Biomedical subjects

J E McNeil

Publications and source records attributed to J E McNeil.

7 recordsLinked to original sources

PubMed1999

Content-specific confabulation.

This report describes a person who confabulated following an anterior communicating artery aneurysm. His confabulation was limited to one very circumscribed area of his life and remained stable for twelve weeks, eventually improving with rehabilitation. It is argued that a content-specific confabulation of this nature challenges current theories of confabulation, and an integrative explanation is given based on previous findings by Burgess and Shallice (1996b) of the mechanisms of autobiographical recollection in healthy people.

Cognition Disorders↗

PubMed1999

A preliminary investigation into the use of virtual environments in memory retraining after vascular brain injury: indications for future strategy?

PURPOSE: In a preliminary investigation of the use of Virtual Environments (VEs) in neurorehabilitation, this study compares the effects of active and passive experience of a VE on two types of memory in vascular brain injury patients and controls. METHOD: Forty-eight patients with vascular brain injury and 48 non-impaired control participants were randomly assigned to active and passive VE conditions. The active participants explored a virtual bungalow seeking a particular object; the passive participants observed, but did not control movement through the VE, also seeking the object. Afterwards, both active and passive participants completed spatial recognition and object recognition tests. RESULTS: Expectedly, the patients were impaired relative to the controls but were able to perform the virtual tasks. Active participation in the VE enhanced memory for its spatial layout in both patients and controls. On object recognition, active and passive patients performed similarly, but passive controls performed better than active controls. CONCLUSIONS: The findings are discussed in relation to their implications for memory rehabilitation strategies.

Adult↗

PubMed1994

The accessibility of proper names.

In this paper we describe a patient with a severe global dysphasia who provides an example of a category specific access impairment. Using matching to sample techniques it was possible to demonstrate the selective preservation of her ability to comprehend proper nouns coupled with impaired comprehension of common nouns. It was found that for the object names category M.E.D. performed better on the first presentation of an item than she did on subsequent presentations. Her performance was also found to be affected by presentation rate and an analysis of her responses showed marked inconsistency when the same stimuli were administered more than once. This category specific access impairment suggests the relative independence of the cognitive mechanisms responsible for the access of different semantic categories.

Auditory Perception↗

PubMed1994

A dissociation between addition and subtraction with written calculation.

A patient with a severe dyscalculia and a mild arabic number dyslexia is described. He could perform simple addition and subtraction sums with oral presentation. However with written arabic number sums he was impaired with addition but not with subtraction. These findings require modifications to current models of arithmetic processing which have suggested that numerical inputs are converted into abstract internal representations before arithmetical processing can occur.

Aged↗

PubMed1993

Spared written naming of proper nouns: a case report.

In this study we describe an investigation into the residual written word retrieval skills of M.E.D., a patient with a severe aphasia. M.E.D.'s performance on written naming and writing to dictation tasks showed a distinctive pattern of performance across semantic categories. The patient's ability to write the names of countries and famous people was consistently superior to her ability to write the names of objects. These results could be considered as indicative of a double dissociation in the proper nouns category, as there are already patients on record who have a selective deficit in retrieving proper nouns.

Anomia↗

PubMed1993

Prosopagnosia: a face-specific disorder.

A follow-up study of a patient, WJ with a very severe prosopagnosia is reported. After a stroke he became a farmer and acquired a flock of sheep. He learn to recognize and name many of his sheep, and his performance on tests of recognition memory and paired-associate learning for sheep was significantly better than on comparable tests using human face stimuli. It is concluded that in some instances prosopagnosia can be a face-specific disorder.

Agnosia↗

PubMed1991

Prosopagnosia: a reclassification.

We report a quantitative investigation of three patients who presented with a profound prosopagnosia. They were tested on a series of tests of face perception, face recognition, and paired associate learning using faces. A patient with marked perceptual difficulties but no difficulty whatever in recognizing faces was tested as a control. The control patient's performance was as bad or worse on the tests of perception of faces, and it is concluded that impaired performance on tests of face perception does not contribute to difficulties in recognizing familiar faces. The major difference between the three prosopagnosic patients was the evidence of covert recognition in two of these cases but not in the third. We use this evidence to argue that the perceptual/mnestic distinction is an inappropriate classification and would suggest instead that the two types may be described in terms either of a disconnection of the face recognition units or of damage to the units themselves.

Aged↗