title: Neurons in the pigeon caudolateral nidopallium differentiate Pavlovian conditioned stimuli but not their associated reward value in a sign-tracking paradigm.
abstract: Animals exploit visual information to identify objects, form stimulus-reward associations, and prepare appropriate behavioral responses. The nidopallium caudolaterale (NCL), an associative region of the avian endbrain, contains neurons exhibiting prominent response modulation during presentation of reward-predicting visual stimuli, but it is unclear whether neural activity represents valuation signals, stimulus properties, or sensorimotor contingencies. To test the hypothesis that NCL neurons represent stimulus value, we subjected pigeons to a Pavlovian sign-tracking paradigm in which visual cues predicted rewards differing in magnitude (large vs. small) and delay to presentation (short vs. long). Subjects' strength of conditioned responding to visual cues reliably differentiated between predicted reward types and thus indexed valuation. The majority of NCL neurons discriminated between visual cues, with discriminability peaking shortly after stimulus onset and being maintained at lower levels throughout the stimulus presentation period. However, while some cells' firing rates correlated with reward value, such neurons were not more frequent than expected by chance. Instead, neurons formed discernible clusters which differed in their preferred visual cue. We propose that this activity pattern constitutes a prerequisite for using visual information in more complex situations e.g. requiring value-based choices.
authors.affiliation: Department of Biopsychology, Faculty of Psychology, Ruhr University, 44780 Bochum, Germany.
authors.forename: Nils
authors.initials: N
authors.lastname: Kasties
authors.affiliation: Department of Biopsychology, Faculty of Psychology, Ruhr University, 44780 Bochum, Germany.
authors.forename: Sarah
authors.initials: S
authors.lastname: Starosta
authors.affiliation: Department of Biopsychology, Faculty of Psychology, Ruhr University, 44780 Bochum, Germany.
authors.forename: Onur
authors.initials: O
authors.lastname: Güntürkün
authors.affiliation: Institute of Pathophysiology, University Medical Center of the Johannes Gutenberg University, 55128 Mainz, Germany.|Focus Program Translational Neurosciences, Johannes Gutenberg University, 55128 Mainz, Germany.
authors.forename: Maik C
authors.initials: MC
authors.lastname: Stüttgen
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D010856:Columbidae / Q000502:physiology*; D003214:Conditioning, Classical; D003463:Cues; D004193:Discrimination Learning; D055724:Electrophysiological Phenomena; D009474:Neurons / Q000166:cytology* / Q000502:physiology*; D010775:Photic Stimulation; D011930:Reaction Time; D012201:Reward; D009435:Synaptic Transmission; D013687:Telencephalon / Q000502:physiology*