Increased alpha power in autistic adults: Relation to sensory behaviors and cortical volume.
Scott O Murray, Daniela L Seczon, Mark Pettet and 4 others
PMID 39555754WHAT IT FOUND
Autistic adults had higher alpha brain activity than nonautistic adults.
Larger cortical volume predicted higher alpha in autistic adults. Sensory scores were also linked to the alpha response. This is a brain measurement study, not a treatment finding.
Key findings
01Alpha amplitude was higher in autistic adults than nonautistic adults during visual stimulation and eyes-closed rest.
02After baseline normalization, autistic adults showed stronger alpha suppression in the brief window after visual stimulus onset, and the onset alpha response was associated with sensory behavior scores.
03Total cortical volume predicted alpha amplitude, and this relationship was specific to autistic adults; after multiple-comparison correction, only the group-by-hippocampal-volume interaction remained significant.
STILL TO COME
How it was doneWhat they foundWhat it means for OTs
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What it does not show
The final analysis used 52 adults, so the sample was small. The study was cross-sectional, so it cannot show that alpha differences cause sensory behaviors or that cortical volume causes alpha differences. The authors note that increased alpha may not be a universal feature of autism and could reflect sample, condition, or method differences. The positive association between alpha and low-threshold sensory behaviors may be driven by a few high scores. After correction for multiple comparisons, only the group-by-hippocampal-volume interaction remained significant. Clinical assessments were adapted for telehealth during the pandemic, and the reliability and validity of the adaptation were still under review. Eye tracking data were usable for only about 70% of subjects, although fixation percentages did not differ substantively between groups.
Declared interests
The authors declared no conflict of interest. The publication types list NIH extramural and non-U.S. government research support.
The easy way to misread this
Do not read the higher alpha activity as a test that explains sensory problems or guides therapy. The study compared autistic and nonautistic adults at one time, did not test treatment, and some sensory associations were trend-level or possibly driven by a few scores.