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Biomedical subjects

J H Goldberg

Publications and source records attributed to J H Goldberg.

At least 19 recordsLinked to original sources
PubMed1999

The effect of mental workload on the visual field size and shape.

Mental workload is known to reduce the area of one's visual field, but little is known about its effects on the shape of the visual field. Considering this, the visual fields of 13 subjects were measured concurrently under three levels of mental workload using a Goldmann visual perimeter. Tone counting tasks were employed to induce mental workload, avoiding interference with visual performance. Various methods of shape measurement and analysis were used to investigate the variation of the shape of the visual field as a function of mental load. As expected, the mean area of visual fields reduced to 92.2% in the medium workload condition and to 86.41% under heavy workload, compared to light load condition. This tunnelling effect was not uniform, but resulted in statistically significant shape distortion as well, as measured by the majority of the 12 shape indices used here. These results have visual performance implications in many tasks that are susceptible to changes in visual fields and peripheral vision. Knowledge of the dynamics of the visual field as a function of mental workload can offer significant advantages also in mathematical modelling of visual search.

Adult↗
PubMed1996

Predicting age-related differences in visual information processing using a two-stage queuing model.

Recent work on age-related differences in some types of visual information processing has qualitatively stated that younger adults are able to develop parallel processing capability, while older adults remain serial processors. A mathematical model based on queuing theory was used to quantitatively predict and parameterize age-related differences in the perceptual encoding and central decision-making aspects of a multiple-frame search task. Statistical results indicated main effects for frame duration, display load, age group, and session of practice. Comparison of the full model and a restricted model indicated an efficient contribution of the encoding speed parameter. The best-fitting parameter set indicated that (1) younger participants processed task information with a two-channel parallel system, while older participants were serial processors; and (2) perceptual encoding had a large impact on age-related differences in task performance. Results are discussed with implications for human factors design principles.

Adult↗
PubMed1994

Acute uveitis associated with rifabutin use in patients with human immunodeficiency virus infection.

PURPOSE: We studied patients with a new anterior uveitis syndrome associated with rifabutin use. METHODS: Nine patients with the acquired immunodeficiency syndrome (AIDS) who developed acute anterior uveitis were identified retrospectively from institutional ophthalmology, infectious disease, and AIDS primary care practices. Five patients initially had hypopyon; in three patients hypopyon was bilateral and recurrent. The medical history, initial signs and symptoms, diagnostic examination, clinical course, and response to therapy were ascertained by a review of the medical records. RESULTS: All nine patients were being treated with rifabutin for treatment of, or prophylaxis against, Mycobacterium avium complex. In no patient was another untreated cause of uveitis found. In each patient the uveitis resolved rapidly without sequelae with treatment with topical corticosteroids alone. In eight patients uveitis resolved completely while treatment or prophylaxis for M. avium complex was maintained. CONCLUSIONS: We studied a new hypopyon uveitis syndrome in patients with AIDS who are being treated with rifabutin. The interaction of multiple drugs may contribute to this uveitis syndrome. This uveitis is remarkable because it is fulminant yet responds rapidly to topical corticosteroids. Characterization of this syndrome is important because hypopyon in the immunocompromised patient generally mandates intensive, and sometimes invasive, ophthalmic and systemic examination and therapy. Additional study is required to determine whether immune status, underlying infection, or drug-related factors contribute to the development of this uveitis syndrome. Although this syndrome remains a diagnosis of exclusion, ophthalmologists must be aware of it, so that intervention is guided appropriately.

AIDS-Related Opportunistic Infections↗