3D user interfaces (3DUI) are increasingly used in a number of applications, spanning from entertainment to industrial design. However, 3D interaction tasks are generally more complex for users since interacting with a 3D environment is more cognitively demanding than perceiving and interacting with a 2D one. As such, it is essential that we could evaluate finely user experience, in order to propose seamless interfaces. To do so, a promising research direction is to measure users’ inner-state based on brain signals acquired during interaction, by following a neuro­ergonomics approach. Combined with existing methods, such tool can be used to strengthen the understanding of user experience. In this paper, we review the work being undergone in this area; what has been achieved and the new challenges that arise. We describe how a mobile brain imaging technique such as electroencephalo­graphy (EEG) brings continuous and non-disruptive measures. EEG-based evaluation of users can give insights about multiple dimensions of the user experience, with realistic interaction tasks or novel interfaces. We investigate four constructs: workload, attention, error recognition and visual comfort. Ultimately, these metrics could help to alleviate users when they interact with computers.