Action-reward Integration In The Amygdalocortical-striatal Network.
Funder
National Health and Medical Research Council
Funding Amount
$757,495.00
Summary
This research focuses on the neural bases of decision making, a general capacity affected by normal ageing, disorders associated with neurodegeneration, major psychiatric conditions, obesity and drug addiction. This program will contribute critical new knowledge on the brain systems through which cognitive and emotional processes are integrated to control choice and decision-making and the influence of neuropathology on this integrative process.
A decade ago the adult brain was thought of as a structurally-fixed organ. Against this are well-documented cases of slow recovery after massive injuries or stroke. Simple models of brain injury using the tactile, visual and auditory systems of animals as models have now revealed multiple stages of recovery (plasticity). Some of these are inbuilt into the wiring of the neural systems such that functional plasticity can result without the need for any structural or cellular changes. A second grou ....A decade ago the adult brain was thought of as a structurally-fixed organ. Against this are well-documented cases of slow recovery after massive injuries or stroke. Simple models of brain injury using the tactile, visual and auditory systems of animals as models have now revealed multiple stages of recovery (plasticity). Some of these are inbuilt into the wiring of the neural systems such that functional plasticity can result without the need for any structural or cellular changes. A second group of plastic phenomena depend upon minute changes in the connections between neurons and these are invoked in the first few days following an injury (synaptic plasticity; changes in the pattern and strength of the connections between neurons). Aside from being model systems, there are also parallels of this plasticity with clinical situations such as losses in hearing and sight, and of the adaptations made by the brain in response to prosthetics (e.g. bionic ear) and resorative surgery but the degree of relevance for these situations is unclear. An intriguing aspect of the experiments on auditory and visual systems is that neurons with inputs from both ears, or both eyes, undergo the plastic changes when the relevant sense organ on only one side is damaged but the other is intact. In fact, on the basis of the limited available evidence, it appears that the changes are independent of there being a normal input from the other side. This is difficult to explain in terms of the modern understanding neuronal plasticity at a cellular level. It is thus proposed to study both auditory and visual models of this brain plasticity with stimuli which are systematically varied to extract the extent of bilateral interaction in the induced plasticity. This will enable prediction of how these plasticity mechanisms will be involved in adaptations made to prosthetics and surgical corrections.Read moreRead less
Combining input from vision and hearing greatly enhances perception when information from one of these senses is degraded or incomplete, such as when tracking objects in foggy, dark or noisy places. This enhancement is of considerable importance because degraded input is the daily situation faced by many people with hearing or vision impairment. We will study the neural processes underlying our ability to combine vision and hearing to create a more reliable and accurate perception of the world.
Development Of Executive Functions In Children With Frontal Lobe Lesions
Funder
National Health and Medical Research Council
Funding Amount
$160,379.00
Summary
Executive functions (EF), refer to the ability to problem solve, think flexibly and in abstract terms and pay attention. EFs are essential for managing daily life activities. The frontal lobes of the brain are believed be important in coordinating EFs. In childhood, frontal areas are developing rapidly and damage may affect ongoing development due to impairments in a child's capacity to function normally within their environment, interfering with adaptive functions such as new learning and reaso ....Executive functions (EF), refer to the ability to problem solve, think flexibly and in abstract terms and pay attention. EFs are essential for managing daily life activities. The frontal lobes of the brain are believed be important in coordinating EFs. In childhood, frontal areas are developing rapidly and damage may affect ongoing development due to impairments in a child's capacity to function normally within their environment, interfering with adaptive functions such as new learning and reasoning. Executive dysfunction in children manifests as disorganisation, impulsivity, inattention and inappropriate behaviour. Such problems are often masked in early chilhood, due to highly structured environments and support of parents and care-givers in day-to-day activities. However, as children mature, expectations of indepence increase and executive deficits become more apparent (ie. child 'grows into' these problems). Appropriate treatment and management is dependent on (i) improvement in early identification of patients at risk for such sequelae; (ii) establishing long-term consequences of executive deficits to ongoing development. This research aims to advance our understanding of EFs and their development through childhood, both in healthy children and children with cerebral lesions to regions believed to subsume EFs(ie the frontal lobes). While anecdotal case data is available, to our knowledge, no other study has attempted to do this using a longitudinal group design. Specific predictions include; (i) Children with frontal lobe damage will perform more poorly on EF measures, in comparison to children with damage to other cerebral areas and healthy children; (ii) Children with frontal lobe damage will show increasing deficits on EF tasks over time, reflecting an inability to acquire executive skills in the expected time frame, when compared with children with localised damage to cerebral areas excluding the frontal lobes, and healthy children.Read moreRead less
The Impact Of Circadian Disturbances On Sleep Quality, Cognition And Psychiatric Symptoms In Neurodegenerative Disease
Funder
National Health and Medical Research Council
Funding Amount
$496,340.00
Summary
There is an increasing awareness that neurodegenerative diseases are associated with disturbances in sleep. Our group have recognised that patterns of sleep disturbance in these patients are also related to problems with memory and mood. The proposed study will be the first of its kind to explore whether disruptions in the circadian system represent a common mechanism underlying these comorbid disease features. Understanding this pathology will hopefully lead to the development of new therapies.
