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 λₑff 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 λₑff < 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 λₑff differences (F=4. 447, p=0. 002) Focalin-treated participants exhibited a field profile consistent with relative normalization toward criticality (pFDR=0. 350 vs controls, not significant) Concerta (pFDR=0. 006, d=0. 712) and amphetamines (pFDR=0. 011, d=0. 633) showed significantly more negative λₑff 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 λₑff 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: λₑff: derived from temporal coherence length ξ via ξ = √ (D₀/|λₑff|) 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