15 mai 2020
Nicolas Masson [SSH/IPSY] will talk about: “Exogenous covert orienting of attention and internal shifts of attention without the ability to plan eye movements”.
The talk will last 40’ max, and will be followed by a time for discussion.
Covert shifts of attention and the programming of eye movements recruit in part the same neural networks. Attention can also be directed internally to representations stored in visual working memory. Interestingly, gaze movements or position reflect the content and the spatial properties of what is held in working memory. The orienting of covert and of internal attention are thus currently assumed to result from the neural mechanisms involved in the programming of saccades (e.g., premotor theory of attention). To test this claim, we assessed the ability to orient attention covertly and internally of individuals born with a congenital vertical or horizontal gaze paralysis, caused by oculomotor nerve dysplasia. We used a classical target detection task, assessed in the vertical and in the horizontal axis, with nonpredictive peripheral cues to investigate exogeneous orientating of covert attention and a retro-cueing task to investigate internal attentional shifts. The individuals with congenital gaze palsy showed a significant exogenous cueing effect and retro-cueing effect in the paralyzed orientation, similarly strong than the one observed in typically developed participants and similarly strong in both orientations. Our findings imply that exogenous covert orientation and shifts of internal attention do not result from the programming of oculomotor saccades. This clear dissociation between motor programming and both cueing effects undermines the currently dominant neurobiological models of exogenous covert spatial orienting centred on oculomotor processes.