Narcolepsy is a chronic neurological disease characterized by dysfunction of the hypocretin system in brain causing disruption in the wake-promoting system. In addition to sleep attacks and cataplexy, patients with narcolepsy commonly report cognitive symptoms while objective deficits in sustained attention and executive function have been observed. Prior resting-state functional magnetic resonance imaging (fMRI) studies in narcolepsy have reported decreased inter/intranetwork connectivity regarding the default mode network (DMN). Recently developed fast fMRI data acquisition allow more precise detection of brain signal propagation with a novel dynamic lag analysis. In this study, we used fast fMRI data to analyze dynamics of inter resting-state network (RSN) information signaling between narcolepsy type 1 patients (NT1, n = 23) and age- and sex-matched healthy controls (HC, n = 23). We investigated dynamic connectivity properties between positive and negative peaks and, furthermore, their anticorrelative (pos ⇔ neg) counterparts. The lag distributions were significantly (p < 0.005, familywise error rate corrected) altered in 24 RSN pairs in NT1. The DMN was involved in 83% of the altered RSN pairs. We conclude that narcolepsy type 1 is characterized with delayed and monotonic inter-RSN information flow especially involving anticorrelations which are known to be characteristic behavior of the DMN regarding neurocognition.

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Social and pragmatic difficulties in autism spectrum disorder (ASD) are widely recognized, although their underlying neural level processing is not well understood. The aim of this study was to examine the activity of the brain network components linked to social and pragmatic understanding in order to reveal whether complex socio-pragmatic events evoke differences in brain activity between the ASD and control groups. Nineteen young adults (mean age 23.6 years) with ASD and 19 controls (mean age 22.7 years) were recruited for the study. The stimulus data consisted of video clips showing complex social events that demanded processing of pragmatic communication. In the analysis, the functional magnetic resonance imaging signal responses of the selected brain network components linked to social and pragmatic information processing were compared. Although the processing of the young adults with ASD was similar to that of the control group during the majority of the social scenes, differences between the groups were found in the activity of the social brain network components when the participants were observing situations with concurrent verbal and non-verbal communication events. The results suggest that the ASD group had challenges in processing concurrent multimodal cues in complex pragmatic communication situations.

Autismikirjon piirteet ulottuvat sosiaalisten taitojen, kommunikaation, mielikuvituksen, tarkkaavuuden siirtämisen ja yksityiskohtien huomioimisen alueille. Näillä osa-alueilla esiintyviä piirteitä voidaan seuloa autismikirjon osamäärän (engl. autism spectrum quotient, AQ) avulla. Tämän tutkimuksen tavoitteena on saada suomalaiset viitearvot AQ:lle sekä tarkastella, erotteleeko AQ-lomake suomalaisia autismikirjon nuoria aikuisia oman sukupuolen nuorista aikuisista, joilla ei ole autismikirjon diagnoosia. Lisäksi tarkastellaan ryhmien suoriutumisessa olevia eroja osioittain sekä AQ:n sisäistä yhtenäisyyttä. Tutkimukseen osallistui 52 autismikirjon nuorta aikuista (39 miestä ja 13 naista) sekä 1686 verrokkia (577 miestä ja 1109 naista). Tulokset osoittavat, että autismikirjon henkilöiden pistemäärät nousevat samaa sukupuolta olevien verrokkihenkilöiden pistemääriä korkeammalle. AQ erottelee autismikirjon miehet melko hyvin verrokkimiehistä, mutta autismikirjon naiset vain kohtalaisesti verrokkinaisista. Osioanalyysissä eniten ryhmien välisiä tilastollisesti merkitseviä eroja tuli esille sosiaalisia taitoja ja kommunikaatiota mittaavissa väittämissä.

Previous studies have suggested that atypical deactivation of functional brain networks contributes to the complex cognitive and behavioral profile associated with autism spectrum disorder (ASD). However, these studies have not considered the temporal dynamics of deactivation mechanisms between the networks. In this study, we examined (a) mutual deactivation and (b) mutual activation‐deactivation (i.e., anticorrelated) time‐lag patterns between resting‐state networks (RSNs) in young adults with ASD (n = 20) and controls (n = 20) by applying the recently defined dynamic lag analysis (DLA) method, which measures time‐lag variations peak‐by‐peak between the networks. In order to achieve temporally accurate lag patterns, the brain imaging data was acquired with a fast functional magnetic resonance imaging (fMRI) sequence (TR = 100 ms). Group‐level independent component analysis was used to identify 16 RSNs for the DLA. We found altered mutual deactivation timings in ASD in (a) three of the deactivated and (b) two of the transiently anticorrelated (activated‐deactivated) RSN pairs, which survived the strict threshold for significance of surrogate data. Of the significant RSN pairs, 80% included the posterior default‐mode network (DMN). We propose that temporally altered deactivation mechanisms, including timings and directionality, between the posterior DMN and RSNs mediating processing of socially relevant information may contribute to the ASD phenotype. Lay Summary To understand autistic traits on a neural level, we examined temporal fluctuations in information flow between brain regions in young adults with autism spectrum disorder (ASD) and controls. We used a fast neuroimaging procedure to investigate deactivation mechanisms between brain regions. We found that timings and directionality of communication between certain brain regions were temporally altered in ASD, suggesting atypical deactivation mechanisms associated with the posterior default‐mode network.