Mills Kathryn L, Goddings Anne-Lise, Clasen Liv S, Giedd Jay N, Blakemore Sarah-Jayne
Institute of Cognitive Neuroscience, University College London, London, UK.
Dev Neurosci. 2014;36(3-4):147-60. doi: 10.1159/000362328. Epub 2014 Jun 27.
Regions of the human brain develop at different rates across the first two decades of life, with some maturing before others. It has been hypothesized that a mismatch in the timing of maturation between subcortical regions (involved in affect and reward processing) and prefrontal regions (involved in cognitive control) underlies the increase in risk-taking and sensation-seeking behaviors observed during adolescence. Most support for this 'dual systems' hypothesis relies on cross-sectional data, and it is not known whether this pattern is present at an individual level. The current study utilizes longitudinal structural magnetic resonance imaging (MRI) data to describe the developmental trajectories of regions associated with risk-taking and sensation-seeking behaviors, namely, the amygdala, nucleus accumbens (NAcc) and prefrontal cortex (PFC). Structural trajectories of gray matter volumes were analyzed using FreeSurfer in 33 participants aged 7-30 years, each of whom had at least three high-quality MRI scans spanning three developmental periods: late childhood, adolescence and early adulthood (total 152 scans). The majority of individuals in our sample showed relatively earlier maturation in the amygdala and/or NAcc compared to the PFC, providing evidence for a mismatch in the timing of structural maturation between these structures. We then related individual developmental trajectories to retrospectively assessed self-reported risk-taking and sensation-seeking behaviors during adolescence in a subsample of 24 participants. Analysis of this smaller sample failed to find a relationship between the presence of a mismatch in brain maturation and risk-taking and sensation-seeking behaviors during adolescence. Taken together, it appears that the developmental mismatch in structural brain maturation is present in neurotypically developing individuals. This pattern of development did not directly relate to self-reported behaviors at an individual level in our sample, highlighting the need for prospective studies combining anatomical and behavioral measures.
在人生的头二十年里，人类大脑的不同区域以不同速度发育，有些区域比其他区域成熟得更早。据推测，皮层下区域（涉及情感和奖励处理）与前额叶区域（涉及认知控制）之间成熟时间的不匹配，是青春期冒险和寻求刺激行为增加的原因。对这一“双系统”假说的大多数支持都依赖于横断面数据，目前尚不清楚这种模式在个体层面是否存在。本研究利用纵向结构磁共振成像（MRI）数据，来描述与冒险和寻求刺激行为相关区域的发育轨迹，即杏仁核、伏隔核（NAcc）和前额叶皮层（PFC）。使用FreeSurfer分析了33名7至30岁参与者的灰质体积结构轨迹，每位参与者至少有三次高质量的MRI扫描，涵盖三个发育阶段：儿童晚期、青春期和成年早期（共152次扫描）。我们样本中的大多数个体，杏仁核和/或伏隔核的成熟相对早于前额叶皮层，为这些结构之间结构成熟时间的不匹配提供了证据。然后，我们将个体发育轨迹与24名参与者子样本中回顾性评估的青少年期自我报告的冒险和寻求刺激行为相关联。对这个较小样本的分析未能发现大脑成熟不匹配与青少年期冒险和寻求刺激行为之间的关系。综上所述，大脑结构成熟的发育不匹配似乎存在于发育正常的个体中。在我们的样本中，这种发育模式在个体层面上与自我报告行为没有直接关系，这凸显了结合解剖学和行为测量的前瞻性研究的必要性。
