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arxiv: 2606.06290 · v1 · pith:CUMDIS4Inew · submitted 2026-06-04 · 🧬 q-bio.NC · cond-mat.stat-mech

Early psychosis shows deviations in scaling behaviour within a critical regime

Irem Topal , Paola Moreno Ancalmo , Guillermo Montana Valverde , Philipp Homan , Wolfram Hinzen This is my paper

Pith reviewed 2026-06-27 22:37 UTC · model grok-4.3

classification 🧬 q-bio.NC cond-mat.stat-mech
keywords early psychosisscaling behaviorcritical regimeresting-state fMRIphenomenological renormalization grouppower spectral densitydetrended fluctuation analysiscollective dynamics
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The pith

Early psychosis shows shifts in scaling exponents while preserving overall critical-like brain dynamics.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper examines scaling properties of resting-state fMRI signals in individuals with early psychosis versus healthy controls. It applies a phenomenological renormalization group approach together with power spectral density and detrended fluctuation analysis to track collective activity across multiple scales. Both groups display non-trivial scale-invariant organization consistent with near-critical dynamics. Psychosis participants exhibit the same regime but with systematic displacements in the measured scaling exponents. This pattern indicates a reorganization of dynamics inside an intact scaling framework rather than an outright departure from critical-like behavior.

Core claim

In resting-state fMRI data, healthy controls exhibit non-trivial scaling behavior consistent with critical-like organization. Early psychosis participants show the same overall phenomenology of scale-invariant organization, but with systematic shifts in scaling exponents across multiple observables. These findings indicate that early psychosis is not characterized by a simple loss of critical-like dynamics, but rather by a reorganization of collective dynamics within a preserved scaling regime.

What carries the argument

Combined phenomenological renormalization group (PRG) framework with power spectral density (PSD) and detrended fluctuation analysis (DFA) applied to resting-state fMRI signals to track collective dynamics across scales.

If this is right

  • Scaling remains present but displaced in early psychosis across the observables examined.
  • Previously scattered reports of altered dynamics may reflect the same underlying reorganization.
  • Coarse-graining combined with temporal scaling measures supplies a unified way to study brain dynamics in psychiatric conditions.
  • The preserved scaling regime suggests that information-processing advantages associated with criticality are retained rather than lost.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The observed exponent shifts could be tested for correlation with specific symptom dimensions in larger cohorts.
  • The same pipeline might reveal comparable reorganizations in other psychiatric conditions that share resting-state fMRI alterations.
  • Longitudinal scans could check whether the shifts precede or follow clinical onset.
  • Application to EEG or MEG data would test whether the pattern generalizes beyond fMRI.

Load-bearing premise

The three measures together reflect a shared alteration in large-scale brain dynamics rather than unrelated effects.

What would settle it

Finding no systematic difference in scaling exponents between groups when the same PRG, PSD, and DFA pipeline is applied to new resting-state fMRI datasets.

Figures

Figures reproduced from arXiv: 2606.06290 by Guillermo Montana Valverde, Irem Topal, Paola Moreno Ancalmo, Philipp Homan, Wolfram Hinzen.

Figure 1
Figure 1. Figure 1: Schematic illustration of the PRG procedure. [PITH_FULL_IMAGE:figures/full_fig_p006_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Resting-state whole-brain activity reveals statistical signatures of criticality. A. [PITH_FULL_IMAGE:figures/full_fig_p009_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Dynamic scaling under coarse-graining for healty controls. A. [PITH_FULL_IMAGE:figures/full_fig_p010_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: Altered scaling exponents in early psychosis. [PITH_FULL_IMAGE:figures/full_fig_p012_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: Temporal scaling of global signals. A. Power spectra of global signals from individual control subjects shown in log-log scale. Each line corresponds to one subject. The dashed gray line indicates the frequency range used for estimating the scaling exponent βP SD. B. DFA plots of global signals from control subjects, showing the fluctuation function F(n) measured at different time-window lengths and plotte… view at source ↗
read the original abstract

