Characterizing higher-order representations through generative diffusion models explains human decoded neurofeedback performance
Pith reviewed 2026-05-22 23:45 UTC · model grok-4.3
The pith
A reinforcement-learned diffusion model captures how humans minimize representational uncertainty in decoded neurofeedback.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
Participants accomplish the decoded neurofeedback task by learning about and then minimizing their own representational uncertainty. The NERD model trains denoising diffusion models via reinforcement learning to infer distributions of noise in fMRI data and mirrors brain-like unsupervised learning. This approach outperforms backpropagation-trained control models, with explanatory power increased by clustering the learned noise distributions, and it identifies individual differences in expected-uncertainty representations that predict task success.
What carries the argument
NERD (Noise Estimation through Reinforcement-based Diffusion), a framework that trains denoising diffusion models via reinforcement learning to infer noise distributions in fMRI data from neurofeedback tasks.
If this is right
- NERD captures human performance in the neurofeedback task better than backpropagation-trained control models.
- Clustering the learned noise distributions increases the explanatory power of the model.
- Individual differences in expected-uncertainty representations predict success in the decoded neurofeedback task.
- The model provides a tool for probing higher-order neural representations.
Where Pith is reading between the lines
- Similar reinforcement-based diffusion training might model uncertainty monitoring in other cognitive tasks.
- The results suggest generative models can approximate unsupervised mechanisms the brain uses for metacognition.
- This framework could be tested on whether it predicts performance in adaptive behaviors outside the lab.
Load-bearing premise
Participants accomplish the decoded neurofeedback task by learning about and minimizing their own representational uncertainty, and the NERD model mirrors brain-like unsupervised learning enough to explain observed performance.
What would settle it
A backpropagation-trained model matching or exceeding NERD in explaining human performance, or no observed correlation between individual expected-uncertainty representations and task success.
Figures
read the original abstract
Brains construct not only "first-order" representations of the environment but also "higher-order" representations about those representations -- including higher-order uncertainty estimates that guide learning and adaptive behavior. Higher-order expectations about representational uncertainty -- i.e., learned through experience -- may play a key role in guiding behavior and learning, but their characterization remains empirically and theoretically challenging. Here, we introduce the Noise Estimation through Reinforcement-based Diffusion (NERD) model, a novel computational framework that trains denoising diffusion models via reinforcement learning to infer distributions of noise in functional MRI data from a decoded neurofeedback task, where healthy human participants learn to achieve target neural states. We hypothesize that participants accomplish this task by learning about and then minimizing their own representational uncertainty. We test this hypothesis with NERD, which mirrors brain-like unsupervised learning. Our results show that NERD outperforms backpropagation-trained control models in capturing human performance with explanatory power enhanced by clustering learned noise distributions. Importantly, our results also reveal individual differences in expected-uncertainty representations that predict task success, demonstrating NERD's utility as a powerful tool for probing higher-order neural representations.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript introduces the Noise Estimation through Reinforcement-based Diffusion (NERD) model, which trains denoising diffusion models via reinforcement learning to infer distributions of noise in fMRI data from a decoded neurofeedback task. It hypothesizes that participants accomplish the task by learning about and minimizing their own representational uncertainty, with NERD mirroring brain-like unsupervised learning. The central claims are that NERD outperforms backpropagation-trained control models in capturing human performance (with explanatory power enhanced by clustering learned noise distributions) and that individual differences in expected-uncertainty representations predict task success.
Significance. If the empirical results and derivations hold, the work would provide a novel generative-modeling framework for probing higher-order neural representations and uncertainty estimates in decoded neurofeedback, with potential to link unsupervised learning mechanisms to behavioral outcomes. The absence of any quantitative results, error bars, data exclusion criteria, or derivation details prevents assessment of whether these advantages are demonstrated.
major comments (2)
- [Abstract] Abstract: the abstract states performance advantages and predictive links but supplies no quantitative results, error bars, data exclusion criteria, or derivation details. Full methods and results sections are required to evaluate whether the data support the claims as stated.
- [Abstract] Abstract: the abstract contains no equations or fitting procedures, so it is impossible to determine whether any reported 'predictions' reduce to fitted quantities by construction or rest on independent grounding.
Simulated Author's Rebuttal
We thank the referee for their comments on the abstract. We address each point below, noting that the full manuscript contains the requested quantitative details, methods, results, and derivations as described in the paper.
read point-by-point responses
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Referee: [Abstract] Abstract: the abstract states performance advantages and predictive links but supplies no quantitative results, error bars, data exclusion criteria, or derivation details. Full methods and results sections are required to evaluate whether the data support the claims as stated.
