The Experts below are selected from a list of 912 Experts worldwide ranked by ideXlab platform
Gregory Hickok - One of the best experts on this subject based on the ideXlab platform.
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Conduction Aphasia sensory motor integration and phonological short term memory an aggregate analysis of lesion and fmri data
Brain and Language, 2011Co-Authors: Bradley R Buchsbaum, Juliana V. Baldo, Nina F. Dronkers, Kayoko Okada, Karen Faith Berman, Mark Desposito, Gregory HickokAbstract:Conduction Aphasia is a language disorder characterized by frequent speech errors, impaired verbatim repetition, a deficit in phonological short-term memory, and naming difficulties in the presence of otherwise fluent and grammatical speech output. While traditional models of Conduction Aphasia have typically implicated white matter pathways, recent advances in lesions reconstruction methodology applied to groups of patients have implicated left temporoparietal zones. Parallel work using functional magnetic resonance imaging (fMRI) has pinpointed a region in the posterior most portion of the left planum temporale, area Spt, which is critical for phonological working memory. Here we show that the region of maximal lesion overlap in a sample of 14 patients with Conduction Aphasia perfectly circumscribes area Spt, as defined in an aggregate fMRI analysis of 105 subjects performing a phonological working memory task. We provide a review of the evidence supporting the idea that Spt is an interface site for the integration of sensory and vocal tract-related motor representations of complex sound sequences, such as speech and music and show how the symptoms of Conduction Aphasia can be explained by damage to this system.
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A functional magnetic resonance imaging study of the role of left posterior superior temporal gyrus in speech production: implications for the explanation of Conduction Aphasia
Neuroscience Letters, 2000Co-Authors: Gregory Hickok, Peter Erhard, Jan Kassubek, A.kate Helms-tillery, Susan Naeve-velguth, John Strupp, Peter L. Strick, Kamil UgurbilAbstract:Conduction Aphasia, characterized by good auditory comprehension and fluent but disordered speech production, is classically viewed as a disconnection syndrome. We review recent evidence which suggests that at least one form of Conduction Aphasia results from damage to cortical fields in the left posterior superior temporal gyrus which participate not only in speech perception, but also in phonemic aspects of speech production. As a test of this hypothesis, we carried out a 4T functional magnetic resonance imaging study in which subjects named visually presented objects sub-vocally. Group-based analyses showed that a majority of participants showed activation in two regions on the dorsal portion of the left posterior superior temporal gyrus.
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Speech Perception, Conduction Aphasia, and the Functional Neuroanatomy of Language
Language and the Brain, 2000Co-Authors: Gregory HickokAbstract:Publisher Summary This chapter explores speech perception, Conduction Aphasia, and the functional neuroanatomy of language. The classic functional-anatomic model of language illustrates that Broca's and Wernicke's Aphasias are the only syndromes that arise from damage to an actual language processing “center.” All the rest result from the extrication of one computational system from another. Atleast one type of Conduction Aphasia is not a disconnection syndrome at all. A damage to the auditory word center leads to impaired comprehension because the sound pattern associated with the individual words cannot be activated; production is fluent because motor memories are preserved and they can be activated via the direct concept-to-motor pathway, but speech errors (parAphasias) are evident because the modulatory influence of auditory word representations on motor selection is lost. Word deafness is a primary Aphasia resulting from damage to speech perception systems. Speech perception systems are organized bilaterally in the posterior supratemporal plane. Conduction Aphasia can be viewed as a syndrome resulting from damage to these systems in the left hemisphere.
Alfredo Ardila - One of the best experts on this subject based on the ideXlab platform.
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A Review of Conduction Aphasia
Current Neurology and Neuroscience Reports, 2010Co-Authors: Alfredo ArdilaAbstract:In this paper, a historical overview of the interpretation of Conduction Aphasia is initially presented. It is emphasized that the name Conduction Aphasia was proposed by Wernicke and was interpreted as a disconnection between the temporal and frontal brain language areas; this interpretation was re-taken by Geschwind, attributing the arcuate fasciculus the main role in speech repetition disturbances and resulting in the so-called Wernicke-Geschwind model of language. With the introduction of contemporary neuroimaging techniques, this interpretation of Conduction Aphasia as a disconnection syndrome due to an impairment of the arcuate fasciculus has been challenged. It has been disclosed that the arcuate fasciculus does not really connect Wernicke’s and Broca’s areas, but Wernicke’s and motor/premotor frontal areas. Furthermore, Conduction Aphasia can be found in cases of cortical damage without subcortical extension. It is concluded that Conduction Aphasia remains a controversial topic not only from the theoretic point of view, but also from the understanding of its neurologic foundations.
