Sepehr Mortaheb

Lab for Equilibrium Investigations and Aerospace (LEIA), University of Antwerp.
Post-Doctoral Researcher

[Sepehr Mortaheb @SMortaheb]

Last week, our team #LEIA @UAntwerpen and our collaborators from @gtec_BCI and @BirkbeckUoL took part in the 85th @esa #parabolic_flight to study the effect of #zero_gravity on verticality detection ability. ✈️🧠
A great and unique experience 🤩 stay tuned for the results 🧐📊

[Sepehr Mortaheb @SMortaheb]

Great commentary by @singletonion and @amykooz on our recent #psychedelics paper! Totally agree that simultaneous EEG-fMRI can help disentangle neural and neurovascular effects to better understand the neural background of the psychedelic state. More work to be done!

[Parker Singleton @singletonion]

My comment with @amykooz on the recent (and very nice) psilocybin fMRI paper by @SMortaheb & @ADemertzi is now live. TLDR: the global signal debate continues!

https://t.co/eRkkHpMYL9

[Sepehr Mortaheb @SMortaheb]

@ashalruwaili Thanks a lot Ashwag. Actually, these were two separate studies. We didn’t induce MB with psychedelics.

[Sepehr Mortaheb @SMortaheb]

Our #OHBM symposium is tomorrow at 15:15. Really excited about it 🥳 Come to Grand Ballroom 103 to discuss about fMRI global signal 🧠

[Sepehr Mortaheb @SMortaheb]

That was a great experience … 🥳

[Sepehr Mortaheb @SMortaheb]

Hello #OHBM … here we are 🥳

[GIGA - CRC Human imaging @Giga_CRCivi]

💡WE ARE HIRING💡

For the “Brain-to-Body MRI” (B2B-MRI) project we have a 2-year MRI physicist postdoc position as part of a local collaboration project to develop/extend 3T and ultra-high field 7T #MRI applications!

All practical details 👉 https://t.co/8uKSBTp9Jx

[Sepehr Mortaheb @SMortaheb]

@Raph_Astro @AschbacherJosef Félicitations @Raph_Astro 🥳

[Sepehr Mortaheb @SMortaheb]

20/20 And big thanks for the support of @Giga_CRCivi , @GIGA_ULiege , @UniversiteLiege , and @frsFNRS .

[Sepehr Mortaheb @SMortaheb]

19/20 This was a highly collaborative work between the @PhysioCognGIGA , and @PIMaastricht , with @LarryDFort , #Jan_Ramaekers, @NL_Mason , @PMallaroni , and @ADemertzi !

[Sepehr Mortaheb @SMortaheb]

18/20 Therefore, we suggest considering GS amplitude as a complementary measure to the extracted connectivity profiles as they illuminate their physiological substrate, as we recently showed for the case of mind-blanking https://t.co/n62JtvptKF

[Sepehr Mortaheb @SMortaheb]

15/20 We found that the transition probabilities to the hyperconnected Pattern 3 and the phenomenological factors related to Oceanic Boundlessness and Visionary Restructuralization showed the highest correlations with the first canonical vector of their associated spaces.

[Sepehr Mortaheb @SMortaheb]

17/20 The decreases in BOLD signal amplitude in the psychedelic state could imply that increased cortical arousal mediates this hyperconnected pattern (e.g. https://t.co/dNlpa761DI).

[Sepehr Mortaheb @SMortaheb]

16/20 In conclusion, we illuminate the intricate interplay between brain dynamics and subjective experience under psilocybin, providing new insights into the neurophenomenology and neurophysiology of the psychedelic state.

[Sepehr Mortaheb @SMortaheb]

14/20 To bridge neural and behavioral data, we performed canonical correlation analysis, by considering between-state transition probabilities as the neural features, and the 11-ASC factors as phenomenological features.

[Sepehr Mortaheb @SMortaheb]

13/20 Also, regressing out the global signal (GS) eliminated the hyperconnectivity pattern in dynamic connectivity states, yielding no significant difference between the Placebo and Psilocybin groups. Therefore, GS is crucial for a more comprehensive analysis.

[Sepehr Mortaheb @SMortaheb]

12/20 Motion did not affect the results. Mean framewise displacement (FD) remained consistent across groups and connectivity patterns, showing no significant differences. Moreover, it did not correlate with mean functional connectivity or BOLD amplitude.

[Sepehr Mortaheb @SMortaheb]

11/20 Changing the number of clusters from 3 to 7 yielded consistent results. Across all conditions, the hyperconnected pattern was notably prevalent in the psilocybin group.

[Sepehr Mortaheb @SMortaheb]

10/20 Also, the psilocybin group showed significantly higher transition probabilities toward this hyperconnected Pattern 3 (Markov modeling).

[Sepehr Mortaheb @SMortaheb]

🎉 Our work "Dynamic Functional Hyperconnectivity after Psilocybin Intake is Primarily Associated with Oceanic Boundlessness" is out in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging! 🧠🍄Have a look here https://t.co/hZf7nrx9ms.
A thread below:

[Sepehr Mortaheb @SMortaheb]

9/20 The patterns concerned both correlations and anti-correlations (P1), anti-correlations of the DMN with other networks (P2), global hyperconnectivity (P3), and low inter-areal connectivity (P4). The hyperconnected Pattern 3 showed the highest occurrence rate after psilocybin.

[Sepehr Mortaheb @SMortaheb]

8/20 To investigate the effect of psilocybin on the dynamics of the whole-brain functional connectome, we estimated phase-based coherence matrices at each scan volume, which were summarized into four connectivity patterns using k-means clustering.