Authors: The abstract is a concise summary of the work, consistent with standard practice in the field. The full manuscript provides detailed methods and results sections, including quantitative performance comparisons (NERD vs. backpropagation controls), error bars on key metrics, explicit data exclusion criteria, and full derivations of the reinforcement learning objective for the diffusion model. These sections directly support the claims regarding outperformance and predictive links to neurofeedback success. We can expand the abstract with select quantitative highlights if requested. revision: partial
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Referee: [Abstract] Abstract: the abstract contains no equations or fitting procedures, so it is impossible to determine whether any reported 'predictions' reduce to fitted quantities by construction or rest on independent grounding.
Authors: The abstract omits equations for accessibility and brevity. The full manuscript details the NERD architecture, the RL-based training procedure for inferring noise distributions from fMRI, the clustering of learned representations, and the independent validation of predictions against held-out behavioral performance data. The individual-difference predictions are tested via cross-validation and compared against control models, establishing that they reflect genuine explanatory power rather than fitting artifacts. revision: no
Circularity Check
No significant circularity detected
full rationale
The provided abstract introduces the NERD model and a hypothesis about uncertainty minimization but contains no equations, fitting procedures, self-citations, or derivation steps that could be inspected for reduction to inputs by construction. Without the full manuscript's technical details on training, controls, or clustering, no load-bearing circular steps (self-definitional, fitted-input-as-prediction, or otherwise) can be identified or quoted. The central claim therefore remains self-contained against external benchmarks as far as the available text allows.
Axiom & Free-Parameter Ledger
Reference graph
Works this paper leans on
-
[1]
Baker, B., Lansdell, B. & Kording, K. P. Three aspects of representation in neuroscience. Trends in cognitive sciences 26, 942–958 (2022)
work page 2022
-
[2]
Tarr, M. J. & Vuong, Q. C. Visual object recognition. Steven’s handbook of experimental psychology 1, 287–314 (2002)
work page 2002
-
[3]
Squire, L. R. & Zola-Morgan, S. The medial temporal lobe memory system. Science 253, 1380–1386 (1991)
work page 1991
-
[4]
Miller, E. K. & Cohen, J. D. An integrative theory of prefrontal cortex function. Annu. Rev. Neurosci. 24, 167–202 (2001)
work page 2001
-
[5]
Cleeremans, A., Timmermans, B. & Pasquali, A. Conscious access to first-order and higher-order representations. Trends Cogn. Sci. 11, 465–472 (2007)
work page 2007
-
[6]
Brown, R., Lau, H. & LeDoux, J. E. Understanding the higher-order approach to consciousness. Trends in Cognitive Sciences 23, 754–768 (2019). URL https://pubmed.ncbi.nlm.nih.gov/31375408/
-
[7]
Fleming, S. M. Awareness as inference in a higher-order state space. Neuroscience of consciousness 2020, niz020 (2020)
work page 2020
-
[8]
Consciousness, metacognition, & perceptual reality monitoring
Lau, H. Consciousness, metacognition, & perceptual reality monitoring. PsyArxiv (2019)
work page 2019
-
[9]
The Perceptual Reality Monitoring Theory (1st edition)
Michel, M. The Perceptual Reality Monitoring Theory (1st edition). In Herzog, M., Schurger, A. & Doerig, A. (eds.) Scientific Theories of Consciousness: The Grand Tour (Cambridge University Press, 2024)
work page 2024
-
[10]
Meyniel, F., Schlunegger, D. & Dehaene, S. The sense of confidence during probabilistic learning: A normative account. PLoS Computational Biology 11, e1004305 (2015). URL https://journals. plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1004305
-
[11]
Meyniel, F., Sigman, M. & Mainen, Z. F. Confidence as a metacognitive source of learning speed. Nat. Rev. Neurosci. 16, 721–729 (2015)
work page 2015
-
[12]
Response-based outcome predictions and confidence regulate feedback processing and learning
