Approfondimento sperimentale sulla capacità delle nuove sorgenti di illuminazione artificiale di influenzare le performance, la qualità e la quantità del sonno

Negli ultimi anni la ricerca internazionale ha dimostrato che esiste una stretta relazione tra radiazione luminosa e ritmi circadiani, influenza del comportamento umano e stimolazione del funzionamento cerebrale; tali effetti non-visivi sembrano dipendere principalmente dall’intensità luminosa, dalla composizione spettrale, dalla durata dell’esposizione e dall’ora del giorno in cui essa avviene, ma ad oggi non sono ancora chiari gli effetti su specifiche funzioni cognitive, né si può considerare sufficientemente nota l’influenza delle nuova tecnologia LED. In quest’ambito, precedenti studi svolti dallo stesso gruppo hanno evidenziato che, rispetto all’illuminazione prodotta con sorgenti alogene, un’illuminazione LED con temperatura correlata di colore (CCT) neutra (4000K), produce effetti positivi su alcuni aspetti dell’attenzione, quali le funzioni esecutive e la vigilanza visiva: con l’illuminazione LED è stata riscontrata la capacità di produrre molteplici rappresentazioni mentali contemporaneamente e di incrementare il livello di vigilanza durante l’esecuzione di un compito di attenzione. La presente attività approfondisce gli studi svolti precedentemente considerando sorgenti con differente composizione spettrale e temperatura di colore: in un primo esperimento sono state confrontate le stesse lampade utilizzate nei lavori precedenti, alogene e LED neutro, ed in un secondo esperimento lo studio è stato ripetuto con due scenari luminosi LED, con temperatura correlata di colore calda (3000 K) e fredda (6800), per investigare la differente influenza che tali sorgenti hanno a livello psicofisiologico. In entrambi gli esperimenti sono stati analizzati sia gli effetti immediati sulle capacità attentive in un compito di vigilanza cross-modale, sia gli effetti conseguenti sul sonno. I risultati di questo studio mostrano un effetto positivo delle illuminazioni sperimentali (LED 4000 K e LED 6800 K) sulle prestazioni di vigilanza visiva, ma non sulla vigilanza acustica, se paragonato alle illuminazioni calde (alogena 2800 K e LED 3000 K), e l’assenza di effetti significativi dell’illuminazione, sia alogena sia LED, sul sonno dei soggetti partecipanti. La conoscenza approfondita dell’influenza che la luce ha sulla mente umana a livello cognitivo apre la strada ad una nuova tipologia di progettazione illuminotecnica, finalizzata tanto al comfort visivo quanto al benessere fisiologico e all’efficienza cognitiva

Executive functions in insomnia disorder: a systematic review and exploratory meta-analysis

Background: Executive functions (EFs) are involved in the control of basic psychological processes such as attention and memory and also contribute to emotion regulation. Research on the presence of EFs impairments in insomnia yielded inconsistent results. Therefore, we performed a systematic review of the literature on three EFs: inhibitory control, working memory, and cognitive flexibility in adults with insomnia in order to investigate the presence and magnitude of insomnia-related EFs impairments. Methods: PubMed, Scopus, Medline, and PsycINFO were searched. Risk of bias assessment of included studies was performed by two independent researchers. Findings were summarised using both a narrative approach and meta-analysis. Cohen’s d was calculated at 95% confidence interval (CI) as effect size of between groups differences. Results: Twenty-eight studies comparing adult individuals with a diagnosis of insomnia and healthy controls on neuropsychological measures of EFs were included. Narrative synthesis revealed substantial variability across study findings. Factors that were primarily hypothesised to account for this variability are: objective sleep impairments and test sensitivity. Exploratory meta-analysis showed impaired performance of small to moderate magnitude in individuals with insomnia as compared to controls in reaction times, but not accuracy rates, of inhibitory control (d = −0.32, 95% CI: −0.52 to −0.13) and cognitive flexibility tasks (d = −0.30, 95% CI: −0.59 to −0.01). Performance in working memory tasks was also significantly impacted (d = −0.19, 95% CI: −0.38 to −0.00). Effects sizes were larger when insomnia was associated with objective sleep impairments, rather than normal sleep. Conclusions: We gathered evidence supporting small to moderate deficits in EFs in individuals with insomnia. Due to the small sample size results should be considered preliminary and interpreted carefully

