The disengagement deficit in spatial attention: evidence from lesion-symptom mapping after focal brain injury

Poster Session F - Tuesday, April 16, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Sélim Coll¹ (selim.coll@unige.ch), Emilie Marti¹, Naz Doganci¹, Radek Ptak^1,2; ¹Laboratory of Cognitive Neurorehabilitation, Faculty of medicine, University of Geneva, 1206 Geneva, Switzerland, ²Division of Neurorehabilitation, University Hospitals of Geneva, Rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland

Posner's spotlight analogy proposes three attention-orienting mechanisms: disengagement, moving, and engagement. Early research linked disengagement deficits to superior parietal damage, regardless of hemisphere and presence of spatial neglect. Subsequent studies suggested the involvement of more ventral parietal regions, especially in the right hemisphere (RH), and linked spatial neglect to disengagement issues from ipsilateral cues. However, prior lesion-symptom mapping (LSM) studies faced limitations, including small sample sizes and absence of control groups. Additionally, some studies employed central cues or used long cue-target intervals, which may fail to reveal impaired disengagement. We used a machine-learning approach to conduct LSM on 89 patients with focal cerebral lesions to the left hemisphere (LH) or RH. A group of 54 healthy participants served as controls. Participants were tested with a cueing task that employed peripheral cues and short cue-target intervals, targeting exogenous attention. The main factors of interest were group (healthy participants, LH, RH), target position (left, right hemifield) and cue validity (valid, invalid). While LH patients showed a general contralesional slowing of RTs, only RH patients additionally exhibited a disengagement deficit, as evidenced by a significant interaction between group, target position and cue validity. LSM associated these behavioral outcomes with a cluster in the right superior temporal gyrus, which additionally affected subcortical white matter of the right arcuate fasciculus, corticothalamic pathway, and superior longitudinal fasciculus. Contrary to previous small-scale lesion studies, our results emphasize the role of superior temporal regions, as well as fronto-temporal and fronto-parietal disconnection in the emergence of the disengagement deficit.

Topic Area: ATTENTION: Spatial