Chromatic Inputs to Cortical Receptive Fields in Primates. The human eye contains three kinds of receptors for daytime vision, named blue, green and red cones for their sensitivity to different regions of the visible spectrum. It is known that blue cones contribute to brain pathways for colour vision, but recent data suggest there is also 'cross-talk' of blue cone signals to pathways for motion and high-acuity vision. This project comprises precise measurement of blue cone signals, and anatomica ....Chromatic Inputs to Cortical Receptive Fields in Primates. The human eye contains three kinds of receptors for daytime vision, named blue, green and red cones for their sensitivity to different regions of the visible spectrum. It is known that blue cones contribute to brain pathways for colour vision, but recent data suggest there is also 'cross-talk' of blue cone signals to pathways for motion and high-acuity vision. This project comprises precise measurement of blue cone signals, and anatomical tracing of blue cone pathways, in a primate model for human vision. The data will improve our basic knowledge of how the brain processes sensory signals.Read moreRead less
Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0452971
Funder
Australian Research Council
Funding Amount
$102,900.00
Summary
Optical imaging of brain activity: Studies of the neural basis of sensory perception, plasticity and behaviour. Basic to the understanding of the brain is to know how the overall architecture of the nervous system relates to its function. We propose to study this by directly visualising the regions that are functionally active in the living brains of animals, down to resolution limits of less than 100 micrometres. Such "optical imaging" will be done by recording light reflected from the surfac ....Optical imaging of brain activity: Studies of the neural basis of sensory perception, plasticity and behaviour. Basic to the understanding of the brain is to know how the overall architecture of the nervous system relates to its function. We propose to study this by directly visualising the regions that are functionally active in the living brains of animals, down to resolution limits of less than 100 micrometres. Such "optical imaging" will be done by recording light reflected from the surface of the brain, which in turn depends upon activity-dependent intrinsic signals (eg. degree of oxygenation of haemoglobin). These signals will be recorded by a special camera and amplified using the requested system.Read moreRead less
Neural Circuits For Active Vision In The Primate Cerebral Cortex
Funder
National Health and Medical Research Council
Funding Amount
$632,938.00
Summary
This project will try to understand how we use visual information to identify objects by their shape and motion, in natural situations in which the eyes are moving all the time. This will be accomplished by recording the electrical activity of brain cells while a trained animal is performing different types of tasks, such as tracking a moving object or exploring a scene with its eyes.
Harnessing non-invasive brain stimulation to improve language function in healthy and pathological ageing. This project will examine how the ability of the ageing brain to process language can be improved by non-invasive brain stimulation. The findings have the potential to reveal new ways to treat language impairments in ageing-associated brain injury and disease.
We are able to identify and discriminate objects in the world because of exquisitely detailed and rapid processing of sensory information by neurons in the cortex of the brain. In this project we will examine these operations in neurons in the cortex that receive input from the large face whiskers of the rat. These whiskers are used for fine-grain discrimination and for gauging distance. They are deflected by being actively moved, under muscle control, over objects (active touch) or by being pas ....We are able to identify and discriminate objects in the world because of exquisitely detailed and rapid processing of sensory information by neurons in the cortex of the brain. In this project we will examine these operations in neurons in the cortex that receive input from the large face whiskers of the rat. These whiskers are used for fine-grain discrimination and for gauging distance. They are deflected by being actively moved, under muscle control, over objects (active touch) or by being passively deflected by objects. Deflection results in inputs to the brain that are processed to form the neural basis for very finely detailed perceptual behaviour. In rats, with impoverished visual and auditory senses, the whiskers are the major sensory system for interacting with the world, and are used in navigating the environment and in finding and distinguishing foods. Thus they contribute strongly to the remarkable success of this species. This elegant sensory system has a number of advantages that make it a very good model for the study of brain mechanisms responsible for active fine-grain sensory function. We plan to take advantage of the unique features of this system to define the information processing that occurs in the cortex in this elegantly complex system. This will address an issue relevant to all sensory systems - namely the neural basis of complex fine grain perceptual behaviour. Understanding the mechanisms underlying active tactile perception also has relevance to clinical conditions involving deficits in active touch e.g., in diabetic polyneuropathy (which eventually affects ~50% of diabetics), in leprosy (in which an early sign is damage to active touch). Knowledge of the core brain processes in active touch gained in this study could eventually underpin the ameliorative technologies for such deficits.Read moreRead less
