Jackson Eric D, Payne Jessica D, Nadel Lynn, Jacobs W Jake
Department of Psychology, University of Arizona, Tucson, Arizona 85721, USA.
Biol Psychiatry. 2006 Mar 15;59(6):516-22. doi: 10.1016/j.biopsych.2005.08.002. Epub 2005 Oct 6.
Stress and stress hormones modulate emotional learning in rats and might have similar effects in humans. Theoretic accounts of posttraumatic stress disorder (PTSD), for example, implicate the stress-induced modulation of fear conditioning in the development of intrusive emotional reactions. The present study examined the impact of acute stress and cortisol (CORT) on classically conditioned fear in men and women.
Ninety-four healthy undergraduates were exposed to a mild stressor (or control condition) while subjective anxiety and glucocorticoid stress responses (salivary CORT) were measured. One hour later, all participants participated in a differential fear conditioning procedure while conditioned skin conductance responses (SCR) were recorded.
Exposure to the stressor increased subjective anxiety and elevated CORT levels. In men, stress exposure facilitated fear conditioning; whereas in women, stress appeared to inhibit fear conditioning. The impact of stress on differential conditioning in men was associated with increased CORT levels.
Consistent with animal models, these results demonstrate that stress exposure can modulate classical conditioning in humans, possibly via hormonal mechanisms. The enhancing effects of stress on the formation of conditioned fear might provide a useful model for the formation of pathological emotional reactions, such as those found in PTSD.
压力和应激激素可调节大鼠的情绪学习，在人类中可能也有类似作用。例如，创伤后应激障碍（PTSD）的理论解释表明，压力诱导的恐惧条件反射调节在侵入性情绪反应的发展中起作用。本研究考察了急性应激和皮质醇（CORT）对男性和女性经典条件性恐惧的影响。
94名健康本科生暴露于轻度应激源（或对照条件），同时测量主观焦虑和糖皮质激素应激反应（唾液CORT）。1小时后，所有参与者参与差异恐惧条件反射程序，同时记录条件性皮肤电反应（SCR）。
暴露于应激源会增加主观焦虑并提高CORT水平。在男性中，应激暴露促进恐惧条件反射；而在女性中，应激似乎抑制恐惧条件反射。应激对男性差异条件反射的影响与CORT水平升高有关。
与动物模型一致，这些结果表明，应激暴露可能通过激素机制调节人类的经典条件反射。应激对条件性恐惧形成的增强作用可能为病理性情绪反应（如PTSD中的反应）的形成提供一个有用的模型。
