NSERC RTI

Upgrade to Eyelink II eye tracker

von Grünau, M., & de Almeida, R. (Concordia University)

Funds from this grant will be used to purchase EyeLink II Head-free Eye-tracking System, supplied by SR Research Ltd. The requested equipment will be used to monitor and measure eye movements during psychophysical, scene processing, and psycholinguistics experiments, involving visual stimuli generated on computer monitors or on a large projection screen. It will also be used in some experiments in conjunction with psychophysical measurements of attention and motion, and simultaneously with recordings of orienting responses such as head and hand movements, and during locomotion on a treadmill.

In the majority of our studies we require subjects to keep steady fixation during stimulus presentation, sometimes for extended periods of time. Even after much training this is a very difficult task, especially if moving stimuli are present, as they often are. Good fixation is essential in order to interpret the obtained results. This is true in a similar way for attention studies, where we try to separate movement of attention from movement of the eyes.

Eye movements are extremely important for visual attention. We are proposing to study the relationships between attention, eye movements and other orienting behaviors in a novel extension of the ongoing research. The tracking and measurement of eye movements before and during attentional shifts (reflexive and directed) will be explored. We also use eye movements as an online indicator of linguistic processing of specifically constructed sentences, and we have started a new program to investigate the interaction of visual, linguistic and attentional variables in this context.