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Mikko Sams - One of the best experts on this subject based on the ideXlab platform.
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Attention to Visual Speech Gestures Enhances Hemodynamic Activity in the Left Planum Temporale
Human Brain Mapping, 2006Co-Authors: Johanna Pekkola, Riikka Möttönen, Iiro P. Jääskeläinen, Taina Autti, Ville Ojanen, Mikko SamsAbstract:Observing a speaker's articulatory gestures can contribute considerably to auditory speech perception. At the level of neural events, seen articulatory gestures can modify auditory cortex responses to speech sounds and modulate auditory cortex activity also in the absence of heard speech. However, possible effects of attention on this modulation have remained unclear. To investigate the effect of attention on visual speech-induced auditory cortex activity, we scanned 10 healthy volunteers with functional magnetic resonance imaging (fMRI) at 3 T during simultaneous presentation of visual speech gestures and moving geometrical forms, with the instruction to either focus on or ignore the seen articulations. Secondary auditory cortex areas in the bilateral posterior superior temporal gyrus and Planum Temporale were active both when the articulatory gestures were ignored and when they were attended to. However, attention to visual speech gestures enhanced activity in the left Planum Temporale compared to the situation when the subjects saw identical stimuli but engaged in a nonspeech motion discrimination task. These findings suggest that attention to visually perceived speech gestures modulates auditory cortex function and that this modulation takes place at a hierarchically relatively early processing level. Hum Brain Mapp 27:471- 477, 2006. © 2006 Wiley-Liss, Inc.
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Attention to visual speech gestures enhances hemodynamic activity in the left Planum Temporale
Human brain mapping, 2006Co-Authors: Johanna Pekkola, Riikka Möttönen, Iiro P. Jääskeläinen, Taina Autti, Ville Ojanen, Mikko SamsAbstract:Observing a speaker's articulatory gestures can contribute considerably to auditory speech perception. At the level of neural events, seen articulatory gestures can modify auditory cortex responses to speech sounds and modulate auditory cortex activity also in the absence of heard speech. However, possible effects of attention on this modulation have remained unclear. To investigate the effect of attention on visual speech-induced auditory cortex activity, we scanned 10 healthy volunteers with functional magnetic resonance imaging (fMRI) at 3 T during simultaneous presentation of visual speech gestures and moving geometrical forms, with the instruction to either focus on or ignore the seen articulations. Secondary auditory cortex areas in the bilateral posterior superior temporal gyrus and Planum Temporale were active both when the articulatory gestures were ignored and when they were attended to. However, attention to visual speech gestures enhanced activity in the left Planum Temporale compared to the situation when the subjects saw identical stimuli but engaged in a nonspeech motion discrimination task. These findings suggest that attention to visually perceived speech gestures modulates auditory cortex function and that this modulation takes place at a hierarchically relatively early processing level.
Godfrey D. Pearlson - One of the best experts on this subject based on the ideXlab platform.
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measurement of the Planum Temporale pt on magnetic resonance imaging scans temporal pt alone and with parietal extension
Psychiatry Research-neuroimaging, 2000Co-Authors: Nancy A Honeycutt, Patrick E. Barta, Anjene Musick, Godfrey D. PearlsonAbstract:The Planum Temporale (PT) has been of interest because of (1) its consistent left greater than right asymmetry among right-handed and most left-handed normal individuals; and (2) its relation to language, another variable shown to be highly left-lateralized in normal subjects. Individuals with neurodevelopmental disorders have been reported to show abnormal PT asymmetry (either reversed or absent asymmetry). Several studies have been conducted measuring the PT on MRI scans, although the results do not always concur. We review some of these studies and discuss methodological differences between them. Additionally, we propose a method that has proved to be highly reliable for the measurement of both temporal PT and its parietal extension (PT+).
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Superior temporal gyrus and Planum Temporale in schizophrenia: a selective review.
