A number of past studies have used mismatch negativity (MMN) to identify auditory processing deficits in individuals with autism spectrum disorder (ASD). Our meta-analysis compared MMN responses for individuals with ASD and typically developing controls (TD). We analyzed 67 experiments across 22 publications that employed passive, auditory-based MMN paradigms with ASD and TD participants. Most studies lacked design characteristics that would lead to an accurate description of the MMN. Variability between experiments measuring MMN amplitude was smaller when limited to studies that counterbalanced stimuli. Reduced MMN amplitude was found among young children with ASD compared to controls and in experiments that used nonspeech sounds. Still, few studies included adolescents or those with below-average verbal IQ. Most studies suffered from small sample sizes, and aggregating these data did not reveal significant group differences. This analysis points to a need for research focused specifically on understudied ASD samples using carefully designed MMN experiments. Study of individual differences in MMN may provide further insights into distinct subgroups within the heterogeneous ASD population.
Alien hand syndrome is a rare neurological disorder in which movements are performed without conscious will. By using functional magnetic resonance imaging in a patient with alien hand syndrome after right parietal lesion, we could identify brain regions activated during involuntary or voluntary actions with the affected left hand. Alien hand movements involved a selective activation of contralateral primary motor cortex (M1), presumably released from conscious control by intentional planning systems. By contrast, voluntary movements activated a distributed network implicating not only the contralateral right M1 and premotor cortex but also the left inferior frontal gyrus, suggesting an important role of the dominant hemisphere in organizing willed actions.
Recent electrophysiological studies suggest that autism spectrum disorder is characterized by aberrant anatomical and functional neural circuitry. During normal brain development, pruning and synaptogenesis facilitate ongoing changes in both short- and long-range neural wiring. In developmental disorders such as autism, this process may be perturbed leading to abnormal neural connectivity. Careful analysis of electrophysiological connectivity patterns using EEG coherence may provide a way to probe the resulting differences in neurological function between people with and without autism. There is general consensus that EEG coherence patterns differ between individuals with and without autism spectrum disorders, however the exact nature of the differences and their clinical significance remain unclear. Here we review recent literature comparing EEG coherence patterns between patients with autism spectrum disorders or at high risk for autism and their non-autistic or low risk for autism peers.
Both TPN and DMN are affected in OSA patients, with nocturnal desaturation affecting both networks; whereas BMI appears to be the major negative factor influencing the TPN and has a significant negative correlation with behavioral performance.
Summary The aim of this study was to assess with a stop task the inhibitory motor control efficiency – a major component of executive control functions – in patients suffering from sleep disorders. Twenty‐two patients with untreated obstructive sleep apnea syndrome (OSAS) (mean age 46 ± 9 years; mean apnea–hypopnea index, AHI = 30 ± 20) and 13 patients with psychophysiological insomnia (mean age 47 ± 12 years) were compared with individually matched healthy controls. Sleep disturbances in the patient populations were clinically and polysomnographically diagnosed. The stop task has a frequent visual ‘Go’ stimulus to set up a response tendency and a less frequent auditory ‘Stop’ signal to withhold the planned or prepotent response. The stop signal reaction time (SSRT) reflects the time to internally suppress the ongoing response. SSRT was slower for the apneic patients than for their respective controls (248 ± 107 versus 171 ± 115 ms, anova, P < 0.05) but not for the insomniac patients compared with their controls (235 ± 112 versus 194 ± 109 ms, NS). Moreover, in apneic patients, slower SSRT was associated with lower nocturnal oxygen saturation (r = −0.477, P < 0.05). By contrast, neither apneics nor insomniacs differed from their matched controls for reaction times on Go trials. To conclude, unlike insomniacs, OSAS patients present an impaired inhibitory motor control, an executive function which is required in many common everyday life situations. Inhibitory motor control relies on the integrity of the inferior prefrontal cortex, which could be affected by nocturnal oxyhemoglobin desaturation in apneic patients.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.