Impaired social brain network for processing dynamic facial expressions in autism spectrum disorders

Abstract

BackgroundImpairment of social interaction via facial expressions represents a core clinical feature of autism spectrum disorders (ASD). However, the neural correlates of this dysfunction remain unidentified. Because this dysfunction is manifested in real-life situations, we hypothesized that the observation of dynamic, compared with static, facial expressions would reveal abnormal brain functioning in individuals with ASD.We presented dynamic and static facial expressions of fear and happiness to individuals with high-functioning ASD and to age- and sex-matched typically developing controls and recorded their brain activities using functional magnetic resonance imaging (fMRI).ResultRegional analysis revealed reduced activation of several brain regions in the ASD group compared with controls in response to dynamic versus static facial expressions, including the middle temporal gyrus (MTG), fusiform gyrus, amygdala, medial prefrontal cortex, and inferior frontal gyrus (IFG). Dynamic causal modeling analyses revealed that bi-directional effective connectivity involving the primary visual cortex–MTG–IFG circuit was enhanced in response to dynamic as compared with static facial expressions in the control group. Group comparisons revealed that all these modulatory effects were weaker in the ASD group than in the control group.ConclusionsThese results suggest that weak activity and connectivity of the social brain network underlie the impairment in social interaction involving dynamic facial expressions in individuals with ASD.

Autistic Traits in Children With and Without ADHD

“…[46][47][48] Also consistent with the extant literature are our findings showing that ADHD + AT children were more likely than ADHD children to fight with and be rejected by peers, to have more school behavior problems, more difficulties utilizing their spare time, and more problems with siblings. Considering the well-established evidence that social difficulties are a core component of ASDs, [49][50][51] our findings also suggest that the social disability observed in the ADHD + CBCL-AT group may be more a reflection of underlying ATs than the presence of ADHD itself. The higher rates of mood, anxiety, disruptive, and substance use disorders, 52 and school failure, school dropout, and delinquent offenses 53 in ADHD + AT children is particularly worrisome.…”

Involvement of Neuroinflammation during Brain Development in Social Cognitive Deficits in Autism Spectrum Disorder and Schizophrenia

“…The STS/STG plays a key role in direct structural connections between verbal-and nonverbalrecognition areas (Kreifelts et al, 2007;Blank et al, 2011). Functional underconnectivity between the visual cortex and STS/STG or VLPFC occurs in ASD adults in response to emotional stimuli (Sato et al, 2012;Khan et al, 2013). Taken together, we hypothesize that abnormalities of verbal and nonverbal communication in ASD are due to cerebellar and thalamic hyperactivation and subsequent dysfunction of the visual cortex, FAA, STS/STG, and VLPFC.…”

“…Underconnectivity between the temporal cortex and VLPFC occurs in adult ASD (Sato et al, 2012). In addition, VLPFC activity is significantly reduced in schoolchildren and adolescents with ASD relative to controls during speech stimulation (Lai et al, 2012).…”

“…The thalamus, fusiform face area (FFA), STS/STG, and VLPFC also play a pivotal role in nonverbal communication, including facial expressions, gestures, eye contact, and body language (Redcay, 2008;Sato et al, 2012). These visual signals from the thalamus are sent to the visual cortex and FFA (Tamietto and de Gelder, 2010;Blank et al, 2011).…”

“…There are neuronal connections between the visual cortex/FFA, STS/STG, and VLPFC (Kreifelts et al, 2007;Blank et al, 2011;Sato et al, 2012). The STS/STG plays a key role in direct structural connections between verbal-and nonverbalrecognition areas (Kreifelts et al, 2007;Blank et al, 2011).…”