Progress in Neuro-psychopharmacology & Biological Psychiatry, 1997Co-Authors: Godfrey D. PearlsonAbstract:Abstract 1. 1. The normal structure of the superior temporal gyrus (STG) has been elucidated from human and non-human primate research. This brain region is structurally complex, contains several distinct cellular regions and the area known as the Planum Temporale. 2. 2. The STG connects with heteromodal neocortical regions and temporolimbic areas. 3. 3. Functional studies of the normal STG in animals and in humans, using electrophysiology and PET/ fMRI, emphasize the STG's role as part of a cortical network important in the interpretation, production and self-monitoring of language. 4. 4. There is evidence for structural abnormalities of the STG in schizophrenia including both volume reductions and disturbances of normal asymmetries. 5. 5. Functional studies of this region in schizophrenic patients, including measurements of evoked potentials and of bloodflow, are abnormal, especially when patients perform language tasks or experience hallucinations. 6. 6. This structural and functional pathology in the STG probably represents one example of a more general disruption in schizophrenia of the neocortical network of which this region is an essential part. This disturbance may be closely associated with the symptoms of formal thought disorder and of auditory hallucinations commonly seen in the disorder.
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Planum Temporale asymmetry reversal in schizophrenia : Replication and relationship to gray matter abnormalities
American Journal of Psychiatry, 1997Co-Authors: Patrick Ernest Barta, Richard M. Royall, Iain K. Mcgilchrist, Allen Y. Tien, Ann E Pulver, Richard E. Powers, Louis B. Brill, Manuel F Casanova, Godfrey D. Pearlson, Sophia FrangouAbstract:Objective: The Planum Temporale, the posterior superior surface of the superior temporal gyrus, is a highly lateralized brain structure involved with language. In schizophrenic patients the authors previously found consistent reversal of the normal left-larger-than-right asymmetry of Planum Temporale surface area. The original subjects plus new patients and comparison subjects participated in this effort to replicate and extend the prior study. Method: High-resolution magnetic resonance imaging of 28 schizophrenic patients and 32 group-matched normal subjects was performed. The authors measured Planum Temporale surface area, gray matter volume underlying the Planum Temporale, and gray matter thickness. Asymmetry indices for areas and volumes were calculated. Results: Overall gray matter and total brain volume were not significantly smaller in the patients than in the comparison subjects. As previously reported, there was striking reversal of the normal asymmetry for Planum Temporale surface area in the male and female schizophrenic subjects. Bilaterally, gray matter volume beneath the Planum Temporale was smaller in the schizophrenic patients, and the gray matter thickness of the right Planum Temporale was only 50% of the comparison value. Volume of Planum Temporale gray matter did not show significant asymmetry in either group. Conclusions: This study extends the finding of reversed Planum Temporale surface area asymmetry in schizophrenic patients and clarifies its relationship to underlying gray matter volume. Although right Planum Temporale surface area is larger than normal in schizophrenia, gray matter volume is less than the comparison value; thus, gray matter thickness is substantially less than normal. (Am J Psychiatry 1997; 154:661‐667)
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Small Planum Temporale volume in Down's syndrome: a volumetric MRI study.
The American journal of psychiatry, 1997Co-Authors: Sophia Frangou, Patrick E. Barta, Elizabeth H. Aylward, Andrew C. Warren, Tonmoy Sharma, Godfrey D. PearlsonAbstract:Objective: Down’s syndrome is associated with structural brain abnormalities and language deficits. The aim of this study was to investigate whether the superior temporal gyrus and the Planum Temporale, both parts of the anatomic substrate for language, are abnormal in Down’s syndrome. Method: The authors examined volumetric magnetic resonance imaging (MRI) measures of the superior temporal gyrus and the Planum Temporale for 17 community-dwelling patients with Down’s syndrome and 17 matched healthy comparison subjects. For the subjects with Down’s syndrome, the correlations of the superior temporal gyrus and Planum Temporale volumes with performance on tests of language function were examined. Results: The Planum Temporale volume of the patients with Down’s syndrome was smaller than that of the healthy subjects, even after differences in whole brain volume were controlled for. The volume of the superior temporal gyrus in the Down’s syndrome patients was proportionally similar to that of the comparison group. For the subjects with Down’s syndrome, neither superior temporal gyrus nor Planum Temporale volume was significantly correlated with performance on language tests after total brain volume was controlled for. Conclusions: In Down’s syndrome, Planum Temporale volume may be selectively smaller than normal, although the effect of this volume deficit on language is not clear. (Am J Psychiatry 1997; 154:1424‐1429)
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The Maudsley Family Study. 4. Normal Planum Temporale asymmetry in familial schizophrenia. A volumetric MRI study.
