Aqil Marco, Roseman Leor
Spinoza Centre for Neuroimaging, the Netherlands; Computational Cognitive Neuroscience and Neuroimaging, Institute for Neuroscience, the Netherlands; Experimental and Applied Psychology, Vrije University Amsterdam, the Netherlands.
Centre for Psychedelic Research, Imperial College London, London, United Kingdom.
Neuropharmacology. 2023 Feb 1;223:109300. doi: 10.1016/j.neuropharm.2022.109300. Epub 2022 Nov 9.
Psychedelics are undergoing a major resurgence of scientific and clinical interest. While multiple theories and frameworks have been proposed, there is yet no universal agreement on the mechanisms underlying the complex effects of psychedelics on subjective experience and brain dynamics, nor their therapeutic benefits. Despite being prominent in psychedelic phenomenology and distinct from those elicited by other classes of hallucinogens, the effects of psychedelics on low-level sensory - particularly visual - dimensions of experience, and corresponding brain dynamics, have often been disregarded by contemporary research as 'epiphenomenal byproducts'. Here, we review available evidence from neuroimaging, pharmacology, questionnaires, and clinical studies; we propose extensions to existing models, provide testable hypotheses for the potential therapeutic roles of psychedelic-induced visual hallucinations, and simulations of visual phenomena relying on low-level cortical dynamics. In sum, we show that psychedelic-induced alterations in low-level sensory dimensions 1) are unlikely to be entirely causally reconducible to high-level alterations, but rather co-occur with them in a dialogical interplay, and 2) are likely to play a causally relevant role in determining high-level alterations and therapeutic outcomes. We conclude that reevaluating the currently underappreciated role of sensory dimensions in psychedelic states will be highly valuable for neuroscience and clinical practice, and that integrating low-level and domain-specific aspects of psychedelic effects into existing nonspecific models is a necessary step to further understand how these substances effect both acute and long-term change in the human brain.
迷幻药正在经历一场科学和临床兴趣的重大复兴。虽然已经提出了多种理论和框架，但对于迷幻药对主观体验和脑动力学产生复杂影响的潜在机制，以及它们的治疗益处，尚未达成普遍共识。尽管在迷幻现象学中很突出，且与其他类致幻剂所引发的效应不同，但迷幻药对低层次感官——尤其是视觉——体验维度以及相应脑动力学的影响，在当代研究中常常被视为“附带现象的副产物”而被忽视。在此，我们回顾了来自神经影像学、药理学、问卷调查和临床研究的现有证据；我们对现有模型进行了扩展，为迷幻药诱发的视觉幻觉的潜在治疗作用提供了可检验的假设，并对依赖低层次皮层动力学的视觉现象进行了模拟。总之，我们表明，迷幻药诱发的低层次感官维度变化：1）不太可能完全因果性地归结为高层次变化，而是在一种对话式相互作用中与它们同时出现；2）在决定高层次变化和治疗结果方面可能发挥因果相关作用。我们得出结论，重新评估感官维度在迷幻状态中目前未得到充分重视的作用，对神经科学和临床实践将具有很高的价值，并且将迷幻药效应的低层次和特定领域方面整合到现有的非特异性模型中是进一步理解这些物质如何影响人类大脑急性和长期变化的必要步骤。
