[推荐]青少年叛逆因为“脑子有问题”

来源：新华网-现代快报

经常与父母发生争执和打斗的孩子，大脑构造与普通孩子不同。澳大利亚研究人员在25日出版的美国《国家科学院院刊》（PNAS）上发表文章说，大脑发育分阶段，叛逆的孩子在青春期早期，大脑内负责情绪的区域发育较正常孩子要快。但随着年龄增长这个现象会消失，因此家长不必太担心。

澳大利亚研究人员选取137名处于青春期早期的孩子，描绘他们的大脑结构并录下他们与父母发生冲突时的大脑活动状况。参与测试的孩子与父母在家庭作业、上床时间、使用手机和上网问题上发生争执时，研究人员观察他们如何与父母沟通，采取何种方式解决矛盾，并录下沟通过程中脑图的变化状况。墨尔本大学研究人员尼古拉斯·艾伦是这项研究的负责人。他说：“我们发现孩子的脑量和大脑结构同他们处理问题的方式有密切联系。”

经常与父母发生冲突的孩子，大脑中与情绪相关的区域比其他孩子发育更早。但是他们大脑内控制情绪的区域发育状况却不佳。这可以解释为什么叛逆的孩子更容易产生焦躁、反常情绪，也更不善于控制局面。通常人长到20多岁时，大脑两个区域的发展才会达到平衡。

艾伦还说，诸多因素会助长孩子叛逆的个性。比如家庭成员间不顺畅的交流，或是孩子本身懒惰，或是孩子需要更多关于自身责任和尊重他人的教育。

研究人员在论文中指出，家庭环境对孩子大脑发育也可能产生影响。早前的研究发现，极度受忽视、遭到性侵犯和受过身体虐待的经历，也会影响大脑发育状况。艾伦还提到，充满压力的家庭环境会影响早期青春期少女的大脑发育。

早前的研究也发现，大脑的发育分阶段进行。青春期早期，孩子解读愤怒语调与面部表情的能力大大减弱，因此12到14岁的孩子在社会智力方面变得迟钝。 所以并不是青少年故意作对或难以相处，而是他们的大脑在特殊时期无法正确感知父母的感情，尤其是悲伤和生气两种感情。这是因为他们大脑结构发生了变化，而基因和荷尔蒙是引发这些变化的原因。到16到17岁时，青少年在感情感知上达到成人水平，会逐渐变得懂事。

（《国家科学院院刊》（PNAS），10.1073/pnas.0709815105，Sarah Whittle, Nicholas B. Allen）

Prefrontal and amygdala volumes are related to adolescents' affective behaviors during parent–adolescent interactions

Sarah Whittle^*,,, Marie B. H. Yap^*,, Murat Yücel^*,, Alex Fornito^,,, Julian G. Simmons^*,, Anna Barrett^*,,, Lisa Sheeber, and Nicholas B. Allen^*,,¶

*ORYGEN Research Centre, Melbourne Neuropsychiatry Centre, Department of Psychiatry, and Department of Psychology, University of Melbourne, Parkville 3052, Victoria, Australia; and Oregon Research Institute, Eugene, OR 97403

Edited by Michael I. Posner, University of Oregon, Eugene, OR, and approved December 31, 2007 (received for review October 16, 2007)

Abstract

Adolescence is a key period for the development of brain circuits underlying affective and behavioral regulation. It remains unclear, however, whether and how adolescent brain structure influences day-to-day affective behavior. Because of significant changes in the nature of family relations that also typically occur during adolescence, parent–child interactions provide a meaningful context where affective behavior and its regulation may be assessed. In a sample of 137 early adolescents, we investigated the relationship between aspects of the adolescents' brain structure and their affective behavior as assessed during observation of parent–child interactions. We found a significant positive association between volume of the amygdala and the duration of adolescent aggressive behavior during these interactions. We also found male-specific associations between the volume of prefrontal structures and affective behavior, with decreased leftward anterior paralimbic cortex volume asymmetry associated with increased duration of aggressive behavior, and decreased leftward orbitofrontal cortex volume asymmetry associated with increased reciprocity of dysphoric behavior. These findings suggest that adolescent brain structure is associated with affective behavior and its regulation in the context of family interactions, and that there may be gender differences in the neural mechanisms underlying affective and behavioral regulation during early adolescence. Particularly as adolescence marks a period of rapid brain maturation, our findings have implications for mental health outcomes that may be revealed later along the developmental trajectory.

在母亲怀孕期间，如果情绪不好，压力太大，也会造成小孩多动。一个原因也可能是脑的发育不正常造成的。