Speaker Bio
I received a PhD from The University of Chicago in 2007, following this with a Postdoctoral Fellowship at Weill Cornell Medicine, Cornell University. I am currently an Associate Professor at University College London. There, I direct ‘The LAB Lab’ and co-direct the ‘Understanding Neuroplasticity Induced by Tryptamines’ or UNITy Project. The long-term objective of my research program has always been to understand the neurobiology of language as it naturally occurs, i.e., in the rich multisensory and social contexts of everyday life. Recently, I expanded this research program to encompass the relationship between the neurobiology of language, consciousness, and mental health and wellbeing. My work uses various methodological approaches, including high-density electroencephalography (hdEEG), functional magnetic resonance imaging (fMRI), mobile phone-based ecological momentary assessment, and pharmacological interventions with psychedelic compounds like 5-MeO-DMT, DMT, LSD, and psilocybin. I pioneered ‘naturalistic neuroimaging’ in 1999 and have developed network-based methods and other tools for analyzing fMRI data from more ecological stimuli. As a contribution to open science, my research team released the ‘Naturalistic Neuroimaging Database’ (NNDb), containing 86 participants undergoing full-length movie-fMRI (and growing). I co-founded and serve on the editorial board of the open-access MIT Press journal, Neurobiology of Language.
ICPR 2024 Abstract
The handiest of the marks: The neurobiology of language partially mediates the psychedelic experience
Background
Humans have language-augmented thought, using language to categorically organise experiences. These categories enable novel computations but can also become entrenched to a degree that is no longer adaptive. Psychedelic phenomenology arguably resembles a brain less mediated by well-learned linguistic categories. Connectedness or ‘oneness’ is expected when perceptual information cannot be organised into linguistically labelled objects. ‘Ego-dissolution’ is expected when linguistic constructs like the ‘narrative self’ are not accessible.
Research Question and Hypothesis
Does the neurobiology of language participate in the acute psychedelic experience? Behavioural experiments suggest that psychedelics decrease the quantity and quality of speech while increasing semantic oddness. Thus, we hypothesised that ‘lower-level’ auditory brain regions will decrease while ‘higher-level’ semantic processing regions will increase in activity under psychedelics and be associated with ego-dissolution.
Methods
We conducted neuroimaging meta-analyses of classic psychedelics and ketamine, a structural magnetic resonance imaging (MRI) study of Ayahuasca, and functional MRI studies of DMT, LSD, and psilocybin (relative to placebo controls).
Results
Meta-analyses demonstrated activity decreases in audiomotor regions involved in speech perception/production and increases in regions associated with semantics. There were significant changes in these regions in the structural and functional MRI studies, with activity predicting individual differences in ego-dissolution.
Conclusion
The neurobiology of language partially mediates the psychedelic experience. This is consistent with behavioural data and provides a concrete model of how psychedelics might lead to improvements in mental health and wellbeing. That is, profound changes in language-related networks and language-mediated categories might lead to changes in self-related narratives post-acutely that underlie (some) positive long-term changes.