Jenny Harasty - Academia.edu (original) (raw)
Papers by Jenny Harasty
Neuroscience Letters, May 1, 1996
Gliat fibrillary acidic protein (GFAP) is the principal marker for brain astrocytes. The present ... more Gliat fibrillary acidic protein (GFAP) is the principal marker for brain astrocytes. The present study aims to examine the variability in GFAP immunohistochemistry in formalin-fixed human brain. Four commercially-available antisera were tested using standardised protocols in the cerebral ce,rtex of three cases with prominent glial reactions and one control. GFAP immunoreactivity was largely confined to the pial surface and white matter in control cortex, with the number of astrocytic cell bodies and processes as well as intensity of staining markedly increased in damaged cortices. A dramatic difference in the pattern of GFAP staining using different antisera was observed and may account for discrepancies between past studies. This variance has important practical implications for the interpretation of results using GFAP immunohistochemistry in human tissue.
Australian journal of human communication disorders, Dec 1, 1993
This paper seeks to summarise and evaluate research into the prevalence of communication impairme... more This paper seeks to summarise and evaluate research into the prevalence of communication impairment in adults. The results of prevalence research in this area depend upon the type of language impairment and the population investigated. As well, the study design has an influence on the eventual prevalence result. Despite these constraints, trends and ranges of prevalence data are described for communication impairment in general and for most specific types of communication impairment. The implications of the prevalence literature for health resource planning are discussed.
Archives of neurology, Feb 1, 1997
Many studies have demonstrated significant sexual dimorphism in verbal ability. However, few stud... more Many studies have demonstrated significant sexual dimorphism in verbal ability. However, few studies have examined anatomical differences between the sexes that may underlie such dimorphism. To examine sex differences in the absolute and proportional volumes of the main language-associated regions of the cerebral cortex. Control neuropathological case series of consecutive autopsies from a teaching hospital. No significant age-related volume changes were identified in the sample. Two language-associated cortical regions, the superior temporal gyrus (part of the Wernicke area) and its subdivisions (planum temporale, Heschl gyrus, and anterior superior temporal gyrus) and the inferior frontal gyrus (Broca area in the dominant hemisphere), and a non-language-associated region, the frontal pole, were measured using stereological techniques in brains fixed with formaldehyde solution serially sectioned at 3-mm intervals. Volume comparisons between the sexes and between brain hemispheres were performed using 2-way analysis of variance. Studies were conducted at the University of Sydney and the Prince of Wales Medical Research Institute, Sydney, Australia. Ten males and 11 females free from neurologic or neuropathological abnormalities. The volume of the superior temporal cortex, expressed as a proportion of total cerebral volume, was significantly larger in females compared with males (17.8% increase; P = .04). This was accounted for by 1 section of the superior temporal cortex, the planum temporale, which was 29.8% larger in females (P = .04). In addition, the cortical volume fraction of the Broca area in females was 20.4% larger than in males (P = .05). In contrast, no significant differences were found in the proportional volume of the frontal pole or in regional volumes between the left and right hemispheres in either sex group. Our results suggest that females have proportionally larger Wernicke and Broca language-associated regions compared with males. These anatomical differences may correlate with superior language skills previously demonstrated in females.
Journal of Neuroscience Methods, Jul 1, 1996
The variability in the external gyri pattern of human brains has made the identification of speci... more The variability in the external gyri pattern of human brains has made the identification of specific cortical areas difficult. Studies correlating cortical structure and function have not consistently controlled for this variability. The aim of the present study was to develop a reliable and reproducible regimen for sampling five speech-associated and one non-speech associated cortical region in the human brain. The gyri of interest were labelled using non-aqueous dye prior to coronal slicing of brains at 3 mm intervals. Using the lab&led gyri, a set of internal brain landmarks was established to aid in sampling one block of each cortical region of interest. The position of each internal landmark was determined as a percentage of the total brain length and breadth. The variability in the position of each isred landmark was investigated using analysis of variance and found to be consistent in three dimensions in alI cases. The correlation of the sampled cortical region to the internal landmark was consistent in different cases with point to point agreement of 100%. This contrasts with the variability between cases in external gyri features. The sampled region was tested to determine cytoarchitectural variability by measuring the depth of each cortical layer. This technique found that the same cytoarchitectural regions were sampled in each case. As expected, these regions were distinguishable by the significant difference in the depth of different cortical layers. Accurate identification of both the external gyri and internal landmarks occurred with interrater point to point agreement of 90-100%.
