Department of Psychology, The University of Texas at San Antonio, 1 UTSA Circle, San Antonio, TX 78249, USA; The Center for Molecular and Behavioral Neuroscience, Rutgers University-Newark, 197 University Avenue, Newark, NJ 07102, USA.
The Center for Molecular and Behavioral Neuroscience, Rutgers University-Newark, 197 University Avenue, Newark, NJ 07102, USA; The Behavioral and Neural Sciences Graduate Program, Rutgers University-Newark, 197 University Avenue, Newark, NJ 07102, USA.
Neurobiol Learn Mem. 2021 Apr;180:107413. doi: 10.1016/j.nlm.2021.107413. Epub 2021 Feb 18.
Rapid Eye Movement (REM) sleep has been shown to modulate the consolidation of fear memories, a process that may contribute to the development of Post-Traumatic Stress Disorder (PTSD). However, contradictory findings have been reported regarding the direction of this modulation and its differential effects on recall versus generalization. In two complementary experiments, we addressed this by employing sleep deprivation protocols together with a novel fear-conditioning paradigm that required the discrimination between coexisting threat and safety signals. Using skin conductance responses and functional imaging (fMRI), we found two opposing effects of REM sleep: While REM impaired recall of the original threat memories, it improved the ability to generalize these memories to novel situations that emphasized the discrimination between threat and safety signals. These results, as well as previous findings in healthy participants and patients diagnosed with PTSD, could be explained by the degree to which the balance between threat and safety signals for a given stimulus was predictive of threat. We suggest that this account can be integrated with contemporary theories of sleep and fear learning, such as the REM recalibration hypothesis.
快速眼动 (REM) 睡眠已被证明可以调节恐惧记忆的巩固，这一过程可能有助于创伤后应激障碍 (PTSD) 的发展。然而，关于这种调节的方向及其对回忆与泛化的不同影响，已有相互矛盾的发现报告。在两项互补的实验中，我们通过采用睡眠剥夺方案以及一种新的恐惧条件反射范式来解决这个问题，该范式要求区分同时存在的威胁和安全信号。使用皮肤电反应和功能成像 (fMRI)，我们发现 REM 睡眠有两种相反的影响：虽然 REM 会损害对原始威胁记忆的回忆，但它会提高将这些记忆泛化到新情况的能力，这些新情况强调了威胁和安全信号之间的区分。这些结果，以及先前在健康参与者和被诊断患有 PTSD 的患者中的发现，可以用特定刺激的威胁和安全信号之间的平衡程度来解释，这种平衡程度可以预测威胁。我们认为，这种解释可以与当代睡眠和恐惧学习理论（如 REM 再校准假说）相结合。
