Baker Kathryn D, Den Miriam L, Graham Bronwyn M, Richardson Rick
School of Psychology, The University of New South Wales, Sydney 2052, Australia.
Neurobiol Learn Mem. 2014 Sep;113:90-100. doi: 10.1016/j.nlm.2013.10.009. Epub 2013 Oct 25.
There have been significant advances made towards understanding the processes mediating extinction of learned fear. However, despite being of clear theoretical and clinical significance, very few studies have examined fear extinction in adolescence, which is often described as a developmental window of vulnerability to psychological disorders. This paper reviews the relatively small body of research examining fear extinction in adolescence. A prominent finding of this work is that adolescents, both humans and rodents, exhibit a marked impairment in extinction relative to both younger (e.g., juvenile) and older (e.g., adult) groups. We then review some potential mechanisms that could produce the striking extinction deficit observed in adolescence. For example, one neurobiological candidate mechanism for impaired extinction in adolescence involves changes in the functional connectivity within the fear extinction circuit, particularly between prefrontal cortical regions and the amygdala. In addition, we review research on emotion regulation and attention processes that suggests that developmental changes in attention bias to threatening cues may be a cognitive mechanism that mediates age-related differences in extinction learning. We also examine how a differential reaction to chronic stress in adolescence impacts upon extinction retention during adolescence as well as in later life. Finally, we consider the findings of several studies illustrating promising approaches that overcome the typically-observed extinction impairments in adolescent rodents and that could be translated to human adolescents.
在理解介导习得性恐惧消退的过程方面已经取得了重大进展。然而，尽管具有明确的理论和临床意义，但很少有研究考察青少年期的恐惧消退，而青少年期通常被描述为易患心理障碍的发育窗口。本文综述了研究青少年期恐惧消退的相对较少的研究文献。这项工作的一个突出发现是，无论是人类还是啮齿动物，青少年相对于较年轻（如幼年）和较年长（如成年）群体在消退方面都表现出明显的损伤。然后，我们综述了一些可能导致在青少年期观察到的显著消退缺陷的潜在机制。例如，青少年期消退受损的一个神经生物学候选机制涉及恐惧消退回路内功能连接的变化，特别是前额叶皮质区域和杏仁核之间的变化。此外，我们综述了关于情绪调节和注意过程的研究，这些研究表明对威胁性线索的注意偏向的发育变化可能是一种认知机制，介导了消退学习中与年龄相关的差异。我们还研究了青少年期对慢性应激的不同反应如何影响青少年期以及成年后的消退保持。最后，我们考虑了几项研究的结果，这些研究说明了一些有前景的方法，这些方法克服了在青少年啮齿动物中通常观察到的消退损伤，并且可以转化应用于人类青少年。
