Our detections vary in accuracy and each detection is different. Indeed the accuracy expressed is an average across users, therefore for some people the detection is more accurate than the quoted figure and for others the accuracy is less.
Mental Commands can achieve very high accuracy for a single command and the accuracy becomes less when more actions are added. But in this case the accuracy is also strongly dependent on the user's skill level and ability to remember the mental state used in training.
Performance Metrics detections vary significantly. Excitement is very accurate, Frustration and Engagement a little less and Meditation covers some types of meditation quite well and others less so (for example, meditation styles may have high or low cognitive involvement).
For Insight they range from about 70% for Interest to over 85% for Excitement when measured against standardised tests and other biosignals in our lab. Measuring accuracy of emotional detections is very difficult because there is not really any objective standard for 'how excited' you are, for example (because everyone is different, therefore we rescale each user's responses onto a 0-100% range which represents their 'normal' range as observed by our system).
All in all, EPOC+ retains higher accuracy in more situations. In good operating conditions both headsets perform well in detecting our key emotional and cognitive outputs.