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Covert skill learning in a cortical-basal ganglia circuit

Nature volume 486, pages 251255 (14 June 2012) | Download Citation


We learn complex skills such as speech and dance through a gradual process of trial and error. Cortical-basal ganglia circuits have an important yet unresolved function in this trial-and-error skill learning1; influential ‘actor–critic’ models propose that basal ganglia circuits generate a variety of behaviours during training and learn to implement the successful behaviours in their repertoire2,3. Here we show that the anterior forebrain pathway (AFP), a cortical-basal ganglia circuit4, contributes to skill learning even when it does not contribute to such ‘exploratory’ variation in behavioural performance during training. Blocking the output of the AFP while training Bengalese finches to modify their songs prevented the gradual improvement that normally occurs in this complex skill during training. However, unblocking the output of the AFP after training caused an immediate transition from naive performance to excellent performance, indicating that the AFP covertly gained the ability to implement learned skill performance without contributing to skill practice. In contrast, inactivating the output nucleus of the AFP during training completely prevented learning, indicating that learning requires activity within the AFP during training. Our results suggest a revised model of skill learning: basal ganglia circuits can monitor the consequences of behavioural variation produced by other brain regions and then direct those brain regions to implement more successful behaviours. The ability of the AFP to identify successful performances generated by other brain regions indicates that basal ganglia circuits receive a detailed efference copy of premotor activity in those regions. The capacity of the AFP to implement successful performances that were initially produced by other brain regions indicates precise functional connections between basal ganglia circuits and the motor regions that directly control performance.

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We thank L. Frank, A. Doupe, M. Stryker and D. Mets for discussion and comments on the manuscript. This work was supported by National Institutes of Health grant NIDCD R01 and National Institute of Mental Health grant P50. J.D.C. and T.L.W. were supported by National Science Foundation graduate fellowships.

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  1. W. M. Keck Center for Integrative Neuroscience, Department of Physiology, and the Neuroscience Graduate Program, University of California, San Francisco, California 94143, USA

    • Jonathan D. Charlesworth
    • , Timothy L. Warren
    •  & Michael S. Brainard


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J.D.C., T.L.W. and M.S.B. designed the experiments. J.D.C. performed the experiments with APV in RA, and T.L.W. performed the experiments with LMAN inactivations. J.D.C. analysed the data. J.D.C. prepared the manuscript, with input from the other authors.

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The authors declare no competing financial interests.

Corresponding author

Correspondence to Jonathan D. Charlesworth.

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