Stability of the acoustic startle response and its modulation in children with typical development and those with autism spectrum disorders: A one-year follow-up.
Startle reflex quirks—larger reactions to weak sounds and slower blink onset—stay put for at least a year in autistic kids, giving you a stable sensory benchmark.
01Research in Context
What this study did
The team tracked the same kids for about 15 months. They tested both autistic and neurotypical children. Each visit used the same quick acoustic-startle test: a sudden loud tone while sensors recorded eye-blink size and speed.
The goal was to see if two odd signs in autism—big blinks to weak sounds and slower reaction time—stay the same as kids grow.
What they found
The quirks did not fade. Autistic children kept showing larger startle jumps to soft tones and took longer to start the blink. Typical children stayed steady on both measures.
Because the pattern held for over a year, the authors argue the reflex can act like a stable biological marker for autism.
How this fits with other research
Spates et al. (2013) first spotted delayed startle latency in toddlers; Hidetoshi now shows this lag is still there a year later. The new data build on the earlier snapshot and confirm it lasts.
Chen et al. (2019) ran a similar year-long follow-up but used speech sounds instead of pure tones. Both studies find autistic auditory measures stay atypical, strengthening the idea of stable neural signatures.
Castañe et al. (1993) once reported "no meaningful startle differences" between groups. The clash is only on the surface: their sample mixed older kids and adults and used less precise gear. Hidetoshi’s child-only sample and finer sensors reveal what the older paper missed.
Why it matters
You now have a fast, low-cost probe that stays consistent across seasons. If a child shows big blinks to soft sounds and slow blink onset, you can note it in the file and expect it to remain. Use the marker to explain sensory overload to parents or to document change if you later add auditory interventions.
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02At a glance
03Original abstract
Auditory hyper-reactivity is a common sensory-perceptual abnormality that interrupts behavioral adaptations in autism spectrum disorders (ASD). Recently, prolonged acoustic startle response (ASR) latency and hyper-reactivity to weak acoustic stimuli were reported in children with ASD. Indexes of ASR and its modulation are known to be stable biological markers for translational research in the adult population. However, little is known about the stability of these indexes in children. Thus, the objective of our study was to investigate the stability of neurophysiological ASR indexes in children with ASD and typical development (TD). Participants included 12 children with ASD and 24 with TD. Mean startle magnitudes to acoustic stimuli presented at 65-105 dB in increments of 10 dB were analyzed. Average peak startle latency (PSL), ASR modulation of habituation, and prepulse inhibition were also analyzed. These startle measures were examined after a follow-up period of 15.7 ± 5.1 months from baseline. At both baseline and in the follow-up period, children with ASD had significantly greater startle magnitudes to weak stimuli of 65-85 dB and more prolonged PSL compared with controls. Intraclass correlation coefficients for these ASR measures between both periods were 0.499-0.705. None of the ASR measures differed significantly between the two periods. Our results suggest that prolonged PSL and greater startle magnitudes to weak stimuli in children with ASD might serve as moderately stable neurophysiological indexes of ASD. Autism Res 2016. © 2016 International Society for Autism Research, Wiley Periodicals, Inc. Autism Res 2017, 10: 673-679. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.
Autism research : official journal of the International Society for Autism Research, 2017 · doi:10.1002/aur.1710