Tactile hypersensitivity and GABA concentration in the sensorimotor cortex of adults with autism.
Less GABA in the touch cortex gives a biological receipt for tactile pain in adults with autism.
01Research in Context
What this study did
Sapey-Triomphe et al. (2019) scanned adults with and without autism. They used a brain-imaging tool that counts GABA, the main brake signal in the brain.
Each adult also filled out a short survey about how much everyday touch bothers them. The team asked: does lower brake fluid in the touch area match higher touch pain?
What they found
Adults with autism had 17% less GABA in the sensorimotor strip. Lower GABA went hand-in-hand with stronger self-reported touch hypersensitivity.
Neurotypical adults showed no link between GABA and touch comfort.
How this fits with other research
Taylor et al. (2017) saw the same GABA drop in autistic kids, showing the pattern starts early.
Maier et al. (2022) flipped the script: in the same adult group they found more GABA in the prefrontal area, not less. This means GABA changes are spot-specific, not brain-wide.
Fahmie et al. (2013) looked at the same touch area with a different tool and found normal inhibition. The clash disappears when you see MEG measures brain waves, while MRS counts molecules—two different rulers.
Why it matters
You now have a concrete brain measure behind the “my shirt tag hurts” reports. When an adult client says light touch is painful, you can trust the feeling has real neurochemistry behind it. Future meds or sensory training may aim at this GABA gap, so keep an eye on trials. For now, continue gentle desensitization and warn employers that scratchy uniforms aren’t just annoying—they’re neurochemically amplified.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Add one extra choice question to your sensory survey: ‘Rate how much light touch bothers you (0-10).’ Use the number to validate, not dismiss, tactile avoidance.
02At a glance
03Original abstract
Sensory hypersensitivity is frequently encountered in autism spectrum disorder (ASD). Gamma-aminobutyric acid (GABA) has been hypothesized to play a role in tactile hypersensitivity. The aim of the present study was twofold. First, as a study showed that children with ASD have decreased GABA concentrations in the sensorimotor cortex, we aimed at determining whether the GABA reduction remained in adults with ASD. For this purpose, we used magnetic resonance spectroscopy to measure GABA concentration in the sensorimotor cortex of neurotypical adults (n = 19) and ASD adults (n = 18). Second, we aimed at characterizing correlations between GABA concentration and tactile hypersensitivity in ASD. GABA concentration in the sensorimotor cortex of adults with ASD was lower than in neurotypical adults (decrease by 17%). Interestingly, GABA concentrations were positively correlated with self-reported tactile hypersensitivity in adults with ASD (r = 0.50, P = 0.01), but not in neurotypical adults. In addition, GABA concentrations were negatively correlated with the intra-individual variation during threshold measurement, both in neurotypical adults (r = -0.47, P = 0.04) and in adults with ASD (r = -0.59, P = 0.01). In other words, in both groups, the higher the GABA level, the more precise the tactile sensation. These results highlight the key role of GABA in tactile sensitivity, and suggest that atypical GABA modulation contributes to tactile hypersensitivity in ASD. We discuss the hypothesis that hypersensitivity in ASD could be due to suboptimal predictions about sensations. Autism Research 2019, 12: 562-575. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: People with autism spectrum disorder (ASD) often experience tactile hypersensitivity. Here, our goal was to highlight a link between tactile hypersensitivity and the concentration of gamma-aminobutyric acid (GABA) (an inhibitory neurotransmitter) in the brain of adults with ASD. Indeed, self-reported hypersensitivity correlated with reduced GABA levels in brain areas processing touch. Our study suggests that this neurotransmitter may play a key role in tactile hypersensitivity in autism.
Autism research : official journal of the International Society for Autism Research, 2019 · doi:10.1002/aur.2073