Shared sound change tests failed in six iEEG patients and 18 fMRI adults; some MRI block refits left no residual variation

We tested whether absolute changes in log sound level predict a higher temporal region response after sound level and word controls. Separate public studies supplied human intracranial EEG amplitude and BOLD fMRI during two English stories. Three patients and four MRI adults supplied development. A local code lock preceded new scores in six other patients and 18 other adults. Mean partial correlations were +0.01570 and -0.06245. Their 95% person Student limits were [-0.00106, +0.03246] and [-0.13972, +0.01483]. The shared positive test failed, Holm p=1. A prediction gain test and an opposite direction test added after development also failed. All negative people and control checks remain. The full MRI controls left 3.48% to 3.61% of target energy after drift removal. A block-refit audit found a numerical failure. In selected MRI draws, controls spanned every retained time sample. Residual target energy was near zero, but direct solvers returned finite correlations from roundoff. We retain all draws and mark the MRI block interval undefined. A first-draw numerical check had missed the failure. The contribution is a benchmark and an audit tool. Related prior work already used absolute band changes. The present extension adds nonlinear level controls, another MRI cohort and explicit design checks. Separate cohorts, stories, clinical coverage, source processing, many MRI controls and absent new motion correction limit scope. No positive common neural effect or cause was established. Code, permitted numeric inputs, source versions and terms, all results, figures and repeat steps are supplied.

human neuroscience · intracranial EEG · fMRI · speech · acoustic change · identifiability · negative result