Integrative Role Of Feedback Projections To Cat Primary Visual Cortex
Funder
National Health and Medical Research Council
Funding Amount
$293,321.00
Summary
Although in the last decade termed The Decade of the Brain we have learned a lot about the brain, the gaps in our understanding of brain functions are still enormous. The analysis of information in the sensory parts of the brain appears to be arranged in a distributed - hierarchical way. For example, different types of nerve fibres leaving the eye carry fairly generalised information about the external visual world along distinct parallel information channels. By the time the signals reach cereb ....Although in the last decade termed The Decade of the Brain we have learned a lot about the brain, the gaps in our understanding of brain functions are still enormous. The analysis of information in the sensory parts of the brain appears to be arranged in a distributed - hierarchical way. For example, different types of nerve fibres leaving the eye carry fairly generalised information about the external visual world along distinct parallel information channels. By the time the signals reach cerebral cortex there is a dramatic increase in complexity of visual stimuli to which cells respond (orientation, length and direction of movement of contours became important). There are at least two parallel feedforward information processing streams across the cerebral cortex involving a number of relay stations at each of which there are further specializations. For example, cells in one area appear to respond only to faces while in some other areas cells respond to motion in particular directions almost irrespective of the position of the stimuli. In the human there are more than 30 visual cortical areas. What is very surprising that from all these areas there are extensive feedback pathways running back to the lower-order areas. The feedback pathways appear to largely criss-cross different information processing streams and their function is very poorly understood. We will record from cells in lower-order areas noting the way they respond to different stimuli. Then we will block the feedback pathway from a particular higher-order area by cooling the area to about 10oC. We have confirmed that this prevents nerve impulses leaving the cooled area. Then we repeat our tests on the cell in the lower-order area. Comparing the responses with and without feedback activity will tell us what the feedback is doing. Understanding the function of feedback pathways hopefully would help us to understand the mechanisms underlying some subtle psychoneurological diseases.Read moreRead less
A Motion Correction Technique For Accurate PET/CT Brain Imaging In Paediatric And Dementia Patients
Funder
National Health and Medical Research Council
Funding Amount
$190,450.00
Summary
PET-CT imaging is a vital tool in the diagnosis and management of patients with brain disorders including dementia, epilepsy and cancer. However images are often distorted by patient motion, particularly in demented and paediatric patients. The CI has recently developed a motion tracking and correction method to derive images nearly free of motion effects. This aim of this project is to evaluate its impact on image quality in a variety of patients referred for PET- CT brain investigations.
Interaction Between Symptoms Of Brainstem Disturbance, Sensory Disturbances And Pain In Migraine
Funder
National Health and Medical Research Council
Funding Amount
$165,509.00
Summary
Migraine affects about 18% of women and 6% of men across their lifespan and usually peaks during the most productive years of life. Although serious neurological effects of migraine are rare, some sufferers are left with permanent physical disability after attacks of migraine-related stroke. More common are debilitating side effects of medication, and the psychological and social disruption of experiencing recurrent attacks of migraine. Apart from the pain and distress experienced during migrain ....Migraine affects about 18% of women and 6% of men across their lifespan and usually peaks during the most productive years of life. Although serious neurological effects of migraine are rare, some sufferers are left with permanent physical disability after attacks of migraine-related stroke. More common are debilitating side effects of medication, and the psychological and social disruption of experiencing recurrent attacks of migraine. Apart from the pain and distress experienced during migraine, recurrent headaches are responsible for considerable health care costs and lost productivity. Thus, there are important economic and social reasons for developing new treatments, particularly treatments that reduce susceptibility to recurrent attacks. This project aims to investigate interactions among symptoms of migraine (head pain, nausea, and changes in facial blood flow), so that the sequence of symptom development can be studied systematically. We will induce motion sickness (which provokes nausea and many other symptoms of migraine), and then study the effects of head pain and strong sensory stimulation. We expect that migraine sufferers will report stronger symptoms and show greater physiological changes to these stimuli, either alone or in combination, than people who rarely suffer from headache. One of the most commonly recognized triggers of migraine is psychological stress. The aim of the second part of this project is to determine whether a substance released during stress (noradrenaline) heightens inflammation in scalp blood vessels, thus increasing the likelihood of migraine. We hope that this approach will help to identify the basis of the abnormality which increases susceptibility to migraine, so that it can be targeted for treatment.Read moreRead less
The Clinical Impact Of Event-based Motion Correction In Paediatric PET-CT Brain Imaging
Funder
National Health and Medical Research Council
Funding Amount
$276,104.00
Summary
Movement of the head during PET-CT brain imaging can prevent accurate diagnosis by blurring and distorting the image. The problem is perhaps most acute in paediatric patients, many of whom must be anaesthetized or sedated to avoid motion. This work will establish whether a recently developed motion correction method can improve the clinical utility of PET-CT brain images in young patients, and reduce the need for sedation and anaesthesia during the PET scan.
