Publications

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Selected Publications

The 'neat' and 'messy' in task-dependent neural geometry and computation
Xue C, Okazawa G
Trends in Neurosciences 49:522–535 (2026)
This review examines how primate brain task-switching involves both "neat" structured, interpretable neural representations and "messy" features like the encoding of task-irrelevant variables, pointing toward future work on brain-constrained theories and data-driven network models.
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A battery of image classification challenges reveals shared and distinct object categorization behavior across monkeys, humans, and deep networks
Zhang H, Zheng Z, Hu J, Wang Q, Xu M, Zhou Z, Li Z, Okazawa G
eLife 111725.1 (2026)
Macaque monkeys rapidly learn to classify natural images across more than 10 binary classification rules (animate/inanimate, natural/man-made, mammal/non-mammal, etc.), generalize to new images, and show error patterns consistent with human judgments — but correlate more strongly with language-free DNNs than language-informed ones.
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Limitation of switching sensory information flow in flexible perceptual decision making
Luo T, Xu M, Zheng Z, Okazawa G
Nature Communications 16:172 (2025)
Immediately after switching a task rule, there is a brief reduction in the efficiency of sensory evidence processing, pinpointing a computational bottleneck in flexible decision-making circuits.
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Representational geometry of perceptual decisions in the monkey parietal cortex
Okazawa G, Hatch CE, Mancoo A, Machens CK, Kiani R
Cell 184:3748–3761 (2021)
Sensory evidence for perceptual decisions is encoded along a non-linear, task-dependent manifold in parietal neural state space — not as the average firing rate of individual neurons as previously assumed.
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Full Publication List

Preprints

1.
A battery of image classification challenges reveals shared and distinct object categorization behavior across monkeys, humans, and deep networks
Zhang H, Zheng Z, Hu J, Wang Q, Xu M, Zhou Z, Li Z, Okazawa G (2026)
eLife 111725.1
Paper PDF
2.
Inferotemporal cortex encodes formation and termination of perceptual decisions
Okazawa G, Kiani R (2025)
bioRxiv
Preprint PDF

Peer-reviewed Articles

1.
The 'neat' and 'messy' in task-dependent neural geometry and computation
Xue C, Okazawa G (2026)
Trends in Neurosciences 49:522–535 (2026)
Paper PDF
2.
Spatiotemporal evidence accumulation through saccadic sampling for object recognition
Zheng Z, Hu J, Okazawa G (2025)
Journal of Neuroscience 45(44): e2453242025
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3.
Single-neuron projectomes of macaque prefrontal cortex reveal refined axon targeting and arborization
Gou L, Wang Y, …, Yan J (2025)
Cell 188(14):3806–3822
Paper PDF
4.
Limitation of switching sensory information flow in flexible perceptual decision making
Luo T, Xu M, Zheng Z, Okazawa G (2025)
Nature Communications 16:172
Paper PDF
5.
Decision uncertainty as a context for motor memory
Ogasa K, Yokoi A, Okazawa G, Nishigaki M, Hirashima M, Hagura N (2024)
Nature Human Behaviour
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6.
Neural mechanisms that make perceptual decisions flexible
Okazawa G, Kiani R (2023)
Annual Review of Physiology 85:191–215
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7.
Representational geometry of perceptual decisions in the monkey parietal cortex
Okazawa G, Hatch CE, Mancoo A, Machens CK, Kiani R (2021)
Cell 184:3748–3761
Paper PDF Code
8.
Linear integration of sensory evidence over space and time underlies face categorization
Okazawa G, Sha L, Kiani R (2021)
Journal of Neuroscience 41(37):7876–7893
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9.
Designing and Interpreting Psychophysical Investigations of Cognition
Waskom ML, Okazawa G, Kiani R (2019)
Neuron 104(1):100–112
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10.
Psychophysical reverse correlation reflects both sensory and decision-making processes
Okazawa G, Sha L, Purcell BA, Kiani R (2018)
Nature Communications 9:3479
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11.
Gradual development of visual texture-selective properties between macaque areas V2 and V4
Okazawa G, Tajima S, Komatsu H (2016)
Cerebral Cortex 27(10):4867–4880
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12.
Image statistics underlying natural texture selectivity of neurons in macaque V4
Okazawa G, Tajima S, Komatsu H (2015)
Proc Natl Acad Sci USA 112(4):E351–E360
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13.
Effects of luminance contrast on the color selectivity of neurons in macaque V4 and IT
Namima T, Yasuda M, Banno T, Okazawa G, Komatsu H (2014)
Journal of Neuroscience 34(45):14934–47
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14.
Representation of the material properties of objects in the visual cortex of nonhuman primates
Goda N, Tachibana A, Okazawa G, Komatsu H (2014)
Journal of Neuroscience 34(7):2660–73
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15.
Color vision test for dichromatic and trichromatic macaque monkeys
Koida K, Yokoi I, Okazawa G, Mikami A, Widayati KA, Miyachi S, Komatsu H (2013)
Journal of Vision 13(13):1, 1–15
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16.
Selective responses to specular surfaces in the macaque visual cortex revealed by fMRI
Okazawa G, Goda N, Komatsu H (2012)
NeuroImage 63(3):1321–33
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17.
Categorical properties of the color term "GOLD"
Okazawa G, Koida K, Komatsu H (2011)
Journal of Vision 11(8):4, 1–19
Paper PDF

