According to the book excerpt below, the BCI research is focused on teaching the BCI of an user to collaborate with it’s user. Strong emotions would lead to rejection of the BCI (something that hurts). The human body treats the BCI more or less as a an extra limb or the prosthesis it really is. Strong emotions are so powerful that they can lead to rejection of the BCI. The question is of course if the induced anger and frustration isn’t because of the researcher’s attempts to teach the BCI to respond to the emotional states in appropriate way, without it being rejected.