The amplitude of fNIRS hemodynamic response in the visual cortex unmasks autistic traits in typically developing children

Abstract

Autistic traits represent a continuum dimension across the population, with autism spectrum disorder (ASD) being the extreme end of the distribution. Accumulating evidence shows that neuroanatomical and neurofunctional profiles described in relatives of ASD individuals reflect an intermediate neurobiological pattern between the clinical population and healthy controls. This suggests that quantitative measures detecting autistic traits in the general population represent potential candidates for the development of biomarkers identifying early pathophysiological processes associated with ASD. Functional near-infrared spectroscopy (fNIRS) has been extensively employed to investigate neural development and function. In contrast, the potential of fNIRS to define reliable biomarkers of brain activity has been barely explored. Features of non-invasiveness, portability, ease of administration, and low-operating costs make fNIRS a suitable instrument to assess brain function for differential diagnosis, follow-up, analysis of treatment outcomes, and personalized medicine in several neurological conditions. Here, we introduce a novel standardized procedure with high entertaining value to measure hemodynamic responses (HDR) in the occipital cortex of adult subjects and children. We found that the variability of evoked HDR correlates with the autistic traits of children, assessed by the Autism-Spectrum Quotient. Interestingly, HDR amplitude was especially linked to social and communication features, representing the core symptoms of ASD. These findings establish a quick and easy strategy for measuring visually-evoked cortical activity with fNIRS that optimize the compliance of young subjects, setting the background for testing the diagnostic value of fNIRS visual measurements in the ASD clinical population.

Looking for “fNIRS Signature” in Autism Spectrum: A Systematic Review Starting From Preschoolers

“…Even if available papers in preschoolers are yet not conclusive to let us claim a "fNIRS signature" of autism, we believe that the use of this technique as an auxiliary diagnostic tool is very promising. Consistently, we recently reported that the variability of fNIRS visually evoked hemodynamic responses correlates with autistic traits in typically developing children, setting the background for testing the diagnostic value of fNIRS visual measurements in the ASD and HR clinical population (Mazziotti et al, 2022).…”

A Potential Biomarker of Brain Activity in Autism Spectrum Disorders: A Pilot fNIRS Study in Female Preschoolers

“…We employed a NIRSport system (8 × 8, NIRx Medical Technologies LLC, Berlin, Germany) consisting of eight red light-sources operating at 760 nm and 850 nm, and seven detectors placed into a textile EEG cap, forming an array of 22 channels centered on occipital cortical areas, as previously described [ 45 ]. Different sizes of the cap were used according to the head circumference of the subject.…”

“…We performed a pilot study on a cohort of high-functioning preschooler females with idiopathic ASD (fASD) with two specific aims: (i) to test the feasibility and reliability of a novel standardized procedure of visual stimulation with a high entertaining value [ 45 ] to measure vHDR in this population; and (ii) to investigate the validity of vHDR as an effective tool to discriminate between preschool girls with TD and sex/age matched peers with ASD.…”

Shedding light on functional near-infrared spectroscopy and open science practices

“…Sharing such tools and materials (see Refs. 34 and 35 , for examples, of sharing fNIRS presentation paradigms) has become easier across all fields with code sharing databases such as GitHub, and fNIRS-specific code sharing databases (e.g., Ref. 36 ).…”