Attention capture outside the oculomotor range

Abstract

Neurophysiological studies demonstrated that attentional orienting is performed by fronto-parietal brain areas which also play an important role in oculomotor control. Accordingly, several studies claimed that exogenous attention can only be allocated to where we can potentially make an eye movement, i.e. within the oculomotor range. We tested this assumption by assessing the disruptive effect of a salient distractor at locations within and beyond participants' oculomotor range. Participants rotated their heads ~38° leftwards to prevent them from performing large rightward saccades. In this posture, participants fixated the screen center and focused their attention on a location on the left side of the screen, where they had to discriminate the orientation of a visual noise patch. While assessing visual orientation sensitivity -an established proxy of visual attention -at this endogenously attended location, we flashed a salient cue either at the attended location or at various locations inside or outside their oculomotor range. We found that whenever the salient cue occurred at a location other than the endogenously attended location, it withdrew visual attention and significantly disrupted endogenous attentional orienting. Crucially, this effect occurred regardless of whether the cue was presented within or beyond participants' oculomotor range, demonstrating that exogenous events equally grab our attention both inside and outside the eyes reach. Since spatial exogenous attention was attracted unrestrictedly toward locations to which no saccade could be executed, the coupling of attention and eye movement control is less tight than, for example, the prominent "Premotor Theory of Attention" suggests. Rather, attention can be shifted freely over the entire visual range, independent of pathological and physiological limitations of the eye movement system.

Presaccadic attention depends on eye movement direction and is related to V1 cortical magnification

“…We arbitrarily defined counter-clockwise responses to counter-clockwise oriented gratings as hits and counter-clockwise responses to clockwise oriented gratings as false-alarms 6,80–83 . To avoid infinite values when computing d’, we substituted hit and false alarm rates of 0 and 1 by 0.01 and 0.99, respectively 5,43,44,61 .…”

Independence of implicitly guided attention from goal-driven oculomotor control

“…When this question was posed in the context of endogenous or exogenous attention, studies have uncovered partial independence of attention from eye movements. For example, people can preferentially attend to locations outside of the eyes’ reach (Hanning & Deubel, 2020 ; Hanning et al, 2019 ; also see Craighero et al, 2004 ). Neuropsychological patients who suffer from paralysis to the eyes nonetheless benefit from attentional cueing (Masson et al, 2020 ).…”

Dissociable roles of human frontal eye fields and early visual cortex in presaccadic attention – evidence from TMS

“…We arbitrarily defined counter-clockwise responses to counter-clockwise oriented gratings as hits and counter-clockwise responses to clockwise oriented gratings as false-alarms 9,48,50,62,99 . To avoid infinite values when computing d', we substituted hit and false alarm rates of 0 and 1 by 0.01 and 0.99, respectively 5,15,16,100 .…”

“…Some behavioral and neural correlates of presaccadic attention and covert attention -which likewise enhances sensitivity, but during fixation 12 -are similar 13 . This resemblance has led to the debatable [13][14][15][16][17][18] notion that presaccadic and covert attention are functionally equivalent and rely on the same neural circuitry [19][20][21] . At a broad scale, oculomotor brain structures (e.g., FEF) are also modulated during covert attention 22-24 -yet by distinct neuronal subpopulations [25][26][27][28] .…”