Accumulating evidence suggests that large-scale brain activity exhibits scale-invariant dynamics consistent with operation in a near-critical regime. Such dynamics have been associated with long-range correlations, efficient information processing, and the emergence of collective organization. While altered criticality-related measures have been reported in psychiatric disorders, previous findings remain fragmented across observables and modalities, making it unclear whether different scaling measures capture a common alteration of large-scale brain dynamics. Here, we investigated scaling properties in resting-state fMRI data from individuals with early psychosis and healthy controls. We combined a phenomenological renormalization group (PRG) framework with power spectral density (PSD) and detrended fluctuation analysis (DFA) to characterize collective dynamics across scales. In healthy controls, resting-state activity exhibited non-trivial scaling behavior consistent with critical-like organization. Early psychosis participants showed the same overall phenomenology of scale-invariant organization, but with systematic shifts in scaling exponents across multiple observables. These findings indicate that early psychosis is not characterized by a simple loss of critical-like dynamics, but rather by a reorganization of collective dynamics within a preserved scaling regime. More broadly, our results suggest that combining coarse-graining approaches with temporal scaling analyses provides a principled framework for studying large-scale brain dynamics in psychiatric disorders.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

0 major / 2 minor

Summary. The manuscript claims that resting-state fMRI activity in healthy controls exhibits non-trivial scale-invariant dynamics consistent with critical-like organization, as characterized jointly by phenomenological renormalization group (PRG) coarse-graining, power spectral density (PSD), and detrended fluctuation analysis (DFA). Early-psychosis participants retain the same functional form of scaling across these observables but display systematic shifts in the extracted exponents, supporting the interpretation that the disorder involves reorganization of collective dynamics inside a preserved scaling regime rather than a simple loss of criticality.

Significance. If the reported phenomenology holds after appropriate controls, the work supplies a unified account of scaling alterations in early psychosis that reconciles previously fragmented observations across measures and modalities. By demonstrating that the same scaling form persists while exponents shift, the study reframes psychiatric deviations as quantitative reorganizations within a critical regime, offering a principled multi-observable framework for future investigations of large-scale brain dynamics in clinical populations.

minor comments (2)
  1. Abstract: sample sizes, statistical tests, effect sizes, preprocessing steps, and exclusion criteria are not stated, which limits immediate assessment of robustness even though the full text presumably contains these details.
  2. Methods/Results: the manuscript should explicitly test and report whether the direction and magnitude of exponent shifts are consistent across the three observables (PRG, PSD, DFA) rather than leaving the reader to infer a common alteration from separate figures.

Simulated Author's Rebuttal

0 responses · 0 unresolved

We thank the referee for the positive assessment of our manuscript, the accurate summary of our findings, and the recommendation for minor revision. No specific major comments were raised in the report.

Circularity Check

0 steps flagged

No significant circularity

full rationale

The paper's central claim rests on direct empirical group comparisons of scaling exponents extracted from PRG coarse-graining, PSD, and DFA applied to resting-state fMRI data. Both cohorts exhibit the same functional form of scale-invariant behavior, with systematic shifts only in the numerical values of the exponents; this phenomenology is reported as observed rather than derived from any fitted parameter or self-referential definition. No equations, uniqueness theorems, or ansatzes are invoked that reduce the reported reorganization to a tautology or to a self-citation chain. The argument that early psychosis involves reorganization inside a preserved regime follows immediately from the measured differences without intermediate steps that equate outputs to inputs by construction.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Abstract-only review; no explicit free parameters, axioms, or invented entities are identifiable. The near-critical regime is invoked as background from prior literature.

pith-pipeline@v0.9.1-grok · 5758 in / 1096 out tokens · 28685 ms · 2026-06-27T22:37:31.348402+00:00 · methodology

discussion (0)

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Reference graph

Works this paper leans on

76 extracted references · 4 canonical work pages

  1. [1]

    Physical Review Letters , author =

    Coarse. Physical Review Letters , author =. 2019 , pages =. doi:10.1103/PhysRevLett.123.178103 , language =

    work page doi:10.1103/physrevlett.123.178103 2019

  2. [2]

    and Brody, Carlos D

    Meshulam, Leenoy and Gauthier, Jeffrey L. and Brody, Carlos D. and Tank, David W. and Bialek, William , month = dec, year =. Coarse--graining and hints of scaling in a population of 1000+ neurons , url =

