Handedness did not significantly alter mirror-matched SEEG spectral differences in 144 RAM patients

This study tested whether handedness was associated with the right-minus-left difference in seven spectral features at mirror-matched bipolar SEEG pairs. It used archived per-patient features from one 60 s task segment in RAM FR1 and catFR1, with handedness labels from OpenNeuro ds004789 and ds004809. Among 144 patients (24 non-right-handed: 18 left-handed and 6 ambidextrous; 120 right-handed), stratified permutation tests with Holm correction across seven features found no significant group difference. No feature met the prespecified equivalence bound of ±0.3 within-patient SD. The minimum detectable difference was 0.52 within-patient SD, so smaller effects are not excluded. Relative alpha had the smallest uncorrected p value (p=0.021; Holm p=0.149): its mean right-minus-left value was −0.35 in non-right-handed patients and −0.02 in right-handed patients. This exploratory pattern was absent for raw differences (p=0.51) and in ds004789 alone (p=0.13); the left-handed-only comparison was a secondary analysis. Asymmetry magnitude was similar between groups (p=0.97). Handedness was a clinical label and only a proxy for language dominance; no Wada or fMRI dominance labels were available. The findings do not rule out effects smaller than the study could detect.

SEEG · handedness · spectral asymmetry · mirror-matched bipolar pairs · RAM · language dominance · permutation test