Abstract
Findlay & Walker's (1999) model of eye movement control specifies a system where the need to fixate and the urge to make a saccade (represented by activation in the ‘FIXATE’ and ‘MOVE’ centres, respectively) are in competition, and are bound together by reciprocal inhibitory links. This has important ramifications for attempts to train eye movements, as any attempt to focus upon one aspect of eye movements may degrade behaviour that is dependent upon the other. In a series of experiments we tested the hypothesis that directing eye movement training towards the MOVE centre would hinder the ability to extract task relevant information when fixating. Participants carried out a difficult discrimination on a centrally presented letter at the start of each trial. This initial task was purposefully designed to compete with the additional requirement to search a simultaneously presented peripheral array for a target digit amongst non-digits. Two participant groups provided the crucial comparison data: one was given No Training (NT) throughout; the second were given eye Movement Training (MT), being informed that the peripheral target appeared in a predictable pattern from one trial to the next. As predicted the MT group showed evidence that their respective training detracted from their ability to initially process the central letter: this group needed to re-fixate the letter for longer durations in order to respond correctly. This research adds to the growing body of evidence about the interplay between top-down and bottom-up factors in visual search by extending the previously underspecified higher levels of Findlay & Walker's model. Moreover the results are highly relevant for applied areas of vision research, such as driving, as they demonstrate that the emphasis often placed upon maintaining vigilant scanning (e.g. Mills, 2005) may be misplaced.
Funded by the Economic and Social Research Council.