Well my first point would be Google and research that way, but from experience in studies it's more sensible to do research by asking people who actually are in that field.
For me, it is noticeable when using a machine with less RAM and a machine with more but it's also the
frequency of the RAM & the timings too. It helps to speed up processes in designer/editor programs (Illustrator, InDesign, Photoshop, After Effects, etc.) - meaning your fonts load quicker, files load and render quicker, and you can also do more complex effects without system hang time or crashing in some instances - with After Effects, effects can be applied faster too but this can also be helped with a better CPU & GPU. Recently, my machine went from a slow frequency 16GB kit to a high frequency 8GB kit, and I have noticed the frequency increase has helped despite it being halved.
Other people may argue but that's my experience
At the end of the day though, you can throw all the RAM at your system you want but if you're bottlenecking it somewhere else it won't make a huge difference.