The British journal of psychiatry : the journal of mental science, 1997Co-Authors: Sophia Frangou, Godfrey D. Pearlson, Patrick E. Barta, Tonmoy Sharma, T. Sigmudsson, Robin M. MurrayAbstract:BACKGROUND Loss or reversal of the normal asymmetry of the Planum Temporale (PT) has been reported in schicophrenia, and may be due to aberations in the gene(s) controlling the development of brain asymmetries. We tested this hypothesis in a sample of schizophrenics and their relatives from families multiply affected with the disorder. METHOD We compared 32 schizophrenics and 55 of their non-schizophrenic first-degree relatives with 39 matched community controls. Volumetric measurements of the cortical volume beneath the PT were obtained using the Cavalieri method from three-dimensionally reconstructed magnetic resonance imaging images. RESULTS PT volume asymmetry coefficients from patients and their relatives did not differ significantly from those of the controls. Gender-specific analysis did not revealany differences. CONCLUSIONS Abnormalities in PT volume asymmetry are not present in familial schizophrenia, where genetic factors appear to predominate.
Johanna Pekkola - One of the best experts on this subject based on the ideXlab platform.
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Attention to Visual Speech Gestures Enhances Hemodynamic Activity in the Left Planum Temporale
Human Brain Mapping, 2006Co-Authors: Johanna Pekkola, Riikka Möttönen, Iiro P. Jääskeläinen, Taina Autti, Ville Ojanen, Mikko SamsAbstract:Observing a speaker's articulatory gestures can contribute considerably to auditory speech perception. At the level of neural events, seen articulatory gestures can modify auditory cortex responses to speech sounds and modulate auditory cortex activity also in the absence of heard speech. However, possible effects of attention on this modulation have remained unclear. To investigate the effect of attention on visual speech-induced auditory cortex activity, we scanned 10 healthy volunteers with functional magnetic resonance imaging (fMRI) at 3 T during simultaneous presentation of visual speech gestures and moving geometrical forms, with the instruction to either focus on or ignore the seen articulations. Secondary auditory cortex areas in the bilateral posterior superior temporal gyrus and Planum Temporale were active both when the articulatory gestures were ignored and when they were attended to. However, attention to visual speech gestures enhanced activity in the left Planum Temporale compared to the situation when the subjects saw identical stimuli but engaged in a nonspeech motion discrimination task. These findings suggest that attention to visually perceived speech gestures modulates auditory cortex function and that this modulation takes place at a hierarchically relatively early processing level. Hum Brain Mapp 27:471- 477, 2006. © 2006 Wiley-Liss, Inc.
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Attention to visual speech gestures enhances hemodynamic activity in the left Planum Temporale
Human brain mapping, 2006Co-Authors: Johanna Pekkola, Riikka Möttönen, Iiro P. Jääskeläinen, Taina Autti, Ville Ojanen, Mikko SamsAbstract:Observing a speaker's articulatory gestures can contribute considerably to auditory speech perception. At the level of neural events, seen articulatory gestures can modify auditory cortex responses to speech sounds and modulate auditory cortex activity also in the absence of heard speech. However, possible effects of attention on this modulation have remained unclear. To investigate the effect of attention on visual speech-induced auditory cortex activity, we scanned 10 healthy volunteers with functional magnetic resonance imaging (fMRI) at 3 T during simultaneous presentation of visual speech gestures and moving geometrical forms, with the instruction to either focus on or ignore the seen articulations. Secondary auditory cortex areas in the bilateral posterior superior temporal gyrus and Planum Temporale were active both when the articulatory gestures were ignored and when they were attended to. However, attention to visual speech gestures enhanced activity in the left Planum Temporale compared to the situation when the subjects saw identical stimuli but engaged in a nonspeech motion discrimination task. These findings suggest that attention to visually perceived speech gestures modulates auditory cortex function and that this modulation takes place at a hierarchically relatively early processing level.
Patrick E. Barta - One of the best experts on this subject based on the ideXlab platform.
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Morphometry of superior temporal gyrus and Planum Temporale in schizophrenia and psychotic bipolar disorder.
