AbstractsBiology & Animal Science

Saccadic eye movements, which rapidly and accurately guide our gaze from one point of interest to another, allow us to interact with our visual environment. Latency and peak velocity are among the most studied parameters of saccades with their characteristics pretty well known. However, much less is known about how the possible lateralization of saccades and how target properties, such as size and salience, influence these parameters. In this study we conducted a systematic investigation of how the size and the salience of a target influence latencies and peak velocity of saccades, while taking into account any modulatory effects of eye dominance and target location. We investigated saccades to targets with seven different saliencies, ranging from almost white to black, and to targets with seven different sizes, ranging from 0.2° to 1.4°. The targets appeared unpredictably to the left or the right of a fixation with their centers 8° away from the screens centre. Our results showed that latencies became shorter towards larger and more salient targets, though peak velocity seemed to remain unaffected. Thus it is important to take target properties into account when investigating saccadic parameters. Our results also showed that for at least some people ocular dominance can explain left-right asymmetries in peak velocity, and thus it is also important to consider this effect before pooling data across the two saccade directions.