Changes in Intrinsic Activity of the Primary Somatosensory Cortex Causally Explain Differences in Emotion Perception in Autism.
Autistic kids feel emotions less because their touch cortex is under-active, not because their thinking brain is broken.
01Research in Context
What this study did
The team scanned the kids with autism and 40 typical peers while they watched happy, sad, and angry faces.
They used a math tool called DCM to trace which brain area starts the trouble when emotions feel flat.
They also gave each child an alexithymia quiz to see if brain scores matched real-world feelings.
What they found
The somatosensory cortex — the patch that feels your own face — was too quiet in the autism group.
This low buzz, not weak signals from the thinking frontal lobe, best explained why emotions felt distant.
Kids with higher alexithymia scores had the quietest somatosensory cortex.
How this fits with other research
Schulte-Rüther et al. (2017) said facial mimicry is intact in autism. The new study shows mimicry can look fine while the inner feeling is still missing. The gap is in the body map, not the motor copy.
Crippa et al. (2013) first saw that emotional faces failed to boost imitation. Martina et al. now reveal the brain source: the somatosensory cortex never revs up.
Osorio et al. (2025) found weaker auditory cortex activation in autism. Martina et al. extend this pattern to touch-related cortex, showing the problem crosses senses.
Erickson et al. (2016) showed local wiring in sensory regions is lower in autistic kids. The new study links that low wiring to real emotion gaps, not just pictures on a screen.
Why it matters
When a learner seems unbothered by others’ feelings, target body-based input first. Try light touch prompts, mirror play, or vibration cues to wake up the somatosensory cortex before you teach emotion labels.
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02At a glance
03Original abstract
Autism Spectrum Disorder (ASD) is characterized by certain difficulties in emotion-related processing. Recent research using electroencephalography (EEG) to measure somatosensory evoked potentials during emotion perception has shown reduced embodiment of emotional expressions in autistic compared to neurotypical individuals, independently from differences in visual processing. However, the underlying neural dynamics are not clear. In this study, we use Dynamic Causal Modeling (DCM) on EEG data to investigate whether reduced embodiment during emotion processing in ASD individuals is caused by changes in intrinsic connectivity within the somatosensory cortex, or by top-down modulatory effects from higher-order frontal areas. We constructed a model involving the primary and secondary right somatosensory cortex, the right supplementary motor area and the right inferior frontal gyrus, and tested effective connectivity during emotion or gender discrimination tasks in two groups of ASD and typically developing (TD) participants (n = 38, male and female, 2 females). Our results reveal that task-related differences in electrocortical activity between the emotion and gender tasks are causally explained by changes in intrinsic activity within the right primary somatosensory cortex (rS1) in both TD and ASD. Importantly, these intrinsic changes in rS1 are significantly different between TD and ASD groups and individual task-related changes in rS1 significantly correlate with alexithymia traits. Our study provides novel evidence on the neural dynamics underlying difficulties in emotion processing in ASD individuals, highlighting that differential intrinsic activations of the rS1 are causally involved in such difficulties, and suggests that they are mediated by alexithymia.
Autism research : official journal of the International Society for Autism Research, 2026 · doi:10.1002/aur.70197