Fast Sequences of Non-spatial State Representations in Humans.
Fast internally generated sequences of neural representations are suggested to support learning and online planning. However, these sequences have only been studied in the context of spatial tasks and never in humans. Here, we recorded magnetoencephalography (MEG) while human subjects performed a novel non-spatial reasoning task. The task required selecting paths through a set of six visual objects. We trained pattern classifiers on the MEG activity elicited by direct presentation of the visual objects alone and tested these classifiers on activity recorded during periods when no object was presented. During these object-free periods, the brain spontaneously visited representations of approximately four objects in fast sequences lasting on the order of 120 ms. These sequences followed backward trajectories along the permissible paths in the task. Thus, spontaneous fast sequential representation of states can be measured non-invasively in humans, and these sequences may be a fundamental feature of neural computation across tasks.
Max Planck-UCL Centre for Computational Psychiatry and Ageing Research, University College London, London WC1B 5EH, UK; Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3BG, UK. Electronic address: zebkurthnelson@gmail.com.
Zeb
Z
Kurth-Nelson
Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3BG, UK.
Marcos
M
Economides
Max Planck-UCL Centre for Computational Psychiatry and Ageing Research, University College London, London WC1B 5EH, UK; Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3BG, UK.
Raymond J
RJ
Dolan
Gatsby Computational Neuroscience Unit, University College London, London W1T 4JG, UK.
Peter
P
Dayan
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000502:physiology*; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D015225:Magnetoencephalography / Q000379:methods; D008297:Male; D013647:Task Performance and Analysis; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult