Effect of Allocentric Landmarks on Primate Gaze Behaviour in a Cue Conflict Task

The brain can remember the location of a peripheral target relative to self (egocentric) or to an external landmark (allocentric). The relative reliabilities of egocentric and allocentric coding had been examined in reach, but it was never explored in the gaze control system. In this study, we utilized a cue conflict task to create a dissociation between egocentric and allocentric information to assess the effect of allocentric cues on gaze behaviour in two macaque monkeys. The results showed that the monkey gaze behaviour is a combination of both reference frames depending on the reliability of the allocentric cue. We also found that the allocentric cue was significantly more reliable when it is located closer to the fixation point, and when the cue shifts further away from the fixation point or the original target. Our findings suggest that the influence of allocentric cues on gaze behaviour depends on various gaze parameters.