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Biomedical subjects

R Varley

Publications and source records attributed to R Varley.

11 recordsLinked to original sources
PubMed2001

Mind over grammar: reasoning in aphasia and development.

Research on propositional reasoning (involving 'theory of mind' understanding) in adult patients with aphasia reveals that reasoning can proceed in the absence of explicit grammatical knowledge. Conversely, evidence from studies with deaf children shows that the presence of such knowledge is not sufficient to account for reasoning. These findings are in keeping with recent research on the development of naming, categorization and imitation, indicating that children's reasoning about objects and actions is guided by inferences about others' communicative intentions. We discuss the extent to which reasoning is supported by, and tied to, language in the form of conversational awareness and experience rather than grammar.

Journal Article↗
PubMed2001

Severe impairment in grammar does not preclude theory of mind.

Debates about the role of language in human thinking are increasingly prominent in the cognitive sciences. There are claims that certain forms of reasoning can only be performed through access to the resources of the language faculty. In particular, a component of social cognition involving the representation of the mental states of others ('theory of mind' reasoning) has been claimed necessarily to involve propositions of natural language. A recent case study reported a man (SA) with severe agrammatic aphasia who was unable to understand or produce language propositions in any modality of language use, but who was able to complete theory of mind tasks. We report a replication of this finding using a modified picture theory of mind task with a second patient (MR). Despite severe aphasia and impaired performance on a test of executive function, MR demonstrated retained theory of mind reasoning. These results reveal the functional autonomy of theory of mind from the capacity for propositional/grammatical language, and support its independence from executive function.

Aphasia, Broca↗
PubMed2000

Evidence for cognition without grammar from causal reasoning and 'theory of mind' in an agrammatic aphasic patient.

Understanding the inter-relationship between language and thought is fundamental to the study of human cognition [1] [2] [3]. Some investigators have proposed that propositions in natural language serve to scaffold thinking, by providing, for example, a sequential structure to a massively parallel process [4]. Others have maintained that certain thoughts, such as inferring the mental states of others, termed 'theory of mind' (ToM) reasoning, and identifying causal relationships, necessarily involve language propositions [5]. It has been proposed that ToM reasoning depends upon the possession of syntactic structures such as those that permit the embedding of false propositions within true statements ('Mary knows that John (falsely) thinks chocolates are in the cupboard') [6]. The performance on reasoning tasks of individuals with severe agrammatic aphasia (an impairment of language following a lesion of the perisylvian areas of the language-dominant hemisphere) offers novel insights into the relation between grammar and cognition. We report the unusual case of a patient with agrammatic aphasia of such severity that language propositions were not apparently available at an explicit processing level in any modality of language use. Despite this profound impairment in grammar, he displayed simple causal reasoning and ToM understanding. Thus, reasoning about causes and beliefs involve processes that are independent of propositional language.

Aphasia↗
PubMed1996

Hemispheric function in developmental language disorders and high-level autism.

Two groups of children with contrasting types of developmental language disorder (phonologic-syntactic and semantic-pragmatic) were compared with a group of children with high-level autism and with a control group of normal children on a broad battery of neuropsychological tests, known to be sensitive to left-right hemisphere damage. Significant differences found between the groups suggest contrasting forms of hemispheric dysfunction.

Analysis of Variance↗
PubMed1996

Social cognition in developmental language disorders and high-level autism.

Two groups of children with contrasting types of developmental language disorder (phonologic-syntactic and semantic-pragmatic) were compared with a group of children with high-level autism and with a control group of normal children on tests of social cognition (theory of mind; social comprehension; and detection of eye direction). The similarly poor performances of the semantic-pragmatic group and the autistic group suggest that semantic-pragmatic language disorder lies on the autistic spectrum.

Analysis of Variance↗
PubMed1995

Lexical-semantic deficits following right hemisphere damage: evidence from verbal fluency tasks.