Schizophrenia research, 2013Co-Authors: J Tilak Ratnanather, Clare B Poynton, Dominic V Pisano, Britni Crocker, Elizabeth Postell, Shannon Cebron, Elvan Ceyhan, Nancy A Honeycutt, Pamela B Mahon, Patrick E. BartaAbstract:Structural abnormalities in temporal lobe, including the superior temporal gyrus (STG) and Planum Temporale (PT), have been reported in schizophrenia (SCZ) and bipolar disorder (BPD) patients. While most MRI studies have suggested gray matter volume and surface area reduction in temporal lobe regions, few have explored changes in laminar thickness in PT and STG in SCZ and BPD. ROI subvolumes of the STG from 94 subjects were used to yield gray matter volume, gray/white surface area and laminar thickness for STG and PT cortical regions. Morphometric analysis suggests that there may be gender and laterality effects on the size and shape of the PT in BPD (n=36) and SCZ (n=31) with reduced laterality in PT in subjects with SCZ but not in BPD. In addition, PT surface area was seen to be larger in males, and asymmetry in PT surface area was larger in BPD. Subjects with SCZ had reduced thickness and smaller asymmetry in PT volume. Thus, the PT probably plays a more sensitive role than the STG in structural abnormalities seen in SCZ.
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measurement of the Planum Temporale pt on magnetic resonance imaging scans temporal pt alone and with parietal extension
Psychiatry Research-neuroimaging, 2000Co-Authors: Nancy A Honeycutt, Patrick E. Barta, Anjene Musick, Godfrey D. PearlsonAbstract:The Planum Temporale (PT) has been of interest because of (1) its consistent left greater than right asymmetry among right-handed and most left-handed normal individuals; and (2) its relation to language, another variable shown to be highly left-lateralized in normal subjects. Individuals with neurodevelopmental disorders have been reported to show abnormal PT asymmetry (either reversed or absent asymmetry). Several studies have been conducted measuring the PT on MRI scans, although the results do not always concur. We review some of these studies and discuss methodological differences between them. Additionally, we propose a method that has proved to be highly reliable for the measurement of both temporal PT and its parietal extension (PT+).
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Small Planum Temporale volume in Down's syndrome: a volumetric MRI study.
The American journal of psychiatry, 1997Co-Authors: Sophia Frangou, Patrick E. Barta, Elizabeth H. Aylward, Andrew C. Warren, Tonmoy Sharma, Godfrey D. PearlsonAbstract:Objective: Down’s syndrome is associated with structural brain abnormalities and language deficits. The aim of this study was to investigate whether the superior temporal gyrus and the Planum Temporale, both parts of the anatomic substrate for language, are abnormal in Down’s syndrome. Method: The authors examined volumetric magnetic resonance imaging (MRI) measures of the superior temporal gyrus and the Planum Temporale for 17 community-dwelling patients with Down’s syndrome and 17 matched healthy comparison subjects. For the subjects with Down’s syndrome, the correlations of the superior temporal gyrus and Planum Temporale volumes with performance on tests of language function were examined. Results: The Planum Temporale volume of the patients with Down’s syndrome was smaller than that of the healthy subjects, even after differences in whole brain volume were controlled for. The volume of the superior temporal gyrus in the Down’s syndrome patients was proportionally similar to that of the comparison group. For the subjects with Down’s syndrome, neither superior temporal gyrus nor Planum Temporale volume was significantly correlated with performance on language tests after total brain volume was controlled for. Conclusions: In Down’s syndrome, Planum Temporale volume may be selectively smaller than normal, although the effect of this volume deficit on language is not clear. (Am J Psychiatry 1997; 154:1424‐1429)
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The Maudsley Family Study. 4. Normal Planum Temporale asymmetry in familial schizophrenia. A volumetric MRI study.
