Somatosensory Temporal Discrimination in Autism Spectrum Disorder.
Autistic teens need longer gaps to feel separate touches, yet parent surveys miss this lag, so quick lab-style timing tests can reveal hidden sensory risk.
01Research in Context
What this study did
Buyuktaskin et al. (2021) asked how well autistic teens feel two quick taps on the finger.
They compared the teens to same-age peers without autism.
A machine delivered pairs of taps with shorter or longer gaps until each teen could just tell them apart.
What they found
Autistic teens needed almost twice the gap between taps to notice two separate touches.
Oddly, this duller sense did not line up with parents’ reports of daily sensory issues.
In plain words: the finger test was slow, but the surveys looked normal.
How this fits with other research
Tavassoli et al. (2016) saw a similar dulling in younger kids using a static-to-moving touch ratio, so the new data extend the same story into adolescence.
Cascio et al. (2008) looks like a contradiction: their autistic adults had normal light-touch detection. The gap is age. Adults may grow into normal thresholds while teens still lag, so both papers can be true.
Taylor et al. (2017) and Sapey-Triomphe et al. (2019) supply the chemistry behind the lag: lower GABA in the sensorimotor cortex links to poor tactile filtering, giving the brain less “brake fluid” to separate near-in-time touches.
Why it matters
You now have a two-minute, equipment-light probe to flag teens who may struggle with fine motor or safety skills because their touch timing is off. Pair it with GABA-informed strategies like weighted input or rhythmic pacing while teaching tasks that demand quick tactile feedback, such as buttoning, keyboarding, or cooking.
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02At a glance
03Original abstract
Sensory differences are common in Autism Spectrum Disorder (ASD). While there is no well-accepted method to measure sensory differences objectively, there is accumulating evidence from recent years concerning sensory perception, including data concerning temporal discrimination thresholds of individuals with ASD as measured by different measures. The somatosensory temporal discrimination (STD) test measures the threshold at which an individual can temporally discriminate multiple tactile stimuli delivered in succession. We aimed to investigate tactile perception in ASD and hypothesized that children with ASD have impaired STD related to their subjective sensory symptoms and daily difficulties. Thirty adolescents with ASD and 30 typically developed subjects were recruited. The Childhood Autism Rating Scale, Strengths and Difficulties Questionnaire, and Adolescent/Adult Sensory Profile were implemented before STD evaluation. Average somatosensory detection (1.48 ± 0.42) and discrimination thresholds (112.70 ± 43.45) of the children with ASD were significantly higher (P = 0.010, P = 0.001, respectively) than those of the controls (1.18 ± 0.42, 79.95 ± 31.60, respectively). Sensory seeking scores of the ASD group (40.8 ± 7.60) were significantly lower (P = 0.024) than those of the control group (45.83 ± 9.17). However, the psychophsycal thresholds did not have any statistically significant relationships with subjective sensory symptoms or daily difficulties. This study demonstrates impaired sensory processing in ASD evaluated by STD and its lack of relationship with subjective sensory symptoms and daily difficulties. This psychophysical evidence of increased STD thresholds and decreased sensory seeking profile supports the disturbances in the regulation of sensory processing in ASD. LAY SUMMARY: Sensory differences are common in autism; however, there is no well-accepted method to measure them objectively. This study aims to investigate somatosensory differences and their relation with sensory and emotional/behavioral difficulties of children with autism. We show that autistic children have higher tactile discrimination thresholds and fewer sensory seeking behaviors. This supports the presence of impairments in sensory processing in autism. Measuring the sensory differences may help understanding clinical symptoms and neurobiological underpinings of autism. Autism Res 2021, 14: 656-667. © 2021 International Society for Autism Research and Wiley Periodicals LLC.
Autism research : official journal of the International Society for Autism Research, 2021 · doi:10.1002/aur.2479