背景:随着对迷幻药(致幻5-HT2A激动剂)的研究的进展,重要的是要描述这种药物类别中所谓的独特作用的可靠性。一个这样的影响是迷幻药如何损害地层(即,编码)海马依赖性回忆(检索特定细节),同时潜在地增强皮质依赖性熟悉度(知道以前已经经历过刺激的感觉)的编码。
方法:在双盲中,安慰剂对照,受试者内研究(N=20),我们测试了两种不同的迷幻药的急性效应,psilocybin和4-溴-2,5-二甲氧基苯乙胺(2C-B),关于情感情景记忆的编码。在急性药物作用期间,参与者认为负面的,中性,积极的图片。第二天(清醒时),参与者对这些图片分别完成了两项记忆测试.
结果:使用记忆置信度的计算模型,我们发现psilocybin和2C-B在编码时的趋势损害了其他测量/分析支持的回忆估计。令人惊讶的是,psilocybin和2C-B在编码时对熟悉度的估计受损,但是这些损害可能是由于熟悉程度提高的错误归因,由于两种药物在编码时选择性地增加了基于熟悉度的错误警报,尤其是消极和积极的刺激。Psilocybin和2C-B在编码时也倾向于削弱对消极和中性记忆的元记忆估计(理解自己的记忆),但增强对积极记忆的元记忆估计,尽管在其他分析中这些影响不太可靠。
结论:尽管它们的化学性质不同,药理学,和主观效果,psilocybin和2C-B都扭曲了情景熟悉度,暗示迷幻药之间的共同神经认知机制可能会驱动其他现象。
BACKGROUND: As research on psychedelics (hallucinogenic 5-HT2A agonists) progresses, it is important to delineate the reliability of supposedly unique effects across this drug class. One such effect is how psychedelics impair the formation (i.e., encoding) of hippocampal-dependent recollections (retrieval of specific details) while potentially enhancing the encoding of cortical-dependent familiarity (a feeling of knowing that a stimulus has been previously experienced).
METHODS: In a double-blind, placebo-controlled, within-subjects study (N = 20), we tested the acute effects of two distinct psychedelics,
psilocybin and 4-bromo-2,5-dimethoxyphenethylamine (2C-B), on the encoding of emotional episodic memories. During acute drug effects, participants viewed negative, neutral, and positive pictures. The following day (while sober), participants completed two separate memory tests for these pictures.
RESULTS: Using computational models of memory confidence, we found trends for
psilocybin and 2C-B at encoding to impair estimates of recollection that were supported by other measures/analyses. Surprisingly,
psilocybin and 2C-B at encoding impaired estimates of familiarity, but these impairments were likely due to a misattribution of heightened familiarity, as both drugs at encoding selectively increased familiarity-based false alarms, especially for negative and positive stimuli.
Psilocybin and 2C-B at encoding also tended to impair estimates of metamemory (understanding one\'s own memory) for negative and neutral memories but enhance estimates of metamemory for positive memories, though these effects were less reliable in additional analyses.
CONCLUSIONS: Despite differences in their chemistry, pharmacology, and subjective effects, both
psilocybin and 2C-B distort episodic familiarity, alluding to a common neurocognitive mechanism across psychedelics that may drive other phenomena.