ARTORG Center for Biomedical Engineering Research

Interactions between attentional networks and their influence on perception: a project in healthy subjects and hemispatial neglect patients

Project Members: Dario Cazzoli, Rebecca Paladini, Lorenzo Diana, Moritz Bader
Project Start: December 2014
Project Funding:  SNF Ambitione (Dario Cazzoli)

Attention can be defined as the preparedness to rapidly and accurately respond to stimuli coming from our environment, and to effectively select between relevant and irrelevant information. According to current models, visual attentional control is based on two separate groups of regions of the cerebral cortex, so-called brain networks. These networks control different attentional aspects (e.g., spatial vs. non-spatial attention), and interact with each other. A disruption of these interactions can lead to attentional disorders, such as hemispatial neglect. Patients with hemispatial neglect, most often after a lesion of the right cerebral hemisphere, have difficulties in directing their attention towards the left side of space, and, in severe cases, they act as though the ‘left side of the world’ would not exist anymore. To date, the interactions between the two attentional networks subtending spatial and non-spatial attentional aspects are poorly understood.


The aim of the project consists in investigating different aspects of these interactions, as well as their influence on visual perception in healthy participants and in patients with hemispatial neglect. Non-invasive brain stimulation techniques (e.g., transcranial magnetic stimulation, TMS; transcranial direct current stimulation, tDCS), are among the principal methods applied in the project. These are painless and non-invasive techniques, which allow: a) to temporarily influence the activity of targeted brain areas, and hence draw causal inferences regarding the functions and interactions of these brain areas; b) in connection with other physiological techniques (such as motor evoked potentials, MEPs) to directly measure the excitability state of said areas.

Moreover, different manipulations of non-spatial attentional aspects (e.g., the alertness level of participants) are applied, and behavioural paradigms as well as eye-tracking are used to assess both spatial and non-spatial attention.

The results of the project can have a significant impact on the understanding of attentional control in the human brain, and they can also provide useful information to better comprehend and treat attentional disorders, such as hemispatial neglect.

Keywords: Spatial attention; non-spatial attention; neglect; non-invasive brain stimulation

Publications:

Paladini, Rebecca Elise; Diana, Lorenzo; Zito, Giuseppe Angelo; Nyffeler, Thomas; Wyss, Patric; Mosimann, Urs Peter; Müri, René Martin; Nef, Tobias; Cazzoli, Dario (2018). Attentional reorienting triggers spatial asymmetries in a search task with cross-modal spatial cueing. PLoS ONE, 13(1), e0190677. Public Library of Science 10.1371/journal.pone.0190677

Paladini, Rebecca Elise; Müri, René Martin; Meichtry, Jurka; Nef, Tobias; Mast, Fred; Mosimann, Urs Peter; Nyffeler, Thomas; Cazzoli, Dario (2017). The influence of alertness on the spatial deployment of visual attention is mediated by the excitability of the posterior parietal cortices.Cerebral cortex, 27(1), pp. 233-243. Oxford University Press 10.1093/cercor/bhw390

Cazzoli, Dario; Chechlacz, Magdalena (2017). A matter of hand: Causal links between hand dominance, structural organization of fronto-parietal attention networks, and variability in behavioural responses to transcranial magnetic stimulation. Cortex, 86, pp. 230-246. Elsevier10.1016/j.cortex.2016.06.015

Chechlacz, Magdalena; Humphreys, Glyn W; Cazzoli, Dario (2016). Spatial and non-spatial aspects of visual attention: Interactive cognitive mechanisms and neural underpinnings.Neuropsychologia, 92, pp. 1-6. Elsevier 10.1016/j.neuropsychologia.2016.08.002

Wantz, Andrea Laura; Martarelli, Corinna; Cazzoli, Dario; Kalla, Roger; Müri, René Martin; Mast, Fred (2016). Disrupting frontal eye-field activity impairs memory recall. NeuroReport, 27(6), pp. 374-378. Lippincott Williams & Wilkins 10.1097/WNR.0000000000000544

Paladini, Rebecca Elise; Diana, Lorenzo; Nyffeler, Thomas; Mosimann, Urs Peter; Nef, Tobias; Müri, René Martin; Cazzoli, Dario (2016). The asymmetrical influence of increasing time-on-task on attentional disengagement. Neuropsychologia, 92, pp. 107-114. Elsevier10.1016/j.neuropsychologia.2016.02.026

Cazzoli, Dario; Rosenthal, Clive R; Kennard, Christopher; Zito, Giuseppe Angelo; Hopfner, Simone; Müri, René Martin; Nyffeler, Thomas (2015). Theta burst stimulation improves overt visual search in spatial neglect independently of attentional load. Cortex, 73, pp. 317-329. Elsevier 10.1016/j.cortex.2015.09.009

Chechlacz, Magdalena; Humphreys, Glyn W.; Sotiropoulos, Stamatios N.; Kennard, Christopher; Cazzoli, Dario (2015). Structural Organization of the Corpus Callosum Predicts Attentional Shifts after Continuous Theta Burst Stimulation. Journal of neuroscience, 35(46), pp. 15353-15368. Society for Neuroscience 10.1523/JNEUROSCI.2610-15.2015