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Biomedical subjects

R Ashton

Publications and source records attributed to R Ashton.

At least 19 recordsLinked to original sources
PubMed1992

Language lateralization in bilinguals: more not less is needed: a reply to Paradis (1990).

Paradis (1990) took an extremely pessimistic view of research to date looking at the lateralization of cerebral function in bilingual subjects. We, however, argue that some of his conclusions are, in fact, incorrect, while others speak more to the youth of the field. The problems in the latter body of work are now acknowledged and are being overcome. That the shortcomings are recognized seems to be more a case for satisfaction than of despair.

Brain Diseases↗
PubMed1992

Characteristics of the frequent nightmare sufferer.

Previous research has found that persons who experience frequent nightmares score highly on scales that measure psychotic symptomatology. Neurotic symptoms have also been implicated as correlates of nightmare frequency. In this study, 30 adult lifelong nightmare sufferers were compared with 30 control subjects, matched for age, sex, and socioeconomic status. Subjects were asked to record all dreams for 1 month and to complete the Minnesota Multiphasic Personality Inventory (MMPI) and the Eysenck Personality Questionnaire (EPQ). Nightmare subjects scored significantly higher on the EPQ Neuroticism scale and on 8 MMPI clinical scales than did the control group. These scales also best discriminated between the groups in a direct discriminant analysis. The results are interpreted as a reflection of global maladjustment rather than of specific psychotic symptomatology.

Adolescent↗
PubMed1992

The apparent shape of afterimages in the Ames room.

When observers project afterimages of circular patterns onto a surface slanting away from them the images are reported as being oval in shape. In this paper it is reported that this does not occur when similar afterimages are projected onto the slanting rear wall of an Ames room. Instead of appearing as ovals, the afterimages remain circular. It appears as though the actually-slanted rear wall of the room not only looks as if it is normal to the line of vision, but also that it functions as if it was in such an orientation as far as a projection surface for afterimages is concerned. While these results are consistent with Emmert's law and with traditional accounts of shape and size constancy, they raise once again the age-old issue of whether the 'image on the retina' constitutes an object of perception that can be described in terms of its shape or size.

Adult↗
PubMed1991

A simple dual-task study of laterality, sex-differences and handedness.

Nine-hundred and eighty-one right-handed and 55 left-handed subjects were required to tap with a pen for 10 secs between targets 6 cm apart whilst either saying nothing, reciting a tongue-twister or saying la-la. The numbers of dots produced in 10 secs in each condition were analysed. The right-handed group demonstrated the usually found degradation in their right-hand performance whilst reciting the meaningful words, but showed a lesser effect when saying la-la. Their left-handed performance was essentially unaffected. Absolutely no evidence for the presence of a sex difference in lateralization of language was found. The much smaller sample of left-handed subjects presented a complex picture of no significant effects, whether they were the sole left-handers in their family, or had other left-handed close relations.

Adolescent↗
PubMed1991

Pain intensity measurement in chronic low back pain.

This study investigated the psychometric properties of eight pain intensity measures used with chronic low back pain patients. All measures were similar in terms of scale distribution and rates of incorrect responses, with all scales apart from the Pain Rating Index significantly correlated. Principal axis factoring of data from 92 patients indicated the presence of one general factor on which all pain intensity measures except the Pain Rating Index loaded. The 101-point Numeric Rating Scale and the Box Scale had the strongest relationship, with loadings of 0.90. The Numeric Rating Scale and the Box Scale appear to be the scales of choice for the measurement of pain intensity in the low back pain patient.

Adult↗
PubMed1990

Emmert's law in the Ames room.

The Ames distorted room illusion, in which the perceived sizes of objects placed within the room differ from their objective sizes, has been used to support arguments for indirect perception. A study is reported in which Emmert's law of the apparent size of after-images was examined in relation to the Ames room's illusory alteration of apparent and actual distances. Size judgments of afterimages projected into the Ames room were compared with control conditions in which both actual and apparent afterimage projection distances were reproduced. Results indicate that Emmert's law may not provide a simple geometrical relationship between proximal image size and actual viewing distance, and that the processes involved in making afterimage size judgments are similar to those processes involved in making size judgments of 'real world' objects.

Adult↗
PubMed1978

Agenesis of the corpus callosum: report of two pre-school children and review of the literature.

The results of neuropsychological examinations of two patients with agenesis of the corpus callosum showed low intelligence-test performance, impared visuo-motor co-ordination and impaired bimanual co-ordination. The most striking deficits were observed in Case A, particularly in her inability to identify objects verbally when placed in the non-dominant hand, and in her ability to complete a task with the non-dominant hand without vision, when she was unable to complete the same task with vision. This patient is unusual insofar as she manifests deficits noted in acallosal patients, as well as some noted in split-brain patients but not previously ascribed to acallosal patients.

Agenesis of Corpus Callosum↗
PubMed1977

A method for producing synchronized audio signals.

An examination of the work dealing with dichotic listening reveals that technical problems prevent clear interpretation of the data. One of the most crucial problems is that of achieving simultaneity of output so that dichotic (simultaneous but different) material is introduced into the auditory system. A simple method for achieving such synchrony on stereotape is described together with a method for testing for degree of simultaneity, if possible.

Acoustic Stimulation↗
PubMed1976

Amnesia for random shapes following unilateral and bilateral electronvulsive shock therapy.

Three 16-point shapes were shown to 15 patients before undergoing either unilateral or bilateral electroconvulsive therapy. They were then tested for recognition following therapy. The same subjects were similarly tested for recognition memory with no intervening shock. Analysis of variance indicated no significant differential effects of the two methods of electroshock application.

Adult↗