Is black always the opposite of white? The comprehension of antonyms in schizophrenia and in healthy participants

In this study, we tested the online comprehension of antonyms in 39 Italian patients with paranoid schizophrenia and in an equal number of pairwise-matched healthy controls. Patients were rather accurate in identifying antonyms, but compared to controls, they showed longer response times and higher priming scores, suggesting an exaggerated contextual facilitation. Presumably, this reflects a deficient controlled semantic processing and an overreliance on stored semantic representations

Gender effects in young road users on road safety attitudes, behaviors and risk perception

In the present study, we investigated gender-related effects on road safety attitudes in 2681 young drivers (1458 males, 54.4%; aged 18-22) who filled out several scales assessing attitudes toward road safety issues, driving behavior in specific hypothetical situations, accident risk perception, and concerns about such a risk. We focused only on young drivers to better understand the role of gender in road safety attitudes in a period of life in which risky behaviors are widespread for males and females. Indeed, there is still no agreement as to the nature of these gender differences. According to some authors, the effects of gender on being involved in a crash due to driving skills are either non-existent or largely explained by differences in alcohol consumption. In our study, we found gender differences in road safety attitudes (i.e., "negative attitude toward traffic rules and risky driving"; "negative attitude toward drugs and alcohol" and "tolerance toward speeding") and in driver behavior (i.e., "errors in inattentive driving" and "driving violations"). This result is consistent in all drivers coming from nine different European countries. Our analyses yielded an important finding concerning risk perception. The results indicate that the level of risk perception during driving is the same for males and females. However, these two groups differ in the level of concern about this risk, with males being less concerned about the risk of a road accident. This suggests that the main difference between these two groups is not strictly related to judgment of the perceived risk probability but rather to the level of concern experienced about the consequences of the risk. This difference between risk perception and worry could explain differences in the frequency of car accidents in the two groups. The present findings may provide new insights for the development of gender-based prevention program

Head centred meridian effect on auditory spatial attention orienting

Six experiments examined the issue of whether one single system or separate systems underlie visual and auditory orienting of spatial attention. When auditory targets were used, reaction times were slower on trials in which cued and target locations were at opposite sides of the vertical head-centred meridian than on trials in which cued and target locations were at opposite sides of the vertical visual meridian or were not separated by any meridian. The head- centred meridian effect for auditory stimuli was apparent when targets were cued by either visual (Experiments 2, 3, and 6) or auditory cues (Experiment 5). Also, the head- centred meridian effect was found when targets were delivered either through headphones (Experiments 2, 3, and 5) or external loudspeakers (Experiment 6). Conversely, participants showed a visual meridian effect when they were required to respond to visual targets (Experiment 4). These results strongly suggest that auditory and visual spatial attention systems are indeed separate, as far as endogenous orienting is concerned

Are the deficits in navigational abilities present in the Williams syndrome related to deficits in the backward inhibition?

Williams syndrome (WS) is associated with a distinct profile of relatively proficient skills within the verbal domain compared to the severe impairment of visuo-spatial processing. Abnormalities in executive functions and deficits in planning ability and spatial working memory have been described. However, to date little is known about the influence of executive function deficits on navigational abilities in WS. This study aimed at analyzing in WS individuals a specific executive function, the backward inhibition (BI) that allows individuals to flexibly adapt to continuously changing environments. A group of WS individuals and a mental age- and gender-matched group of typically developing children were subjected to three task-switching experiments requiring visuospatial or verbal material to be processed. Results showed that WS individuals exhibited clear BI deficits during visuospatial task-switching paradigms and normal BI effect during verbal task-switching paradigm. Overall, the present results suggest that the BI involvement in updating environment representations during navigation may influence WS navigational abilitie

