Encore Episode: How Psychedelics Affect the Brain with Manesh Girn, PhD

Encore Episode: How Psychedelics Affect the Brain with Manesh Girn, PhD

Author: Lynn Marie Morski, MD, JD January 22, 2026 Duration: 38:02

In this encore episode of the Psychedelic Medicine Podcast, psychedelic science researcher and educator Dr. Manesh Girn discusses his studies investigating psychedelic brain action. Manesh earned PhD in neuroscience at McGill University and is an author on over a dozen peer-reviewed articles on psychedelics and related topics. He is also chief research officer at EntheoTech Bioscience and runs the YouTube channel the Psychedelic Scientist. 

In this conversation, Manesh discusses his recent article in Trends in Cognitive Sciences titled "A complex systems perspective on psychedelic brain action."He explains the complexity science approach used in the article, which emphasizes the brain is a holistic, interconnected system, rather than individual component networks that can be isolated. From this standpoint, Manesh critiques some simplistic explanations of the neural mechanisms of psychedelics which focus exclusively on interactions with the default mode network isolated from other brain systems.

He also explains how individual some of the neural effects of psychedelics are, citing different findings from different studies and observed variations between brain scans of different people. By better understanding these individual differences, and placing these different responses into a complexity science framework, Manesh believes that more individually-tailored psychedelic therapies are possible once the systems involved are more comprehensively understood. 

Manesh closes this discussion by explaining the difference between genuine complexity and sheer chaos.  Complexity, he explains, is a delicate balance of novelty and order, which is why psychedelic experiences can be both destabilizing and productive of novel insights and personal transformation. 

 

In this episode:

  • The research into psychedelics and the default mode network
  • Using frameworks from complexity science in psychedelic research
  • Measuring entropy in the brain
  • Differences in neurological effects from taking between different studies and different individuals
  • How a complexity science approach to neuroscience could better inform precision psychiatry

 

Quotes:

"You can't just look at a specific brain region or network [in psychedelic research], you've gotta talk about the brain as a whole, in this sense of seeing the brain as a system of interacting parts." [4:49]

"The core idea of this paper is that psychedelics put our brain into this state that is more dynamically flexible, it's more diverse in its activity patterns, and it's more sensitive to inputs that come in." [14:17]

"What we find in the brain imaging findings is that different studies disagree, but also if you look at individual people, they can have radically different effects on their brain—almost opposite." [21:37]

 

Links:

Manesh' recent article in Trends in Cognitive Sciences: "A complex systems perspective on psychedelic brain action"

​​Psilocybin vs Placebo Brain Connectivity Diagram from Dr. Robin Carhart-Harris

The Psychedelic Scientist YouTube Channel

The Psychedelic Scientist on Instagram

The Psychedelic Scientist on Twitter

Manesh on LinkedIn

EntheoTech website

Psychedelic Medicine Association

Porangui


Exploring the frontier of mind and medicine, the Psychedelic Medicine Podcast with Dr. Lynn Marie Morski delves into the complex world of psychedelic substances and their potential to heal. Hosted by Lynn Marie Morski, a physician and attorney, this podcast navigates the intricate intersection of cutting-edge science, clinical practice, and evolving policy. Each episode brings a grounded, expert perspective to conversations about psilocybin, MDMA, ketamine, LSD, ayahuasca, ibogaine, and other compounds, moving beyond hype to examine the real-world implications of this therapeutic renaissance. Listeners will hear detailed discussions on the latest peer-reviewed research, practical insights from medical professionals integrating these approaches, and thoughtful analysis of the legal landscape shaping access. The dialogue is rooted in a commitment to safety, ethics, and evidence, offering a clear-eyed look at both the profound promise and the challenges inherent in psychedelic medicine. Whether you're a healthcare provider, a patient, a researcher, or simply intellectually curious, this podcast provides an essential, nuanced resource for understanding how these ancient and modern substances are reshaping perspectives on mental health, consciousness, and treatment. It’s a space for serious inquiry, where complex questions about healing, neuroscience, and society are met with informed, accessible conversation.
Author: Language: English Episodes: 50

Psychedelic Medicine Podcast with Dr. Lynn Marie Morski
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