  3. [3]

    Theiler and S

    J. Theiler and S. Eubank and A. Longtin and B. Galdrikian and J. D. Farmer , title =. Physica D , year =

  4. [4]

    , journal=

    Welch, P. , journal=. The use of fast Fourier transform for the estimation of power spectra: A method based on time averaging over short, modified periodograms , year=

  5. [5]

    , TITLE=

    Tagliazucchi, Enzo and Balenzuela, Pablo and Fraiman, Daniel and Chialvo, Dante R. , TITLE=. Frontiers in Physiology , VOLUME=. 2012 , DOI=

    2012

  6. [6]

    Proceedings of the National Academy of Sciences , volume =

    Yumeng Xin and Yue Cui and Shan Yu and Ning Liu , title =. Proceedings of the National Academy of Sciences , volume =. 2025 , doi =

    2025

  7. [7]

    Clinician Version (SCID-5-CV) , year=

    Structured clinical interview for DSM-5 disorders , author=. Clinician Version (SCID-5-CV) , year=

  8. [8]

    Nature methods , volume=

    fMRIPrep: a robust preprocessing pipeline for functional MRI , author=. Nature methods , volume=. 2019 , publisher=

    2019

  9. [9]

    Neuroimage , volume=

    Spurious but systematic correlations in functional connectivity MRI networks arise from subject motion , author=. Neuroimage , volume=. 2012 , publisher=

    2012

  10. [10]

    Proceedings of the National Academy of Sciences , volume=

    The human brain is intrinsically organized into dynamic, anticorrelated functional networks , author=. Proceedings of the National Academy of Sciences , volume=. 2005 , publisher=

    2005

  11. [11]

    Neuroimage , volume=

    An improved framework for confound regression and filtering for control of motion artifact in the preprocessing of resting-state functional connectivity data , author=. Neuroimage , volume=. 2013 , publisher=

    2013

  12. [12]

    PLOS Computational Biology , volume=

    Continuous evaluation of denoising strategies in resting-state fMRI connectivity using fMRIPrep and Nilearn , author=. PLOS Computational Biology , volume=. 2024 , publisher=

    2024

  13. [13]

    Nature Reviews Neuroscience , volume=

    Imaging-based parcellations of the human brain , author=. Nature Reviews Neuroscience , volume=. 2018 , publisher=

    2018

  14. [14]

    Cerebral cortex , volume=

    Local-global parcellation of the human cerebral cortex from intrinsic functional connectivity MRI , author=. Cerebral cortex , volume=. 2018 , publisher=

    2018

  15. [15]

    Magnetic resonance in medicine , volume=

    Movement-related effects in fMRI time-series , author=. Magnetic resonance in medicine , volume=. 1996 , publisher=

    1996

  16. [16]

    and Buldyrev, S

    Peng, C.-K. and Buldyrev, S. V. and Havlin, S. and Simons, M. and Stanley, H. E. and Goldberger, A. L. , title =. Physical Review E , volume =. 1994 , doi =

    1994

  17. [17]

    Reviews of Modern Physics , volume=

    Colloquium: Criticality and dynamical scaling in living systems , author=. Reviews of Modern Physics , volume=. 2018 , publisher=

    2018

  18. [18]

    Journal of neuroscience , volume=

    Neuronal avalanches in neocortical circuits , author=. Journal of neuroscience , volume=. 2003 , publisher=

    2003

  19. [19]

    Journal of Neuroscience , volume=

    Microscale neuronal activity collectively drives chaotic and inflexible dynamics at the macroscale in seizures , author=. Journal of Neuroscience , volume=. 2023 , publisher=

    2023

  20. [20]

    Neuron , volume=

    Whole-brain neuronal activity displays crackling noise dynamics , author=. Neuron , volume=. 2018 , publisher=

    2018

  21. [21]

