Conférence: Attentional load effects on normal and pathological spatial processing.

IONS

Dr. Mario BONATO (Ghent University) donnera une conférence le 4 juillet sur l'effet de la charge attentionnelle sur le traitement spatial.

 

Cet événement (invitation ) se tiendra à l'UCL dans la salle de séminaire MARTIN V 42B (Jardin Martin V, 42B), à 12 heures, sur le campus de Louvain-en-Woluwe.

Abstract : An efficient processing of the surrounding environment depends on the complex interplay between spatial attention and awareness. This interplay can be dramatically and asymmetrically hampered by a brain lesion as in the case of Unilateral Spatial Neglect. When multiple features have to be processed in parallel spatial processing can become impossible for brain damaged patients but also difficult for healthy participants. In six different studies (4 with brain-damaged patients and 2 with healthy participants) we capitalized on a task recruiting both lateralized and non-lateralized attention (i.e. dual tasking-load). More than fifty stroke patients with chronic brain damage (20 left and >30 right hemisphere damaged) but with no clinical signs of neglect and forty healthy participants (plus 10 MCI cases) were tested. The computerized task required to monitor for the appearance of lateralized target(s)s in isolation or while performing a concurrent secondary task (visual or auditory). In patients, severe unawareness for contralesional space emerged in the target monitoring task when attentional load was increased by the concurrent task, whether visual or auditory. Strikingly, this pattern emerged also in patients with left brain damage and at a temporal distance of several years from the brain insult. We therefore provided compelling evidence that presence, severity and time course of spatial awareness disorders are strongly modulated by task demands and dramatically underestimated in classic clinical tests. In healthy participants neurophysiological measures were also collected. ERPs revealed an early suppression of visual areas under load while pupil dilation allowed to disentangle the load due to the focusing on different features from the load due to their maintenance in WM. This dual-tasking approach mimics everyday life requirements, maximally triggers competitive mechanisms and selectively exacerbates contralesional spatial deficits after brain damage.

Contact : Dr. Emanuele Pasqualotto (emanuele.pasqualotto@uclouvain.be)

Publié le 04 juillet 2016