I've read that Lecithin isnt very good at crossing the blood brain barrier. Some other forms work better as choline donors such as Alpha-GPC and CDP-Choline.
From a list I saw at ImmInst.org, weakest to strongest choline donors:
PhosphatidylCholine Choline (As bitartrate, Chloride, and Citrate) DMAE CDP-Choline Alpha-GPC
Many studies have been done on CDP itself as a nootropic. So you might want to give that or Alpha a try and see if it helps in combo. You can get Alpha I believe in bulknutrition or one of the sources for sure.