Abnormal functional connectivity in autism spectrum disorders during face processing

Abstract

Abnormalities in the interactions between functionally linked brain regions have been suggested to be associated with the clinical impairments observed in autism spectrum disorders (ASD). We investigated functional connectivity within the limbic system during face identification; a primary component of social cognition, in 19 high-functioning adults with ASD and 21 age-and IQ-matched control adults. Activation during identification of previously viewed faces and houses using a one-back paradigm was compared. The fusiform face area (FFA) was individually localized in each participant and used as the seed point for functional connectivity analyses. The degree of correlation between FFA and the extended neural circuitry involved in face identification was tested. A whole brain analysis was also conducted in order to determine whether connectivity from the FFA to aberrant brain locations was present in the ASD group. Measures of clinical severity (ADOS social score and ADI-R social score) were included as independent variables into the functional connectivity analyses. Significant FFA-amygdala and FFA-superior temporal sulcus functional connectivity was found in both the ASD and control participants. However, the control group had significantly increased connectivity to the left amygdala and the posterior cingulate compared to ASD. Post hoc analyses additionally found increased connectivity to the thalamus in the controls. A significant relationship between abnormal functional connectivity and clinical severity in the ASD group was observed. Specifically, greater social impairment was associated with reduced FFA-amygdala connectivity and increased FFA-right inferior frontal connectivity. These results suggest that abnormal neural connections within the limbic system may contribute to the social impairments observed in ASD.

A common MECP2 haplotype associates with reduced cortical surface area in humans in two independent populations

“…MECP2 expression in the fusiform gyrus, and frontal cortex in general, is reduced in autistic patients (24). The fusiform gyrus and cuneus show reduced functional connectivity in autistic patients (25). Our findings are consistent with results from the MECP2 literature, and the replication of association with specific cortical regions in 2 cohorts is strong evidence of a real effect in these populations.…”

Cortical patterns of category‐selective activation for faces, places and objects in adults with autism

“…One study found no consistent differences in cortical object activation in individuals with autism [Schultz et al, 2000], whereas others found no differences in activation for houses [Bird et al, 2006;Kleinhans et al, 2008]. However, in a magnetoencephalography (MEG) study, the sources of object-related signals were more variable in the autism than the typical group [Bailey et al, 2005].…”

“…Many [e.g. Dalton et al, 2005;Deeley et al, 2007;Hubl et al, 2003;Pierce et al, 2001;Schultz et al, 2000] have found reduced BOLD activation in the fusiform face area [FFA; Kanwisher et al, 1997], but five studies have failed to replicate this finding [Bird et al, 2006;Hadjikhani et al, 2004Hadjikhani et al, , 2007Kleinhans et al, 2008;Pierce et al, 2004]. Furthermore, it has been proposed that FFA activation is normalized when people with autism look at the face stimuli [Hadjikhani et al, 2004], specifically the eye region [Dalton et al, 2005[Dalton et al, , 2007.…”

Brain dynamics in ASD during movie‐watching show idiosyncratic functional integration and segregation

“…Accordingly, coordinated processing between separate brain regions, known as functional connectivity (FC), that is, typically quantified by correlational measures of statistical interdependency (Friston, 1994), has been assessed in resting‐state (Di Martino et al, 2014; Gotts et al, 2012; Supekar et al, 2013) and in a variety of tasks probing speech comprehension (Just, Cherkassky, Keller, & Minshew, 2004), visuomotor performance (Mizuno, Villalobos, Davies, Dahl, & Müller, 2006; Turner, Frost, Linsenbardt, McIlroy, & Müller, 2006; Villalobos, Mizuno, Dahl, Kemmotsu, & Müller, 2005), visuospatial abilities (Damarla et al, 2010; Liu, Cherkassky, Minshew, & Just, 2011), face processing (Kleinhans et al, 2008; Rudie et al, 2012), or executive functions (Just, Cherkassky, Keller, Kana, & Minshew, 2007; Kana, Keller, Minshew, & Just, 2007; Koshino et al, 2008). The big picture emerging from those reports is lowered FC between frontal and posterior brain regions (see Vissers, Cohen, & Geurts, 2012 for a review), as formulated in the underconnectivity theory of autism (Just, Keller, Malave, Kana, & Varma, 2012).…”