Schematic of task visual presentations per task. An example of the screen as viewed by the participants during the active or 'on' period of (1) sustained attention task, (2) selective attention task and (3) dual attention task. During the sustained attention task, the circles move vertically and the colour in the centre of the circles change. The participants are asked to respond when the colour changes from green (non-target) to red (target). During the selective attention task, participants are asked to respond when any of the five surrounding letters match the one in the middle (target). Positive feedback is given in the form of highlighted matches (target). During the dual attention task, participants are asked to simultaneously monitor the circles and respond to letter matches at the same time as previously described.