For those of us still trying to avoid illness, I give high marks for the OHBM venue (Brisbane convention center): CO2 levels have stayed quite low in the auditorium, poster hall, and common areas. The symposium rooms were not as good; if more than a quarter or so full the CO2 increases rapidly. I also like that there are many easy-to-reach nice outdoor gathering places, and the opening night reception included a large patio.

None of that helps much when unmasked folks are talking loudly at close proximity, unfortunately, which happens a lot at posters, dinners, bars, etc. I'm not the only attendee masking (and no hassle about it), but we are in the distinct minority.

Mentions and black humor about covid and "colds" started at the opening ceremony and keep popping up; plenty of coughing and at least one person saying they were currently running a fever. It'd be interesting to track proportion coughing on the audio recordings over the conference and see if it actually increases or just seems to.

I haven't usually been the only person masking on trains, buses, or in shops around Brisbane, either, which is nice.

#stillMasking #Aranet4 #OHBM2025 #CovidIsNotOver #OHBM

OHBM is going very well (say hello if you're here), but its mirror-brain logo feels all too appropriate; we're through the looking glass.

At a symposium two speakers presented via recording because of "visa issues", a euphemism for "if they left the US they may not have been able to return". Conversations veer between current projects, methodological minutiae, and who just had their funding stopped, what strategy might keep a lab going, what non-science jobs might exist, how long US science may last.

Would frank discussion of what we as scientists could do help? Heck if I know. Not everyone is a US citizen or resident of course, but everyone does interact with US scientists and their work; "the current situation" feels like the elephant in the room; the devil we don't name for fear to do so could cause his attention to fall upon us.

#OHBM #OHBM2025

#OHBM coming up next week; anyone else planning to be there?

I'll have a poster (1046) about #fMRI "crescent" artifacts; it's uploaded to the OHBM site and https://osf.io/pzj39.

I posted a bit of poster commentary at https://mvpa.blogspot.com/2025/06/ohbm-2025-lets-chat-about-crescents.html, excerpted here. I still don't know exactly how much the artifact affects fMRI signal quality, but am confident that there is enough likelihood of a substantial negative impact that they shouldn't be ignored.

It seems to be a given in the MR physics literature that Nyquist ghosts appreciably degrade EPI. Quantifying the impact in GLM results is difficult, however, especially after preprocessing, smoothing, in group analyses , and when runs of different encoding directions are analyzed together. Qualitatively, I can see crescents in single-subject statistical images, but that's of course not a typical analysis.

Even so, I think there's enough evidence to recommend that crescent artifacts be one of the criteria for choosing acquisition protocols: select parameters so that crescent artifacts are minimized and/or appear in brain areas of low theoretical interest. Since the crescent artifact likely reduces BOLD signal quality somewhat, and is more often prominent in people with smaller brains, there's a risk of bias if an experimentally-important participant characteristic (e.g., age, sex) is associated with differences in head size; extra care should be taken in these cases.

Engaging backstory on the evolution of meta-analyses and large scale collaborations ( i.e., #ABCD ) by Angela Laird as interviewed by Peter Bandettini on the #neurosalience podcast ( #FMRI , #neuroscience , #ohbm ):

https://www.youtube.com/watch?v=d7Jh7JFGf1Q

Long shot, but if you're planning to attend #OHBM2025 and interested in a session I'd like to propose, please contact me.

Its working title is “Proactive human subjects research: identifying new privacy-related risks and strategies for their minimization”.

I’m thinking of things like not asking participants about pregnancy or sex assigned at birth unnecessarily; also less direct possible risks like use of AI, cloud storage, and phone apps (e.g., for passive sensing).

#OHBM #privacy #research

My talk on "Reinforcement Learning via Brain Feedback" (RLBF) is now on the #OHBM YouTube channel!

Our approach can be used to generate/find the best paradigm or stimulation to modulate brain activity with real-time fMRI & Reinforcement Learning. Check out our proof-of-concept study!

#brain #neuroscience #AI #workinprogress

https://www.youtube.com/watch?v=StpmubPRwJI&t=84s