Sackler Institute for Developmental Psychobiology, Weill Cornell Medical College, 1300 York Avenue, Box 140, New York, NY 10065, USA.
J Cogn Neurosci. 2011 Sep;23(9):2123-34. doi: 10.1162/jocn.2010.21572. Epub 2010 Sep 7.
Adolescent risk-taking is a public health issue that increases the odds of poor lifetime outcomes. One factor thought to influence adolescents' propensity for risk-taking is an enhanced sensitivity to appetitive cues, relative to an immature capacity to exert sufficient cognitive control. We tested this hypothesis by characterizing interactions among ventral striatal, dorsal striatal, and prefrontal cortical regions with varying appetitive load using fMRI scanning. Child, teen, and adult participants performed a go/no-go task with appetitive (happy faces) and neutral cues (calm faces). Impulse control to neutral cues showed linear improvement with age, whereas teens showed a nonlinear reduction in impulse control to appetitive cues. This performance decrement in teens was paralleled by enhanced activity in the ventral striatum. Prefrontal cortical recruitment correlated with overall accuracy and showed a linear response with age for no-go versus go trials. Connectivity analyses identified a ventral frontostriatal circuit including the inferior frontal gyrus and dorsal striatum during no-go versus go trials. Examining recruitment developmentally showed that teens had greater between-subject ventral-dorsal striatal coactivation relative to children and adults for happy no-go versus go trials. These findings implicate exaggerated ventral striatal representation of appetitive cues in adolescents relative to an intermediary cognitive control response. Connectivity and coactivity data suggest these systems communicate at the level of the dorsal striatum differentially across development. Biased responding in this system is one possible mechanism underlying heightened risk-taking during adolescence.
青少年冒险行为是一个公共卫生问题,增加了不良终身结局的可能性。人们认为,影响青少年冒险倾向的一个因素是对奖赏线索的敏感性增强,而认知控制能力不成熟。我们使用 fMRI 扫描来描述腹侧纹状体、背侧纹状体和前额皮质区域与不同奖赏负荷的相互作用,从而验证了这一假设。儿童、青少年和成年参与者进行了带有奖赏(快乐面孔)和中性线索(平静面孔)的 Go/No-Go 任务。对中性线索的冲动控制随年龄呈线性改善,而青少年对奖赏线索的冲动控制呈非线性下降。青少年在这方面的表现下降与腹侧纹状体的活动增强相平行。前额皮质的募集与整体准确性相关,并在无 Go 与 Go 试验中随年龄呈线性反应。连接分析确定了一个包括下额回和背侧纹状体的腹侧额纹状体回路,用于无 Go 与 Go 试验。从发展的角度研究招募情况表明,与儿童和成人相比,青少年在快乐的无 Go 与 Go 试验中,腹侧-背侧纹状体的共同激活程度更高。这些发现表明,与中间认知控制反应相比,青少年对奖赏线索的腹侧纹状体表现出夸张的反应。连接和共同活动数据表明,这些系统在发展过程中通过背侧纹状体以不同的方式进行交流。该系统的偏向反应是青少年冒险行为增加的一个可能机制。