Attention: Temporal Dynamics After Stroke
Attention deficits (neglect, extinction, simultanagnosia) are at the core of behavioural impairments occurring after stroke. Our understanding of the neural underpinnings of such disorders remains primarily rooted in neuropsychological studies relying on anatomical characterisations of brain deficits. The few studies of functional brain activity have relied mainly on methods lacking the temporal resolution to chart changes in the modulatory dynamics that are essential to the operation of attention. Members of the Brain & Cognition Lab have begun investigating how the temporal dynamics of visual attention are altered by focal brain lesions by combining non-invasive methods with high temporal resolution (MEG and EEG) with methods with high spatial resolution (fMRI) and psychophysical methods. The studies will shed light on the neuronal signatures of attention deficits commonly observed in stroke survivors.
We are using novel tasks to investigate the interplay between spatial selective attention and temporal orienting of attention after unilateral stroke. Stroke survivors will perform the tasks while their brain activity is recorded, on separate occasions, with high spatial (functional magnetic resonance imaging) and high temporal resolution (magnetoencephalography). We will investigate the relationship between the locations of the lesion, behavioural impairments, and the resulting changes in behavioural networks of attention as well as temporal dynamics.
The innovatory step taken by this project is to combine imaging methods with high temporal resolution with neuropsychological investigation of individuals with specific lesions in order to understand the relative causal contributions of core nodes of the attention network in a dynamic way. The combined MEG-MRI-neuropsychology approach will be extremely fruitful in linking dynamic patterns of neural deficits to behavioural deficits, as well as to chart how dynamic reorganisation of neural activity over time can lead to compensation or remediation of deficits. The findings will contribute to our basic understanding of how spatial and temporal orienting of attention interact dynamically in the brain, as well as contribute clinically relevant markers of attention-related deficits at the individual level in order to develop and evaluate effective personalized therapeutic interventions.
Investigators and Collaborators
Celine Gillebert and Kia Nobre are the lead B&C investigators. Alex Luettich is B&C the doctoral student supported by the INDIREA ITN. Oxford collaborators include Glyn Humphreys (Experimental Psychology), Masud Husain (Experimental Psychology), and Nele Demeyere Experimental Psychology). The INDIREA project also includes colleagues at Pompeu-Fabra, Magdeburg, Copenhagen, and Trinity College Dublin.
Our programme of work is supported by a Sir Henry Wellcome Postdoctoral Fellowship from the Wellcome Trust to Celine Gillebert and by our participation in the EU Initial Training Network INDIREA (Individualised Diagnostics and Rehabilitation of Attention Disorders).
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