Adolescents, Adults and Rewards: Comparing Motivational Neurocircuitry Recruitment Using fMRI

• Published in: PloS one Vol. 5; no. 7; p. e11440
• Main Authors: Bjork, James M., Smith, Ashley R., Chen, Gang, Hommer, Daniel W.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 06.07.2010; Public Library of Science (PLoS)
• Subjects: Adolescent; Adolescents; Adult; Adults; Alcoholism; Attention deficit hyperactivity disorder; Brain; Brain mapping; Child; Cues; Functional magnetic resonance imaging; Humans; Magnetic resonance; Magnetic Resonance Imaging; Medical imaging; Mesolimbic system; Motivation - physiology; Neostriatum; Neural circuitry; Neural Pathways - physiology; Neuroimaging; Neurology; Neuroscience/Behavioral Neuroscience; Neuroscience/Cognitive Neuroscience; Neuroscience/Neurodevelopment; Nucleus accumbens; Nucleus Accumbens - metabolism; Nucleus Accumbens - physiology; Pediatrics and Child Health/Child and Adolescent Psychiatry; Pediatrics and Child Health/Child Development; Predictive control; Public Health and Epidemiology/Social and Behavioral Determinants of Health; Reinforcement; Reward; Risk taking; Signaling; Studies; Teenagers; Young Adult; Youth; United States > US; Maryland
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0011440

Adolescent risk-taking, including behaviors resulting in injury or death, has been attributed in part to maturational differences in mesolimbic incentive-motivational neurocircuitry, including ostensible oversensitivity of the nucleus accumbens (NAcc) to rewards. To test whether adolescents showed increased NAcc activation by cues for rewards, or by delivery of rewards, we scanned 24 adolescents (age 12-17) and 24 adults age (22-42) with functional magnetic resonance imaging while they performed a monetary incentive delay (MID) task. The MID task was configured to temporally disentangle potential reward or potential loss anticipation-related brain signal from reward or loss notification-related signal. Subjects saw cues signaling opportunities to win or avoid losing $0, $.50, or $5 for responding quickly to a subsequent target. Subjects then viewed feedback of their trial success after a variable interval from cue presentation of between 6 to 17 s. Adolescents showed reduced NAcc recruitment by reward-predictive cues compared to adult controls in a linear contrast with non-incentive cues, and in a volume-of-interest analysis of signal change in the NAcc. In contrast, adolescents showed little difference in striatal and frontocortical responsiveness to reward deliveries compared to adults. In light of divergent developmental difference findings between neuroimaging incentive paradigms (as well as at different stages within the same task), these data suggest that maturational differences in incentive-motivational neurocircuitry: 1) may be sensitive to nuances of incentive tasks or stimuli, such as behavioral or learning contingencies, and 2) may be specific to the component of the instrumental behavior (such as anticipation versus notification).