The role of attention in the programming of saccades

Abstract

Accurate saccadic programming in natural visual scenes requires a signal designating which of the many potential targets is to be the goal of the saccade. Is this signal controlled by the allocation of perceptual attention, or do saccades have their own independent selective filter? We found evidence for the involvement of perceptual attention, namely: (1) summoning perceptual attention to a target also facilitated saccades; (2) perceptual identification was better at the saccadic goal than elsewhere; and (3) attempts to dissociate the locus of attention from the saccadic goal were unsuccessful, i.e. it was not possible to prepare to look quickly and accurately at one target while at the same time making highly accurate perceptual judgements about targets elsewhere. We also studied the trade-off between saccadic and perceptual performance by means of a novel application of the "attentional operating characteristic" (AOC) to oculomotor performance. This analysis revealed that some attention could be diverted from the saccadic goal with virtually no cost to either saccadic latency or accuracy, showing that there is a ceiling on the attentional demands of saccades. The links we discovered between saccades and attention can be explained by a model in which perceptual attention determines the endpoint of the saccade, while a separate trigger signal initiates the saccade in response to transient changes in the attentional locus. The model will be discussed in the context of current neurophysiological work on saccadic control.

SWIFT: A Dynamical Model of Saccade Generation During Reading.

“…On the basis of these attentional shifts, saccadic eye movements are prepared (Deubel & Schneider, 1996;Kowler, Anderson, Dosher, & Blaser, 1995;Kustov & Robinson, 1996). At the same time, parafoveal information is used to start word recognition.…”

“…33 The mechanism of SAS was introduced first by Morrison (1984), motivated by the attentional "spotlight" metaphor from attentional cuing experiments (Posner, 1980). Basic research on the relation between attention shifts and saccade programming resulted in the observation that attentional shifts precede saccades obligatorily (e.g., Deubel & Schneider, 1996;Kowler et al, 1995). In the E-Z Reader model, however, the basic mechanism for starting a saccade program is a preliminary stage of word processing called the familiarity check.…”

Attentional changes during implicit learning: Signal validity protects a target stimulus from the attentional blink.

“…These include overt attentional changes, such as orienting responses (e.g. Sokolov, 1963) or changes in gaze direction (Deubel & Schneider, 1996;Kowler, Anderson, Dosher, & Blaser, 1995) in response to a CS becoming meaningful, which have a direct impact on the physical sampling of the stimulus. Even where the locus of attention diverges from gaze direction (e.g.…”

Crossmodal coupling of oculomotor control and spatial attention in vision and audition

“…Typically, saccades are preceded by covert shifts of visual attention to the target location (Deubel and Schneider 1996;Hoffman and Subramaniam 1995;Kowler et al 1995) and can enhance hearing performance at that location prior to the movement (Rorden and Driver 1999). In turn, shifts of covert attention were linked to saccade preparation (Kustov and Robinson 1996;Rizzolatti et al 1987Rizzolatti et al , 1994) but do not necessarily initiate saccades, i.e., we can attend to locations in the visual periphery without large eye movements.…”