

Participants 120 We analyzed fMRI data from N = 15 (2 male, 13 female) participants aged between 22 and 35 121 years (mean: 25.5) who took part in a previously published fMRI study about color vision 122 (Bannert & Bartels, 2018). The participants were the subset from the prior study for whom the 123 cortical retinotopic representations of the visual field were measured along both the polar and 124 the eccentricity axis of the visual field. All participants had normal or corrected-to-normal visual 125 acuity and were tested for normal color vision using Ishihara color plates (Ishihara, 2011). Each 126 participant gave written informed consent before the first study session. The experiment was 127 approved by the local ethics committee of the Tübingen University Hospital.
Ignore the numbers 120-127, those are line numbers.
Doesn’t say. To be fair, you normally aren’t allowed to collect biographical data or any additional identifying data without a specific purpose tied directly to your research question. If they wanted to answer your question they would have to redo the study under a different IRB application. Interesting question, but I would guess you wouldn’t see a difference in an fmri. The voxel sizes for functional are normally 2mm while what you are eluding to is the difference of a few thousand neurons wired a little differently. That difference would be extremely difficult to detect with 2mm voxels. Even at 1mm it would be difficult. When it comes to brain structures there really aren’t significant different between races or cultures more than the variance that already exists between people.
N=15 is a normal size on FMRI studies. It is about the smallest size you can have and still make your significance cut offs while still detecting decently small effects. The time and cost is so much higher than other studies. Some of the bigger FMRI studies start to reach 30-40 ppl. Getting into clinical trial sizes of subjects is unheard of.
The other thing with FMRI studies that most everyone doesn’t understand is that they aren’t actually looking at activity. They are looking at the BOLD response (blood oxygen level dependance) and that is then correlated to activity. Meaning You can only see blood oxygen uptake. You are not seeing neuron firing, just the metabolic side effect of oxygen use after increased neuron use. This is why you will never be able to see something like a “thought process”. You can only track structures/locations used.
At the same time we know that no two brains are wired the same even for the smallest of tasks, but they will “structure” their wiring the same. There have been literally hundreds of studies that indirectly see that. Soeach other. Plot out cultural differences versus individual differences would be basically two variance plots on top of eachother.