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Biomedical subjects

H J Chenery

Publications and source records attributed to H J Chenery.

12 recordsLinked to original sources

The effect of repeated prime-target presentation in manipulating attention-induced priming in persons with dementia of the Alzheimer's type.

The present experiment manipulated attention-induced semantic priming in seven persons with dementia of the Alzheimer's type (DAT) and 16 healthy aged controls in a word-nonword lexical decision task by means of repeated prime-target presentations. The experimental paradigm allowed for the simultaneous comparison of automatic processing and attention-induced strategic processing. The results showed that both the healthy aged subjects and the subjects with DAT demonstrated semantic facilitation in the automatic processing of information. The two groups differed, however, on the attention-induced component of the task. The control subjects consciously generated a strategic response bias favoring the real word targets and thus used their processing of the prime to induce an expectancy about the following target. The DAT subjects showed no such attention-dependent expectancy, a deficit which is most probably related to the general cognitive impairments which are a hallmark of the disease.

Aged

Respiratory kinematics in speakers with cerebellar disease.

The respiratory abilities of a group of 12 speech disordered subjects with cerebellar disease were assessed using both spirometric and kinematic techniques and compared to those of a group of 12 non-neurologically impaired controls matched for age and gender. Results of the spirometric assessment showed that although all of the cerebellar-diseased subjects had normal total lung capacities, almost half had vital capacities below normal limits. All except 1 of the cerebellar-diseased subjects exhibited irregularities in their chest wall movements while performing sustained vowel and syllable repetition tasks. Over half of the cerebellar-diseased subjects also displayed similar irregularities when reading and conversing. The same irregularities were not present in the chest wall movements exhibited by the control subjects suggesting that their presence was caused by the cerebellar disease. Results are discussed in terms of the effects of cerebellar disease on neuromuscular function.

Adult

Automatic and volitional semantic processing in aphasia.

The present study investigated the status of semantic information in aphasia by comparing the performances of aphasic and nonaphasic subjects on two tasks: an automatic semantic facilitation task and a volitional task of relatedness judgment. Both the aphasic and nonaphasic groups evidenced a semantic facilitation effect, in an on-line task of semantic processing. However, those aphasics with severe comprehension and naming disturbances (termed low comprehension aphasics) demonstrated considerable difficulty in judging the relatedness between a pictured object and members of that object's semantic field, the severity of the impairment being greater for those pictures that the low comprehension aphasics were unable to name. The pattern of results can best be explained by supposing the structural integrity of the store of semantic information in aphasia, and in particular in low comprehension aphasia: information that is retrieved and manipulated in judgment-mediated tasks with considerable difficulty.

Adult

Semantic abilities in dementia of the Alzheimer type. 1. Lexical semantics.

The lexical semantic abilities of 18 Alzheimer patients were investigated using confrontation naming tasks (including both visual and tactile naming tests) and compared to those of a group of institutionalized, nonneurologically impaired control subjects matched for age, sex, and educational level. The Alzheimer patients produced a greater number of naming errors than the control subjects. The errors made by subjects during the naming tasks were analyzed according to a set of 16 error response types. The Alzheimer patients' response patterns suggest that they do recognize objects which they are unable to name and are able to identify the semantic class to which the target belongs, but cannot provide the lexeme corresponding to the correct individual class member. The results support a semantic network disruption rather than a visual perceptual deficit as the basis of the naming disturbance observed in Alzheimer patients.

Aged

Semantic abilities in dementia of the Alzheimer type. II. Grammatical semantics.

The grammatical semantic abilities of 18 Alzheimer patients were investigated using picture description tasks and compared to those of a group of institutionalized, nonneurologically impaired control subjects matched for age, sex, and educational level. During picture description, Alzheimer patients showed that they were able to provide as much information about the target picture as control subjects, but were less concise in their verbal representation of the information. The lack of conciseness was reflected in the DAT patients requiring more time and more syllables to communicate a similar quantity of information than the control subjects. The appropriateness of using a picture description task which involves a perceptual step-by-step account of unrelated events to assess sentential semantics and the conveying of information at a conceptual level is discussed.

Alzheimer Disease

Respiratory function in Parkinson's subjects exhibiting a perceptible speech deficit: a kinematic and spirometric analysis.

