Carter Olivia L, Hasler Felix, Pettigrew John D, Wallis Guy M, Liu Guang B, Vollenweider Franz X
Vision Touch and Hearing Research Center, School of Biomedical Science, University of Queensland, Brisbane, Australia.
Psychopharmacology (Berl). 2007 Dec;195(3):415-24. doi: 10.1007/s00213-007-0930-9. Epub 2007 Sep 14.
Binocular rivalry occurs when different images are simultaneously presented to each eye. During continual viewing of this stimulus, the observer will experience repeated switches between visual awareness of the two images. Previous studies have suggested that a slow rate of perceptual switching may be associated with clinical and drug-induced psychosis.
The objective of the study was to explore the proposed relationship between binocular rivalry switch rate and subjective changes in psychological state associated with 5-HT2A receptor activation.
This study used psilocybin, the hallucinogen found naturally in Psilocybe mushrooms that had previously been found to induce psychosis-like symptoms via the 5-HT2A receptor. The effects of psilocybin (215 microg/kg) were considered alone and after pretreatment with the selective 5-HT2A antagonist ketanserin (50 mg) in ten healthy human subjects.
Psilocybin significantly reduced the rate of binocular rivalry switching and increased the proportion of transitional/mixed percept experience. Pretreatment with ketanserin blocked the majority of psilocybin's "positive" psychosis-like hallucinogenic symptoms. However, ketanserin had no influence on either the psilocybin-induced slowing of binocular rivalry or the drug's "negative-type symptoms" associated with reduced arousal and vigilance.
Together, these findings link changes in binocular rivalry switching rate to subjective levels of arousal and attention. In addition, it suggests that psilocybin's effect on binocular rivalry is unlikely to be mediated by the 5-HT2A receptor.
当不同图像同时呈现给双眼时会发生双眼竞争。在持续观看这种刺激时，观察者会经历两种图像视觉意识之间的反复切换。先前的研究表明，感知切换速度缓慢可能与临床和药物诱发的精神病有关。
本研究的目的是探讨双眼竞争切换率与5-HT2A受体激活相关的心理状态主观变化之间的假定关系。
本研究使用了裸盖菇素，这是一种在裸盖菇中天然存在的致幻剂，此前已发现它通过5-HT2A受体诱发类似精神病的症状。在10名健康人类受试者中，单独考虑了裸盖菇素（215微克/千克）的作用，以及在使用选择性5-HT2A拮抗剂酮色林（50毫克）预处理后的作用。
裸盖菇素显著降低了双眼竞争的切换率，并增加了过渡/混合感知体验的比例。用酮色林预处理可阻断裸盖菇素的大部分“阳性”类似精神病的致幻症状。然而，酮色林对裸盖菇素引起的双眼竞争减慢或与唤醒和警觉性降低相关的药物“阴性症状”均无影响。
这些发现共同将双眼竞争切换率的变化与唤醒和注意力的主观水平联系起来。此外，这表明裸盖菇素对双眼竞争的影响不太可能由5-HT2A受体介导。
