Center for Neuroscience Graduate Program, University of Pittsburg, Pittsburg, United States
Heather M Wied
Program in Neuroscience, University of Maryland School of Medicine, Baltimore, United States
Tzu-Lan Liu
Department of Psychology, National Taiwan University, Taipei, Taiwan
Thomas A Stalnaker
Intramural Research Program, National Institute on Drug Abuse, Baltimore, United States
Joshua L Jones
Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, United States
Jason Trageser
Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, United States
Geoffrey Schoenbaum
Intramural Research Program, National Institute on Drug Abuse, Baltimore, United States; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, United States; Department of Neuroscience, Johns Hopkins University, Baltimore, United States
The orbitofrontal cortex (OFC) has been described as signaling outcome expectancies or value. Evidence for the latter comes from the studies showing that neural signals in the OFC correlate with value across features. Yet features can co-vary with value, and individual units may participate in multiple ensembles coding different features. Here we used unblocking to test whether OFC neurons would respond to a predictive cue signaling a ‘valueless’ change in outcome flavor. Neurons were recorded as the rats learned about cues that signaled either an increase in reward number or a valueless change in flavor. We found that OFC neurons acquired responses to both predictive cues. This activity exceeded that exhibited to a ‘blocked’ cue and was correlated with activity to the actual outcome. These results show that OFC neurons fire to cues with no value independent of what can be inferred through features of the predicted outcome.