Fr¨ omer, R.et al. Response-based outcome predictions and confidence regulate feedback processing and learning. eLife 10, e62825 (2021). URL https://elifesciences.org/articles/62825
work page 2021
-
[13]
Hainguerlot, M., Vergnaud, J.-C. & de Gardelle, V. Metacognitive ability predicts learning cue- stimulus associations in the absence of external feedback. Scientific Reports 8, 5602 (2018). URL https://www.nature.com/articles/s41598-018-23936-9 . 21
work page 2018
-
[14]
Meyniel, F. & Dehaene, S. Brain networks for confidence weighting and hierarchical inference during probabilistic learning. Proceedings of the National Academy of Sciences 114, E3859–E3868 (2017). URL https://www.pnas.org/doi/10.1073/pnas.1615773114
-
[15]
Guggenmos, M., Wilbertz, G., Hebart, M. N. & Sterzer, P. Mesolimbic confidence signals guide perceptual learning in the absence of external feedback. eLife 5, e13388 (2016)
work page 2016
-
[16]
Reverse engineering of metacognition
Guggenmos, M. Reverse engineering of metacognition. eLife 11, e75420 (2022). URL https:// elifesciences.org/articles/75420
work page 2022
-
[17]
Peters, M. A. Introspective psychophysics for the study of subjective experience. Cerebral Cortex 35, 49–57 (2025)
work page 2025
-
[18]
Shekhar, M. & Rahnev, D. How do humans give confidence? a comprehensive comparison of process models of perceptual metacognition. Journal of Experimental Psychology: General 153, 656 (2024)
work page 2024
-
[19]
Boundy-Singer, Z. M., Ziemba, C. M. & Goris, R. L. T. Confidence reflects a noisy decision reliability estimate. Nature Human Behaviour 7, 142–154 (2023). URL https://www.nature.com/articles/ s41562-022-01464-x
work page 2023
-
[20]
Confidence forced-choice and other metaperceptual tasks
Mamassian, P. Confidence forced-choice and other metaperceptual tasks. Perception 47, 1023–1035 (2018)
work page 2018
-
[21]
Mamassian, P. & de Gardelle, V. Modeling perceptual confidence and the confidence forced-choice paradigm. Psychol. Rev. 129, 976–998 (2022)
work page 2022
-
[22]
Mamassian, P. & de Gardelle, V. The confidence-noise confidence-boost (cncb) model of confi- dence rating data. bioRxiv (2024). URL https://www.biorxiv.org/content/10.1101/2024.09. 04.611165v2
-
[23]
Peters, M. A. et al. Perceptual confidence neglects decision-incongruent evidence in the brain. Nature human behaviour 1, 0139 (2017)
work page 2017
- [24]
-
[25]
Winter, C. J. & Peters, M. A. Variance misperception under skewed empirical noise statistics explains overconfidence in the visual periphery. Attention, Perception, & Psychophysics 84, 161–178 (2022). 22
work page 2022
-
[26]
Knill, D. C. & Richards, W. (eds.) Perception as Bayesian Inference (Cambridge University Press, 1996). URL https://www.cambridge.org/core/books/perception-as-bayesian-inference/ 0442F577F5E4CD874FA6819978574C8F
work page 1996
-
[27]
Bang, D. & Fleming, S. M. Distinct encoding of decision confidence in human medial prefrontal cortex. Proceedings of the National Academy of Sciences 115, 6082–6087 (2018). URL https://doi.org/10. 1073/pnas.1800795115
work page 2018
-
[28]
Cortese, A., Amano, K., Koizumi, A., Lau, H. & Kawato, M. Decoded fmri neurofeedback can induce bidirectional confidence changes within single participants. NeuroImage 149, 323–337 (2017)
work page 2017
-
[29]
Kiani, R. & Shadlen, M. N. Representation of confidence associated with a decision by neurons in the parietal cortex. Science (2009)
work page 2009
-
[30]
Odegaard, B. et al. Superior colliculus neuronal ensemble activity signals optimal rather than subjective confidence. Proceedings of the National Academy of Sciences 115, E1588–E1597 (2018). URL https: //www.pnas.org/doi/abs/10.1073/pnas.1711628115
-
[31]
Walker, E. Y. et al. Studying the neural representations of uncertainty. Nat. Neurosci. 26, 1857–1867 (2023)
work page 2023
-
[32]
Peters, M. A. K. Towards characterizing the canonical computations generating phenomenal experi- ence. Neurosci. Biobehav. Rev. 142, 104903 (2022)
work page 2022
-
[33]
Ma, W. J., Beck, J. M., Latham, P. E. & Pouget, A. Bayesian inference with probabilistic population codes. Nat. Neurosci. 9, 1432–1438 (2006)