The British journal of psychiatry : the journal of mental science, 1997Co-Authors: Sophia Frangou, Godfrey D. Pearlson, Patrick E. Barta, Tonmoy Sharma, T. Sigmudsson, Robin M. MurrayAbstract:BACKGROUND Loss or reversal of the normal asymmetry of the Planum Temporale (PT) has been reported in schicophrenia, and may be due to aberations in the gene(s) controlling the development of brain asymmetries. We tested this hypothesis in a sample of schizophrenics and their relatives from families multiply affected with the disorder. METHOD We compared 32 schizophrenics and 55 of their non-schizophrenic first-degree relatives with 39 matched community controls. Volumetric measurements of the cortical volume beneath the PT were obtained using the Cavalieri method from three-dimensionally reconstructed magnetic resonance imaging images. RESULTS PT volume asymmetry coefficients from patients and their relatives did not differ significantly from those of the controls. Gender-specific analysis did not revealany differences. CONCLUSIONS Abnormalities in PT volume asymmetry are not present in familial schizophrenia, where genetic factors appear to predominate.
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Asymmetry of the Planum Temporale : methodological considerations and clinical associations
Psychiatry research, 1995Co-Authors: Patrick E. Barta, Iain K. Mcgilchrist, Richard E. Powers, Louis B. Brill, Manuel F Casanova, Richard G. Petty, Robert W. Lewis, Matthew Jerram, Godfrey D. PearlsonAbstract:Asymmetry of the Planum Temporale, a region on the posterosuperior surface of the temporal lobe involved in the production and comprehension of language, is a notable feature of the normal human brain. Several attempts have been made to measure it using both post-mortem and magnetic resonance imaging (MRI) methods, but previous approaches made inadequate allowance for the convoluted nature of the structure. The current study used rigorous criteria to define the Planum and examined three separate approaches for its measurement on MRI scans. A method involving triangulation of the surface consistently gave larger values for the surface area of the Planum, suggesting that this method takes account of the convoluted nature of the structure.
Helmuth Steinmetz - One of the best experts on this subject based on the ideXlab platform.
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Significant relation between MR measures of Planum Temporale area and dichotic processing of syllables in dyslexic children.
Neuropsychologia, 2003Co-Authors: Kenneth Hugdahl, Helmuth Steinmetz, Einar Heiervang, Lars Ersland, Arvid Lundervold, Alf Inge SmievollAbstract:In the present study, we investigated differences between dyslexic and normal reading children in asymmetry of the Planum Temporale area in the upper posterior part of the temporal lobe and dichotic listening performance to consonant-vowel syllables. The current study was an extension of previous studies in our laboratory on the same participants, now including also girls and left-handers. There were 20 boys and 3 girls in the dyslexic group and 19 boys and 4 girls in the normal reading group. The age of the participants was 10-12 years for both groups. The participants were screened from a population of 950 students in the fourth school grade in the greater Bergen district. The Planum Temporale area was measured in sagittal magnetic resonance (MR) images. Mean left and right area and asymmetry index were compared between the groups. Dichotic presentations of consonant-vowel syllables made it possible to separately probe left and right hemisphere phonological function, and to correlate this with Planum Temporale area. The results showed a significantly larger left than right Planum Temporale area for both groups. However, while the right Planum Temporale area was similar for the dyslexic and control groups, the left Planum Temporale was significantly (one-tailed t-test) smaller in the dyslexic group. Both groups also showed a significant right ear advantage to the consonant-vowel syllables in the dichotic listening test. The relation between Planum Temporale and dichotic listening asymmetry showed a significant correlation for the dyslexic group only, indicating a positive relation between brain structure and function in dyslexic children. The results are discussed in terms of important subject characteristics with regard to brain markers of dyslexia.
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Planum Temporale Planum parietale and dichotic listening in dyslexia
Neuropsychologia, 2000Co-Authors: Einar Heiervang, Helmuth Steinmetz, Kenneth Hugdahl, Lars Ersland, Alf Inge Smievoll, Jim Stevenson, Anders Lund, Arvid LundervoldAbstract:A reduction or reversal of the normal leftward asymmetry of the Planum Temporale (PT) has been claimed to be typical of dyslexia, although some recent studies have challenged this view. In a population-based study of 20 right-handed dyslexic boys and 20 matched controls, we have measured the PT and the adjacent Planum parietale (PP) region in sagittal magnetic resonance images. For the PT, mean left and right areas and asymmetry coefficients were compared. Since a PP area often could not be identified in one or both hemispheres, a qualitative comparison was used for this region. The total planar area (sum of PT and PP) was also compared between the two groups. A dichotic listening (DL) test with consonant–vowel syllables was administered to assess functional asymmetry of language. The results showed a mean leftward PT asymmetry in both the dyslexic and the control group, with no significant difference for the degree of PT asymmetry. Planned comparisons revealed however, a trend towards smaller left PT in the dyslexic group. In control children, but not in the dyslexic children, a significant correlation between PT asymmetry and reading was observed. A mean leftward asymmetry was also found for the total planar area, with no difference between the groups for the degree of asymmetry. Significantly fewer dyslexic children than control children showed a rightward asymmetry for the PP region. Both groups showed a normal right ear advantage on the DL task, with no significant difference for DL asymmetry. No significant correlation was observed between PT asymmetry and DL asymmetry. The present population-based study adds to recent reports of normal PT asymmetry in dyslexia, but indicates that subtle morphological abnormalities in the left planar area may be present in this condition.
