Abnormal Auditory System Function In Schizophrenia: An ERP And MEG Study Of Its Origin, Course And Generality.
Funder
National Health and Medical Research Council
Funding Amount
$250,770.00
Summary
In 1991, an Australian group found that schizophrenia patients have a reduced brain response to deviant sounds in a repeating pattern of identical sounds. Deviant sounds produce a brain electrical response known as mismatch negativity which is generated by the auditory cortex in the brain's temporal lobes and by adjacent areas in the frontal lobes. A smaller mismatch negativity in patients has since been replicated in laboratories in the US, Europe and Australia. The importance of this finding i ....In 1991, an Australian group found that schizophrenia patients have a reduced brain response to deviant sounds in a repeating pattern of identical sounds. Deviant sounds produce a brain electrical response known as mismatch negativity which is generated by the auditory cortex in the brain's temporal lobes and by adjacent areas in the frontal lobes. A smaller mismatch negativity in patients has since been replicated in laboratories in the US, Europe and Australia. The importance of this finding is that it had not been previously recognised that patients have low level auditory problems that could potentially have a profound impact on higher level functions. Finnish researchers have gone on to show in healthy individuals that mismatch negativity can reveal important features about how well the auditory system works, e.g., for the brain to respond to a deviant sound, it must have a memory of what happened in the past. Mismatch negativity provides a measure of the integrity of these memory functions. But it also provides an index of how well the auditory system discriminates different aspects of sound, pitch, loudness, and temporal features, such as duration. There are hints in our data and from US researchers that processing of the temporal features of sounds is particularly impaired in schizophrenia. We have also recently discovered that first-degree relatives of patients may have a similar deficit. The aim of this project is to use mismatch negativity to probe what is wrong with the auditory system in schizophrenia and those at risk (first degree relatives). Is it the areas of the brain primarily involved in sound perception (the temporal lobes) that are faulty or is the problem in the frontal lobes? Is it the case that processing of temporal features are particularly compromised and if so, is this a biological marker for schizophrenia. Answers to these questions will greatly enhance our understanding of the nature of the brain dysfunction in schizophrenia.Read moreRead less
The Neurobiology Of Auditory Hallucinations: Characterisation Of Dysfunction Within A Neural Circuitry Model.
Funder
National Health and Medical Research Council
Funding Amount
$299,625.00
Summary
This is a highly innovative research proposal which is based on years of extensive research by our group. Auditory hallucinations are a prominent and potentially disabling symptom of psychosis, however it is extremely difficult to study them scientifically. Past research by our group (and other groups internationally) has indicated that an extensive network in the brain is activated whenever auditory hallucinations occur, but the source of this brain activity is unclear. It was thought that the ....This is a highly innovative research proposal which is based on years of extensive research by our group. Auditory hallucinations are a prominent and potentially disabling symptom of psychosis, however it is extremely difficult to study them scientifically. Past research by our group (and other groups internationally) has indicated that an extensive network in the brain is activated whenever auditory hallucinations occur, but the source of this brain activity is unclear. It was thought that the source may be the same brain circuits that are involved in generating inner speech or monitoring it, but our past research has ruled out these possibilities. Instead, our recent work suggests that auditory hallucinations may be associated with poorly functioning connections within central auditory processing circuits, specifically between left and right auditory association cortical regions. We conceptualise hallucinations as an abnormal and involuntary form of memory retrieval consequent to this dysfunction. Our study will pioneer methods of measuring connectivity in the brain circuits identified in our model, using a combination of functional magnetic resonance imaging (fMRI) and electroencephalographic (EEG) techniques in tandem with tests of central auditory processing. We believe that sufferers may benefit from understanding the physical processes which cause hallucinations. We also believe that a better understanding of hallucinations may lead to a better understanding of schizophrenia and the psychoses, which may in turn help in the development of better ways of treating these illnesses.Read moreRead less
Early Detection Of Infants And Young Children With Autism
Funder
National Health and Medical Research Council
Funding Amount
$268,250.00
Summary
Autism is a severely handicapping condition adversely affecting social interaction, communication, behaviour, interests, and activities. Autism requires treatment at an early age (before 4 years). Despite finding that parents notice problems with their child's development within the first 2 years, on average diagnoses are made around 6 years of age. Treatment for autism should begin as early as possible to improve outcome. Diagnosis requires specialist assessment and these services are limited. ....Autism is a severely handicapping condition adversely affecting social interaction, communication, behaviour, interests, and activities. Autism requires treatment at an early age (before 4 years). Despite finding that parents notice problems with their child's development within the first 2 years, on average diagnoses are made around 6 years of age. Treatment for autism should begin as early as possible to improve outcome. Diagnosis requires specialist assessment and these services are limited. Therefore it is not possible to undertake such assessments with all children who have developmental problems. This project therefore proposes to evaluate a method for screening large populations of children for autism, thus enabling timely and more appropriate referral to assessment services. Previous work by the investigators has developed a potential screening tool (DBC Early Screen) for autism in young children under 4 years with developmental delay that has high levels of accuracy in identifying those infants and children who are at risk of autism and require specialist assessment. This project proposes to undertake a community field trial to assess the accuracy and reliability of this early screen and to establish its suitability for wide use as a population screening tool. The preliminary testing of DBC Early Screen demonstrated that a community field trial was feasible. The results of this study will facilitate the referral of infants and young children to specialist autism assessment services, thus enabling the commencement of appropriate early intervention for children and their families from an early age.Read moreRead less
Episodic Memory Dysfunction As A Basis For Auditory Hallucinations In Schizophrenia
Funder
National Health and Medical Research Council
Funding Amount
$278,517.00
Summary
