Abstract: In a system for measuring biopotential signals generated by the physiological activity of a subject, it is necessary to monitor the measured biopotentials against a reliable reference. An apparatus and method of deriving a reference suitable for use in referencing and grounding of the subject are described.

Abstract: There is provided a sensor for an electroencephalographic (EEC) device for measuring electrical signals generated by the neuronal activity of a subject. The sensor has at least one blade-like contact surface and the contact surface has a curved profile adapted for user comfort and electrical contact.

Abstract: A method and system for tracking visual attention are disclosed. By generating at least one visual stimulus with a characteristic modulation, the characteristic modulation being applied to high spatial frequency, HSF, components of the visual stimulus and displaying the or each visual stimulus via a graphical user interface, GUI, of a display, a neural response may be induced in the user's brain. By receiving neural signals of a user from a neural signal capture device, such as an EEG device, a point of focus of the user (when the user views the visual stimulus) may be determined based on the neural signals, since the neural signals include information associated with the characteristic modulation of a visual stimulus to which the user's visual attention is directed.

Abstract: A system and method relating to a brain-computer interface in which visual stimuli are presented in direct association with real world objects such that the intention of the user with respect to objects in the real world can be inferred without the interposition of a screen or other display device.

Abstract: According to one aspect, the present description relates to a portable device (10) for acquiring electroencephalographic (EEG) signals emitted by a user. The portable device comprises a flexible support (11) intended to fit a localized region of the skull of the user and a set of sensors (13) of electrical signals generated by the neuronal activity of the user, arranged on said support (11) so as to form contacts with the scalp when the device is worn by the user. For each sensor, an electronic circuit for filtering and amplifying electrical signals detected by said sensor is incorporated in the flexible support (11) and forms, with said sensor, an active electrode. The portable device also comprises a housing (12) comprising an electronic system for processing signals from said electronic filtering and amplification circuits, said housing being linked mechanically to the flexible support to form, with said support, a means of attachment to a garment or accessory (101) intended to be worn by the user.