Journal of Histotechnology, Mar 1, 1996
... and Jillian ~ ril ' ? ~ ... Material and Methods Case rnaterial Brains were referred... more ... and Jillian ~ ril ' ? ~ ... Material and Methods Case rnaterial Brains were referred for the confirmation of clinical di-agnosis of probable Alzheimer's disease to the Neuropa-thology Unit (Department of Pathology, University of Syd-ney) from the Geriatric Units of Concord and St. ...
Australian journal of human communication disorders, Jun 1, 1994
Children from kindergarten through grade 6 in two mainstream Sydney metropolitan schools were ass... more Children from kindergarten through grade 6 in two mainstream Sydney metropolitan schools were assessed for speech and/or language impairment. The two schools were selected to represent children from a range of socio-economic status groups and to include children from disadvantaged and non-English speaking backgrounds. Of the 437 children assessed, 145 were estimated to be speech and/or language impaired. The proportion of children with a communication impairment was estimated to be from 28.8% to 37.6% (95% confidence interval). Estimated prevalence results for impairments of voice, articulation/phonology, language and stuttering are presented, as well as results for pupils of non-English speaking backgrounds.
Neurobiology of Aging, Jul 1, 1996
Topography of brain atrophy during normal aging and Alzheimer's disease. NEUROBIOL AGING 17(4) 51... more Topography of brain atrophy during normal aging and Alzheimer's disease. NEUROBIOL AGING 17(4) 513-521, 1996.-The present study investigated the effect of age on total and regional brain volumes and compared age-associated changes in 20 healthy controls with those observed in 12 patients with Alzheimer's disease (AD). Weights and volumes of the whole brain and cerebrum, as well as the fractional volumes of the frontal, temporal, and parieto-occipital cortices, medial temporal structures, deep brain structures, and white matter were measured. Males had larger and heavier brains than females of comparable age. A small decline in brain volume with age was found (approximately 2 ml per year), but only within the white matter. In comparison, no further loss of white matter occurred in AD; however, the cerebral cortex was significantly reduced in volume, with the greatest loss from the medial temporal structures. This loss was related to disease progression; greater proportional loss was associated with more rapid decline in older patients. This study suggests that significant brain atrophy is not a consequence of advancing age. In addition, it suggests a regional specificity of damage in AD.
Clinical Linguistics & Phonetics, 1994
... Acknowledgements The authors are most grateful for the comments and help of Mark Fey, Martin ... more ... Acknowledgements The authors are most grateful for the comments and help of Mark Fey, Martin Ball, Chris Code and anonymous reviewers. Thanks also to Sue-Ellen Linvale and Liora Baron for help with the reliability data measurement process. Appendix A ...
Laterality, 2003
We present histological data from 21 post-mortem, adult human cases that indicate the neocortex o... more We present histological data from 21 post-mortem, adult human cases that indicate the neocortex on the left planum temporale (secondary auditory cortex) is thinner but longer than that on the right side. The volumes of the left and right regions are approximately equal. Thus, the left planum temporale cortex is long and thin and the right short and thick. The present data fit excellently with previous studies of the volume, surface area, cytoarchitectonics, and neuronal structures of these areas. From these studies we suggest that the hemispheric differences arise from a so-called "balloon model" of cortical development. In this the cortex is extended and stretched by white matter growth. The stretching is greater on the left side, leaving greater distances between neuronal columns and more tangentially (to the pial surface) oriented dendrites on that side. This difference in fine structure can result in more independent activity of individual columns on the left, and could be an anatomical factor in the usual dominance of the left hemisphere for speech perception (Seldon, 1982, 1985).