    Journal of Neuroscience , volume=

    Neuronal avalanches in the resting MEG of the human brain , author=. Journal of Neuroscience , volume=. 2013 , publisher=

    2013

  22. [22]

    Frontiers in physiology , volume=

    Criticality in large-scale brain fMRI dynamics unveiled by a novel point process analysis , author=. Frontiers in physiology , volume=. 2012 , publisher=

    2012

  23. [23]

    Journal of Neuroscience , volume=

    Long-range temporal correlations and scaling behavior in human brain oscillations , author=. Journal of Neuroscience , volume=. 2001 , publisher=

    2001

  24. [24]

    Physica A: Statistical Mechanics and its Applications , volume=

    Scaling laws and persistence in human brain activity , author=. Physica A: Statistical Mechanics and its Applications , volume=. 2003 , publisher=

    2003

  25. [25]

    Herrmann and Lucilla

    Fabrizio Lombardi and Oren Shriki and Hans J. Herrmann and Lucilla. Long-range temporal correlations in the broadband resting state activity of the human brain revealed by neuronal avalanches , journal =. 2021 , issn =. doi:https://doi.org/10.1016/j.neucom.2020.05.126 , url =

    work page doi:10.1016/j.neucom.2020.05.126 2021

  26. [26]

    Journal of Neuroscience , volume=

    Scale-free properties of the functional magnetic resonance imaging signal during rest and task , author=. Journal of Neuroscience , volume=. 2011 , publisher=

    2011

  27. [27]

    Journal of computational neuroscience , volume=

    Comparative power spectral analysis of simultaneous elecroencephalographic and magnetoencephalographic recordings in humans suggests non-resistive extracellular media , author=. Journal of computational neuroscience , volume=. 2010 , publisher=

    2010

  28. [28]

    Frontiers in neural circuits , volume=

    Why brain criticality is clinically relevant: a scoping review , author=. Frontiers in neural circuits , volume=. 2020 , publisher=

    2020

  29. [29]

    Schizophrenia Research , volume=

    Alteration of power law scaling of spontaneous brain activity in schizophrenia , author=. Schizophrenia Research , volume=. 2021 , publisher=

    2021

  30. [30]

    Frontiers in Neural Circuits , volume=

    Altered brain criticality in schizophrenia: new insights from magnetoencephalography , author=. Frontiers in Neural Circuits , volume=. 2022 , publisher=

    2022

  31. [31]

    Scientific Reports , volume=

    Multiscale criticality measures as general-purpose gauges of proper brain function , author=. Scientific Reports , volume=. 2021 , publisher=

    2021

  32. [32]

    Communications Biology , volume=

    Critical scaling of whole-brain resting-state dynamics , author=. Communications Biology , volume=. 2023 , publisher=

    2023

  33. [33]

    Physical Review Letters , volume=

    Interdependent scaling exponents in the human brain , author=. Physical Review Letters , volume=. 2025 , publisher=

    2025

  34. [34]

    The Annals of Statistics , volume=

    Spectrum estimation from samples , author=. The Annals of Statistics , volume=. 2017 , publisher=. doi:10.1214/16-AOS1525 , url=

    work page doi:10.1214/16-aos1525 2017

  35. [35]

    Proceedings of the National Academy of Sciences , volume=

    Altered global brain signal in schizophrenia , author=. Proceedings of the National Academy of Sciences , volume=. 2014 , publisher=

    2014

  36. [36]

    Proceedings of the National Academy of Sciences , volume=

    Neural basis of global resting-state fMRI activity , author=. Proceedings of the National Academy of Sciences , volume=. 2010 , publisher=

    2010

  37. [37]

    Neuroimage , volume=

    The global signal in fMRI: Nuisance or Information? , author=. Neuroimage , volume=. 2017 , publisher=

    2017

  38. [38]

