Children with autism show reduced somatosensory response: an MEG study.
Boys with autism show dampened and delayed brain reactions to light touch, a pattern that holds across ages and links to low GABA.
01Research in Context
What this study did
Researchers used MEG brain scans on boys with autism. They puffed light air on the kids' fingers. The team watched how fast the somatosensory cortex fired back.
The study compared the brain waves to those of typically developing boys.
What they found
Kids with autism had smaller and slower brain responses to touch. The delay showed up in the left primary sensory area. Parents who rated their kids as extra touch-sensitive had the smallest brain waves.
The slower the brain wave, the more the child disliked tags, socks, or haircuts.
How this fits with other research
Taylor et al. (2017) and Sapey-Triomphe et al. (2019) extend this finding. They link the weak touch response to low GABA, a calming brain chemical. Less GABA in the sensorimotor cortex tracks with worse tactile scores in both kids and adults.
Two papers seem to clash. Fahmie et al. (2013) saw normal cortical inhibition in young autistic adults. Cascio et al. (2008) found normal light-touch detection thresholds in adults. The difference is age and task. The target paper tested boys with a single light puff. The others used paired finger taps or asked adults to report when they felt something. Peripheral feeling can look fine while the early brain wave is still sluggish.
Buyuktaskin et al. (2021) fill the gap between child and adult. Autistic teens needed longer gaps between touches to notice two separate taps. The timing trouble starts in late elementary years and stays.
Why it matters
You now have a brain-based reason for the sock seam meltdown. If a child pulls away from light touch, don't assume he's being difficult. His S1 cortex literally takes longer to register the input. Use firmer, slower touch when you need his attention. Give warning before applying stickers, glue, or band-aids. Pairing gentle touch with preferred activities can help the brain re-map the input. Track progress with parent logs, not just child report, since the parent rating matched the brain measure.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Before applying any light tactile prompt, give firm deep pressure first and count to three so the child's brain has time to register.
02At a glance
03Original abstract
The neural underpinnings of sensory processing differences in autism remain poorly understood. This prospective magnetoencephalography (MEG) study investigates whether children with autism show atypical cortical activity in the primary somatosensory cortex (S1) in comparison with matched controls. Tactile stimuli were clearly detectable, and painless taps were applied to the distal phalanx of the second (D2) and third (D3) fingers of the right and left hands. Three tactile paradigms were administered: an oddball paradigm (standard taps to D3 at an interstimulus interval (ISI) of 0.33 and deviant taps to D2 with ISI ranging from 1.32 s to 1.64 s); a slow-rate paradigm (D2) with an ISI matching the deviant taps in the oddball paradigm; and a fast-rate paradigm (D2) with an ISI matching the standard taps in the oddball. Study subjects were boys (age 7-11 years) with and without autism disorder. Sensory behavior was quantified using the Sensory Profile questionnaire. Boys with autism exhibited smaller amplitude left hemisphere S1 response to slow and deviant stimuli during the right-hand paradigms. In post-hoc analysis, tactile behavior directly correlated with the amplitude of cortical response. Consequently, the children were re-categorized by degree of parent-report tactile sensitivity. This regrouping created a more robust distinction between the groups with amplitude diminution in the left and right hemispheres and latency prolongation in the right hemisphere in the deviant and slow-rate paradigms for the affected children. This study suggests that children with autism have early differences in somatosensory processing, which likely influence later stages of cortical activity from integration to motor response.
Autism research : official journal of the International Society for Autism Research, 2012 · doi:10.1186/1471-2202-8-21