Human-computer interaction (HCI) researchers continually work to increase the communication bandwidth and quality between humans and computers. We have explored visualizations and multimodal presentations so that computers may use as many sensory channels as possible to send information to a human. Similarly, we have devised hardware and software innovations to increase the information a human can quickly input into the computer. Since we have traditionally interacted with the external world only through our physical bodies, these input mechanisms have required performing some form of motor activity, be it moving a mouse, hitting buttons, or speaking. However, advances in cognitive neuroscience and brain imaging technologies provide us with the ability to interface directly with the human brain. This ability is made possible through the use of sensors that can monitor the electrical and chemical changes within the brain that correspond with certain forms of thought.

At Microsoft Research, we believe that the full potential of brain sensing as an input mechanism lies in the extremely rich information it could potentially provide about the state of the user. Having access to this state is valuable to HCI researchers because it may allow us to derive more direct measures of traditionally elusive phenomena such as task engagement, cognitive workload, surprise, satisfaction, or frustration. These measures could open new avenues for evaluating systems and interfaces. Additionally, knowing the state of the user as well as the tasks they are performing may provide key information that would allow us to design context sensitive systems that dynamically adapt themselves to optimally support the user's current state and goals. We are currently working on systems that allow us to classify such states using EEG, EMG, and other physiological sensors.