Australian Journal of Psychology, 2001
Cerebellar morphology in developmental dyslexia, 2002
Recent evidence has suggested cerebellar anomalies in developmental dyslexia. Therefore, we inves... more Recent evidence has suggested cerebellar anomalies in developmental dyslexia. Therefore, we investigated cerebellar morphology in subjects with documented reading disabilities. We obtained T1-weighted magnetic resonance images in the coronal and sagittal planes from 11 males with prior histories of developmental dyslexia, and nine similarly-aged male controls. Proton magnetic resonance spectra (TE = 136 ms, TR = 2.4 s) were obtained bilaterally in the cerebellum. Phonological decoding skill was measured using non-word reading. Handedness was assessed using both the Annett questionnaire of hand preference and Annett's peg moving task. Cerebellar symmetry was observed in the dyslexics but there was significant asymmetry (right grey matter > left grey matter) in controls. The interpretation of these results depended whether a motor-or questionnaire-based method was used to determine handedness. The degree of cerebellar symmetry was correlated with the severity of dyslexics' phonological decoding deficit. Those with more symmetric cerebella made more errors on a nonsense word reading measure of phonological decoding ability. Left cerebellar metabolite ratios were shown to correlate significantly with the degree of cerebellar asymmetry (P < 0.05) in controls. This relationship was absent in developmental dyslexics. Cerebellar morphology reflects the higher degree of symmetry found previously in the temporal and parietal cortex of dyslexics. The relationship of cerebellar asymmetry to phonological decoding ability and handedness, together with our previous finding of altered metabolite ratios in the cerebellum of dyslexics, lead us to suggest that there are alterations in the neurological organisation of the cerebellum which relate to phonological decoding skills, in addition to motor skills and handedness.
Brain and Language, 1999
We examined cerebral activation patterns with positron emission tomography (PET) in 12 righthande... more We examined cerebral activation patterns with positron emission tomography (PET) in 12 righthanded normal volunteers while they were completing simple calculation tasks or merely repeating numbers. Using a parametric experimental design, during calculation we found activation in the medial frontal/ cingulate gyri, left dorsolateral prefrontal cortex, left anterior insular cortex and right anterior insular cortex/putamen, left lateral parietal cortex, and the medial thalamus. Number repetition engaged bilateral inferior sensorimotor cortex, bilateral temporal areas, and left inferior frontal cortex. These results suggest a functional anatomical network for simple calculation, which includes aspects of attention, auditory, and motor processing and the phonological store and articulatory loop components of working memory; they add some support for a special role of the parietal cortex in calculation tasks.
Journal of Histotechnology, 1996
... and Jillian ~ ril ' ? ~ ... Material and Methods Case rnaterial Brains were referred... more ... and Jillian ~ ril ' ? ~ ... Material and Methods Case rnaterial Brains were referred for the confirmation of clinical di-agnosis of probable Alzheimer's disease to the Neuropa-thology Unit (Department of Pathology, University of Syd-ney) from the Geriatric Units of Concord and St. ...
Australian Journal of Human Communication Disorders, 1993
This paper seeks to summarise and evaluate research into the prevalence of communication impairme... more This paper seeks to summarise and evaluate research into the prevalence of communication impairment in adults. The results of prevalence research in this area depend upon the type of language impairment and the population investigated. As well, the study design has an influence on the eventual prevalence result. Despite these constraints, trends and ranges of prevalence data are described for communication impairment in general and for most specific types of communication impairment. The implications of the prevalence literature for health resource planning are discussed.