    Power spectrum of resting-state blood-oxygen-level-dependent signal , author =. Phys. Rev. E , volume =. 2019 , month =. doi:10.1103/PhysRevE.100.022418 , url =

    work page doi:10.1103/physreve.100.022418 2019

  39. [39]

    and Madison, Cindee and Clark, Dav and Halchenko, Yaroslav O

    Gorgolewski, Krzysztof and Burns, Christopher D. and Madison, Cindee and Clark, Dav and Halchenko, Yaroslav O. and Waskom, Michael L. and Ghosh, Satrajit S. , TITLE=. Frontiers in Neuroinformatics , VOLUME=. 2011 , ISSN=

    2011

  40. [40]

    IEEE transactions on medical imaging , volume=

    N4ITK: improved N3 bias correction , author=. IEEE transactions on medical imaging , volume=. 2010 , publisher=

    2010

  41. [41]

    Medical image analysis , volume=

    Symmetric diffeomorphic image registration with cross-correlation: evaluating automated labeling of elderly and neurodegenerative brain , author=. Medical image analysis , volume=. 2008 , publisher=

    2008

  42. [42]

    IEEE transactions on medical imaging , volume=

    Segmentation of brain MR images through a hidden Markov random field model and the expectation-maximization algorithm , author=. IEEE transactions on medical imaging , volume=. 2002 , publisher=

    2002

  43. [43]

    Segmentation and surface reconstruction , author=

    Cortical surface-based analysis: I. Segmentation and surface reconstruction , author=. Neuroimage , volume=. 1999 , publisher=

    1999

  44. [44]

    PLoS computational biology , volume=

    Mindboggling morphometry of human brains , author=. PLoS computational biology , volume=. 2017 , publisher=

    2017

  45. [45]

    Neuroimage , volume=

    Improved optimization for the robust and accurate linear registration and motion correction of brain images , author=. Neuroimage , volume=. 2002 , publisher=

    2002

  46. [46]

    NMR in Biomedicine: An International Journal Devoted to the Development and Application of Magnetic Resonance In Vivo , volume=

    Software tools for analysis and visualization of fMRI data , author=. NMR in Biomedicine: An International Journal Devoted to the Development and Application of Magnetic Resonance In Vivo , volume=. 1997 , publisher=

    1997

  47. [47]

    Neuroimage , volume=

    Accurate and robust brain image alignment using boundary-based registration , author=. Neuroimage , volume=. 2009 , publisher=

    2009

  48. [48]

    neuroimage , volume=

    Methods to detect, characterize, and remove motion artifact in resting state fMRI , author=. neuroimage , volume=. 2014 , publisher=

    2014

  49. [49]

    Neuroimage , volume=

    A component based noise correction method (CompCor) for BOLD and perfusion based fMRI , author=. Neuroimage , volume=. 2007 , publisher=

    2007

  50. [50]

    Journal of the Society for Industrial and Applied Mathematics, Series B: Numerical Analysis , volume=

    Evaluation of noisy data , author=. Journal of the Society for Industrial and Applied Mathematics, Series B: Numerical Analysis , volume=. 1964 , publisher=

    1964

  51. [51]

    Frontiers in neuroinformatics , volume=

    Machine learning for neuroimaging with scikit-learn , author=. Frontiers in neuroinformatics , volume=. 2014 , publisher=

    2014

  52. [52]

    Neuropsychopharmacology , volume=

    Connectome-based predictive modeling of early and chronic psychosis symptoms , author=. Neuropsychopharmacology , volume=. 2025 , publisher=

    2025

  53. [53]

    Journal of The Royal Society Interface , volume=

    Self-similar correlation function in brain resting-state functional magnetic resonance imaging , author=. Journal of The Royal Society Interface , volume=. 2011 , publisher=

    2011

  54. [54]

    Nature communications , volume=

    Griffiths phases and the stretching of criticality in brain networks , author=. Nature communications , volume=. 2013 , publisher=

    2013

  55. [55]

    default mode

    Aberrant “default mode” functional connectivity in schizophrenia , author=. American journal of psychiatry , volume=. 2007 , publisher=

    2007

  56. [56]

    Neuroimage , volume=

    Altered resting state complexity in schizophrenia , author=. Neuroimage , volume=. 2012 , publisher=

    2012

  57. [57]

