Cortical Field Dynamics as a Candidate Pharmacological Biomarker in Pediatric ADHD: A Ginzburg-Landau Analysis of fMRI Visual Task Data, with Evidence for a Sex-Dependent Baseline

This paper presents an exploratory Ginzburg-Landau/CIFT (Cortical Informational Field Theory) analysis of publicly available pediatric fMRI data (ds002424, OpenNeuro) to test whether the effective cortical field control parameter λ_eff differentiates stimulant medication classes in children with ADHD. The GL cortical field model predicts that ADHD corresponds to a near-critical cortical regime (RC³) with λ_eff < 0. Different stimulant classes — dexmethylphenidate (Focalin), amphetamines (Adderall/Vyvanse), and methylphenidate (Concerta) — are predicted to produce distinguishable displacements in the cortical field state space through their differential receptor selectivity profiles. Key findings: ANOVA across five medication groups (n=79 children, age 8.6–12.0 years) revealed significant λ_eff differences (F=4.447, p=0.002) Focalin-treated participants exhibited a field profile consistent with relative normalization toward criticality (p_FDR=0.350 vs controls, not significant) Concerta (p_FDR=0.006, d=0.712) and amphetamines (p_FDR=0.011, d=0.633) showed significantly more negative λ_eff than controls The Focalin vs Concerta contrast was the most robust finding (d=1.208, p=0.011), surviving FDR correction and sex restriction BOLD signal entropy (C2) correlated significantly with scan time post-dose (r=0.350, p=0.009), most strongly for Focalin (r=0.70, p=0.024) A significant sex difference in λ_eff was observed in neurotypical controls (d=0.724, p=0.0006), suggesting a possible sex-dependent baseline component of cortical field organization C1 = |⟨Φ⟩| was not validly estimable from spatially averaged BOLD signals — a methodological negative finding motivating future EEG/MEG studies CIFT observables: λ_eff: derived from temporal coherence length ξ via ξ = √(D₀/|λ_eff|) C2 = H(Φ): BOLD signal entropy as proxy for temporal-distributional differentiation ξ: temporal autocorrelation lag at e⁻¹ threshold Dataset: ds002424 (Lytle, Hammer & Booth, 2020) · doi:10.18112/openneuro.ds002424.v1.0.4 · Visual load tasks VLD and VLI · 147 fMRI runs · 79 children (35 ADHD, 44 controls) Related CIFT publications: Paper I — Ginzburg-Landau effective field theory for mesoscopic cortical coherence and scaling · doi:10.5281/zenodo.19715586 · Physical Review E (under review, MS ES12577) Paper II — Dynamic admittance and slow structural bias generate history-dependent state selection · doi:10.5281/zenodo.19462041 · Frontiers in Computational Neuroscience (submitted) Paper V — Neural reconfiguration in ADHD: A cortical field theory approach · doi:10.5281/zenodo.19256243 · Scientific Reports (under review) Paper VIII — Genomic bases of RC³: heritability and polygenic architecture · doi:10.5281/zenodo.19953150 Paper Fundacional CIFT — Antes de la Experiencia: Transiciones de Fase en la Emergencia del Campo Cortical · doi:10.5281/zenodo.19953784 Simulation code CIFT Paper II · doi:10.5281/zenodo.20162426 Empirical anchor: Allen Institute Synaptic Physiology dataset r2.1 · Campagnola et al. Science 2022 · doi:10.1126/science.abj5861 Target journal: Human Brain Mapping (under preparation for submission) Part of the CIFT Research Program — a multi-paper framework applying Ginzburg-Landau field theory to mesoscopic cortical dynamics, consciousness, and neurodevelopmental conditions. · dankostjepovic.com · ORCID 0009-0002-2186-1195