Australian Journal of Human Communication Disorders, 1994
Children from kindergarten through grade 6 in two mainstream Sydney metropolitan schools were ass... more Children from kindergarten through grade 6 in two mainstream Sydney metropolitan schools were assessed for speech and/or language impairment. The two schools were selected to represent children from a range of socio-economic status groups and to include children from disadvantaged and non-English speaking backgrounds. Of the 437 children assessed, 145 were estimated to be speech and/or language impaired. The proportion of children with a communication impairment was estimated to be from 28.8% to 37.6% (95% confidence interval). Estimated prevalence results for impairments of voice, articulation/phonology, language and stuttering are presented, as well as results for pupils of non-English speaking backgrounds.
Nuclear Medicine Communications, 2000
We examined cerebral activation patterns with positron emission tomography (PET) in 12 righthande... more We examined cerebral activation patterns with positron emission tomography (PET) in 12 righthanded normal volunteers while they were completing simple calculation tasks or merely repeating numbers. Using a parametric experimental design, during calculation we found activation in the medial frontal/ cingulate gyri, left dorsolateral prefrontal cortex, left anterior insular cortex and right anterior insular cortex/putamen, left lateral parietal cortex, and the medial thalamus. Number repetition engaged bilateral inferior sensorimotor cortex, bilateral temporal areas, and left inferior frontal cortex. These results suggest a functional anatomical network for simple calculation, which includes aspects of attention, auditory, and motor processing and the phonological store and articulatory loop components of working memory; they add some support for a special role of the parietal cortex in calculation tasks.
Neuroscience Letters, 1996
Gliat fibrillary acidic protein (GFAP) is the principal marker for brain astrocytes. The present ... more Gliat fibrillary acidic protein (GFAP) is the principal marker for brain astrocytes. The present study aims to examine the variability in GFAP immunohistochemistry in formalin-fixed human brain. Four commercially-available antisera were tested using standardised protocols in the cerebral ce,rtex of three cases with prominent glial reactions and one control. GFAP immunoreactivity was largely confined to the pial surface and white matter in control cortex, with the number of astrocytic cell bodies and processes as well as intensity of staining markedly increased in damaged cortices. A dramatic difference in the pattern of GFAP staining using different antisera was observed and may account for discrepancies between past studies. This variance has important practical implications for the interpretation of results using GFAP immunohistochemistry in human tissue.
Neurology, 2001
Objective: To compare the pattern of cortical degeneration associated with different language def... more Objective: To compare the pattern of cortical degeneration associated with different language deficits in cases of AD.Methods: Cases for detailed neuropathologic analysis (Patients 1 and 2) were selected because of their detailed clinical and neuropsychological assessments of language dysfunction in AD. Patient 1 had severe phonologic impairment with relatively preserved semantic aspects of language. Patient 2 had severe semantic language impairment with relatively preserved phonologic skills. The tissue volume of cortical regions associated with speech and language function was measured using standardized three-dimensional techniques. Neuronal areal fraction was also measured from histologic tissue samples. The degree of volume atrophy and neuronal loss was calculated in comparison to control measures (n = 10 men and 11 women). Measurements more than 2 SD from controls were considered abnormal.Results: Both AD cases had significant degeneration of the superior temporal gyrus and ar...
NeuroImage, 2000
We examined cerebral activation patterns with positron emission tomography (PET) in 12 righthande... more We examined cerebral activation patterns with positron emission tomography (PET) in 12 righthanded normal volunteers while they were completing simple calculation tasks or merely repeating numbers. Using a parametric experimental design, during calculation we found activation in the medial frontal/ cingulate gyri, left dorsolateral prefrontal cortex, left anterior insular cortex and right anterior insular cortex/putamen, left lateral parietal cortex, and the medial thalamus. Number repetition engaged bilateral inferior sensorimotor cortex, bilateral temporal areas, and left inferior frontal cortex. These results suggest a functional anatomical network for simple calculation, which includes aspects of attention, auditory, and motor processing and the phonological store and articulatory loop components of working memory; they add some support for a special role of the parietal cortex in calculation tasks.
