Slow Drift of Neural Activity as a Signature of Impulsivity in Macaque Visual and Prefrontal Cortex

Neuron. 2020 Nov 11;108(3):551-567.e8. doi: 10.1016/j.neuron.2020.07.021. Epub 2020 Aug 17.


An animal's decision depends not only on incoming sensory evidence but also on its fluctuating internal state. This state embodies multiple cognitive factors, such as arousal and fatigue, but it is unclear how these factors influence the neural processes that encode sensory stimuli and form a decision. We discovered that, unprompted by task conditions, animals slowly shifted their likelihood of detecting stimulus changes over the timescale of tens of minutes. Neural population activity from visual area V4, as well as from prefrontal cortex, slowly drifted together with these behavioral fluctuations. We found that this slow drift, rather than altering the encoding of the sensory stimulus, acted as an impulsivity signal, overriding sensory evidence to dictate the final decision. Overall, this work uncovers an internal state embedded in population activity across multiple brain areas and sheds further light on how internal states contribute to the decision-making process.

Keywords: PFC; arousal; decision making; impulsivity; neural fluctuation; neural population; prefrontal cortex; slow drift; stimulus encoding; vision; visual area V4.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Attention / physiology*
  • Decision Making / physiology*
  • Impulsive Behavior / physiology
  • Macaca mulatta
  • Male
  • Neurons / physiology*
  • Prefrontal Cortex / physiology*
  • Visual Cortex / physiology*
  • Visual Perception / physiology