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The role of the arcuate fasciculus in Conduction Aphasia
Brain, 2009Co-Authors: Byron Bernal, Alfredo ArdilaAbstract:In Aphasia literature, it has been considered that a speech repetition defect represents the main constituent of Conduction Aphasia. Conduction Aphasia has frequently been interpreted as a language impairment due to lesions of the arcuate fasciculus (AF) that disconnect receptive language areas from expressive ones. Modern neuroradiological studies suggest that the AF connects posterior receptive areas with premotor/motor areas, and not with Broca's area. Some clinical and neurophysiological findings challenge the role of the AF in language transferring. Unusual cases of inter-hemispheric dissociation of language lateralization (e.g. Broca's area in the left, and Wernicke's area in the right hemisphere) have been reported without evident repetition defects; electrocortical studies have found that the AF not only transmits information from temporal to frontal areas, but also in the opposite direction; transferring of speech information from the temporal to the frontal lobe utilizes two different streams and Conduction Aphasia can be found in cases of cortical damage without subcortical extension. Taken altogether, these findings may suggest that the AF is not required for repetition although could have a subsidiary role in it. A new language network model is proposed, emphasizing that the AF connects posterior brain areas with Broca's area via a relay station in the premotor/motor areas.
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Conduction Aphasia and verbal apraxia
Journal of Neurolinguistics, 2002Co-Authors: Alfredo Ardila, Monica RosselliAbstract:Abstract A typical case of Conduction Aphasia with oral and written deficits in a patient whose CT scan revealed an insular and parietal vascular accident is analyzed. The patient language deficit correlates with a very notorious idcomotor apraxia. Different explanations and subtypes of Conduction Aphasia are considered. It is proposed that the patient language defect can be interpreted as a segmentary ideomotor apraxia.
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Phonological transformations in Conduction Aphasia
Journal of Psycholinguistic Research, 1992Co-Authors: Alfredo ArdilaAbstract:Different explanations and subtypes of Conduction Aphasia are analyzed. Characteristics of literal parAphasias in parietal-insular Conduction Aphasia are discussed, emphasizing that parAphasias in Conduction Aphasia are articulatory-based (articulatory literal parAphasias) and due mainly to phoneme substitutions and phoneme deletions; they result basically in switches in phoneme manner and place of articulation. Similarities between errors in ideomotor apraxia and Conduction Aphasia language deficits are presented. It is proposed that language deviations (in oral as in written language) in Conduction Aphasia can be understood as a segmentary apraxia of speech.
Jeffrey C. Allen - One of the best experts on this subject based on the ideXlab platform.
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Conduction Aphasia in a 3 year old with a left posterior cortical subcortical abscess
Brain and Language, 1998Co-Authors: Ruth Nass, Fern Leventhal, Beth Levine, Diana Lebron, Carol Maxfield, Patricia R. Mccaul, Ajax E. George, Jeffrey C. AllenAbstract:A 3-year-old, right-handed girl developed a Conduction-type Aphasia following a second generalized seizure in the setting of a developing abscess involving left subcortical and cortical angular gyrus and arcuate fasciculus, and the posterior corpus callosum. The language disorder was fluent, characterized by age appropriate mean length of utterance and syntax, but with markedly reduced spontaneity of output, rapid rate of speech and mild dysarthria. Comprehension was relatively, but not completely spared. Naming, repetition, and reading (letters) were initially markedly impaired. Improvements in naming and repetition were associated with both literal and semantic parAphasias. Writing skills in the form of drawing were spared, but a mild apraxia to verbal command and imitation was initially present. Despite her young age, this child's fluent Conduction Aphasia and lesion localization were adult-like. Multimodal memory difficulties appeared to underlie what is best described as Conduction Aphasia.
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Conduction Aphasia in a 3-year-old with a left posterior cortical/subcortical abscess.
Brain and Language, 1998Co-Authors: Ruth Nass, Fern Leventhal, Beth Levine, Diana Lebron, Carol Maxfield, Patricia R. Mccaul, Ajax E. George, Jeffrey C. AllenAbstract:A 3-year-old, right-handed girl developed a Conduction-type Aphasia following a second generalized seizure in the setting of a developing abscess involving left subcortical and cortical angular gyrus and arcuate fasciculus, and the posterior corpus callosum. The language disorder was fluent, characterized by age appropriate mean length of utterance and syntax, but with markedly reduced spontaneity of output, rapid rate of speech and mild dysarthria. Comprehension was relatively, but not completely spared. Naming, repetition, and reading (letters) were initially markedly impaired. Improvements in naming and repetition were associated with both literal and semantic parAphasias. Writing skills in the form of drawing were spared, but a mild apraxia to verbal command and imitation was initially present. Despite her young age, this child's fluent Conduction Aphasia and lesion localization were adult-like. Multimodal memory difficulties appeared to underlie what is best described as Conduction Aphasia.