Neuroscience Letters, May 1, 1996
Gliat fibrillary acidic protein (GFAP) is the principal marker for brain astrocytes. The present ... more Gliat fibrillary acidic protein (GFAP) is the principal marker for brain astrocytes. The present study aims to examine the variability in GFAP immunohistochemistry in formalin-fixed human brain. Four commercially-available antisera were tested using standardised protocols in the cerebral ce,rtex of three cases with prominent glial reactions and one control. GFAP immunoreactivity was largely confined to the pial surface and white matter in control cortex, with the number of astrocytic cell bodies and processes as well as intensity of staining markedly increased in damaged cortices. A dramatic difference in the pattern of GFAP staining using different antisera was observed and may account for discrepancies between past studies. This variance has important practical implications for the interpretation of results using GFAP immunohistochemistry in human tissue.
Australian journal of human communication disorders, Dec 1, 1993
This paper seeks to summarise and evaluate research into the prevalence of communication impairme... more This paper seeks to summarise and evaluate research into the prevalence of communication impairment in adults. The results of prevalence research in this area depend upon the type of language impairment and the population investigated. As well, the study design has an influence on the eventual prevalence result. Despite these constraints, trends and ranges of prevalence data are described for communication impairment in general and for most specific types of communication impairment. The implications of the prevalence literature for health resource planning are discussed.
Archives of neurology, Feb 1, 1997
Many studies have demonstrated significant sexual dimorphism in verbal ability. However, few stud... more Many studies have demonstrated significant sexual dimorphism in verbal ability. However, few studies have examined anatomical differences between the sexes that may underlie such dimorphism. To examine sex differences in the absolute and proportional volumes of the main language-associated regions of the cerebral cortex. Control neuropathological case series of consecutive autopsies from a teaching hospital. No significant age-related volume changes were identified in the sample. Two language-associated cortical regions, the superior temporal gyrus (part of the Wernicke area) and its subdivisions (planum temporale, Heschl gyrus, and anterior superior temporal gyrus) and the inferior frontal gyrus (Broca area in the dominant hemisphere), and a non-language-associated region, the frontal pole, were measured using stereological techniques in brains fixed with formaldehyde solution serially sectioned at 3-mm intervals. Volume comparisons between the sexes and between brain hemispheres were performed using 2-way analysis of variance. Studies were conducted at the University of Sydney and the Prince of Wales Medical Research Institute, Sydney, Australia. Ten males and 11 females free from neurologic or neuropathological abnormalities. The volume of the superior temporal cortex, expressed as a proportion of total cerebral volume, was significantly larger in females compared with males (17.8% increase; P = .04). This was accounted for by 1 section of the superior temporal cortex, the planum temporale, which was 29.8% larger in females (P = .04). In addition, the cortical volume fraction of the Broca area in females was 20.4% larger than in males (P = .05). In contrast, no significant differences were found in the proportional volume of the frontal pole or in regional volumes between the left and right hemispheres in either sex group. Our results suggest that females have proportionally larger Wernicke and Broca language-associated regions compared with males. These anatomical differences may correlate with superior language skills previously demonstrated in females.
Journal of Neuroscience Methods, Jul 1, 1996
The variability in the external gyri pattern of human brains has made the identification of speci... more The variability in the external gyri pattern of human brains has made the identification of specific cortical areas difficult. Studies correlating cortical structure and function have not consistently controlled for this variability. The aim of the present study was to develop a reliable and reproducible regimen for sampling five speech-associated and one non-speech associated cortical region in the human brain. The gyri of interest were labelled using non-aqueous dye prior to coronal slicing of brains at 3 mm intervals. Using the lab&led gyri, a set of internal brain landmarks was established to aid in sampling one block of each cortical region of interest. The position of each internal landmark was determined as a percentage of the total brain length and breadth. The variability in the position of each isred landmark was investigated using analysis of variance and found to be consistent in three dimensions in alI cases. The correlation of the sampled cortical region to the internal landmark was consistent in different cases with point to point agreement of 100%. This contrasts with the variability between cases in external gyri features. The sampled region was tested to determine cytoarchitectural variability by measuring the depth of each cortical layer. This technique found that the same cytoarchitectural regions were sampled in each case. As expected, these regions were distinguishable by the significant difference in the depth of different cortical layers. Accurate identification of both the external gyri and internal landmarks occurred with interrater point to point agreement of 90-100%.
