced one month (n = 713, infection in April 2020-February 2022) and three months after COVID-19 (n = 333, infection in April 2020-December 2021). In April 2022, participants also reported how many weeks passed to fully recover from COVID-19. Zero-inflated negative binomial models were used to estimate the effect of previous sleep on the number of long-term symptoms. Binomial logistic regressions were performed to evaluate the association between sleep variables, the incidence of each post-COVID-19 symptom, and the odds of recovery four/twelve weeks after infection. Results: Analyses highlighted a significant effect of pre-infection sleep on the number of symptoms one/three months after COVID-19. Previous higher PSQI and ISI scores, and shorter sleep duration significantly increased the risk of almost every long-term symptom at one/three months from COVID-19. Baseline sleep problems were also associated with longer recovery times to return to the pre-infection daily functioning level after COVID-19. Conclusions: This study suggested a prospective dose-dependent association of pre-infection sleep quality/quantity and insomnia severity with the manifestation of post-COVID-19 symptoms. Further research is warranted to determine whether preventively promoting sleep health may mitigate the COVID-19 sequelae, with substantial public health and societal implications
The assessment of somatosensory cortex plasticity during sleep deprivation by paired associative stimulation
No full textMany animal studies suggest that during sleep deprivation (SD) synaptic strength should progressively increase, leading to the saturation of the ability to induce long-term potentiation (LTP). Nevertheless, direct evidences about the effects of sustained wakefulness on cortical plasticity in humans are still lacking. The aim of the present study was to assess changes in the ability to induce LTP-like mechanism in humans during a period of SD by means of a paired associative stimulation (PAS) protocol, which combines median nerve stimulation with transcranial magnetic stimulation (TMS) applied over the contralateral somatosensory cortex. During a 41-h SD protocol, 16 healthy subjects, defined as responders to the PAS protocol after a pre-selection session, were involved in 4 experimental sessions (11.00 a.m. and 11.00 p.m. of first and second day) with: a) pre-PAS somatosensory evoked potentials (SEPs) recordings; b) PAS protocol; c) post-PAS SEPs recordings. The effect of PAS on SEPs early components (N20-P25 complex) was assessed. During the first experimental session (without SD) no significant PAS effects on SEPs components amplitude have been found, and large intra- and inter-individual variability have been observed. A lack of significant changes has been observed also in the subsequent sessions. Our results index a low intra- and inter-individual reliability of the PAS protocol, suggesting particular caution when longitudinally evaluating the effect of this technique on cortical plasticit
Demographic, psychological, chronobiological, and work-related predictors of sleep disturbances during the COVID-19 lockdown in Italy
No full textThe first COVID-19 contagion wave caused unprecedented restraining measures worldwide. In Italy, a period of generalized lockdown involving home confinement of the entire population was imposed for almost two months (9 March–3 May 2020). The present is the most extensive investigation aimed to unravel the demographic, psychological, chronobiological, and work-related predictors of sleep disturbances throughout the pandemic emergency. A total of 13,989 Italians completed a web-based survey during the confinement period (25 March–3 May). We collected demographic and lockdown-related work changes information, and we evaluated sleep quality, insomnia and depression symptoms, chronotype, perceived stress, and anxiety using validated questionnaires. The majority of the respondents reported a negative impact of confinement on their sleep and a delayed sleep phase. We highlighted an alarming prevalence of sleep disturbances during the lockdown. Main predictors of sleep disturbances identified by regression models were: female gender, advanced age, being a healthcare worker, living in southern Italy, confinement duration, and a higher level of depression, stress, and anxiety. The evening chronotype emerged as a vulnerability factor, while morning-type individuals showed a lower predisposition to sleep and psychological problems. Finally, working from home was associated with less severe sleep disturbances. Besides confirming the role of specific demographic and psychological factors in developing sleep disorders during the COVID-19 pandemic, we propose that circadian typologies could react differently to a particular period of reduced social jetlag. Moreover, our results suggest that working from home could play a protective role against the development of sleep disturbances during the current pandemic emergency
EEG topography during sleep inertia upon awakening after a period of increased homeostatic sleep pressure
No full textOBJECTIVE:
Behavioral and physiological indexes of high sleep inertia (SI) characterize the awakening from recovery (REC) sleep after prolonged wakefulness, but the associated electroencephalogram (EEG) topography has never been investigated. Here, we compare the EEG topography following the awakening from baseline (BSL) and REC sleep.
METHODS:
We have recorded the EEG waking activity of 26 healthy subjects immediately after the awakening from BSL sleep and from REC sleep following 40 h of prolonged wakefulness. In both BSL and REC conditions, 12 subjects were awakened from stage 2 sleep, and 14 subjects from rapid eye movement (REM) sleep. The full-scalp waking EEG (eyes closed) was recorded after all awakenings.
RESULTS:
Subjects awakened from REC sleep showed a reduction of fronto-central alpha and beta-1 activities, while no significant effects of the sleep stage of awakening have been observed. Positive correlations between pre- and post-awakening EEG modifications following REC sleep have been found in the posterior and lateral cortices in the frequency ranges from theta to beta-2 and (only for REM awakenings) extending to the fronto-central regions in the beta-1 band, and in the midline central and parietal derivations for the alpha and delta bands, respectively.
