Deployment of spatial attention without moving the eyes is boosted by oculomotor adaptation

Abstract

Vertebrates developed sophisticated solutions to select environmental visual information, being capable of moving attention without moving the eyes. A large body of behavioral and neuroimaging studies indicate a tight coupling between eye movements and spatial attention. The nature of this link, however, remains highly debated. Here, we demonstrate that deployment of human covert attention, measured in stationary eye conditions, can be boosted across space by changing the size of ocular saccades to a single position via a specific adaptation paradigm. These findings indicate that spatial attention is more widely affected by oculomotor plasticity than previously thought.

Reactive saccade adaptation boosts orienting of visuospatial attention

“…Also, while the present behavioral study focused on leftward saccades, investigating saccades in the rightward direction would be an important follow-up study. This would test if this framework underlying the link between SA and attention is completely symmetrical relative to saccade direction, or if, as predicted from the findings of Habchi et al 14 in the reactive/exogenous modality and of Nicolas et al 35 in the voluntary/endogenous modality, is restricted to the leftward direction tested here.…”

“…Also, according to this framework, we can speculate about backward adaptation of rightward saccades: the error signal arising from the left cerebellum would inhibit the right IPS and in turn, activate the left IPS. However, as the PPC of the left hemisphere is not likely to be involved in the capture of attention 39 , this increase of excitability following RS adaptation would not affect performance in an attentional task, as suggested by data published by Habchi et al 14 .…”

“…Our study provides the first demonstration of an effect of SA on covert exogenous attention specifically after adaptation of leftward reactive saccades (RS). The only similar study we are aware of dealt with backward adaptation of both RS and VS, and reported a specific increase of detection performance after adaptation of RS, but not after VS adaptation 14 . This specificity was interpreted in the framework of segregated parieto-frontal systems involved in exogenous and endogenous attention 11 with a partial overlap of the cortical substrates of adaptation mechanisms for RS and VS, respectively 6 .…”

“…Second, and conversely, McFadden et al 13 showed that it is possible to adapt the exogenous shift of attention by ‘stepping the attentional target’ during a covert attentional task (eye movements not allowed) and that this adaptive change transfers to saccades. Third, the reaction time to unpredictable visual stimuli presented in the left hemifield decreased following adaptation of leftward RS 14 . Finally, coupling this behavioral assessment with magnetoencephalography revealed that adaptation of leftward RS increased neural excitability, as indexed by an elevated gamma band power, in a right parietal cortex network including the ventral stream of exogenous shifts of attention 15 .…”

Peer Presence Effects on Eye Movements and Attentional Performance

“…We use the same three tasks as in the above studies, namely, pro-/antisaccades, visual search, and CPT. All three are well-established tools in the attention literature to assess the oculomotor, spatial, and temporal facets of attention, respectively, and our lab has extensive experience with them (Gerardin et al, 2015;Habchi et al, 2015;Nicolas et al, 2019). The difference with earlier studies is that, first, all three tasks are tested in the same group of subjects, rather than across different groups, and second, social presence is embodied by a familiar peer rather than by a stranger or a group of strangers.…”