Conference Abstracts

  1. Li Z, Wu J, Zhou Z, Okazawa G (2026) Many-to-one transformation from object identities to action plans in the primate prefrontal cortex. Cosyne (Lisbon, Portugal)
  2. Luo T*, Wu J*, Okazawa G (2026) Convergence of prefrontal decision-making dynamics during learning to generalize perceptual tasks. Cosyne (Lisbon, Portugal) (*equal contribution)
  3. Hu J, Xu M, Okazawa G (2026) Reshaping sensory neuron-behavior correlation through neurofeedback training. Cosyne (Lisbon, Portugal)
  4. Li Z, Wu J, Zhou Z, Okazawa G (2025) Many-to-one transformation from object identities to action plans in the primate prefrontal cortex. 18th Annual Meeting of Chinese Neuroscience Society (Xi'an, China)
  5. Luo T*, Wu J*, Okazawa G (2025) Prefrontal cortex represents the convergence on shared decision-making processes for similar perceptual tasks. 18th Annual Meeting of Chinese Neuroscience Society (Xi'an, China) (*equal contribution)
  6. Hu J, Xu M, Okazawa G (2025) Closed-loop training of monkeys that strengthens the link between visual cortical activity and behavior. 49th Annual Meeting of the Japan Neuroscience Society (Niigata, Japan)
  7. Wu J*, Luo T*, Okazawa G (2024) Graded encoding of task context and its generalization in prefrontal cortex during face categorization. Society for Neuroscience 2024 (Chicago, USA) (*equal contribution)
  8. Zhang H, Zheng Z, Hu J, Wang Q, Xu M, Li Z, Okazawa G (2024) Rapid learning of visual categorization of abstract object concepts by macaque monkeys. Society for Neuroscience 2024 (Chicago, USA)
  9. Okazawa G, Kiani R (2024) Inferotemporal neurons represent decision formation during face categorization. Society for Neuroscience 2024 (Chicago, USA)
  10. Wu J*, Luo T*, Okazawa G (2024) Graded encoding and generalization of task context for perceptual tasks in prefrontal cortex. 17th Annual Meeting of Chinese Neuroscience Society (Suzhou, China) (*equal contribution)
  11. Hu J, Xu M, Okazawa G (2024) Linking neural responses in area V4 and perceptual reports through neurofeedback training of macaque monkeys. 17th Annual Meeting of Chinese Neuroscience Society (Suzhou, China)
  12. Zhang H, Zheng Z, Hu J, Wang Q, Xu M, Li Z, Okazawa G (2024) Monkeys rapidly learn visual object categorization based on abstract concepts. 17th Annual Meeting of Chinese Neuroscience Society (Suzhou, China)
  13. Zhang H, Zheng Z, Hu J, Wang Q, Li Z, Xu M, Okazawa G (2024) Novel binary categorization task to study high-level visual object classification in macaque monkeys. Cognitive Computational Neuroscience (CCN) 2024 (Boston, USA)
  14. Luo T, Zheng Z, Xu M, Okazawa G (2024) Limited efficiency in switching relevant sensory dimensions during flexible perceptual decision making. 48th Annual Meeting of the Japan Neuroscience Society (Fukuoka, Japan)
  15. Luo T, Zheng Z, Xu M, Okazawa G (2023) Reduced sensory processing efficiency after switching relevant sensory dimensions in flexible perceptual decision making. Society for Neuroscience 2023 (Washington DC, USA)
  16. Zheng Z, Hu J, Okazawa G (2023) Spatiotemporal integration of sensory evidence during saccadic sampling for face and object categorization. Society for Neuroscience 2023 (Washington DC, USA)
  17. Zhang Y, Shen X, Okazawa G, Min B (2023) Elucidating the circuit mechanism underlying task-dependent representational geometry of perceptual decisions. Society for Neuroscience 2023 (Washington DC, USA)
