A control panel for controlling the actions of an object using Brain Computer Interface technology. The panel includes a plurality of controls (1) adapted to select a plurality of actions. The control comprises a visible marker (7, 8, 9), and means for effecting continuous relative rotation of the marker with respect to a background (6). The background includes at least one visible target sector (5). The control further comprises a visible indicator (12) whose extent can be varied by a user whilst there is relative rotation between the marker and the background. For an action to be selected, alignment of the marker and the target sector must coincide with the indicator (12) having reached a predetermined extent (11). The control may be adaptive to display differing numbers of markers and different target sectors, depending on the actions permissible at any given time.