Where does brain neural activation in aesthetic responses to visual art occur? Meta-analytic evidence from neuroimaging studies

Here we aimed at finding the neural correlates of the general aspect of visual aesthetic experience (VAE) and those more strictly correlated with the content of the artworks. We applied a general activation likelihood estimation (ALE) meta-analysis to 47 fMRI experiments described in 14 published studies. We also performed four separate ALE analyses in order to identify the neural substrates of reactions to specific categories of artworks, namely portraits, representation of real-world-visual-scenes, abstract paintings, and body sculptures. The general ALE revealed that VAE relies on a bilateral network of areas, and the individual ALE analyses revealed different maximal activation for the artworks' categories as function of their content. Specifically, different content-dependent areas of the ventral visual stream are involved in VAE, but a few additional brain areas are involved as well. Thus, aesthetic-related neural responses to art recruit widely distributed networks in both hemispheres including content-dependent brain areas of the ventral visual stream. Together, the results suggest that aesthetic responses are not independent of sensory, perceptual, and cognitive processe

The effects of one night of partial sleep deprivation on executive functions in individuals reporting chronic insomnia and good sleepers

Background and objectives The aim of the present study was to investigate the effects of a partial sleep deprivation night on executive functions in participants reporting chronic insomnia and good sleepers using a Task Switching paradigm. Methods Sixteen participants reporting symptoms of chronic insomnia and sixteen good sleepers were tested after a night of habitual sleep and after a night of partial sleep deprivation (5\u202fh of sleep allowed). The Switch Cost (SC) and the Backward Inhibition (BI) were computed as measures of switching attention and response inhibition, respectively. Results We observed a marginally significant interaction Night\u202f 7\u202fGroup on SC (F(1,29)\u202f=\u202f4.06, p\u202f=\u202f0.053, \u3b72\u202f=\u202f0.123. Fisher's least significant difference (LSD) post-hoc revealed a smaller SC after the sleep deprived night relative to the habitual night for the good sleepers (p\u202f=\u202f0.027;M\u202f=\u202f192.23\u202f\ub1\u202f201.81 vs M\u202f=\u202f98.99\u202f\ub1\u202f141.16). Differently, participants with insomnia did not show any change after the two nights. Limitations Several limitations must be acknowledged including the use of a convenient sample of university students and the use of a single task of cognitive performance. Conclusions We found that SC was smaller in the good sleepers after a night of partial sleep deprivation compared to a habitual night, indicating a better switching performance. The insomnia group showed no differences in performance after the two experimental nights. Several factors may account for these results, including increased levels of arousal and cognitive effort during task execution

Bilateral 5 Hz transcranial alternating current stimulation on fronto-temporal areas modulates resting-state EEG

Rhythmic non-invasive brain stimulations are promising tools to modulate brain activity by entraining neural oscillations in specific cortical networks. The aim of the study was to assess the possibility to influence the neural circuits of the wake-sleep transition in awake subjects via a bilateral transcranial alternating current stimulation at 5 Hz (theta-tACS) on fronto-temporal areas. 25 healthy volunteers participated in two within-subject sessions (theta-tACS and sham), one week apart and in counterbalanced order. We assessed the stimulation effects on cortical EEG activity (28 derivations) and self-reported sleepiness (Karolinska Sleepiness Scale). theta-tACS induced significant increases of the theta activity in temporo-parieto-occipital areas and centro-frontal increases in the alpha activity compared to sham but failed to induce any online effect on sleepiness. Since the total energy delivered in the sham condition was much less than in the active theta-tACS, the current data are unable to isolate the specific effect of entrained theta oscillatory activity per se on sleepiness scores. On this basis, we concluded that theta-tACS modulated theta and alpha EEG activity with a topography consistent with high sleep pressure conditions. However, no causal relation can be traced on the basis of the current results between these rhythms and changes on sleepines