Cortical Neuroprosthesis To Restore Visual Perception To Bling Patients.
Funder
National Health and Medical Research Council
Funding Amount
$189,250.00
Summary
We will develop a medical device to restore visual perception to profoundly blind patients. This device will act to electrically stimulate the visual area of the brain. Electrical stimulation of this area leads to the visual perception of small spots of light in patients who are otherwise blind. By correlating the stimulation of the brain, which leads to the perception of spots of light, with an image of the surrounding environment acquired by a camera and digitally enhanced, we aim to provide b ....We will develop a medical device to restore visual perception to profoundly blind patients. This device will act to electrically stimulate the visual area of the brain. Electrical stimulation of this area leads to the visual perception of small spots of light in patients who are otherwise blind. By correlating the stimulation of the brain, which leads to the perception of spots of light, with an image of the surrounding environment acquired by a camera and digitally enhanced, we aim to provide blind patients with a very basic visual perception of their surroundings.Read moreRead less
Headache Prophylaxis By Cortico-brainstem Mechanisms
Funder
National Health and Medical Research Council
Funding Amount
$616,437.00
Summary
In this project we hope to discover the cause of migraine headache. Many triggers lead to migraine, but we do not know how. We believe the triggers produce a defect in pain control by the brainstem, which normally keeps sensation from the head below the pain threshold. In migraine, trigger factors acting high in the brain open a pain control gate lower in the brain, producing a migraine headache. If we can prove this, we can develop therapies that will prevent migraine before it starts.
Multidimensional Coding Of Visual Information In The Retina
Funder
National Health and Medical Research Council
Funding Amount
$359,431.00
Summary
Although both the retina and visual cortex are part of the central nervous system, the coding of visual information in the two laminar structures differs markedly in that all three dimensions of the cortical sheet are used to code multiple response axes but only one dimension of the retinal sheet. This project examines how visual response properties are mapped through the depth of the retina and this will provide a comparatively simple paradigm of complex information processing in the brain.
Temporal Processing In The Superior Olivary Complex: Impact Of Deafness And Peripheral Electrical Stimulation Strategies
Funder
National Health and Medical Research Council
Funding Amount
$225,500.00
Summary
The brain can use timing or temporal information to extract the frequency and location of sound. Timing information is coded by the pattern of responses of brain cells that match the period of the sound wave. These responses can be measured as small voltage spikes or action potentials. Integration of these responses from one brain-processing site to another relies on precise (temporally matched) firing among a population of cells that are activated in response to sound. Sound localisation relies ....The brain can use timing or temporal information to extract the frequency and location of sound. Timing information is coded by the pattern of responses of brain cells that match the period of the sound wave. These responses can be measured as small voltage spikes or action potentials. Integration of these responses from one brain-processing site to another relies on precise (temporally matched) firing among a population of cells that are activated in response to sound. Sound localisation relies on this temporal integration from information coming from both ears. Specifically, the integration of this information relies on the balance of incoming inputs from both ears, which maintains an appropriate time window depending on the location of sound in space. Recent evidence suggests that in deafness this process of integration is disrupted which may be possibly due to an inability to regulate the coherent activation of cells. This has implications for cochlear implant users whose ability to process temporal information is compromised by a loss of temporal coding ability resulting from prior deafness. In this project we will measure voltage changes occurring inside cells of the superior olivary complex, which contains a group of structures that integrate input from both ears. We will examine the ability of these cells to process temporal information in normal and deafened conditions. This study will lead not only to an understanding of basic mechanisms for auditory coding but also to improved electrical stimulation strategies for patients with cochlear implants.Read moreRead less
Extraction Of Key Features Of Natural Speech By Ventral Cochlear Nucleus Neurons
Funder
National Health and Medical Research Council
Funding Amount
$225,330.00
Summary
Little is known about how speech is processed and transformed by the central auditory pathway, and how the critical temporal and spectral features that identify a speech sound segment (a phoneme) are extracted. To date, most studies have approached this issue by using synthetic speech and examined the responses of the peripheral auditory nerve only. The aim of this study is to examine how important features of naturally-spoken speech are encoded by the cochlear nucleus (CN) - the first station i ....Little is known about how speech is processed and transformed by the central auditory pathway, and how the critical temporal and spectral features that identify a speech sound segment (a phoneme) are extracted. To date, most studies have approached this issue by using synthetic speech and examined the responses of the peripheral auditory nerve only. The aim of this study is to examine how important features of naturally-spoken speech are encoded by the cochlear nucleus (CN) - the first station in the auditory pathway located in the brainstem. The CN is a complex of different cell types that have the capacity to transmit, transform, and encode complex acoustic information in different ways. The proposed experiments involve recording the bioelectrical signal from single CN cells in anaesthetised rats while presenting naturally-spoken syllables, both in quiet and in the presence of noise. It is important to examine what happens to the neural responses in the latter condition, because all animals must cope with the problem of extracting important signals from background noise. While noise clearly interferes with the perception of another sound, the auditory system is in fact quite good at extracting signals in the presence of noise. This is well demonstrated by our ability to understand speech in the presence of quite high noise levels. This ability is severely degraded in the hearing impaired. Thus, one of the aims of this study is to examine the mechanisms and limits of the CN's ability to encode speech in a noisy background. A greater understanding of the mechanisms the nervous system uses to extract critical features of speech will not only build on our knowledge of auditory brainstem processes, but may also provide clues to improving processing strategies for cochlear implants.Read moreRead less
Nerve pathways exist that carry information from the highest parts of the brain to the peripheral hearing organ, the inner ear. These descending control pathways have the potential to affect the hearing process in a number of ways; protecting from loud sounds, improving the detection of signals in noisy backgrounds, selecting stimuli of interest and regulating a variety of aspects of inner ear function. Abnormal function of these pathways can affect hearing sensitivity and may be important in ph ....Nerve pathways exist that carry information from the highest parts of the brain to the peripheral hearing organ, the inner ear. These descending control pathways have the potential to affect the hearing process in a number of ways; protecting from loud sounds, improving the detection of signals in noisy backgrounds, selecting stimuli of interest and regulating a variety of aspects of inner ear function. Abnormal function of these pathways can affect hearing sensitivity and may be important in phenomena such as tinnitus and other disorders of hearing. This project will investigate the subtle effects that selective activation of these pathways has on inner ear function and will attempt to unravel the different influences that subcomponents of the pathways have on the different aspects of hearing.Read moreRead less