Article

Mixed selectivity morphs population codes in prefrontal cortex

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Abstract

The prefrontal cortex maintains working memory information in the presence of distracting stimuli. It has long been thought that sustained activity in individual neurons or groups of neurons was responsible for maintaining information in the form of a persistent, stable code. Here we show that, upon the presentation of a distractor, information in the lateral prefrontal cortex was reorganized into a different pattern of activity to create a morphed stable code without losing information. In contrast, the code in the frontal eye fields persisted across different delay periods but exhibited substantial instability and information loss after the presentation of a distractor. We found that neurons with mixed-selective responses were necessary and sufficient for the morphing of code and that these neurons were more abundant in the lateral prefrontal cortex than the frontal eye fields. This suggests that mixed selectivity provides populations with code-morphing capability, a property that may underlie cognitive flexibility.

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Acknowledgements

We thank A. Tan for comments and suggestions on an earlier version of this manuscript. We thank C. Lim, M.N. Lynn, L. Chan, K. Chng, and E.M. Peña for help with animal training, surgery, and care. This work was supported by startup grants from the Ministry of Education Tier 1 Academic Research Fund and SINAPSE to C.L., a grant from the NUS-NUHS Memory Networks Program to S.-C.Y., and a grant from the Ministry of Education Tier 2 Academic Research Fund to C.L. and S.-C.Y. (MOE2016-T2-2-117).

Author information

Author notes

    • Aishwarya Parthasarathy

    Present address: Institute of Molecular and Cell Biology, A*STAR, Singapore, Singapore

  1. Camilo Libedinsky and Shih-Cheng Yen contributed equally to this work.

Affiliations

  1. NUS Graduate School of Integrative Science and Engineering, National University of Singapore (NUS), Singapore, Singapore

    • Aishwarya Parthasarathy
    •  & Shih-Cheng Yen
  2. Department of Electrical and Computer Engineering, NUS, Singapore, Singapore

    • Roger Herikstad
    • , Jit Hon Bong
    •  & Shih-Cheng Yen
  3. Department of Psychology, NUS, Singapore, Singapore

    • Felipe Salvador Medina
    •  & Camilo Libedinsky
  4. Singapore Institute for Neurotechnology, NUS, Singapore, Singapore

    • Camilo Libedinsky
  5. Institute of Molecular and Cell Biology, A*STAR, Singapore, Singapore

    • Camilo Libedinsky

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Contributions

C.L., A.P., R.H., J.H.B., and S.-C.Y. designed the experiments. A.P., R.H., and J.H.B. collected behavioral and electrophysiological data. F.S.M. and A.P. performed the microstimulation verification experiments. A.P. and R.H. analyzed behavioral and electrophysiological data. S.-C.Y. and C.L. guided the data analysis. All authors discussed the results, and A.P., C.L., and S.-C.Y. wrote the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Camilo Libedinsky or Shih-Cheng Yen.

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