Organization And Function Of Primate Auditory Cortex
Funder
National Health and Medical Research Council
Funding Amount
$271,671.00
Summary
The conscious perception of speech and other sounds depends on processing within a brain region known as the auditory cortex. Compared to other brain areas, relatively little is known about the organization and function of this structure. Recent studies have proposed that the auditory cortex may be anatomically subdivided into functional modules, each of which is specialized for processing different types of information. However, the evidence for multiple processing streams is fragmentary, and n ....The conscious perception of speech and other sounds depends on processing within a brain region known as the auditory cortex. Compared to other brain areas, relatively little is known about the organization and function of this structure. Recent studies have proposed that the auditory cortex may be anatomically subdivided into functional modules, each of which is specialized for processing different types of information. However, the evidence for multiple processing streams is fragmentary, and not entirely consistent. The proposed experiments will combine anatomical and physiological approaches to evaluate the functional organization of auditory cortex in the primate brain. We will map the electrical responses of single brain cells to various complex sounds across the brain surface, and inject dyes to label pathways linking brain areas to one another. The data will allow us to determine whether specific subdivisions of the auditory cortex are specialized for processing different types of infomation, and whether specific subdivisions are linked together to form processing streams specialized for sound recognition and space perception. The results will advance our understanding of the neuronal processing involved in the perception of sound, with possible implications for speech perception. This will help to understand the consequences of brain damage, and may inform the development of hearing aids and artificial voice recognition systems. In addition, this study will help to develop a primate model for studying brain mechanisms of sound recognition that should be useful in research on cochlear implants.Read moreRead less
Evaluating The Effectiveness Of Therapy For Word Production Impairments In Aphasia.
Funder
National Health and Medical Research Council
Funding Amount
$231,500.00
Summary
This project addresses the remediation of language disorders following brain damage (aphasia). It targets the difficulties people with aphasia have in retrieving and accurately producing the words they need to communicate. These word production impairments are an extremely common symptom of aphasia and may be of different types. They are often severe but can be improved with treatment. However, there is no one task that is effective for every person with word production impairments in aphasia. U ....This project addresses the remediation of language disorders following brain damage (aphasia). It targets the difficulties people with aphasia have in retrieving and accurately producing the words they need to communicate. These word production impairments are an extremely common symptom of aphasia and may be of different types. They are often severe but can be improved with treatment. However, there is no one task that is effective for every person with word production impairments in aphasia. Unfortunately, to date research has failed to investigate adequately the relationship between the type of word production disorder and the appropriate treatment task to successfully remediate it - matching treatment to impairment remains a process of 'trial and error'. As therapy is a time consuming (and hence costly) process, it is clearly desirable to be able to select the best treatment as quickly as possible. This project aims to address this issue. We will investigate the effectiveness of two tasks which are commonly used by speech pathologists in their treatment of people with word retrieval impairments: answering a question regarding the meaning of a word (e.g. Does a cat purr?), and naming a picture with the help of the first sound of the word (e.g. the sound kuh' to help name a picture of a cat). We will determine if after treatment with these tasks, word retrieval and conversation skills improve; and in particular if one task is more effective for one type of word retrieval problem (e.g. retrieving the sounds of the word) than for another (e.g. impaired word meanings). The results of this study will enable Speech Pathologists to select the correct treatment with more accuracy than is currently possible, providing benefits in terms of increased communication ability for aphasic individuals (and hence greater social participation, quality of life, and reduced depression) and benefiting the Health Service Providers through more cost effective service delivery.Read moreRead less
In the normal process of hearing, the brain actively selects sounds of interest from competing background sounds. This normal auditory function is indispensible for children and adults to cope in non-optimal listening environments, however the mechanisms by which such performance is achieved are poorly understood. This project will investigate the nerve circuits that enable this to occur and will also investigate how these circuits malfunction in various types of partial deafness. The results wi ....In the normal process of hearing, the brain actively selects sounds of interest from competing background sounds. This normal auditory function is indispensible for children and adults to cope in non-optimal listening environments, however the mechanisms by which such performance is achieved are poorly understood. This project will investigate the nerve circuits that enable this to occur and will also investigate how these circuits malfunction in various types of partial deafness. The results will improve our understanding of how we detect sounds and the impact of hearing pathologies on this process.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
Most adults will have already sustained damage to the tiny connections between hearing cells and nerve cells; a missing link in their auditory pathway. There is no way to repair the damage and our hearing will worsen over time. We now have compelling evidence that a growth factor therapy to the inner ear restores the connections. We will deliver world-first data to justify and set the parameters for a clinical trial for a therapy to treat hearing loss for the first time.
Improving Speech Perception Outcomes In Deaf Adults And Children Using Cochlear Implants
Funder
National Health and Medical Research Council
Funding Amount
$160,604.00
Summary
This project aims to further improve on speech understanding by deaf adults and children using the cochlear implant. In particular, we aim to individually modify the speech coding scheme on the basis of the basic hearing skills of the subject. In this manner, more speech information should be available and the users will likely gain more benefit from their cochlear implants. The speech processing strategy of the multiple-electrode cochlear implant, manufactured by the Australian biomedical compa ....This project aims to further improve on speech understanding by deaf adults and children using the cochlear implant. In particular, we aim to individually modify the speech coding scheme on the basis of the basic hearing skills of the subject. In this manner, more speech information should be available and the users will likely gain more benefit from their cochlear implants. The speech processing strategy of the multiple-electrode cochlear implant, manufactured by the Australian biomedical company Cochlear Limited, codes acoustic frequency information on electrodes which are located in the cochlea. The assignment of frequencies to electrodes is consistent with the ordering of pitch in the cochlea. For optimum performance, all electrodes would need to be perceptually distinct from each other. Recent research with adults and children has shown that this is not the case for a number of subjects as adjacent electrodes sound the same. Thus important speech information may not be heard by these subjects. In this project, we will determine how well adults and children are able to hear differences between the electrodes, and then provide speech processing schemes which exclude those electrodes which sound the same as others in close proximity. The project will compare these modified strategies with the standard strategy currently used by the subjects over time, so that any differences in the way adults and children are able to improve on speech understanding will be determined. As far as can be determined, this project will be the first investigation to improve on speech understanding in children using the cochlear implant.Read moreRead less
Nanoparticle Based Neurotrophin Delivery To Promote Directed Neurite Growth And Auditory Nerve Rescue Following Deafness
Funder
National Health and Medical Research Council
Funding Amount
$506,724.00
Summary
The cochlear implant provides hearing information to the severe-profoundly deaf by electrically stimulating the auditory nerves of the inner ear. Deafness causes these auditory nerves to gradually degenerate leaving fewer nerves for the cochlear implant to stimulate. We propose to reverse this neural degeneration by delivering therapeutic drugs to the inner ear using tiny nanoparticles. This novel technology is expected to have application in other areas of neural degenerative disease.