Risk-responsive orbitofrontal neurons track acquired salience.
Decision making is impacted by uncertainty and risk (i.e., variance). Activity in the orbitofrontal cortex, an area implicated in decision making, covaries with these quantities. However, this activity could reflect the heightened salience of situations in which multiple outcomes-reward and reward omission-are expected. To resolve these accounts, rats were trained to respond to cues predicting 100%, 67%, 33%, or 0% reward. Consistent with prior reports, some orbitofrontal neurons fired differently in anticipation of uncertain (33% and 67%) versus certain (100% and 0%) reward. However, over 90% of these neurons also fired differently prior to 100% versus 0% reward (or baseline) or prior to 33% versus 67% reward. These responses are inconsistent with risk but fit well with the representation of acquired salience linked to the sum of cue-outcome and cue-no-outcome associative strengths. These results expand our understanding of how the orbitofrontal cortex might regulate learning and behavior.
Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn Street, HSF-2 S251, Baltimore, MD 21201, USA. seri0722@gmail.com
Masaaki
M
Ogawa
Matthijs A A
MA
van der Meer
Guillem R
GR
Esber
Domenic H
DH
Cerri
Thomas A
TA
Stalnaker
Geoffrey
G
Schoenbaum
D000818:Animals; D003463:Cues; D003657:Decision Making / Q000502:physiology*; D005625:Frontal Lobe / Q000166:cytology / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D012201:Reward; D012307:Risk Factors