title: Diminished neural responses predict enhanced intrinsic motivation and sensitivity to external incentive.
abstract: The duration and quality of human performance depend on both intrinsic motivation and external incentives. However, little is known about the neuroscientific basis of this interplay between internal and external motivators. Here, we used functional magnetic resonance imaging to examine the neural substrates of intrinsic motivation, operationalized as the free-choice time spent on a task when this was not required, and tested the neural and behavioral effects of external reward on intrinsic motivation. We found that increased duration of free-choice time was predicted by generally diminished neural responses in regions associated with cognitive and affective regulation. By comparison, the possibility of additional reward improved task accuracy, and specifically increased neural and behavioral responses following errors. Those individuals with the smallest neural responses associated with intrinsic motivation exhibited the greatest error-related neural enhancement under the external contingency of possible reward. Together, these data suggest that human performance is guided by a "tonic" and "phasic" relationship between the neural substrates of intrinsic motivation (tonic) and the impact of external incentives (phasic).
authors.affiliation: Baylor College of Medicine, Houston, TX, USA.
authors.forename: Karen E
authors.initials: KE
authors.lastname: Marsden
authors.forename: Wei Ji
authors.initials: WJ
authors.lastname: Ma
authors.forename: Edward L
authors.initials: EL
authors.lastname: Deci
authors.forename: Richard M
authors.initials: RM
authors.lastname: Ryan
authors.forename: Pearl H
authors.initials: PH
authors.lastname: Chiu
mesh_terms: D001921:Brain / Q000098:blood supply / Q000502:physiology*; D001931:Brain Mapping; D002755:Choice Behavior; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D009042:Motivation; D010100:Oxygen / Q000097:blood; D011237:Predictive Value of Tests; D025341:Principal Component Analysis; D011340:Problem Solving; D011930:Reaction Time; D012201:Reward
chemical_list: D010100:Oxygen