•Neural synchrony during movie watching was measured in children with and without ASD.•The ASD group had significantly less neural synchrony across the whole brain.•The ASD group also had ...significantly less synchrony in the theory of mind network.•Autistic traits did not predict neural synchrony in non-ASD children.•These results suggest children with ASD process movies in a unique way.
Children who have been diagnosed with autism spectrum disorder (ASD) often show a marked deficit in measures of social cognition. In autistic adults, measures of social cognition have been shown to relate to differences in brain synchronization (as measured by fMRI) when individuals are processing naturalistic stimuli, such as movies. However, whether children who differ in their degree of autistic traits, with or without a diagnosis of ASD, differ in their neural responses to movies has not yet been investigated. In the current study, neural synchrony, measured using fMRI, was examined in three groups of children aged 7 to 12, who differed with respect to scores on a measure of autistic traits associated with social impairment and whether or not they had been diagnosed with ASD. While watching the movie ‘Despicable Me’, those diagnosed with ASD had significantly less neural synchrony in areas that have been previously shown to be associated with social cognition (e.g. areas related to ‘theory of mind’), and plot following (e.g. the lateral prefrontal cortex), than those who did not have an ASD diagnosis. In contrast, two groups who differed in their degree of autistic traits, but did not have a diagnosis of ASD, showed no significant differences in neural synchrony across the whole brain. These results shed some light on how autistic traits may contribute to an individual’s conscious experience of the world, and how, for children with ASD, that experience may differ markedly from that of those without ASD.
At 03:56 local time on November 26, 2019, an earthquake with a Mw = 6.4 struck western part of Albania. The duration of the tremor lasted less than 50 s and was felt largely also in Albania's capital ...Tirana, and in places as far away more than 300 km northeast of the epicenter. It caused damage to many public and residential buildings in districts of Durres, Tirana, Lezha, Shkodra, Diver, Berat and surrounding areas. This paper describes rapid visual assessment of the damaged buildings (169 in total) in affected areas by IZIIS teams’ inspection of damaged buildings. Severe damages were identified in structural and non-structural elements as a result of inconsistent application of recent knowledge in design, construction and quality control of earthquake resistant structures. Structural errors in design and construction as well as inappropriate quality of built-in materials have been observed. Such results from the rapid damage assessment leads to the necessity of taking specific measures as detailed engineering inspection of vital structures as a basis of definition corresponding technical solutions for repair and strengthening with aim of restoring their operational mode. Last but not least, the biggest effect of earthquake damage was observed in non-structural elements which made the structures not-usable for citizens of the earthquake region.
To isolate the neural mechanisms associated with recognizing objects from those processing basic visual properties, control stimuli are required that contain the same perceptual properties as the ...objects but are unrecognizable. We demonstrate that conventional methods for generating control stimuli (phase scrambling, box scrambling, texture scrambling) yield poor controls because they dramatically distort the basic visual properties (e.g., spatial frequency, perceptual organization) to which even the earliest stages of visual processing are sensitive. We developed a new scrambling method, using a diffeomorphic transformation that preserves the basic perceptual properties of the image while removing meaning. We acquired perceptual ratings to determine the least amount of scrambling necessary to remove recognition. We hypothesized that our "diffeomorphic" images would produce neural activity at the earliest stages of the visual system that more closely matched activity in response to intact images relative to the other scrambling methods. To test this hypothesis, we used the HMAX computational model of object recognition and compared the simulated neural activity at the earliest stages of the visual system (layers S1, C1, and S2) between a set of 149 images scrambled using each distortion method to their intact version. We found that scrambled "diffeomorphed" images were indistinguishable to intact images in each layer of the model, but all of the other distortion methods yielded quite different patterns. Our results indicate that "diffeomorphed" images serve as more appropriate control stimuli in neuroimaging studies that aim to disentangle the representations of perceptual and semantic object properties.
A toggle switch of visual awareness? Le, Ada; Stojanoski, Bobby B.; Khan, Saniah ...
Cortex,
March 2015, 2015-Mar, 2015-03-00, 20150301, Letnik:
64
Journal Article
Recenzirano
Major clues to the human brain mechanisms of spatial attention and visual awareness have come from the syndrome of neglect, where patients ignore one half of space. A longstanding puzzle, though, is ...that neglect almost always comes from right-hemisphere damage, which suggests that the two sides of the brain play distinct roles. But tests of attention in healthy people have revealed only slight differences between the hemispheres. Here we show that major differences emerge if we look at the timing of brain activity in a task optimized to identify attentional functions. Using EEG to map cortical activity on a millisecond timescale, we found transient (20–30 ms) periods of interhemispheric competition, followed by short phases of marked right-sided activity in the ventral attentional network. Our data are the first to show interhemispheric interactions that, much like a toggle switch, quickly allocate neural resources to one or the other hemisphere.
Abstract
Introduction
The behavioural and cognitive consequences of severe sleep deprivation are well understood. Surprisingly, relatively little is known about the EEG correlates of mild and acute ...sleep restriction during tasks demanding sustained vigilance for prolonged periods of time during the day. Event-related potential (ERP) paradigms can reveal insight into the neural correlates of sensory processing and behavior that is impaired with reduced alertness as a consequence of sleep loss. Here, we investigated the impact of reduced vigilance following mild sleep restriction (vs. well-rested) to better understand the associated behavioural consequences and changes in information processing revealed by EEG.
Methods
Eighteen participants (age 20–26, median=21) were instructed to sleep from 1-6am in the “sleep restricted” (SR) condition, or from 12-9am in the “normal sleep” (NS) condition, verified via actigraphy. Following each night, participants completed 6 sessions of 100 trials of the Psychomotor Vigilance Task (PVT) with simultaneous EEG recording. All testing was completed between 1-3pm (during the circadian trough).
Results
More lapses occurred and responses slowed in the SR vs. NS condition (F(1,17)=8.89,p=0.008; F(1,17)=4.78,p=0.043). Lapses increased and responses slowed over the course of the 6 sessions (F(5,85)=10.05,p<0.001; F(5,85)=4.49,p=0.001). A similar pattern was observed for subjective sleepiness. We compared visually-evoked potentials (VEP) in SR vs. NS and found differences at 316–449 ms, maximal at parietal/occipital cortex. We also investigated electrophysiological signs of motor-related processing by comparing lateralized readiness potentials (LRP), and found reduced LRPs in the fastest responses in the SR vs. NS condition at 70-40ms before, and 115-158ms after a response was made.
Conclusion
As expected, vigilance was reduced (e.g., increased lapses, response slowing) following mild and acute SR. Late VEPs were reduced after SR, as was motor-related LRPs for the fastest reaction times. These results suggest that even a single night of mild sleep restriction can negatively impact vigilance, reflected by reduced sensory processing capacity, and dulls motor preparation and execution.
Support (If Any)
Research support from NSERC Engage and Engage Plus grants to SF and ACS-Corp.
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