The arrest came at around 8.20am, after she went live on the United Front of Thammasat and Demonstration group's Facebook page asking supporters to join a fresh political protest at 4pm at Ratchaprasong Intersection.
Another protester named Natchanon Pirote, who was also in the same room, was arrested.
There were reportedly three to four people in the room.
According to a video on the Free Youth Facebook page, no video was recorded of the scene when a policeman stated the charges against Panusaya. But there was a recording of the police charges against Natchanon, who was charged with sedition, illegal gathering, using an amplifier without permission and computer crime.
Earlier, Prime Minister Prayut Chan-o-cha declared a state of emergency in Bangkok effective from 4am on Thursday to control the escalating pro-democracy protest in front of Government House since Wednesday.
Police subsequently arrested four rally leaders – Parit Chiwarak (Penguin), Anon Nampa, Prasit Utharoj and Phanuphong Jadnok – and cleared the area of the protesters.