The evidence of lexical-semantic deficits following right, non-language-dominant hemisphere injury was assessed using word (or verbal) fluency tests. Two groups of subjects (non-brain-damaged controls and right hemisphere-damaged patients) were indistinguishable in their performances on convergent lexical tasks. Subjects completed verbal fluency tasks by five semantic criteria. The brain-damaged subjects produced significantly fewer responses on two of the categories and demonstrated fewer lexical retrieval strategies. The results were interpreted as evidence that lexical-semantic knowledge is largely intact following right-hemisphere damage, and that apparent lexical deficits result from failure to use lexical knowledge flexibility, suggesting that right-hemisphere language disorders may stem from broader cognitive failures.

Aged↗
PubMed1995

Using electropalatography to treat severe acquired apraxia of speech.

This paper reports on the use of electropalatography (EPG) in the treatment of a patient with severe acquired apraxia of speech. At 2 years post-onset and after a period of conventional speech and language therapy, the patient, AD, presented with severe speech production problems affecting articulation, phonation and resonance. Treatment using EPG is described and both the patient's progress and his continued limitations are outlined. EPG provided a valuable form of visual feedback for the patient and revealed and clarified aspects of oral movements for speech and non-speech activity which had been difficult to capture via auditory perception.

Apraxias↗
PubMed1994

Mast cell ultrastructure in the adenoids of children with and without secretory otitis media.

This study was designed to compare the differences in morphology of the mast cells from the adenoid in children with otitis media with effusion (OME) and those from children with recurrent tonsillitis. Tissue for electron microscopy was prepared in the standard manner and between three and 10 blocks were examined for each child. All the mast cells with nuclei were photographed and the condition of the granules noted. The number of electron dense granules in each cell was assessed on a scale between zero and 10. Sixteen unselected children with OME were compared with 19 children with recurrent tonsillitis. There were no obvious differences in the degree of degranulation between the two groups although there was more vacuolation than previously described in the normal nose but less than in those patients with perennial allergic rhinitis. Allergy and mast cell reactions do not seem to predispose to OME. It was concluded that the adenoids are not the ideal tissue in which to study normal mast cells.

Adenoids↗
PubMed1993

Deictic terms, lexical retrieval and utterance length in aphasia: an investigation of inter-relations.

This study quantified the number of deictic forms in the conversational speech of non-brain-damaged control, right hemisphere-damaged, and fluent and non-fluent aphasic subjects. The relationship between use of deictic terms and performance on single-word level lexical tests was examined, together with the number of deictics with increasing clause length. In the latter case, evidence of trade-off between lexical-semantic complexity and sentence length was sought. Fluent aphasics were found to use significantly more deictics than other groups, and non-fluent aphasics significantly fewer. No significant correlations were observed between deictic use and performance on the lexical tests. Analysis at the level of the group revealed no inverse relationship between deictic use and number of elements in the clause. However, this pattern could be observed in individual fluent aphasics.

Aphasia↗
PubMedDate not supplied

Contribution of finger tracing to the recognition of Chinese characters.

Finger tracing is a simulation of the act of writing without the use of pen and paper. It is claimed to help in the processing of Chinese characters, possibly by providing additional motor coding. In this study, blindfolded subjects were equally good at identifying Chinese characters and novel visual stimuli through passive movements made with the index finger of the preferred hand and those made with the last finger of that hand. This suggests that finger tracing provides a relatively high level of coding specific to individual characters, but non-specific to motor effectors. Beginning each stroke from the same location, i.e. removing spatial information, impaired recognition of the familiar characters and the novel nonsense figures. Passively tracing the strokes in a random sequence also impaired recognition of the characters. These results therefore suggest that the beneficial effect of finger tracing on writing or recall of Chinese characters is mediated by sequence and spatial information embedded in the motor movements, and that proprioceptive channel may play a part in mediating visuo-spatial information. Finger tracing may be a useful strategy for remediation of Chinese language impairments.

Adult↗