CONCLUSIONS:
These findings suggest that the higher SI after REC sleep may be due to the fronto-central decrease of alpha and beta-1 activity and to the persistence of the sleep EEG features after awakening in the posterior, lateral, and fronto-central cortices, without influences of the sleep stage of awakenin
Modulating emotional attentional bias through targeted memory reactivation during sleep: Preliminary data
No full textIntroduction: Attentional Bias (AB) is the tendency among individuals
with emotional dysregulation to preferentially allocate attention
toward negative emotional stimuli rather than positive ones, influencing
the encoding and consolidation of emotional events. Targeted
Memory Reactivation (TMR) holds promise in memory enhancement
by reactivating specific memory traces during sleep. We aimed to
explore the potential of TMR in modulating AB.
Methods: Eighteen females (mean age ± standard deviation, 21.56
± 2.04) participated in a between-subjects design. AB was assessed
using a modified Dot-Probe Task (DPT) before (T1) and after (T2) a
nocturnal sleep with acoustic stimulation (TMR vs. Control) during
slow-wave sleep (SWS). During DPT, participants viewed pairs of
emotional faces (positive/negative) followed by a probe. They indicated
the probe's position (left/right) while simultaneously being
exposed to a specific auditory cue, one for positive and one for negative
image-probe association (positive valence/negative valence). During
sleep, the TMR group was exposed to the sound associated with
the positive valence of the DPT, while a novel sound was presented
to the Control group. To assess the effect of the acoustic stimulation
during sleep, mixed ANOVA was applied to the reaction times (RTs) of
the DPT, with valence (positive/negative), session (T1/T2), and group
(TMR/Control) as within/between factors. To evaluate the EEG correlates
of TMR, unpaired t-tests were employed comparing ERPs
between TMR and Control groups in terms of amplitude and timefrequency
analysis.
Results: ANOVA on RTs showed a significant effect of the session factor
(p = 0.02), with a general reduction in RTs at T2. The EEG correlates
of nocturnal stimulation revealed a higher ERP amplitude 1000
post-stimulation at the frontal site (p < 0.01). Concurrently, timefrequency
analysis highlighted an increased slow spindle activity in
the frontal and central regions (all p < 0.01) 1000 ms poststimulation.
Conclusion: TMR does not seem to modulate AB in healthy subjects,
although it appears to reactivate declarative memory traces, as indicated
by increased ERP amplitudes and spindle activity. These findings
suggest that the implicit memory process underlying AB modification,
potentially independent from hippocampal processes, is not susceptible
to modulation through TMR during SWS
The effect of 5 nights of sleep restriction on empathic propensity
No full textLiterature supports the existence of a significant relationship between sleep quality/
quantity and empathy. However, empathic ability and empathic propensity are
distinct constructs. Expression of empathic propensity depends on the subjective
cognitive costs attributed to the empathic experience. Studies on the effects of
the experimental reduction in sleep duration on empathic behaviour are still lacking.
Therefore, we investigated the consequences of 5 consecutive nights of sleep
restriction on empathic propensity. A total of 42 university students (mean [SEM]
age 24.09 [0.65] years; 22 females) underwent a cross-over
design consisting of 5consecutive nights of sleep restriction with
a maximum of 5 hr sleep/night. After each condition, all participants were evaluated
using the Empathy Selection Task, a new test assessing the motivated avoidance
of empathy for its associated cognitive costs. The results showed different effects
of sleep restriction depending on the habitual way of responding in the empathic
context. Participants with baseline high levels of empathic propensity reduced their
empathic propensity after prolonged sleep restriction. Differently, participants who
tended to avoid empathising already in the habitual sleep condition maintained their
empathic behaviour unchanged after sleep curtailment. In conclusion, inter-individual
variability should be taken into account when evaluating the effects of sleep restriction
on empathic propensity. People with habitual higher tendency to empathise
could choose to avoid empathic experience following several consecutive nights of
inadequate sleep
The differential impact of COVID-19 lockdown on sleep quality, insomnia, depression, stress, and anxiety among late adolescents and elderly in Italy
No full textThe restraining measures due to the COVID-19 outbreak deeply affected the general population’s sleep health and psychological status. The current literature proposes young and older people as two particularly at-risk groups. However, the differential impact of the lockdown period in these specific age categories needs to be disentangled. Through a web-based survey adopting validated questionnaires, we evaluated and compared sleep quality/habits, insomnia, perceived stress, depression, and anxiety symptoms of Italian late adolescents (n = 670; mean age ± SD, 19.38 ± 0.74, 18–20 years) and elderly (n = 253; 68.18 ± 2.79, 65–75 years). Young respondents reported more severe insomnia symptoms, worse subjective sleep quality, longer sleep latency, higher daytime dysfunction, and a more prevalent disruption of sleep habits (bedtime, get-up time, nap) than the elderly. On the other hand, older participants showed shorter sleep duration, lower habitual sleep efficiency, and greater use of sleep medications. Finally, the younger population displayed higher levels of depression and perceived stress. Our findings indicate that the lockdown period had more pervasive repercussions on sleep and the mental health of late adolescents. The implementation of supportive strategies is encouraged for this vulnerable population group
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