Yes it requires training for each individual. In addition, they tested using a trained model from one person to try to decode a different person and the results were no better than chance.
They also said that the person must cooperate for the decoding to work, meaning the person could reduce the decoding accuracy by thinking of specific things (e.g. counting).
CORRECTION: The paper I read was not the correct paper, ignore this comment. The actual paper states that the model is transferrable across subjects.
They also said that the person must cooperate for the decoding to work, meaning the person could reduce the decoding accuracy by thinking of specific things (e.g. counting).
CORRECTION: The paper I read was not the correct paper, ignore this comment. The actual paper states that the model is transferrable across subjects.