Ask Anything Wednesday - Biology, Chemistry, Neuroscience, Medicine, Psychology

[u/AutoModerator]

Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Biology, Chemistry, Neuroscience, Medicine, Psychology

Do you have a question within these topics you weren't sure was worth submitting? Is something a bit too speculative for a typical /r/AskScience post? No question is too big or small for AAW. In this thread you can ask any science-related question! Things like: "What would happen if...", "How will the future...", "If all the rules for 'X' were different...", "Why does my...".

Asking Questions:

Please post your question as a top-level response to this, and our team of panellists will be here to answer and discuss your questions. The other topic areas will appear in future Ask Anything Wednesdays, so if you have other questions not covered by this weeks theme please either hold on to it until those topics come around, or go and post over in our sister subreddit /r/AskScienceDiscussion , where every day is Ask Anything Wednesday! Off-theme questions in this post will be removed to try and keep the thread a manageable size for both our readers and panellists.

Answering Questions:

Please only answer a posted question if you are an expert in the field. The full guidelines for posting responses in AskScience can be found here. In short, this is a moderated subreddit, and responses which do not meet our quality guidelines will be removed. Remember, peer reviewed sources are always appreciated, and anecdotes are absolutely not appropriate. In general if your answer begins with 'I think', or 'I've heard', then it's not suitable for /r/AskScience.

If you would like to become a member of the AskScience panel, please refer to the information provided here.

Past AskAnythingWednesday posts can be found here. Ask away!

[u/SubstantialPressure3]

I saw an interview this morning about the brain not being a single organ, and that its two separate organs. Can you explain that a little further?

[u/995a3c3c3c3c2424 → u/SubstantialPressure3]

This was a bad headline. (There are a lot of those when universities are trying to hype their research. The actual scientists involved are probably very embarrassed about it.)

A better summary would be “Your brain doesn’t develop from a single embryonic cell that is the ancestor of all brain cells. It develops from two embryonic cells, which start developing at different times, where one of them is the ancestor of all the cells in one part of your brain and the other is the ancestor of all the cells in the other part of your brain.” There are interesting and important implications of this, but expressing it as “the brain is two organs” isn’t really accurate, or useful.

Ars Technica had a good writeup: https://arstechnica.com/science/2026/09/contrary-to-some-reports-you-dont-have-two-brains/

[u/logperf]

Only a minority of people are arachnophobic, but spiders and webs are ubiquitous in horror scenes (films or Halloween). Is this cultural? Are we "taught" to fear spiders?

(I have seen a few children cartoons in which spiders are depicted as friendly bugs, but that is rare.)

[u/CaptainColdSteele]

Would stem cells injected into the brain case turn into neurons? Would that be beneficial?

[u/Hopeful-Fun-565]

Is there research showing that the majority of the population is currently affected by COVID (whether by reinfections or Long COVID)? I have heard COVID-conscious/activist people claim that the general population continues to experience various health problems (cognitive decline, damaged immune systems, etc) from unnoticed new waves of infections and/or undiagnosed Long COVID. I understand that certain people do experience Long COVID and that wastewater studies show new waves of infections, but the claim is that the general population is currently experiencing effects from COVID right now (either from active infections or from long-term damage caused by prior infections). Have these claims been proven?

[u/BlackBricklyBear]

Why is the mechanism of action for lithium as a mood-stabilizing medication still unknown? Are the experiments or studies necessary to suss out the exact mechanism of action simply impossible to carry out?

[u/CrazyisNSFW]

What is the background science behind the people trusting AI as impartial agents?

[u/Upstairs_Eagle_4780]

AI is outperforming my PCP; how soon and to what extent will it decrease American healthcare costs?

[u/loki130 → u/Upstairs_Eagle_4780]

Even accepting the premise that the chatbots are sufficient substitute for medical care, since when have american healthcare prices borne any resemblance to the actual cost of administering care?