The respiratory abilities of a group of 19 speech-disordered subjects with idiopathic Parkinson's disease were assessed using both spirometric and kinematic techniques and compared to those of a group of 19 nonneurologically impaired controls matched for age and sex. Results of the spirometric assessment showed that only a minority of the Parkinson's subjects had lung volumes and capacities outside normal limits. Consequently in the majority of cases, the speech disorder could not be related to any abnormality in lung function determined spirometrically. Chest wall dynamics during both conversation and reading were essentially normal in all cases. Approximately half of the Parkinson's subjects, however, exhibited irregularities in their chest wall movements while performing vowel prolongation and syllable repetition tasks. The same irregularities were not present in the chest wall movements exhibited by the control subjects, suggesting that their presence was in some way related to the Parkinson's disease. Results are discussed in terms of the effects of Parkinson's disease on neuromuscular function.

Aged

Language disorders in dementia of the Alzheimer type.

The language profile of a group of 18 Alzheimer patients is documented and their performance on a standard aphasia test battery compared to a group of institutionalized, nonneurologically impaired control subjects matched for age, sex, and educational level. The Alzheimer patients scored significantly lower than the controls in the areas of verbal expression, auditory comprehension, repetition, reading, and writing. Articulation abilities were the same in each group. A language deficit was evident in all Alzheimer patients. The language disorder exhibited resembled a transcortical sensory aphasia. Syntax and phonology remained relatively intact but semantic abilities were impaired. The results support the inclusion of a language deficit as a diagnostic criterion of Alzheimer's disease.

Aged

Aphemia associated with bilateral striato-capsular lesions subsequent to cerebral anoxia.

A case is presented of a 13-year-old right-handed male who exhibited bilateral striato-capsular lesions following an episode of cerebral anoxia and a range of clinical features typical of aphemia. The findings of a neurological assessment, neuroradiological assessment and battery of speech/language tests are described and their implications for current theories regarding the role of the basal ganglia in speech/language function discussed. The patient initially demonstrated an isolated loss of the ability to articulate words without the loss of the ability to write or comprehend spoken language. His initial mutism later resolved into a dysarthria with features similar to those seen in hypokinetic dysarthria. It was concluded that striato-capsular lesions in childhood are capable of producing temporary language disturbances and in some cases a persistent dysarthria.

Adolescent

Hypernasality in dysarthric speakers following severe closed head injury: a perceptual and instrumental analysis.

Hypernasality in the dysarthric speech of 20 severely closed-head-injured (CHI) subjects was investigated using both perceptual and instrumental techniques. A perceptual analysis of the speech of the CHI subjects was performed using a four-point rating scale for hypernasality. Instrumental assessment was carried out using a computerized accelerometric technique yielding a nasal coupling index. Results revealed a high incidence of perceived hypernasality (95%) in the speech of subjects in the CHI group. More than half of these subjects exhibited hypernasality of speech to a moderate to severe degree. When compared with a control group matched for age and sex the severely CHI subjects were perceived as being significantly more hypernasal. Instrumental assessment revealed that the functioning of the velopharyngeal valve in the group of CHI subjects was significantly impaired compared to the control group. The study highlighted the need to evaluate the perceptual and instrumental assessment results for the severely CHI subjects on an individual basis. The clinical implications of these findings are discussed.

Adolescent

Abnormal patterns of speech breathing in dysarthric speakers following severe closed head injury.

The respiratory abilities of a group of 20 subjects with a speech disorder resulting from severe closed head injury (CHI) were assessed using both spirometric and kinematic techniques and compared with those of a group of 20 non-neurologically impaired controls matched for age and gender. Results of the spirometric assessment showed that the CHI subjects as a group had lower vital capacities and lower forced expiratory volumes 1 second than the controls. Kinematic assessment also showed that the CHI subjects had problems co-ordinating the action of the rib-cage and abdomen when carrying out speech tasks such as vowel prolongations, syllable repetitions and reading. Results are discussed in terms of the effects of CHI on neuromuscular function.

Abdominal Muscles

Perceptual speech characteristics of dysarthric speakers following severe closed head injury.

The perceptual speech characteristics of a group of 20 severely closed head-injured (CHI) subjects were compared with those of a normal non-neurologically impaired control group matched for age and sex. The CHI subjects were found to be significantly less intelligible than the controls, and exhibited deficits in the prosodic, resonatory, articulatory, respiratory and phonatory aspects of speech production. The most frequently occurring deviant speech dimensions related to disturbances of prosody, resonance, articulation and respiration, with those deviant speech dimensions pertaining to phonation being less apparent in the speech of the CHI subjects. The findings are discussed in relation to the heterogeneity of the CHI population and the effects of CHI on neuromuscular function. The study highlights the need for accurate, instrumental physiological evaluation of the motor subsystems involved in speech production.

Adolescent