Poster No:
2024
Submission Type:
Abstract Submission
Authors:
Christopher Timmermann1, Winson Yang2, MAtthew Sacchet2
Institutions:
1University College London, London, London, 2Harvard Medical School, Boston, MA
First Author:
Co-Author(s):
Introduction:
States achieved during advanced concentrative absorption meditation jhana (ACAM-J) can progressively reduce layers of spontaneous mental activity and the processing of environmental input while sparing awareness, thereby granting a minimal model of consciousness.1–3 States induced by psychoactive compounds are driven by specific neurotransmitters and also deconstruct consciousness in ways that have some phenomenological similarities to states induced by advanced meditation (e.g., experiences of ego-dissolution)1,4. In this study we provide the first neurochemical assessment of advanced meditation by establishing overlaps of intensively-sampled fMRI-determined ACAM-J states with the receptor density of 19 neurotransmitters, and 10 consciousness altering drugs.
Methods:
A highly advanced meditator with 25 years of meditation experience (male, 51 years) underwent 5 study visits where 27 runs of fMRI data were collected. Transitions into separate ACAM-J states were marked by a button press. Control conditions (counting and a memory task) were also collected (see2 for details).
Following preprocessing (see2), the data was segmented according to the separate ACAM-J (27 each) and control states (16 each). After parcellation,5 the weighted degree of functional connectivity (wdFC) was obtained.
Brain maps of wdFC for 10 psychoactive drugs and 19 receptor density maps (PET) were obtained from an open access repository.6 Overlaps between ACAM-J states and drug / receptor density maps were established by performing Spearman correlations (significance using Fisher R to Z test) and dominance analyses.
Results:
LSD, propofol recovery, and acute propofol (all ps<0.05, FDR-corrected) were positively correlated with most ACAM-J states. 'Formless' ACAM-J states (displaying loss of sensory processing, space, and time) showed an additional positive correlation with methylphenidate. Dominance analyses showed that propofol recovery dominated 'form' ACAM-J states (displaying bliss and loss of spontaneous mental activity), whereas LSD dominated formless ACAM-J states.
Correlations between ACAM-J brain maps and receptor maps revealed consistent positive associations for most ACAM-J states and an acetylcholine receptor (A4B2), norepinephrine transporter, and serotonin receptor 5-HT1B maps (all ps<0.05, FDR-corrected). Negative correlations were found across most serotonin, dopaminergic, GABAergic, and NMDA receptor maps (all ps<0.05, FDR-corrected). Dominance analyses revealed that for form ACAM-J states, A4B2 has the higher contribution across receptors, whereas for formless ACAM-J states, dopamine receptors (especially D1) show dominance.
Conclusions:
We found a distinct pattern of FC and overlaps with drug/receptor maps for form versus formless ACAM-J states. Form ACAM-J states were marked by overlaps with acetylcholine receptors, and anaesthesia recovery and implicated motor and high-level brain regions, consistent with reported phenomenology of bliss and reductions of spontaneous mental activity in initial stages.
Formless ACAM-J instead overlapped more strongly with LSD / dopamine receptor maps, and were related with a heterogeneous increases in brain connectivity, which is consistent with the brain-wide effects induced by LSD and its receptor mechanisms.7
These findings are consistent with claims of phenomenological overlaps between psychedelics and advanced meditation,4 and inform common underlying mechanisms of experiences elicited through mental training, drug-induced states, and the habitual functioning of the brain, and thus foster several important directions for future research in both clinical and non-clinical contexts.
Modeling and Analysis Methods:
fMRI Connectivity and Network Modeling 2
PET Modeling and Analysis
Perception, Attention and Motor Behavior:
Consciousness and Awareness 1
Physiology, Metabolism and Neurotransmission:
Pharmacology and Neurotransmission
Keywords:
Consciousness
Dopamine
FUNCTIONAL MRI
Neurotransmitter
Other - Pharmacology
1|2Indicates the priority used for review
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Please indicate below if your study was a "resting state" or "task-activation” study.
Resting state
Healthy subjects only or patients (note that patient studies may also involve healthy subjects):
Healthy subjects
Was this research conducted in the United States?
No
Were any human subjects research approved by the relevant Institutional Review Board or ethics panel?
NOTE: Any human subjects studies without IRB approval will be automatically rejected.
Yes
Were any animal research approved by the relevant IACUC or other animal research panel?
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Not applicable
Please indicate which methods were used in your research:
PET
Functional MRI
For human MRI, what field strength scanner do you use?
7T
Which processing packages did you use for your study?
AFNI
FSL
Provide references using APA citation style.
1. Sacchet, M. D., Fava, M. & Garland, E. L. Modulating self-referential processing through meditation and psychedelics: is scientific investigation of self-transcendence clinically relevant? World Psychiatry vol. 23 296–298 Preprint at https://doi.org/10.1002/wps.21213 (2024).
2. Chowdhury, A. et al. Multimodal neurophenomenology of advanced concentration absorption meditation: An intensively sampled case study of Jhana. Neuroimage 305, 120973 (2025).
3. Yang, W. F. Z., Sparby, T., Wright, M., Kim, E. & Sacchet, M. D. Volitional mental absorption in meditation: Toward a scientific understanding of advanced concentrative absorption meditation and the case of jhana. Heliyon vol. 10 Preprint at https://doi.org/10.1016/j.heliyon.2024.e31223 (2024).
4. Timmermann, C. et al. A neurophenomenological approach to non-ordinary states of consciousness: hypnosis, meditation, and psychedelics. Trends Cogn Sci 27, 139–159 (2023).
5. Schaefer, A. et al. Local-Global Parcellation of the Human Cerebral Cortex from Intrinsic Functional Connectivity MRI. Cerebral Cortex 28, 3095–3114 (2018).
6. Luppi, A. I. et al. In vivo mapping of pharmacologically induced functional reorganization onto the human brain’s neurotransmitter landscape. Sci Adv 9, (2023).
7. Nichols, D. E. Psychedelics. Pharmacol Rev 68, 264–355 (2016).
No