Neuroimaging Of Human Visual Cortex Using Functional Magnetic Resonance Imaging: Improving Multivariate Techniques For Decoding Brain Activity
Funder
National Health and Medical Research Council
Funding Amount
$316,449.00
Summary
This research will investigate how the brain processes visual information using non-invasive functional magnetic resonance imaging (fMRI). The aims of this project are to advance techniques for "decoding" human brain activity from fMRI and to increase our understanding of how the brain uses visual information. Improvements in fMRI analysis will allow this cutting-edge technique to be applied more readily in clinical settings for improved treatment and diagnosis of neurological disorders.
One of the main trends in the evolution of the primate brain was the huge expansion of the cortical areas devoted to visual processing. However, the exact role of individual areas remains highly controversial, making detailed physiological and anatomical studies in suitable primate models a key step to elucidating their function in the human brain. In this project, we will address the organization of a poorly known group of visual areas, which is located deep in a part of the brain called the in ....One of the main trends in the evolution of the primate brain was the huge expansion of the cortical areas devoted to visual processing. However, the exact role of individual areas remains highly controversial, making detailed physiological and anatomical studies in suitable primate models a key step to elucidating their function in the human brain. In this project, we will address the organization of a poorly known group of visual areas, which is located deep in a part of the brain called the interhemispheric fissure (the medial complex of visual areas). Preliminary evidence suggests that these areas may provide anatomical shortcuts linking vision, behavioural reactions, and emotion. Suppose, for example, that you are sitting outside reading. Although deep in concentration, you are still able to detect the sudden movement of an approaching object in your peripheral field of vision. In many cases you can react (e.g., by ducking , or raising your arms to protect the face) long before you register what the object actually is. An adrenaline rush often accompanies these quick motor reactions, implying a parallel activation of the autonomic nervous system. While the mechanism by which the brain promotes these quick reactions remains poorly understood, we believe that the medial complex of visual areas holds the key. The aim of this study is to map the anatomical framework underlying our ability to react to sudden stimuli in our peripheral visual field. Such work is fundamental for understanding the functional organization of the brain. It also has the potential to lay the groundwork for developments in areas of applied research, including medicine (e.g. the design of better rehabilitation strategies for people with brain damage) and the cognitive sciences (e.g. a better understanding of the factors that limit human responses to visual stimuli).Read moreRead less
Neural Mechanisms That Limit The Visual Sensitivity Of Primates
Funder
National Health and Medical Research Council
Funding Amount
$379,400.00
Summary
This project concerns the way nerve cells in the brain enable the detection and perception of objects in the visual world. It is thought that nerve cells early in the visual pathway signal the presence or absence of light in a small part of the visual field, but the nature of the neuronal code carried by these pathways remains poorly understood. The aim of our project is to address this basic question, in experimental studies of the intact primate visual system. We will conduct two sets of exper ....This project concerns the way nerve cells in the brain enable the detection and perception of objects in the visual world. It is thought that nerve cells early in the visual pathway signal the presence or absence of light in a small part of the visual field, but the nature of the neuronal code carried by these pathways remains poorly understood. The aim of our project is to address this basic question, in experimental studies of the intact primate visual system. We will conduct two sets of experiments. Firstly, we will test the hypothesis that nerve cells in the early visual system are sensitive to only a small part of the visual field. We will determine whether the signals of pre-cortical nerve cells are dependant on spatial context. Secondly we wll study the signals of several nerve cells simultaneously using multiple electrodes. We will determine if the signals of many nerve cells are required to detect small visual stimuli like those used in perimetry. These experiments address basic questions, but have application to human vision and visual dysfunction. Good acuity is essential for everyday tasks such as reading, and defects in visual sensitivity are used for early detection of neurological dysfunction in diseases such as glaucoma and macular degeneration. Understanding the properties of neurons which underlie visual perception can thus help us to understand normal visual performance, and how this changes in partial sight. This can help develop better methods for detection and treatments for such disorders.Read moreRead less
Discovery Early Career Researcher Award - Grant ID: DE190101043
Funder
Australian Research Council
Funding Amount
$404,956.00
Summary
Tackling facial prejudice. This project aims to investigate individual differences in facial prejudice, a powerful psychological bias whereby people rely on inaccurate first impressions to guide key decisions, such as whom to trust. Utilising recent advances in electrophysiology, the project will develop a new neural marker of individual differences in facial impressions that lead to prejudice. The project expects to lead to insights into the link between visual perception and social behaviour, ....Tackling facial prejudice. This project aims to investigate individual differences in facial prejudice, a powerful psychological bias whereby people rely on inaccurate first impressions to guide key decisions, such as whom to trust. Utilising recent advances in electrophysiology, the project will develop a new neural marker of individual differences in facial impressions that lead to prejudice. The project expects to lead to insights into the link between visual perception and social behaviour, and to develop strategies to reduce facial prejudice given the pervasive influence it has on everyday life.Read moreRead less
Who may judge a book by its cover? This project aims to build a model of how and why people vary in their impressions of others and in the accuracy of these impressions. People readily form impressions of others from their faces and these impressions influence crucial decisions: election results, court case outcomes and partner choices. To build this model, the project will apply twin data and construct a psychometric test to measure variation in facial impressions. The research is expected to l ....Who may judge a book by its cover? This project aims to build a model of how and why people vary in their impressions of others and in the accuracy of these impressions. People readily form impressions of others from their faces and these impressions influence crucial decisions: election results, court case outcomes and partner choices. To build this model, the project will apply twin data and construct a psychometric test to measure variation in facial impressions. The research is expected to lead to insights into this aspect of social perception, and to identify the sources of atypical or inaccurate facial judgements. This has applications in health contexts (to identify social impairment) and in security contexts (for personnel selection).Read moreRead less
Attention vs Perception: When is selection optimal, when relational? This project aims to investigate an important, newly discovered dissociation between early visual selection and perceptual decision-making. Contrary to current theories, attentional and perceptual processes are tuned to different stimulus attributes described in the relational vs. optimal account, which implies that current theories of attention do not describe early attention but later, decisional processes. This project will ....Attention vs Perception: When is selection optimal, when relational? This project aims to investigate an important, newly discovered dissociation between early visual selection and perceptual decision-making. Contrary to current theories, attentional and perceptual processes are tuned to different stimulus attributes described in the relational vs. optimal account, which implies that current theories of attention do not describe early attention but later, decisional processes. This project will provide an accurate description of these processes, which promises important theoretical breakthroughs. Work on this project will also significantly advance methods to detect and describe early attentional processes, by identifying error-prone methods of Psychophysics and Neuroscience studies, and proposing remedies.Read moreRead less