Resting state arousal and functional connectivity in autism spectrum disorder

Abstract

Brain 137: 153-171, 2014) demonstrated that resting state electrodermal activity is correlated with different patterns of brain activity in subjects with autism spectrum disorder (ASD) than in typical controls. These results are considered in light of theories of atypical arousal in ASD.arousal; autism; skin conductance; functional connectivity AROUSAL REFERS TO PHYSIOLOGICAL states and behaviors associated with an alert state. Atypical arousal has been hypothesized to explain some of the symptoms of autism spectrum disorder (ASD). Recently, Eilam-Stock et al. (2014) showed that electrodermal activity (EDA), a sensitive measure of sympathetic arousal, is differentially related to the blood oxygen leveldependent (BOLD) signal during rest in people with ASD compared with typical controls. In this article, I discuss these findings and put them in a broader context with special emphasis on the implications for research on attention and emotional processes in ASD.Scientific interest in arousal in ASD stems from various sources. Early theories hypothesized that either elevated or attenuated tonic arousal was a causal factor behind some of the core ASD symptoms, such as repetitive behaviors and avoidance of social interaction (Rogers and Ozonoff 2005) Other theories have linked arousal to atypical development of face perception and other forms of social cognition. According to other influential theories, atypical regulation of arousal could cause impairments in attentional functions, an associated feature of ASD (Keehn et al. 2013;Orekhova and Stroganova 2014). In addition, brain functions involved in the generation and representation of arousal have been linked to social cognition in typical development (Critchley 2005), which suggests that they may be important to disorders of social interaction such as ASD. However, although many theories link ASD to atypical arousal, the empirical findings are not conclusive. Previous studies have mainly assessed peripheral autonomic nervous system (ANS) arousal. However, arousal is a homeostatic process that critically involves brain mechanisms for representation and generation of peripheral responses (Critchley 2005). Impairments in any of these processes could potentially lead to disruptions in behavior and cognition. The study by Eilam-Stock et al. thus represents an important methodological improvement. Eilam-Stock et al. (2014) hypothesized that resting state EDA would have different neural correlates in subjects with ASD compared with typically developed (TD) participants. They further hypothesized that group differences in EDA would be related to functional hypoconnectivity in the ASD group. Although a number of previous studies have found evidence of hypoconnectivity between distal brain regions in ASD (e.g., Uddin and Menon 2009), the literature is so far inconclusive. Functional connectivity is typically operationalized as correlations in fMRI BOLD signal time series between distal parts of the brain. Thus group differences in functional connectivity can reflect differe...

Is autonomic function during resting-state atypical in Autism: A systematic review of evidence

“…heart rate variability), electrodermal activity, and pupil size, both at rest and during pre-task baseline periods. We did not include evidence from studies measuring CNS arousal or cortisol/ neurotransmitters, because indices of arousal at CNS are debated, and some of this evidence has been reviewed (Berman et al, 2015;Kleberg, 2015;Wang et al, 2013).…”

Neuromodulation Based on rTMS Affects Behavioral Measures and Autonomic Nervous System Activity in Children with Autism

“…According to other current theories, atypical regulation of arousal could cause impairment in attention, another symptom commonly associated with ASD (Orekhova & Stroganova, 2014). A series of current studies of autonomic dysfunctions in ASD were reported in the literature showing drastically increased interest in the investigation of autonomic system functioning abnormalities in children with autism (Benevides & Lane, 2015;Cohen, Masyn, Mastergeorge, & Hessl, 2015;Kleberg, 2015;Kushki et al, 2013Kushki et al, , 2014Patriquin, Lorenzi, & Scarpa, 2013;Smeekens et al, 2015). As noted by Rees (2014), there is an urgent need to recognize the importance of the ANS in pediatrics, not limited to neurodevelopmental disorders.…”

“…Furthermore, children with ASD demonstrate dampened HR reactivity, unusually small deceleratory HR responses, and generally low cardiac reactions to auditory stimulation including socially relevant speech, phrases, and tones (Corona, Dissanayake, Arbelle, Wellington, & Sigman, 1998;Palkovitz & Wiesenfeld, 1980;Zahn, Rumsey, & Van Kammen, 1987). Kleberg (2015) emphasized that atypical autonomic arousal has been used to explain some of the core symptoms of ASD. In effect, it has been hypothesized that either elevated or attenuated tonic arousal was a causal factor behind some of the core autism symptoms, such as repetitive behaviors (Hirstein et al, 2001;Toichi & Kamio, 2003;Toichi et al, 1999) and avoidance of social interaction (Rogers & Ozonoff, 2005).…”