Isn't choosing to engage as a participant in a study more analogous to entering a contract which is also generally deemed inappropriate/invalid while under the influence?

Just saying there's a ton of grey area. I've never taken sex too seriously, meaning if I did something I regretted while impaired, I just shrugged it off. Other people obviously feel sex is a much bigger issue and regrettable situations are absolutely unacceptable to the point where it's their partners fault for somehow knowing how impaired you are, determining whether your consent is valid, etc. I personally don't get it, how it's become victim shaming to expect people to control their own selves. I get that date rape type stuff is very real and tragic but again, lots of grey area between that and regrettable drunk night out type stuff that's way more common. All to say, there exists a wide spectrum of what any given person may feel about this exact subject.