Journal of Histotechnology, Mar 1, 1996
... and Jillian ~ ril ' ? ~ ... Material and Methods Case rnaterial Brains were referred... more ... and Jillian ~ ril ' ? ~ ... Material and Methods Case rnaterial Brains were referred for the confirmation of clinical di-agnosis of probable Alzheimer's disease to the Neuropa-thology Unit (Department of Pathology, University of Syd-ney) from the Geriatric Units of Concord and St. ...
Australian journal of human communication disorders, Jun 1, 1994
Children from kindergarten through grade 6 in two mainstream Sydney metropolitan schools were ass... more Children from kindergarten through grade 6 in two mainstream Sydney metropolitan schools were assessed for speech and/or language impairment. The two schools were selected to represent children from a range of socio-economic status groups and to include children from disadvantaged and non-English speaking backgrounds. Of the 437 children assessed, 145 were estimated to be speech and/or language impaired. The proportion of children with a communication impairment was estimated to be from 28.8% to 37.6% (95% confidence interval). Estimated prevalence results for impairments of voice, articulation/phonology, language and stuttering are presented, as well as results for pupils of non-English speaking backgrounds.
Neurobiology of Aging, Jul 1, 1996
Topography of brain atrophy during normal aging and Alzheimer's disease. NEUROBIOL AGING 17(4) 51... more Topography of brain atrophy during normal aging and Alzheimer's disease. NEUROBIOL AGING 17(4) 513-521, 1996.-The present study investigated the effect of age on total and regional brain volumes and compared age-associated changes in 20 healthy controls with those observed in 12 patients with Alzheimer's disease (AD). Weights and volumes of the whole brain and cerebrum, as well as the fractional volumes of the frontal, temporal, and parieto-occipital cortices, medial temporal structures, deep brain structures, and white matter were measured. Males had larger and heavier brains than females of comparable age. A small decline in brain volume with age was found (approximately 2 ml per year), but only within the white matter. In comparison, no further loss of white matter occurred in AD; however, the cerebral cortex was significantly reduced in volume, with the greatest loss from the medial temporal structures. This loss was related to disease progression; greater proportional loss was associated with more rapid decline in older patients. This study suggests that significant brain atrophy is not a consequence of advancing age. In addition, it suggests a regional specificity of damage in AD.
Clinical Linguistics & Phonetics, 1994
... Acknowledgements The authors are most grateful for the comments and help of Mark Fey, Martin ... more ... Acknowledgements The authors are most grateful for the comments and help of Mark Fey, Martin Ball, Chris Code and anonymous reviewers. Thanks also to Sue-Ellen Linvale and Liora Baron for help with the reliability data measurement process. Appendix A ...
Laterality, 2003
We present histological data from 21 post-mortem, adult human cases that indicate the neocortex o... more We present histological data from 21 post-mortem, adult human cases that indicate the neocortex on the left planum temporale (secondary auditory cortex) is thinner but longer than that on the right side. The volumes of the left and right regions are approximately equal. Thus, the left planum temporale cortex is long and thin and the right short and thick. The present data fit excellently with previous studies of the volume, surface area, cytoarchitectonics, and neuronal structures of these areas. From these studies we suggest that the hemispheric differences arise from a so-called "balloon model" of cortical development. In this the cortex is extended and stretched by white matter growth. The stretching is greater on the left side, leaving greater distances between neuronal columns and more tangentially (to the pial surface) oriented dendrites on that side. This difference in fine structure can result in more independent activity of individual columns on the left, and could be an anatomical factor in the usual dominance of the left hemisphere for speech perception (Seldon, 1982, 1985).
