title: Experience-dependent adult cortical plasticity requires cognitive association between sensation and reward.
abstract: We tested the involvement of cognition in adult experience-dependent neuroplasticity using primate cortical implants. In a prior study, learning an operant sensory discrimination increased cortical excitability and target selectivity. Here, the prior task was separated into three behavioral phases. First, naive animals were exposed to stimulus-reward pairings from the prior study. These yoked animals did not have to discriminate to be rewarded and did not learn the discrimination. The plasticity observed in the prior study did not occur. Second, the animals were classically conditioned to discriminate the same stimuli in a simplified format. Learning was accompanied by increased sensory response strength and an increased range of sensory inputs eliciting responses. The third study recreated the original operant discrimination, and selectivity for task targets increased. These studies demonstrate that cognitive association between sensory stimuli and reinforcers accompanies adult experience-dependent cortical plasticity and suggest that selectivity in representation and action are linked.
authors.affiliation: Center for Synapses and Cognitive Neuroscience, Department of Neurology, Medical College of Georgia, Augusta, Georgia 30912, USA. dblake@mcg.edu
authors.forename: David T
authors.initials: DT
authors.lastname: Blake
authors.forename: Marc A
authors.initials: MA
authors.lastname: Heiser
authors.forename: Matthew
authors.initials: M
authors.lastname: Caywood
authors.forename: Michael M
authors.initials: MM
authors.lastname: Merzenich
mesh_terms: D000161:Acoustic Stimulation; D000200:Action Potentials / Q000502:physiology; D000367:Age Factors; D000375:Aging / Q000502:physiology; D000818:Animals; D001029:Aotus trivirgatus; D001303:Auditory Cortex / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology; D001522:Behavior, Animal / Q000502:physiology; D003071:Cognition / Q000502:physiology*; D003213:Conditioning, Psychological / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology*; D009483:Neuropsychological Tests; D012054:Reinforcement, Psychology; D012201:Reward; D012677:Sensation / Q000502:physiology*