The MRC Institute of Hearing Research is studying the brain networks involved in covert spatial orienting of attention across visual and auditory modalities using an fMRI scanner in the Sir Peter Mansfield Magnetic Resonance Centre at the University of Nottingham.
In a visual task, participants are presented with an object that moves in a circular trajectory and required to judge whether the object changes in velocity. In an auditory task, participants are required to make a judgement about a sound that is presented either to the left or to the right ear.
Participants are tested in an fMRI scanner in order to measure which brain areas are activated by shifts in attention. However, saccadic eye-movements can activate the same brain areas so it is essential that participants maintain fixation (keep their eyes still) throughout the experiment.
The IHR uses the iView X MEyetrack SV (iView X in conjunction with the Avotec Silent Vision fibreoptic goggles system) to monitor eye-movements in the scanner, and to present visual stimuli to the participant. The iView X RED remote system is also used to run the same experiments outside the scanner. An ethernet link synchronises eye-movement data with fMRI data and stimulus presentation, and BeGaze is used to automatically detect when participants made an eye-movement to ensure that these trials are removed from fMRI analysis.