Frontal-striatal-parietal Activation In Children With ADHD, Combined Type: A Functional Magnetic Resonance Imaging Study
Funder
National Health and Medical Research Council
Funding Amount
$91,750.00
Summary
Attention Deficit Hyperactivity Disorder, combined type (ADHD-CT) is a common neuropsychiatric disorder that has serious consequences for affected children's educational and social development and success in later life. Despite a large investment in research investigating aetiology and therapeutic strategies that arise from these aetiological investigations, ADHD-CT remains poorly understood and it is often viewed with therapeutic pessimism. Understanding the neurobiological basis of ADHD-CT is ....Attention Deficit Hyperactivity Disorder, combined type (ADHD-CT) is a common neuropsychiatric disorder that has serious consequences for affected children's educational and social development and success in later life. Despite a large investment in research investigating aetiology and therapeutic strategies that arise from these aetiological investigations, ADHD-CT remains poorly understood and it is often viewed with therapeutic pessimism. Understanding the neurobiological basis of ADHD-CT is of tremendous importance for the development of more specific and targeted medication and-or psychological treatments and, ultimately, to obtain the best clinical outcome for individual children with ADHD-CT. We have previously examined the function of frontal-striatal-parietal brain networks in adolescent boys with ADHD-CT, showing dysfunction of brain systems important for the control of visuospatial attention. In this project, we aim to examine whether these changes in frontal-striatal-parietal brain function also occur in pre-pubertal 8-12 year-old boys with ADHD-CT. This is important for two major reasons: Firstly, adolescents and young adults examined in previous brain imaging studies of ADHD-CT, including our own, are not truly representative of the core of the disorder, as ADHD-CT has its peak prevalence from 8 to 12 years of age. Secondly, by now comparing pre-pubertal ADHD-CT and healthy control children we can determine whether the changes in brain function we have previously identified represent developmental stage independent brain dysfunction that is characteristic of ADHD-CT.Read moreRead less
One of the main trends in the evolution of the primate brain was the huge expansion of the cortical areas devoted to visual processing. However, the exact role of individual areas remains highly controversial, making detailed physiological and anatomical studies in suitable primate models a key step to elucidating their function in the human brain. We will address one particular aspect of this problem, namely the organisation of the cortical areas that provide visual control for skilled movement ....One of the main trends in the evolution of the primate brain was the huge expansion of the cortical areas devoted to visual processing. However, the exact role of individual areas remains highly controversial, making detailed physiological and anatomical studies in suitable primate models a key step to elucidating their function in the human brain. We will address one particular aspect of this problem, namely the organisation of the cortical areas that provide visual control for skilled movements. It is proposed that there are two parallel brain circuits involved in the analysis of motion, one tracking the movement of objects, and the other analysing a person s self-motion. Consider, for example, the task of a tennis player who has to return a serve. In order to achieve this, the brain must precisely integrate information about the ball s motion, as well as information about the player s speed and direction. This requires precise control of eye movements (to keep the eyes on the ball), as well as the ability to control the limb and trunk muscles. The aim of this study will be to map the anatomical framework underlying our ability to process all the relevant visual motion information, and to coordinate the appropriate motor responses. Such work is fundamental for understanding the functional organisation of the brain. It also has the potential to lay the groundwork for developments in areas of applied research, including medicine (e.g. the design of better rehabilitation strategies for people with brain damage), robotics- artificial intelligence (e.g. the improvement of artificial systems capable of vision), and the cognitive sciences (e.g. a better understanding of factors that limit human responses to visual stimuli).Read moreRead less