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Biomedical subjects

R Fox

Publications and source records attributed to R Fox.

At least 307 records · Page 17Linked to original sources
PubMed1980

Stereopsis in human infants.

Stereoscopic depth perception was tested in human infants by a new method based on attracting the infant's attention through movement of a stereoscopic contour formed from a dynamic random-element stereogram. The results reveal that stereopsis emerges at 3 1/2 to 6 months of age, an outcome consistent with evidence for rapid postnatal development of the visual system.

Age Factors↗
PubMed1980

Effect of depth separation on metacontrast masking.

In most investigations of visual masking, spatially adjacent contours are located in the same depth plane, a practice derived from the assumption that depth is not a critical variable in contour formation. In nine experiments, the dependence of masking on the relative depth positions of the target and mask was examined. To permit facile manipulation of depth without introducing confounding changes in proximal stimulation, the stimuli were stereoscopic contours formed from dynamic random-element stereograms generated as anaglyphs on a projection color-television display. The target was a briefly presented Landolt C with gap position randomly varied; the mask was an annulus that surrounded the target. Masking with stereoscopic contours was robust and subject to the same spatial and temporal variables influential in masking with physical contours. Depth separation of the target and mask produced significant reductions in masking and interacted with temporal order and egocentric stimulus position. These results have implications for models of visual masking and indicate that perceived depth is important in contour formation.

Attention↗
PubMed1980

Incidental learning in mildly retarded children.

Fifteen mildly retarded children (mean CA = 11 years, MA = 8 years, IQ = 71), Including nine males and six females, were compared with the same number of both CA- and MA-matched intellectually normal children, including 14 males and 16 females, on a Type I incidental learning task involving simple recognition and recall skills. The results of this comparison found that the retarded group learned incidentally, as well as the MA-matched normal group, but exhibited significantly poorer incidental learning than the CA-matched normal group. These results supported the hypothesis that an incidental learning deficiency exists for the retarded group compared with the CA-matched intellectually normal children but not with the MA-matched normal children.

Child↗
PubMed1980

Assessment of stereopsis in human infants.

A new method for testing stereopsis in infants is described for use in the early assessment of binocular function. Four 6- and 12-month-old infants were presented with a dynamic random-element stereogram generated on a color television monitor. A stereoscopic form was moved laterally, either left or right, to elicit the visual attention of the infant. An observer, unaware of the direction of form movement, made a forced-choice judgment of the direction of form displacement based on information gleaned from observations of the infant's behavior. The observer's performance for all three age groups exceeded chance levels of responding (p < 0.001). Individual infants within each age group also provided strong evidence of stereopsis. The applicability of the method for the screening of binocular anomalies is discussed.

Age Factors↗
PubMed1979

Lymphomatoid granulomatosis in a renal transplant recipient.

Lymphomatoid granulomatosis is a multi-system disorder of high mortality and characterised by angiocentric and angiodestructive lymphoreticular proliferative and granulomatous change. A case is described of this disease occurring in a renal transplant patient. The patient underwent a rapid remission of the disease after a course of combined cytotoxic therapy and remains free of disease three years after treatment. This case is the second described renal transplant patient to develop the disease and the first to be successfully treated. It is likely that the disease originated as a consequence of immunosuppression similar to the development of lymphomas in allograft recipients.

Adult↗
PubMed1979

The chronicity of symptoms and disability in Reiter's syndrome. An analysis of 131 consecutive patients.

To assess the natural history of Reiter's disease, we evaluated 131 consecutive patients at a university clinic or at a community center. One hundred twenty-two patients (93%) were available for follow-up at a mean of 5.6 years. The results showed that there were no major differences between patients at the two centers; at follow-up, 101 (83%) had some disease activity, 27 (22%) had annoying symptoms, 42 (34%) had sustained disease activity, 19 (16%) had had to change jobs, and 13 (11%) were unemployable; there were no major differences between the 19 (15%) females and 112 (85%) males or between the HLA-B27-positive (83%) and -negative (17%) patients, except for increased prevalence of sacroilitis and chronic uveitis in HLA-B27-positive patients; and, at entry, only increased heel disease differentiated those destined to have a poor prognosis. Most patients with Reiter's syndrome have persisting symptoms that can lead to chronic disability.

Adult↗