Eye Movements and Illusions of Alignment

Extraction of the location of a target in the visual periphery is a fundamental visual process which may be manifested both in conscious judgments of location, such as decisions about alignment, and in the processing required to execute an eye movement to a peripheral target. In both cases, location judgement is affected by the neighbouring visual configuration. An experiment is reported in which the amplitude of saccadic eye movements has been measured to study the effect of a configuration consisting of a single 'induction line'. The results demonstrate systematic effects of this line on the size of the saccade which are closely similar to those previously found in an alignment task.