RogueLeader said:
. . . maybe Ben isn’t trying to use Vader’s helmet to somehow reconnect with Rey, but instead, he is trying to confirm what Palpatine told him, and the flood of painful memories and revelations inadvertently reconnects him with Rey, since those feelings are something they both shared. So not only could it be a more sympathetic angle for Ben to see how he was manipulated, but it could also give more clues as to how Palpatine survived.

Building on this, it occurs to me to imply throughout TFA and TLJ - and maybe a little in TROS - that Kylo’s trying to use the helmet to contact Vader’s spirit. Possibly some Vader lines from prior films but also other media, such as the Battlefront games, could be dubbed in to make Kylo think that contact has been made - but it turns out later that it was Palp manipulating him.