Auditory hallucinations (AHs) occur frequently in people who suffer from schizophrenia. This symptom usually involves hearing voices that the hallucinator firmly believes originate from other people. The voices are often intrusive, abusive and persecutory. They are a source of significant stress and may result in self harm or harm to others. Our investigations will attempt to provide experimental support for the theory that AHs represent a misremembering of voices which were heard in the past. W ....Auditory hallucinations (AHs) occur frequently in people who suffer from schizophrenia. This symptom usually involves hearing voices that the hallucinator firmly believes originate from other people. The voices are often intrusive, abusive and persecutory. They are a source of significant stress and may result in self harm or harm to others. Our investigations will attempt to provide experimental support for the theory that AHs represent a misremembering of voices which were heard in the past. We will do this by attempting to characterise specific problems that hallucinators have in identifying when they heard verbal fragments and who said them. We plan to conduct our investigations at five levels. First, we will determine how accurate hallucinators' memories are for context by the use of special neuropsychological tests. Second, we will find out if hallucinators form more false memories than comparison subjects using a test in which such incorrect recollections occur commonly. Third, we will determine if hallucinators have a tendency to reconstruct the characteristics of false verbal memories in the same way that they reconstruct the characteristics of their hallucinations. Fourth, we will attempt to suppress these false verbal memories and finally, we will characterise those brain regions which are activated during true and false memory formation by using blood flow analysis technology in order to identify networks of brain activity which preferentially malfunction in hallucinating patients. This study provides the prospect of adding substantially to our understanding of the mechanisms underlying auditory hallucinations and to lead to the development of new cognitively-based treatments for the symptom.Read moreRead less
I am a consultant psychiatrist and clinical researcher. Over the last 15 years I have been trying to detect people at risk of development of schizophrenia and other psychotic disorders by the prospective identification of the prodromal phase of these diso
Emerging Mental Disorders In Young People: Using Clinical Staging For Prediction, Prevention And Early Intervention
Funder
National Health and Medical Research Council
Funding Amount
$10,598,601.00
Summary
Mental disorders are a major cause of disability in Australia, especially for young people. We have developed a clinical staging model covering the earliest symptoms through persistent disorder to chronic disability. We are investigating neurobiological, personal and social factors which increase the risk of progression through these stages, and novel treatment strategies which may prevent or delay onset and relapse, reduce the impact of illness, and promote recovery. Major public health benefit ....Mental disorders are a major cause of disability in Australia, especially for young people. We have developed a clinical staging model covering the earliest symptoms through persistent disorder to chronic disability. We are investigating neurobiological, personal and social factors which increase the risk of progression through these stages, and novel treatment strategies which may prevent or delay onset and relapse, reduce the impact of illness, and promote recovery. Major public health benefits and better understanding of the onset and progression of illness will result.Read moreRead less
Promotion Of Self-help Strategies For Sub-threshold Depression Via The Internet: Randomised Controlled Trial
Funder
National Health and Medical Research Council
Funding Amount
$91,573.00
Summary
Depressive symptoms are common, impair individual functioning, and may develop into a full depressive disorder. Self-help for depressive symptoms is well-liked and often used, but some strategies are not as effective as others. This project will test the feasibility of promoting helpful self-help strategies to those with a high level of depressive symptoms, using the internet. The aim is to reduce the overall level of depressive symptoms and the number developing a full depressive disorder.
The Role Of Stress, HPA-axis Dysfunction And CNS Structural And Functional Change In The Development Of Psychosis.
Funder
National Health and Medical Research Council
Funding Amount
$345,538.00
Summary
This research will further understanding of the processes underlying the development of serious mental illnesses such as schizophrenia and may lead to the development of strategies to prevent these devastating disorders. Although there have been advances in the management of psychotic disorders in recent years, their underlying causes remain largely unknown. We aim to investigate the potential roles of stress, HPA-axis function and structural and functional brain changes. The neurodevelopmental ....This research will further understanding of the processes underlying the development of serious mental illnesses such as schizophrenia and may lead to the development of strategies to prevent these devastating disorders. Although there have been advances in the management of psychotic disorders in recent years, their underlying causes remain largely unknown. We aim to investigate the potential roles of stress, HPA-axis function and structural and functional brain changes. The neurodevelopmental model of psychosis suggests that small structural CNS changes occur very early in life conferring a degree of vulnerability on the affected individual. We propose that the psychological and neurobiological processes listed above interact with the pre-existing vulnerability, resulting in the development of psychotic symptoms. This is in line with the stress-vulnerability model of psychosis. We aim to investigate this model by monitoring the level of stress reported by young people at risk of psychosis over 12 months. We will also obtain measures of their biological response to stress by assessing cortisol levels over time and brain structure and functioning will be assessed. By monitoring these processes in the high risk group, we will be able to identify any changes that occur if a psychotic illness develops. This research also has practical applications in the identification of young people at high risk of developing a psychotic disorder, Moreover it will inform the development of medical and psychological strategies aimed at preventing or delaying the onset of schizoprenia and related illnesses in the high risk population.Read moreRead less
Early Detection Of MCI And Dementia Using Multidimensional Analysis Of Structural MRI By Computational Methods
Funder
National Health and Medical Research Council
Funding Amount
$583,601.00
Summary
Dementia in elderly is a major public health problem, and mild cognitive impairment (MCI), is even more common. We propose to use recent computational anatomy algorithms from our group to develop novel multidimensional imaging biomarkers for early detection of brain anatomical changes due to MCI-dementia. We aim at identifying early signatures of MCI-dementia, thus making early treatment possible. The completion of our research will provide clinicians with new methods for the early diagnosis.