There is a large interest in user experience today, both from a usability and accessibility point of view. However, in order to verify what the users actually like and don't like, user testing must be conducted. Traditionally, user experience is measured retrospective with surveys and interviews, but this is not the most optimal approach since it does not measure user experience in the moment and it is prone for human error because of our inaccurate memory recollection. Here we propose a method that does semi-automated evaluation of user experience by utilizing electrophysiological equipment that monitors electrical activity of the brain. We describe an approach that together with brain activity monitoring will collect and quantify user experience in a non-intrusive manner. We demonstrate the method by showing how a low cost device can record brain activity during a user test, and auto-detect where the user has difficulties understand or navigating a solution. All this is done in an unsupervised manner, but an observer must still verify the feedback with the actual user to remove false positives. Our method is not limited to digital solutions and can also be used for evaluating user experience of physical installations.