Hyperreactivity to weak acoustic stimuli and prolonged acoustic startle latency in children with autism spectrum disorders

Abstract

BackgroundPeople with autism spectrum disorders (ASD) are known to have enhanced auditory perception, however, acoustic startle response to weak stimuli has not been well documented in this population. The objectives of this study are to evaluate the basic profile of acoustic startle response, including peak startle latency and startle magnitude to weaker stimuli, in children with ASD and typical development (TD), and to evaluate their relationship to ASD characteristics.MethodsWe investigated acoustic startle response with weak and strong acoustic stimuli in 12 children with ASD and 28 children with TD, analyzing the relationship between startle measures and quantitative autistic traits assessed with the Social Responsiveness Scale (SRS). The electromyographic activity of the left orbicularis oculi muscle to acoustic stimuli of 65 to 115 dB sound pressure level (SPL), in increments of 5 dB, was measured to evaluate acoustic startle response. The average eyeblink magnitude for each acoustic stimuli intensity and the average peak startle latency of acoustic startle response were evaluated.ResultsThe magnitude of the acoustic startle response to weak stimuli (85 dB or smaller) was greater in children with ASD. The peak startle latency was also prolonged in individuals with ASD. The average magnitude of the acoustic startle response for stimulus intensities greater than 85 dB was not significantly larger in the ASD group compared with the controls. Both greater startle magnitude in response to weak stimuli (particularly at 85 dB) and prolonged peak startle latency were significantly associated with total scores, as well as several subscales of the SRS in the whole sample. We also found a significant relationship between scores on the social cognition subscale of the SRS and the average magnitude of the acoustic startle response for stimulus intensities of 80 and 85 dB in the TD group.ConclusionsChildren with ASD exhibited larger startle magnitude to weak stimuli and prolonged peak startle latency. These startle indices were related to several characteristics of ASD. A comprehensive investigation of acoustic startle response, including the magnitude of startle responses to weak stimuli and peak startle latency, might further our understanding of the neurophysiological impairments underlying ASD.

Altered Auditory Processing, Filtering, and Reactivity in theCntnap2Knock-Out Rat Model for Neurodevelopmental Disorders

“…In cases of peripheral deficits such as cochlear synaptopathy, loss of auditory nerve fibers, or noise-induced hidden hearing loss, reduced wave I amplitudes have been reported (Sergeyenko et al, 2013;Bourien et al, 2014;Shi et al, 2016). Because we observed no differences in the amplitude of wave I between Cntnap2 Ϫ/Ϫ and wild-type animals, we suggest that peripheral auditory function is preserved in these animals (Fig.…”

“…5B). Therefore, the underlying mechanism for the overreactivity in Cntnap2 knock-out animals must occur outside of the primary auditory pathway, possibly in the sensorimotor interface of the startle pathway, the PnC, where cochlear root neurons synapse on premotor neurons (for review, see Koch, 1999;Larrauri and Schmajuk, 2006;Simons-Weidenmaier et al, 2006;Fig. 10, green).…”

“…The auditory system undergoes tremendous remodeling and plasticity in early development, which has a profound effect on how the adult brain handles acoustic information. The typical maturation is perturbed in individuals with neurodevelopmental disorders, such as autism spectrum disorder (ASD), which can ultimately lead to long-term auditory processing deficits (for review, see Sinclair et al, 2017). Apart from varying degrees of language impairment (Kjelgaard and Tager-Flusberg, 2001;Deriziotis and Fisher, 2017), individuals with ASD have shown deficits in how their central auditory system processes the basic features of sound (Hitoglou et al, 2010), including delayed neurotransmission throughout the successive relay nuclei of the brainstem (Wong and Wong, 1991;Rosenhall et al, 2003;Kwon et al, 2007;Tas et al, 2007;Fujikawa-Brooks et al, 2010;Magliaro et al, 2010;Gonçalves et al, 2011;Roth et al, 2012;Miron et al, 2016).…”

“…In 2011, Peñagarikano et al first characterized a mutant mouse model with a loss-of-function mutation of the contactin associated protein-like 2 gene (Cntnap2). Homozygous loss-of-function mutations in CNTNAP2 are a rare single gene cause for ASD (Strauss et al, 2006;Poot, 2017) and multiple studies have identified various other CNTNAP2 mutations being associated with, or a risk factor for, ASD and language-related disorders (Alarcó n et al, 2008;Arking et al, 2008;Rodenas-Cuadrado et al, 2014Murphy and Benítez-Burraco, 2017;Poot, 2017). CNTNAP2, which codes for the neurexin CASPR2, is known to be in important in language development in humans, with its structure and biological functions appearing to be conserved Whalley et al, 2011;Whitehouse et al, 2011;Poot, 2015).…”

Atypical Color Preference in Children with Autism Spectrum Disorder

“…In the auditory domain, they exhibit enhanced discrimination between auditory stimuli, more accurate local target detection of auditory stimuli, and diminished global interference with auditory processing (Takahashi et al, 2014). In the visual domain, they exhibit enhanced visual discrimination capabilities, faster target detection in feature and conjunctive visuals searches, more accurate local target detection, etc (Markram and Markram, 2010).…”