NEURONAL RESPONSES ELICITED BY VIEWING HUMAN BODY MOTION AND GESTURE.
Funder
National Health and Medical Research Council
Funding Amount
$135,822.00
Summary
This project aims to study human brain regions active in viewing movements of the body, face and hands, as well as gestures (i.e. movements with meaning). We will map the location of these human motion sensitive brain regions relative to brain areas dealing with other visual functions. We will use a new method of brain scanning (functional MRI) and recordings of the electrical activity of the brain to achieve these goals. Subjects for this project will be epilepsy patients undergoing investigati ....This project aims to study human brain regions active in viewing movements of the body, face and hands, as well as gestures (i.e. movements with meaning). We will map the location of these human motion sensitive brain regions relative to brain areas dealing with other visual functions. We will use a new method of brain scanning (functional MRI) and recordings of the electrical activity of the brain to achieve these goals. Subjects for this project will be epilepsy patients undergoing investigation for seizure surgery at the A and RMC and Royal Children's Hospitals in Melbourne. Functional MRI - a new non-invasive method for studying brain function - will locate the brain structures involved in the detection and analysis of human motion. Recording electrodes are surgically placed inside the brains of these patients in order to find the source of their seizures, and these electrodes will be utilised for this study. A number of facial, hand and body movement and gestural stimuli will be used. First, brain locations responding to face, hand and body movements will be identified. It is predicted that regions sensitive to hand motion could be located near areas known to participate in adjusting the subject's own visually-guided reaching behaviour. Similarly, regions sensitive to facial motion could be located near areas thought to deal with lip-reading. Second, differences in brain activity to gestures and movements of the face and hand will be studied, so as identify brain regions that process increasingly complex information. Third, differences in brain responses to incompatible (e.g. head facing left and moving right) versus compatible human motion will be studied. A brain 'map' with locations of these human motion sensitive regions relative to visually sensitive regions will be generated. These data will not only aid planning for future seizure surgery, but have implications for our understanding of the visual aspects of motor apraxia.Read moreRead less
Information Delivery from Segmented Textual Data Streams. This project will contribute to the advancement of ICT innovation in Australia by developing a robust, reusable language understanding engine. The technology will be tailored to web applications, in the form of a conceptually-aware web search engine capable of tracking cross-document dialogues and identifying the core semantic thread of the dialogue. It will place Australia at the forefront of next-generation language technology developme ....Information Delivery from Segmented Textual Data Streams. This project will contribute to the advancement of ICT innovation in Australia by developing a robust, reusable language understanding engine. The technology will be tailored to web applications, in the form of a conceptually-aware web search engine capable of tracking cross-document dialogues and identifying the core semantic thread of the dialogue. It will place Australia at the forefront of next-generation language technology development, with applications in areas including concept-based multi-document summarisation and email surveillance.Read moreRead less
A scalable and portable question-answering system. The current availability of large volumes of free text digitally stored demands the development of methodologies that can automatically find specific answers to user questions about this "unstructured" information. The goal of this project is to develop a scalable portable and domain-independent real-time natural-language question-answering system that explores the logical contents of the text. To achieve this we will fuse current approaches to ....A scalable and portable question-answering system. The current availability of large volumes of free text digitally stored demands the development of methodologies that can automatically find specific answers to user questions about this "unstructured" information. The goal of this project is to develop a scalable portable and domain-independent real-time natural-language question-answering system that explores the logical contents of the text. To achieve this we will fuse current approaches to question answering with approaches that look at the logical contents of the questions and answer candidates. A central part of the project will be the characterisation of the optimal logical forms, the determination of efficient methods to create and store sentence logical forms of potentially large volumes of text, and the treatment of difficult questions by incorporating summarisation and text generation techniques.Read moreRead less