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Child Age and Planum Temporale Asymmetry
Brain and cognition, 1999Co-Authors: Sabine Preis, Lutz Jäncke, Jan Schmitz-hillebrecht, Helmuth SteinmetzAbstract:Investigations using in vivo magnetic resonance (MR) morphometry have shown that left–right asymmetry of the Planum Temporale (PT) is a structural correlate of hemispheric functional asymmetries in adult humans (e.g., handedness, language representation). Postmortem studies of brains of fetuses and newborns have demonstrated that PT asymmetry becomes visible as early as in the last gestational trimester. The same studies could not clarify when the full (adult) degree of PT asymmetry is reached during brain development and whether this process may be influenced by functional specialization during childhood. We examined 61 neuropsychiatrically normal right-handed children aged 3 to 14 years (mean age ±SD, 8.4 ± 2.7 years; cross-sectional study). MR morphometry showed no change in PT or Planum parietale asymmetry with increasing age or brain volume. An unexpected gender difference of unknown significance emerged, with girls displaying a stronger leftward PT asymmetry, independently of age. For the age range studied, the results suggest that functional differentiation follows a structural asymmetry that is already “preset.”
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Structure, Function and Cerebral Asymmetry: In Vivo Morphometry of the Planum Temporale
Neuroscience and biobehavioral reviews, 1996Co-Authors: Helmuth SteinmetzAbstract:Using high-resolution magnetic resonance (MR) imaging, the normal left-right asymmetry of the Planum Temporale (PT) can be quantified accurately and reliably in the intact human brain. The following main results have emerged from MR measurements of individual direction and degree of PT asymmetry. (1) Normal left-handers are less left-lateralized than normal right-handers, without significant gender effects. This confirms a structural-functional correlation in cerebral asymmetry. (2) The aforementioned handedness difference in PT asymmetry is also found in pairs of normal monozygotic twins discordant for handedness. Thus, structural brain asymmetry may not be genetically determined. (3) Whereas right-handed patients with developmental deficits of phonological processing have been reported to show decrease PT asymmetry, musicians with perfect pitch display exaggerated leftward asymmetry. Thus, increasing leftward asymmetry of auditory-related cortices covering the PT may be correlated with the processing capacity for certain auditory features. Studies of the PT as a structural marker of cerebral asymmetry will continue to contribute to a better understanding of the phylogeny and ontogeny of laterality.
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In vivo morphometry of Planum Temporale asymmetry in first-episode schizophrenia
Schizophrenia research, 1994Co-Authors: Andreas Kleinschmidt, Peter Falkai, Thomas Schneider, Yanxiong Huang, Günter Fürst, Helmuth SteinmetzAbstract:Magnetic resonance imaging is a promising tool for in vivo analysis of the neuropathology underlying schizophrenia. One of the most consistent features emerging from the majority of published studies is the lateralization of pathological findings, and this has led to hypotheses of impaired hemispheric specialization in schizophrenia. In previous work, we have validated morphometry of supratemporal language-related cortex using high-resolution magnetic resonance imaging and analyzed the relation of the so defined Planum Temporale to functional parameters of hemispheric specialization. In the present study, we examined Planum Temporale structural asymmetry in first-episode schizophrenics. Asymmetry coefficients obtained in these patients did not differ significantly from those in equally right-handed controls and were not correlated to standard psychopathological measures. These data are contrasted with other studies reporting lateralized brain pathology in schizophrenia with special emphasis on methodological considerations in neuroimaging procedures.