Yup. You need Insight points. Then open the character sheet in the game itself. Put in Insight points to get +5 exp points to the desired Ability. Alternatively, exp points are gained automatically for passing checks. If their amount is sufficient, the Ability will automatically level up.
Actually, it's all described on the two "tutorial" pages (Abilities and Insight). A hint is in the settings if you missed them during character generation.
I'm not quite sure I understand what you mean by "temporary" and "permanent" methods. Abilities gain experience and grow either automatically (by passing checks) or by manually pouring Insight into them on the character screen (1 point of Insight = +5 experience points to chosen Ability). In the latter case, you need at least 1 (or more) Insight points in the "Inspire" column for the clickable button to appear. Otherwise, the button there will be gray with the inscription "No Insight".