work page 2006
-
[34]
Ma, W. J. & Pouget, A. Population codes, correlations, and coding. In Gazzaniga, M. S. (ed.) The Cognitive Neurosciences, 135–144 (MIT Press, 2009), 4th edn
work page 2009
-
[35]
van Bergen, R. S. & Jehee, J. F. M. Tafkap: An improved method for probabilistic decoding of cortical activity. bioRxiv (2021)
work page 2021
- [36]
-
[37]
Prince, J. S. et al. Improving the accuracy of single-trial fmri response estimates using glmsingle. Elife 11, e77599 (2022)
work page 2022
-
[38]
LaConte, S. M. Decoding fmri brain states in real-time. Neuroimage 56, 440–454 (2011). 23
work page 2011
-
[39]
Watanabe, T., Sasaki, Y., Shibata, K. & Kawato, M. Advances in fmri real-time neurofeedback. Trends in cognitive sciences 21, 997–1010 (2017)
work page 2017
-
[40]
Gottlieb, J., Oudeyer, P.-Y., Lopes, M. & Baranes, A. Information-seeking, curiosity, and attention: computational and neural mechanisms. Trends in Cognitive Sciences 17, 585–593 (2013)
work page 2013
-
[41]
Gottlieb, J. & Oudeyer, P.-Y. Towards a neuroscience of active sampling and curiosity. Nature Reviews Neuroscience 19, 758–770 (2018)
work page 2018
-
[42]
Cortese, A., Lau, H. & Kawato, M. Unconscious reinforcement learning of hidden brain states sup- ported by confidence. Nature Communications 11, 4429 (2020). URL https://www.nature.com/ articles/s41467-020-17828-8
work page 2020
-
[43]
Cross, L., Cockburn, J., Yue, Y. & O’Doherty, J. Using deep reinforcement learning to reveal how the brain encodes abstract state-space representations in high-dimensional environments. Neuron 109, 724–738.e7 (2021)
work page 2021
- [44]
-
[45]
Nunez-Elizalde, A. O., Huth, A. G. & Gallant, J. L. Voxelwise encoding models with non-spherical multivariate normal priors. NeuroImage 197, 482–492 (2019)
work page 2019
-
[46]
Nishimoto, S. et al. Reconstructing visual experiences from brain activity evoked by natural movies. Current Biology 21, 1641–1646 (2011)
work page 2011
-
[47]
Yamins, D. L. K. et al. Performance-optimized hierarchical models predict neural responses in higher visual cortex. Proceedings of the National Academy of Sciences 111, 8619–8624 (2014). URL https: //www.pnas.org/doi/10.1073/pnas.1403112111
-
[48]
Cortese, A. et al. The decnef collection, fmri data from closed-loop decoded neurofeedback experiments. Scientific Data 8, 69 (2021)
work page 2021
-
[49]
Azimi Azrari, H. & Peters, M. A. Diffusion models and reinforcement learning: Novel pathways to modeling decoded fmri neurofeedback. Proceedings of the Cognitive Computational Neuroscience Meeting (2024)
work page 2024
-
[50]
Azimi Asrari, H. & Peters, M. A. K. Diffusion models and reinforcement learning: Novel pathways to modeling decoded fmri neurofeedback. Conference on Cognitive Computational Neuroscience (CCN) (2024). 24
work page 2024
-
[51]
Wang, C., Chen, J., Jiang, H. & other authors. Diffusion-driven policy optimization. In International Conference on Learning Representations (2023)
work page 2023
-
[52]
Training Diffusion Models with Reinforcement Learning
Black, K., Janner, M., Du, Y., Kostrikov, I. & Levine, S. Training diffusion models with reinforcement learning. arXiv preprint arXiv:2305.13301 (2023)
work page internal anchor Pith review Pith/arXiv arXiv 2023
-
[53]
Shibata, K., Watanabe, T., Kawato, M. & Sasaki, Y. Differential activation patterns in the same brain region led to opposite emotional states. PLOS Biology (2016)
work page 2016
-
[54]
Bishop, C. M. Pattern Recognition and Machine Learning (Springer, 2006)
work page 2006
-
[55]
Cunningham, J. P. & Yu, B. M. Dimensionality reduction for large-scale neural recordings. Nature neuroscience 17, 1500–1509 (2014)
work page 2014
-
[56]
Jazayeri, M. & Ostojic, S. Interpreting neural computations by examining intrinsic and embedding dimensionality of neural activity. Current opinion in neurobiology 70, 113–120 (2021)
work page 2021
-
[57]
Pang, R., Lansdell, B. J. & Fairhall, A. L. Dimensionality reduction in neuroscience. Current Biology 26, R656–R660 (2016)
work page 2016
-
[58]
On lines and planes of closest fit to systems of points in space
