Shared neural control of attentional shifts and eye movements

Abstract

We are able to move visual attention away from the direction of gaze, fixating on one object while attending to something else at a different location, within the region of peripheral vision. It has been widely assumed that the attentional neural systems are separate from the motor systems, but some studies challenge this idea. It has now been suggested that the attentional system is part of the premotor processing in the brain. This model proposes that attentional processes evolved as part of the motor systems, with isolated attentional shifts representing an artificial separation of a natural linkage. Here we test how attentional shifts might be linked to the preparations for making saccadic eye movements. We studied the superior colliculus in monkeys as they shifted their attention during different tasks, and found that each attentional shift is associated with eye-movement preparation.

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

“…Findlay and Walker 1999;Rizzolatti et al 1987Rizzolatti et al , 1994) have proposed such a coupling of spatial shifts of attention (independent of modality) and the preparation of saccadic movements for some time. The SC is the usual suspect in being a neurological counterpart to these models since it is involved in the coordination of covert shifts of attention (Albano et al 1982;Desimone et al 1989;Kustov and Robinson 1996) and the initiation of saccades (reviews in Munoz et al 2000;Scudder et al 2002;Sparks 2002). Moreover, cell organization in the SC is well adapted to the task of shifting gaze to peripheral targets.…”

“…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. However, microsaccades (smaller than 1° of visual angle), the fastest component of miniature eye movements involuntarily altering eye position during fixation, were recently shown to be influenced by covert shifts of attention.…”

Impaired visual search in patients with unilateral neglect: an oculographic analysis

“…Because the pattern of eye movements is often taken as a robust and transparent index of the distribution of attention [19,27,44,45], we might gain insight into the nature of the attentional deficit underlying the visuospatial behavior of these patients through a detailed oculographic analysis. While deficits in eye movement pattern have been documented previously in patients with brain damage and visuospatial deficits (e.g., [9,16,20,30]), there has been little consideration of what gives rise to the observed deficit.…”

Drivers from the deep: the contribution of collicular input to thalamocortical processing

“…Such selection-related activity occurs at the same time that neuronal activity in visual areas of the cortex is enhanced during attentional tasks (Reynolds and Desimone, 1999;Ghose and Maunsell, 2002). This SC selection-related activity is modulated when the monkey attends to a region of the visual field (Kustov and Robinson, 1996), and this modulation occurs only with a spatial cue for that region (Ignashchenkova et al, 2004). The logic then is that the delay activity of these SC neurons might be directed not only to preparing for a saccade to one part of the visual field but also to providing a spatial attention signal to cortex that modulates the activity of visual cortical neurons related to the same part of the visual field.…”