Is it obligatory for me to visit my aunt who has lost her memory, become bedridden, does not speak, and does not recognize visitors?

You must visit your sick aunt because she needs care and assistance. Your visit to her is an act of filial piety towards your mother, a way of maintaining kinship ties, and a visit to the sick. There is immense reward and recompense in this. The Prophet, peace and blessings be upon him, said: "Whoever wishes that his provision be expanded for him and his life span be extended, let him maintain his ties of kinship."