Australian Journal of Psychology, 2001
Cerebellar morphology in developmental dyslexia, 2002
Recent evidence has suggested cerebellar anomalies in developmental dyslexia. Therefore, we inves... more Recent evidence has suggested cerebellar anomalies in developmental dyslexia. Therefore, we investigated cerebellar morphology in subjects with documented reading disabilities. We obtained T1-weighted magnetic resonance images in the coronal and sagittal planes from 11 males with prior histories of developmental dyslexia, and nine similarly-aged male controls. Proton magnetic resonance spectra (TE = 136 ms, TR = 2.4 s) were obtained bilaterally in the cerebellum. Phonological decoding skill was measured using non-word reading. Handedness was assessed using both the Annett questionnaire of hand preference and Annett's peg moving task. Cerebellar symmetry was observed in the dyslexics but there was significant asymmetry (right grey matter > left grey matter) in controls. The interpretation of these results depended whether a motor-or questionnaire-based method was used to determine handedness. The degree of cerebellar symmetry was correlated with the severity of dyslexics' phonological decoding deficit. Those with more symmetric cerebella made more errors on a nonsense word reading measure of phonological decoding ability. Left cerebellar metabolite ratios were shown to correlate significantly with the degree of cerebellar asymmetry (P < 0.05) in controls. This relationship was absent in developmental dyslexics. Cerebellar morphology reflects the higher degree of symmetry found previously in the temporal and parietal cortex of dyslexics. The relationship of cerebellar asymmetry to phonological decoding ability and handedness, together with our previous finding of altered metabolite ratios in the cerebellum of dyslexics, lead us to suggest that there are alterations in the neurological organisation of the cerebellum which relate to phonological decoding skills, in addition to motor skills and handedness.
Brain and Language, 1999
We examined cerebral activation patterns with positron emission tomography (PET) in 12 righthande... more We examined cerebral activation patterns with positron emission tomography (PET) in 12 righthanded normal volunteers while they were completing simple calculation tasks or merely repeating numbers. Using a parametric experimental design, during calculation we found activation in the medial frontal/ cingulate gyri, left dorsolateral prefrontal cortex, left anterior insular cortex and right anterior insular cortex/putamen, left lateral parietal cortex, and the medial thalamus. Number repetition engaged bilateral inferior sensorimotor cortex, bilateral temporal areas, and left inferior frontal cortex. These results suggest a functional anatomical network for simple calculation, which includes aspects of attention, auditory, and motor processing and the phonological store and articulatory loop components of working memory; they add some support for a special role of the parietal cortex in calculation tasks.
Journal of Histotechnology, 1996
... and Jillian ~ ril ' ? ~ ... Material and Methods Case rnaterial Brains were referred... more ... and Jillian ~ ril ' ? ~ ... Material and Methods Case rnaterial Brains were referred for the confirmation of clinical di-agnosis of probable Alzheimer's disease to the Neuropa-thology Unit (Department of Pathology, University of Syd-ney) from the Geriatric Units of Concord and St. ...
Australian Journal of Human Communication Disorders, 1993
This paper seeks to summarise and evaluate research into the prevalence of communication impairme... more This paper seeks to summarise and evaluate research into the prevalence of communication impairment in adults. The results of prevalence research in this area depend upon the type of language impairment and the population investigated. As well, the study design has an influence on the eventual prevalence result. Despite these constraints, trends and ranges of prevalence data are described for communication impairment in general and for most specific types of communication impairment. The implications of the prevalence literature for health resource planning are discussed.