Pearson, K. On lines and planes of closest fit to systems of points in space. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science 2, 559–572 (1901)
work page 1901
- [59]
- [60]
-
[61]
Attention, learning, and the value of information
Gottlieb, J. Attention, learning, and the value of information. Neuron 76, 281–295 (2012). URL https://pubmed.ncbi.nlm.nih.gov/23083732/
-
[62]
Jiwa, M., Rothkopf, C. & Gottlieb, J. Generating saccades for reducing uncertainty: Cognitive and sensorimotor trade-offs. Journal of Vision 24 (2024). URL https://doi.org/10.1167/jov.24.10. 908
-
[63]
Mobbs, D., Trimmer, P. C., Blumstein, D. T. & Dayan, P. Foraging for foundations in decision neuroscience: insights from ethology. Nature Reviews Neuroscience 19, 419–427 (2018). URL https: //www.nature.com/articles/s41583-018-0010-7 . 25
work page 2018
-
[64]
The central role of uncertainty reduction in determining behaviour
Inglis, I. The central role of uncertainty reduction in determining behaviour. Behaviour 137, 1567–1599 (2000). URL https://brill.com/view/journals/beh/137/12/article-p1567_1.xml
work page 2000
-
[65]
Shibata, K. et al. Toward a comprehensive understanding of the neural mechanisms of decoded neu- rofeedback. Neuroscience & Biobehavioral Reviews (2021)
work page 2021
-
[66]
Taschereau-Dumouchel, V., Cushing, C. A. & Lau, H. Real-time functional mri in the treatment of mental health disorders. Annual review of clinical psychology 18, 125–154 (2022)
work page 2022
-
[67]
Taschereau-Dumouchel, V. et al. Towards an unconscious neural reinforcement intervention for com- mon fears. Proceedings of the National Academy of Sciences 115, 3470–3475 (2018)
work page 2018
-
[68]
Pospisil, D. A. & Pillow, J. W. Revisiting the high-dimensional geometry of population responses in visual cortex. bioRxiv (2024). URL https://doi.org/10.1101/2024.02.16.580726
-
[69]
Stringer, C., Pachitariu, M., Steinmetz, N., Carandini, M. & Harris, K. D. High-dimensional geometry of population responses in visual cortex. Nature 571, 361–365 (2019). URL https://www.nature. com/articles/s41586-019-1346-5
work page 2019
- [70]
- [71]
-
[72]
Deep Unsupervised Learning using Nonequilibrium Thermodynamics
Sohl-Dickstein, J., Weiss, E., Maheswaranathan, N. & Ganguli, S. Deep unsupervised learning using nonequilibrium thermodynamics. arXiv preprint arXiv:1503.03585 (2015)
work page internal anchor Pith review Pith/arXiv arXiv 2015
-
[73]
Proximal Policy Optimization Algorithms
Schulman, J., Wolski, F., Dhariwal, P., Radford, A. & Klimov, O. Proximal policy optimization algorithms. arXiv preprint arXiv:1707.06347 (2017)
work page internal anchor Pith review Pith/arXiv arXiv 2017
-
[74]
Williams, R. J. Simple statistical gradient-following algorithms for connectionist reinforcement learn- ing. Machine learning 8, 229–256 (1992)
work page 1992
-
[75]
Schneider, S., Lee, J. H. & Mathis, M. W. Learnable latent embeddings for joint behavioural and neural analysis. Nature 617, 360–368 (2023). URL https://www.nature.com/articles/ s41586-023-06031-6 . 26
work page 2023
-
[76]
Steinmetz, N. A. et al. Neuropixels 2.0: A miniaturized high-density probe for stable, long-term brain recordings. Science 372, eabf4588 (2021). URL https://www.science.org/doi/abs/10.1126/ science.abf4588
work page 2021
-
[77]
V´ azquez-Garc´ ıa, C., Mart´ ınez-Murcia, F., Segovia Rom´ an, F. & G´ orriz, J. M. A review of latent representation models in neuroimaging. arXiv preprint arXiv:2412.19844 (2024). URL https:// arxiv.org/abs/2412.19844
-
[78]
Favela, L. H. & Machery, E. Investigating the concept of representation in the neural and psychological sciences. Frontiers in Psychology 14, 1165622 (2023)
work page 2023
-
[79]
Favela, L. H. & Machery, E. Contextualizing, eliminating, or glossing: What to do with unclear scientific concepts like representation. Mind & Language (2025)
work page 2025
-
[80]
Neural representations: A normative account
Machery, E. Neural representations: A normative account. Mind & Language (2025). URL https: //onlinelibrary.wiley.com/doi/10.1111/mila.12531
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