Periodic reminder of what fMRI's BOLD signal is measuring, and its temporal dynamics:
"blood oxygenation level–dependent (BOLD) contrast. [...] increased signal in a voxel measured with an EPI [echo planar imaging] sequence indicates recent neuronal activity because of the relative increase in local blood oxygenation that accompanies such activity. The temporal profile of this BOLD response, known as the hemodynamic response function, looks like a bell curve with a long tail, peaking around 4 to 5 seconds after local neural activity and returning to baseline after 12 to 15 seconds."
From "Principles of Neural Science", Kandel et al. 6th edition, page 115.
No matter how fast the EPI imaging is (~100 ms), the BOLD dynamics makes GCaMP look lighting fast. Temporally deconvolving BOLD is possible, to a point, but remember its spatial resolution is measured in millimetres, whereas neuronal somas measure ~0.025 millimetres.
I’m currently using the web interface of mastodon.social [edit: on Apple devices] —
Do I need to use an app, or switch instances, or a different Fediverse alternative?
I don’t really need much, I would be okay with just bold and italics.
We've improved the navigation like a lot. The pink button has come to stay with you! It can take you home, or you can post from anywhere in the webapp!
Fixes
We've fixed some issueswith the fonts, and also you can reblog now from the blog page or the post page!