Australian Journal of Human Communication Disorders, 1994
Children from kindergarten through grade 6 in two mainstream Sydney metropolitan schools were ass... more Children from kindergarten through grade 6 in two mainstream Sydney metropolitan schools were assessed for speech and/or language impairment. The two schools were selected to represent children from a range of socio-economic status groups and to include children from disadvantaged and non-English speaking backgrounds. Of the 437 children assessed, 145 were estimated to be speech and/or language impaired. The proportion of children with a communication impairment was estimated to be from 28.8% to 37.6% (95% confidence interval). Estimated prevalence results for impairments of voice, articulation/phonology, language and stuttering are presented, as well as results for pupils of non-English speaking backgrounds.
Nuclear Medicine Communications, 2000
We examined cerebral activation patterns with positron emission tomography (PET) in 12 righthande... more We examined cerebral activation patterns with positron emission tomography (PET) in 12 righthanded normal volunteers while they were completing simple calculation tasks or merely repeating numbers. Using a parametric experimental design, during calculation we found activation in the medial frontal/ cingulate gyri, left dorsolateral prefrontal cortex, left anterior insular cortex and right anterior insular cortex/putamen, left lateral parietal cortex, and the medial thalamus. Number repetition engaged bilateral inferior sensorimotor cortex, bilateral temporal areas, and left inferior frontal cortex. These results suggest a functional anatomical network for simple calculation, which includes aspects of attention, auditory, and motor processing and the phonological store and articulatory loop components of working memory; they add some support for a special role of the parietal cortex in calculation tasks.
Neuroscience Letters, 1996
Gliat fibrillary acidic protein (GFAP) is the principal marker for brain astrocytes. The present ... more Gliat fibrillary acidic protein (GFAP) is the principal marker for brain astrocytes. The present study aims to examine the variability in GFAP immunohistochemistry in formalin-fixed human brain. Four commercially-available antisera were tested using standardised protocols in the cerebral ce,rtex of three cases with prominent glial reactions and one control. GFAP immunoreactivity was largely confined to the pial surface and white matter in control cortex, with the number of astrocytic cell bodies and processes as well as intensity of staining markedly increased in damaged cortices. A dramatic difference in the pattern of GFAP staining using different antisera was observed and may account for discrepancies between past studies. This variance has important practical implications for the interpretation of results using GFAP immunohistochemistry in human tissue.
Neurology, 2001
Objective: To compare the pattern of cortical degeneration associated with different language def... more Objective: To compare the pattern of cortical degeneration associated with different language deficits in cases of AD.Methods: Cases for detailed neuropathologic analysis (Patients 1 and 2) were selected because of their detailed clinical and neuropsychological assessments of language dysfunction in AD. Patient 1 had severe phonologic impairment with relatively preserved semantic aspects of language. Patient 2 had severe semantic language impairment with relatively preserved phonologic skills. The tissue volume of cortical regions associated with speech and language function was measured using standardized three-dimensional techniques. Neuronal areal fraction was also measured from histologic tissue samples. The degree of volume atrophy and neuronal loss was calculated in comparison to control measures (n = 10 men and 11 women). Measurements more than 2 SD from controls were considered abnormal.Results: Both AD cases had significant degeneration of the superior temporal gyrus and ar...
NeuroImage, 2000
We examined cerebral activation patterns with positron emission tomography (PET) in 12 righthande... more We examined cerebral activation patterns with positron emission tomography (PET) in 12 righthanded normal volunteers while they were completing simple calculation tasks or merely repeating numbers. Using a parametric experimental design, during calculation we found activation in the medial frontal/ cingulate gyri, left dorsolateral prefrontal cortex, left anterior insular cortex and right anterior insular cortex/putamen, left lateral parietal cortex, and the medial thalamus. Number repetition engaged bilateral inferior sensorimotor cortex, bilateral temporal areas, and left inferior frontal cortex. These results suggest a functional anatomical network for simple calculation, which includes aspects of attention, auditory, and motor processing and the phonological store and articulatory loop components of working memory; they add some support for a special role of the parietal cortex in calculation tasks.