Bradley R Buchsbaum - One of the best experts on this subject based on the ideXlab platform.
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Conduction Aphasia sensory motor integration and phonological short term memory an aggregate analysis of lesion and fmri data
Brain and Language, 2011Co-Authors: Bradley R Buchsbaum, Juliana V. Baldo, Nina F. Dronkers, Kayoko Okada, Karen Faith Berman, Mark Desposito, Gregory HickokAbstract:Conduction Aphasia is a language disorder characterized by frequent speech errors, impaired verbatim repetition, a deficit in phonological short-term memory, and naming difficulties in the presence of otherwise fluent and grammatical speech output. While traditional models of Conduction Aphasia have typically implicated white matter pathways, recent advances in lesions reconstruction methodology applied to groups of patients have implicated left temporoparietal zones. Parallel work using functional magnetic resonance imaging (fMRI) has pinpointed a region in the posterior most portion of the left planum temporale, area Spt, which is critical for phonological working memory. Here we show that the region of maximal lesion overlap in a sample of 14 patients with Conduction Aphasia perfectly circumscribes area Spt, as defined in an aggregate fMRI analysis of 105 subjects performing a phonological working memory task. We provide a review of the evidence supporting the idea that Spt is an interface site for the integration of sensory and vocal tract-related motor representations of complex sound sequences, such as speech and music and show how the symptoms of Conduction Aphasia can be explained by damage to this system.
Naama Friedmann - One of the best experts on this subject based on the ideXlab platform.
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Phonological short-term memory in Conduction Aphasia
Aphasiology, 2012Co-Authors: Aviah Gvion, Naama FriedmannAbstract:Background: Within cognitive neuropsychological models Conduction Aphasia has been conceptualised as a phonological buffer deficit. It may affect the output buffer, the input buffer, or both. The phonological output buffer is a short-term storage, responsible for the short-term maintenance of phonological units until their articulation, as well as for phonological and morphological composition. The phonological input buffer holds input strings until they are identified in the input lexicon. Thus the phonological buffers are closely related to phonological short-term memory (pSTM), and hence it is important to assess pSTM in Conduction Aphasia. Because the input and output buffers play different roles, impairment in each of them predicts different impairments in the patient's ability to understand certain sentences, to learn new words and names, and to remember and recall lists of words and numbers for short time periods. This research was supported by a research grant from the National Institute for Psych...
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Does phonological working memory impairment affect sentence comprehension? A study of Conduction Aphasia
Aphasiology, 2012Co-Authors: Aviah Gvion, Naama FriedmannAbstract:Background: The nature of the relation between phonological working memory and sentence comprehension is still an open question. This question has theoretical implications with respect to the existence of various working memory resources and their involvement in sentence processing. It also bears clinical implications for the language impairment of patients with phonological working memory limitation, such as individuals with Conduction Aphasia. Aims: This study explored whether limited phonological working memory impairs sentence comprehension in Conduction Aphasia. Methods & Procedures: The participants were 12 Hebrew-speaking individuals with Conduction Aphasia who, according to 10 recall and recognition span tasks, had limited phonological short-term memory in comparison to 296 control participants. Experiments 1 and 2 tested their comprehension of relative clauses, which require semantic-syntactic reactivation, using sentence–picture matching and plausibility judgement tasks. Experiments 3 and 4 test...
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As far as individuals with Conduction Aphasia understood these sentences were ungrammatical: Garden path in Conduction Aphasia
Aphasiology, 2007Co-Authors: Naama Friedmann, Aviah GvionAbstract:Background: Recent studies have indicated that working memory is not a unitary resource and that different types of working memory are used for different types of linguistic processing: syntactic, semantic, and phonological. Phonological working memory was found to support the comprehension of sentences that require re‐access to the word‐form of a word that appeared earlier in the sentence. The research was supported by a research grant from the National Institute for Psychobiology in Israel (Friedmann 2004‐5‐2b), and by the Joint German–Israeli Research Program grant (Friedmann GR‐01791). We thank Irena Botwinik‐Rotem, Tali Siloni, and Michal Biran for discussions of this study. Aims: This study explored the relation between phonological working memory and sentence comprehension by testing the comprehension of garden path sentences in individuals with Conduction Aphasia who have very limited phonological working memory. Our prediction was that if phonological working memory limitation hampers word‐form r...