Other permitted activities under the non-lucrative residency in Spain

Hi All,

I am Filipino and based in the US. I am thinking of moving to Spain next year under the non-lucrative residency. I have enough financial/economic resources to live well in Spain for a year, and possibly for two years.

I am well aware that the non-lucrative residency will not allow me to take up paid employment in Spain. My question: will I be allowed to take up non-paid volunteer work, or perhaps study masters or doctorado programs with this residence permit?

Thank you!