  18. Zheng Z, Hu J, Okazawa G (2023) Global spatiotemporal integration of sensory evidence during saccadic sampling in face categorization. 16th Annual Meeting of Chinese Neuroscience Society (Zhuhai, China)
  19. Luo T, Zheng Z, Xu M, Okazawa G (2022) Modulation of decision-making processes after switching task rule during face categorization. 15th Annual Meeting of Chinese Neuroscience Society (Suzhou, China)
  20. Okazawa G, Hatch CE, Mancoo A, Machens CK, Kiani R (2021) What do distinct parietal neural responses for face and motion discrimination tasks reveal about the mechanisms of the decision-making process? Vision Science Society (VSS) 2021 (online)
  21. Okazawa G, Hatch CE, Mancoo A, Machens CK, Kiani R (2021) The geometry of the representation of decision variable and stimulus difficulty in the parietal cortex. COSYNE 2021 (online)
  22. Okazawa G, Hatch CE, Mancoo A, Machens CK, Kiani R (2020) The geometry of the representation of decision variable and stimulus difficulty in the macaque parietal cortex. 43rd Annual Meeting of the Japan Neuroscience Society (Kobe, Japan)
  23. Okazawa G, Kiani R (2019) Distinct representations of decision variable and task difficulty in the monkey lateral intraparietal cortex. Society for Neuroscience 49th Annual Meeting (Chicago, USA)
  24. Okazawa G, Kiani R (2019) Task difficulty has a distinct representation from the decision variable in the monkey parietal cortex. 9th International Workshop Statistical Analysis of Neuronal Data (SAND9) (Pittsburgh, PA)
  25. Okazawa G, Kiani R (2018) Representation of the dynamics of decision-making process in the lateral intraparietal cortex during face discrimination. Society for Neuroscience 48th Annual Meeting (San Diego, USA)
  26. Okazawa G, Sha L, Kiani R (2017) Psychophysical reverse correlation reflects both sensory filters and the decision-making process [refereed]. COSYNE 2017 (Salt Lake City, USA)
  27. Okazawa G, Sha L, Kiani R (2016) Face discrimination under uncertainty depends on linear integration of visual features over space and time. Society for Neuroscience 46th Annual Meeting (San Diego, USA)
  28. Okazawa G, Tajima S, Komatsu H (2015) Comparison of natural texture selectivity and underlying image-statistics representation between macaque V2 and V4. 38th Annual Meeting of the Japan Neuroscience Society (Kobe, Japan)
  29. Okazawa G, Tajima S, Komatsu H (2014) Image statistics explaining natural texture selectivity in macaque V4. 37th Annual Meeting of the Japan Neuroscience Society (Yokohama, Japan)
  30. Okazawa G, Tajima S, Komatsu H (2013) Natural texture selectivity of macaque V4 neurons examined by adaptive sampling. Society for Neuroscience 43rd Annual Meeting (San Diego, USA)
  31. Okazawa G, Tajima S, Komatsu H (2013) Image features determining texture selectivity of macaque V4 neurons revealed by adaptive sampling. 36th Annual Meeting of the Japan Neuroscience Society (Kyoto, Japan)
  32. Okazawa G, Komatsu H (2013) Image statistics for golden appearance of a painting by a Japanese edo-era artist Jakuchu Ito [refereed]. 4th Computational Color Imaging Workshop (CCIW 2013) (Chiba, Japan)
  33. Okazawa G, Goda N, Komatsu H (2012) Localizing regions activated by surface gloss in macaque visual cortex by fMRI. 8th Asia-Pacific Conference on Vision (Incheon, Korea)
  34. Okazawa G, Goda N, Komatsu H (2011) Cortical regions activated by surface gloss in the macaque visual cortex localized using fMRI. Society for Neuroscience 41st Annual Meeting (Washington DC, USA)