Dissociating neural learning signals in human sign- and goal-trackers

Nat Hum Behav. 2020 Feb;4(2):201-214. doi: 10.1038/s41562-019-0765-5. Epub 2019 Nov 11.


Individuals differ in how they learn from experience. In Pavlovian conditioning models, where cues predict reinforcer delivery at a different goal location, some animals-called sign-trackers-come to approach the cue, whereas others, called goal-trackers, approach the goal. In sign-trackers, model-free phasic dopaminergic reward-prediction errors underlie learning, which renders stimuli 'wanted'. Goal-trackers do not rely on dopamine for learning and are thought to use model-based learning. We demonstrate this double dissociation in 129 male humans using eye-tracking, pupillometry and functional magnetic resonance imaging informed by computational models of sign- and goal-tracking. We show that sign-trackers exhibit a neural reward prediction error signal that is not detectable in goal-trackers. Model-free value only guides gaze and pupil dilation in sign-trackers. Goal-trackers instead exhibit a stronger model-based neural state prediction error signal. This model-based construct determines gaze and pupil dilation more in goal-trackers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Amygdala / diagnostic imaging
  • Amygdala / physiology
  • Anticipation, Psychological / physiology
  • Basal Ganglia / diagnostic imaging
  • Basal Ganglia / physiology*
  • Brain Mapping*
  • Cerebral Cortex / diagnostic imaging
  • Cerebral Cortex / physiology*
  • Conditioning, Classical / physiology*
  • Eye Movement Measurements
  • Fixation, Ocular / physiology
  • Goals*
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Models, Biological*
  • Nucleus Accumbens / diagnostic imaging
  • Nucleus Accumbens / physiology
  • Parietal Lobe / diagnostic imaging
  • Parietal Lobe / physiology
  • Prefrontal Cortex / diagnostic imaging
  • Prefrontal Cortex / physiology
  • Pupil / physiology
  • Putamen / diagnostic imaging
  • Putamen / physiology
  • Reward*
  • Young Adult