Neuroanatomical Dynamics Of Attention In Stroke Patients And Healthy Individuals: A Magnetic Stimulation Investigation
Funder
National Health and Medical Research Council
Funding Amount
$360,363.00
Summary
Mechanisms of selective attention are of central importance in guiding human behaviour. The brain uses attention to enhance the processing of information that is behaviourally relevant, and to suppress irrelevant information. The operation of attention within sensory modalities (vision, touch, hearing) has been studied for many decades; however, little is known about how attention combines information between different senses. An understanding of 'crossmodal' attention is important for many reas ....Mechanisms of selective attention are of central importance in guiding human behaviour. The brain uses attention to enhance the processing of information that is behaviourally relevant, and to suppress irrelevant information. The operation of attention within sensory modalities (vision, touch, hearing) has been studied for many decades; however, little is known about how attention combines information between different senses. An understanding of 'crossmodal' attention is important for many reasons. First, real events in the environment provide inputs simultaneously from different locations to multiple senses, and these inputs must be integrated to yield coherent perception. Second, the most basic aspects of human perception depend upon attention; the brain implements selective mechanisms in order to filter the immense quantities of information that constantly bombard our sensory receptors. Finally, many neurological disorders are characterised by impairments of attention; these syndromes are debilitating for the patients themselves, and also place a heavy burden on caregivers and the healthcare system. This project will examine mechanisms of attention in healthy individuals and in stroke patients with attentional deficits. In all experiments, we will employ a new technique in neuroscience called 'transcranial magnetic stimulation' (TMS). TMS enables the safe and reversible stimulation of brain activity in humans. In the current project, we will use TMS with two broad objectives: (i) to determine the key brain areas involved in crossmodal attention in healthy individuals, and (ii) to treat attentional deficits that occur within and between the senses in stroke patients ('magnetic stimulation rehabilitation'). This research will provide important insights into the brain mechanisms that govern selective attention in the healthy brain, and will help guide future methods for managing and treating neurological disorders in which deficits of attention are prominent.Read moreRead less
Crossmodal Interactions In Selective Attention: A Combined Human Lesion/transcranial Magnetic Stimulation Study
Funder
National Health and Medical Research Council
Funding Amount
$188,182.00
Summary
Aspects of attention are of central importance in guiding human behaviour. The brain uses these mechanisms to enhance the processing of sensory information that is currently relevant for behaviour, and to suppress irrelevant sensory information. Although there is a considerable body of knowledge, from both animal and human research, on how attention operates within individual sensory modalities (vision, touch, hearing, etc.), very little is known about how attention integrates information across ....Aspects of attention are of central importance in guiding human behaviour. The brain uses these mechanisms to enhance the processing of sensory information that is currently relevant for behaviour, and to suppress irrelevant sensory information. Although there is a considerable body of knowledge, from both animal and human research, on how attention operates within individual sensory modalities (vision, touch, hearing, etc.), very little is known about how attention integrates information across these different modalities. An understanding of these 'crossmodal' attentional mechanisms is important for several reasons. First, much brain activity in primary sensory areas is modulated by the attentive state of the individual, so discovering how crossmodal attention works will facilitate our understanding of the neural mechanisms of sensory processing generally. Second, the most basic aspects of human perception are fundamentally dependent upon attention; without attention we would perceive inputs from the different senses as fragmentary, rather than as bound together into coherent multimodal representations. Finally, many acquired and developmental neurological disorders are characterised by debilitating impairments of attention. This project will examine crossmodal spatial attention in stroke patients with damage to an exclusively visual brain area (occipital cortex), or to a multisensory brain area (parietal cortex). It will also measure the extent of crossmodal interactions in healthy participants, using cortical transcranial magnetic stimulation (TMS) to induce reversible, 'virtual' lesions that mimic those of the stroke patients. The specific goals of the research are to explain how inputs from the senses of vision and touch interact to give rise to coherent perception; and to provide an empirical foundation for the development of more effective rehabilitative techniques for stroke patients, by exploiting any preserved crossmodal attentional mechanisms.Read moreRead less