    Archives of general psychiatry , volume=

    Glutamate receptor dysfunction and schizophrenia , author=. Archives of general psychiatry , volume=. 1995 , publisher=

    1995

  58. [58]

    Trends in neurosciences , volume=

    Circuit-based framework for understanding neurotransmitter and risk gene interactions in schizophrenia , author=. Trends in neurosciences , volume=. 2008 , publisher=

    2008

  59. [59]

    Biological psychiatry , volume=

    Impaired tuning of neural ensembles and the pathophysiology of schizophrenia: a translational and computational neuroscience perspective , author=. Biological psychiatry , volume=. 2017 , publisher=

    2017

  60. [60]

    The neuroscientist , volume=

    The functional benefits of criticality in the cortex , author=. The neuroscientist , volume=. 2013 , publisher=

    2013

  61. [61]

    Journal of Neuroscience , volume=

    Critical-state dynamics of avalanches and oscillations jointly emerge from balanced excitation/inhibition in neuronal networks , author=. Journal of Neuroscience , volume=. 2012 , publisher=

    2012

  62. [62]

    Biological psychiatry , volume=

    The dual-state theory of prefrontal cortex dopamine function with relevance to catechol-o-methyltransferase genotypes and schizophrenia , author=. Biological psychiatry , volume=. 2008 , publisher=

    2008

  63. [63]

    Schizophrenia research , volume=

    The disconnection hypothesis , author=. Schizophrenia research , volume=. 1998 , publisher=

    1998

  64. [64]

    Schizophrenia bulletin , volume=

    Dysconnection in schizophrenia: from abnormal synaptic plasticity to failures of self-monitoring , author=. Schizophrenia bulletin , volume=. 2009 , publisher=

    2009

  65. [65]

    Behavioral and Brain Sciences , volume=

    Convergence of biological and psychological perspectives on cognitive coordination in schizophrenia , author=. Behavioral and Brain Sciences , volume=. 2003 , publisher=

    2003

  66. [66]

    Frontiers in psychiatry , volume=

    The computational anatomy of psychosis , author=. Frontiers in psychiatry , volume=. 2013 , publisher=

    2013

  67. [67]

    Nature Reviews Neuroscience , volume=

    Computational models of schizophrenia and dopamine modulation in the prefrontal cortex , author=. Nature Reviews Neuroscience , volume=. 2008 , publisher=

    2008

  68. [68]

    Nature physics , volume=

    Emergent complex neural dynamics , author=. Nature physics , volume=. 2010 , publisher=

    2010

  69. [69]

    Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences , volume=

    The criticality hypothesis: how local cortical networks might optimize information processing , author=. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences , volume=. 2008 , publisher=

    2008

  70. [70]

    Nature physics , volume=

    Optimal dynamical range of excitable networks at criticality , author=. Nature physics , volume=. 2006 , publisher=

    2006

  71. [71]

    Frontiers in physiology , volume=

    Detrended fluctuation analysis: a scale-free view on neuronal oscillations , author=. Frontiers in physiology , volume=. 2012 , publisher=

    2012

  72. [72]

    Proceedings of the national academy of sciences , volume=

    Fractal dynamics in physiology: alterations with disease and aging , author=. Proceedings of the national academy of sciences , volume=. 2002 , publisher=

    2002

  73. [73]

    Proceedings of the National Academy of Sciences , volume=

    Quasiuniversal scaling in mouse-brain neuronal activity stems from edge-of-instability critical dynamics , author=. Proceedings of the National Academy of Sciences , volume=. 2023 , publisher=

    2023

  74. [74]

    arXiv preprint arXiv:2602.17820 , year=

    Scaling and tuning to criticality in resting-state human magnetoencephalography , author=. arXiv preprint arXiv:2602.17820 , year=

    arXiv

  75. [75]

    Physical Review Research , volume=

    Scaling and criticality in a phenomenological renormalization group , author=. Physical Review Research , volume=. 2020 , publisher=

    2020

  76. [76]

    Frontiers in Physiology , volume=

    Fractal structure of brain electrical activity of patients with mental disorders , author=. Frontiers in Physiology , volume=