From Pathfinder Gamemastery Guide, which isn't enabled.

Linguistic Nexus

ACTION

Aspect mind

Your relic grants you a powerful neural plasticity, and as a result, you can learn languages more easily. You learn an additional language of your choice for every 2 levels of the relic (minimum 1). You can retrain one of the languages from the relic with only a single week of downtime.

Pathfinder Gamemastery GuideOGL