Functional Connectivity Between Visual Cortical Areas In The Non-human Primate
Funder
National Health and Medical Research Council
Funding Amount
$387,585.00
Summary
Visual information going from the eyes to the brain is processed in different parts of the brain to extract useful information. However, to be able to select what is important from among the vast number of objects in the scene, top-down signals from higher areas need to act on incoming signals in earlier areas. This project aims to identify what sort of neural pathways are involved in this and how it is done at the cellular level.
The Role Of Ten-m3 In Patterning Ipsilateral Retinal Projections
Funder
National Health and Medical Research Council
Funding Amount
$453,042.00
Summary
The normal functioning of the brain depends on connections of billions of nerve cells or neurons. We have found that a protein called Ten_m3 plays a very important role in specifying the way that neurons from the eye connect to the brain. The role of this protein is so important that mice which lack the protein behave as if they are blind. The aim of this project is to understand how this protein controls the development of the visual system.
Network Properties Of Colour Pathways In Primates.
Funder
National Health and Medical Research Council
Funding Amount
$594,891.00
Summary
This project concerns the way in which the eye and brain work together, to enable perception of the colour, form, and movements of objects in the visual world. It is thought that these different attributes of the visual environment are signalled by several parallel nerve pathways in the visual system, 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 visu ....This project concerns the way in which the eye and brain work together, to enable perception of the colour, form, and movements of objects in the visual world. It is thought that these different attributes of the visual environment are signalled by several parallel nerve pathways in the visual system, 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 plan two sets of experiments. Firstly, we will test the hypothesis that signals for both high-acuity form vision and red-green colour vision can be carried along a single neuronal pathway. We will determine whether response timing in nerve pathways provides a clue by which colour and brightness variation in the environment can be discriminated. Secondly, we will study the segregation of colour and acuity-related signals in the brain, using the method of functional optical imaging. This method, which allows nerve activity to be monitored at high resolution, over relatively large areas of the brain surface (cortex), will allow us test the hypothesis that colour signals are segregated to distinct regions of the visual cortex. 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 specific defects in colour vision are used for early detection of neurological dysfunction in diseases such as glaucoma and multiple sclerosis. Understanding the properties of neurons which underlie visual perception can thus help us to understand normal visual performance, and to develop better methods for detection and treatments for such disorders.Read moreRead less
Functional Interactions Between Primate Cortical Areas In Tasks Involving Attention And Short-term Memory
Funder
National Health and Medical Research Council
Funding Amount
$267,280.00
Summary
To navigate and operate in the cluttered and dynamic sensory world around us, our brains need to be able to attend to specific objects or features in the environment, identify them and also know where they exist at any one instant of time, prior to performing the appropriate action. The attention, memory, decision and motor components involved in this process possibly involve a variety of cortical areas and neuronal operations. The special primate preparation we have developed permits us to eluc ....To navigate and operate in the cluttered and dynamic sensory world around us, our brains need to be able to attend to specific objects or features in the environment, identify them and also know where they exist at any one instant of time, prior to performing the appropriate action. The attention, memory, decision and motor components involved in this process possibly involve a variety of cortical areas and neuronal operations. The special primate preparation we have developed permits us to elucidate at a neuronal level many of these brain mechanisms. By recording neuronal activities in two different cortical areas simultaneously as the monkey performs a memory task that he has been trained on, we will test the following ideas: (1) A cortical region in the dorsal, parietal stream directs spatial attention by gating other visual areas to process only a selected region of the visual world (2) A region in the ventral, temporal stream directs attention to specific features in the visual world by gating earlier cortical areas (3) The parietal cortical areas that mediate intention for action hold the relevant information in working memory till it is forwarded to the more anterior premotor areas. These experiments have the potential to reveal the basic neuronal scheme that underpins functions such as attention, visual recognition and memory, which are impaired in many neurological disorders.Read moreRead less
Understanding The Organisation Of The Medial Parietal Cortex: Sensorimotor Integration For Goal-directed Behaviour
Funder
National Health and Medical Research Council
Funding Amount
$551,862.00
Summary
Reaching and grasping are of obvious significance for a productive life, and many of the brain areas known to be involved in the direction of arm movements are located in the parietal lobe. Stroke affecting this part of the brain causes disability, as people become unable to reach accurately, or to close their hands around objects with appropriate strength. This project will combine modern physiological and anatomical methods to reveal the brain circuitry responsible for such crucial skills.
While there has been recent excitement about possible treatments for the symptoms of Autism, advances in understanding the underlying neuroscience of abnormal brain function that underlies autistic tendency are still painfully slow. This application aims to establish fully a physiological mechanism for altered autistic perception, to see if it can be applied to early diagnosis in infants and young children and to establish whether in such plastic young brains it is possible to guide perceptual l ....While there has been recent excitement about possible treatments for the symptoms of Autism, advances in understanding the underlying neuroscience of abnormal brain function that underlies autistic tendency are still painfully slow. This application aims to establish fully a physiological mechanism for altered autistic perception, to see if it can be applied to early diagnosis in infants and young children and to establish whether in such plastic young brains it is possible to guide perceptual learning to permanent improvement.Read moreRead less
Novel Approaches To Understanding Peripheral Vision In Patients With Central Vision Loss
Funder
National Health and Medical Research Council
Funding Amount
$367,101.00
Summary
The aim of my research is to develop novel interventions that enhance the peripheral vision of patients with central vision loss, and to investigate the neural correlates of visual perception in peripheral vision in typical adults. My research will inform rehabilitation strategies that optimise the visual function of patients with partial blindness, and provide a more thorough understanding of the underlying neural mechanisms that reduce the quality of peripheral vision.
The superior colliculus is a brain centre which uses visual information from the eyes and other sensory information, such as sound, to direct the head and eyes towards objects of interest. This project will use current advancements in optogenetics to activate connections to this brain region in order to understand its role in coordinating head and eye movements. This will advance our understanding of how the brain collects and processes visual information to subserve behavioural functions.
Functional Anisotropies In The Processing Of Orientation And Direction-of-motion By Human Visual Cortex
Funder
National Health and Medical Research Council
Funding Amount
$366,164.00
Summary
We will study patterns of activity in the human brain to identify the cortical signature of normal visual function. The correspondences between patterns of brain activity and the structure and motion of the visual image in the normal human brain will provide data against which brain activity in a range of disorders from amblyopia to schizophrenia can be assessed.
The human brain has many subdivisions (�areas�) that are dedicated to vision, but in many cases their functions remain unclear. This project will study an area located deep in the brain, about which very little is known, and which appears to be affected from early stages in conditions such as Alzheimer�s disease. By understanding the patterns of electrical activity of cells in this region, and their connections with other brain areas, we hope to decipher their contribution to sensory cognition.