Improving Oral health is a priority of the NHMRC Strategic Plan 2003-06. The proposed research is consistent with this priority as we will achieve a better understanding of the cortical control of human jaw muscles, which serves as the foundation for understanding conditions in which their function is impaired, and the development of rational therapies for these conditions. Transcranial magnetic stimulation will be used to activate the motor cortex and corticobulbar descending pathway to the jaw ....Improving Oral health is a priority of the NHMRC Strategic Plan 2003-06. The proposed research is consistent with this priority as we will achieve a better understanding of the cortical control of human jaw muscles, which serves as the foundation for understanding conditions in which their function is impaired, and the development of rational therapies for these conditions. Transcranial magnetic stimulation will be used to activate the motor cortex and corticobulbar descending pathway to the jaw muscles. The AIM 1 study will provide important new information about the functional organisation of the motor cortex in the control of jaw muscles during speech. This information is needed to improve understanding of dysarthria, a common disturbance of speech due to impaired muscular control following unilateral cortical stroke, and less common conditions involving speech motor control such as spasmodic dysphonia (a cranial dystonia) and dysprosody (disturbance of speech articulation and rhythm found in Parkinson s disease). The AIM 2 and 3 studies will provide a comprehensive characterization of cortical inhibitory mechanisms that are an important but poorly understood component of the cortical control of jaw muscles. This information is necessary to understand normal function, and the mechanisms of disturbances to jaw muscle function with neurological disease or injury. The AIM 4 studies will show whether impaired cortical inhibition contributes to the pathophysiology of two poorly understood disorders affecting jaw muscles (bruxism and oromandibular dystonia). Current therapies for these conditions are unsatisfactory, due to a limited understanding of the mechanisms involved. If cortical inhibition is abnormal in these conditions this will lead to novel treatment therapies (e.g., drugs to correct the imbalance, or strategies to induce plastic change in the cortex).Read moreRead less
Position perception, attention, object motion, and action. The research will achieve a deeper understanding of the neural processing of the visual perception of position, and of the associated behavioural limits. This will provide a foundation for the development of a range of technologies to assist disabled and elderly people. The results will help reveal the link between the perception of moving objects and the capacity for visually guided movement. This link will benefit areas such as enginee ....Position perception, attention, object motion, and action. The research will achieve a deeper understanding of the neural processing of the visual perception of position, and of the associated behavioural limits. This will provide a foundation for the development of a range of technologies to assist disabled and elderly people. The results will help reveal the link between the perception of moving objects and the capacity for visually guided movement. This link will benefit areas such as engineering of vehicles and road systems, and the design of telepresence systems. The first applications are likely to be in the rehabilitation of brain injury and the decline of mental function with age.Read moreRead less
Functional imaging of colour pathways in the living eye. In order to repair or regenerate a diseased eye, we require knowledge of the normal pattern or nerve cell connections, and knowing how biology solves the problem of colour vision can be used to improve the design of artificial vision systems. The adaptive optics machine we will build in this project can be used to image nerve cells, fine blood vessels, and nerve fibre bundles in the normal and diseased eye. This will improve Australia's re ....Functional imaging of colour pathways in the living eye. In order to repair or regenerate a diseased eye, we require knowledge of the normal pattern or nerve cell connections, and knowing how biology solves the problem of colour vision can be used to improve the design of artificial vision systems. The adaptive optics machine we will build in this project can be used to image nerve cells, fine blood vessels, and nerve fibre bundles in the normal and diseased eye. This will improve Australia's research and development capacity in this new area of medical diagnostics. Our machine will be made available to other Australian laboratories and will improve the national capacity for making further scientific discoveries about how the visual system works.Read moreRead less
Listen and learn - statistical learning and the adapting auditory brain. This project aims to explore the link between rapid neural adaptation - a form of learning referred to as statistical learning - and human listening performance in noisy environments. The project aims to generate a new understanding of mechanisms that contribute to listeners' abilities to understand speech in noise, and to complex communication disorders such as dyslexia. Expected outcomes will include increased capacity to ....Listen and learn - statistical learning and the adapting auditory brain. This project aims to explore the link between rapid neural adaptation - a form of learning referred to as statistical learning - and human listening performance in noisy environments. The project aims to generate a new understanding of mechanisms that contribute to listeners' abilities to understand speech in noise, and to complex communication disorders such as dyslexia. Expected outcomes will include increased capacity to investigate a broad range of cognitive and communication functions. Benefits will include potential technologies and algorithms to assist listening (in devices such as hearing aids), language development and reading.Read moreRead less
Relationship of the functional architecture of the mammalian brain to its microcircuitry. The project seeks to understand a very fundamental issue in neuroscience: how the connectivity and architecture of the cortex are related to the functions of neurones in that area? This will be investigated by imaging the surface of the visual cortex of anaesthetised cats and monkeys as special visual patterns are shown to the eye/s. The overall picture gained of the active and inactive cortical areas will ....Relationship of the functional architecture of the mammalian brain to its microcircuitry. The project seeks to understand a very fundamental issue in neuroscience: how the connectivity and architecture of the cortex are related to the functions of neurones in that area? This will be investigated by imaging the surface of the visual cortex of anaesthetised cats and monkeys as special visual patterns are shown to the eye/s. The overall picture gained of the active and inactive cortical areas will be related to the properties of neurones in those areas and to those of individual input and output fibres. An optical imaging equipment will be acquired in 2004 using a recently awarded LIEF grant to the CI.Read moreRead less