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S E Watson

Publications and source records attributed to S E Watson.

4 recordsLinked to original sources
PubMed1999

Object-based visual selective attention and perceptual organization.

We report the results of four experiments that were conducted to examine both the representations that provide candidate entities available for object-based attentional selection and the influence of bottom-up factors (i.e., geometric and surface characteristics of objects) and top-down factors (i.e., context and expectancies) on the selection process. Subjects performed the same task in each of the experiments. They were asked to determine whether two target properties, a bent end and an open end of a wrench, appeared in a brief display of two wrenches. In each experiment, the target properties could occur on a single wrench or one property could occur on each of two wrenches. The question of central interest was whether a same-object effect (faster and/or more accurate performance when the target properties appeared on one vs. two wrenches) would be observed in different experimental conditions. Several interesting results were obtained. First, depending on the geometric (i.e., concave discontinuities on object contours) and surface characteristics (i.e., homogeneous regions of color and texture) of the stimuli, attention was preferentially directed to one of three representational levels, as indicated by the presence or absence of the same-object effect. Second, although geometric and surface characteristics defined the candidate objects available for attentional selection, top-down factors were quite influential in determining which representational level would be selected. Third, the results suggest that uniform connectedness plays an important role in defining the entities available for attention selection. These results are discussed in terms of the manner in which attention selects objects in the visual environment.

Adolescent↗
PubMed1997

Object-based attentional selection--grouped arrays or spatially invariant representations?: comment on vecera and Farah (1994).

S. P. Vecera and M. J. Farah (1994) have addressed the issue of whether visual attention selects objects or locations. They obtained data that they interpreted as evidence for attentional selection of objects from an internal spatially invariant representation. A. F. Kramer, T. A. Weber, and S. E. Watson question this interpretation on both theoretical and empirical grounds. First, the authors suggest that there are other interpretations of the Vecera and Farah data that are consistent with location-mediated selection of objects. Second, they provide data, using the displays employed by Vecera and Farah in conjunction with a postdisplay probe technique, that suggests that attention is directed to the locations of the target objects. The implications of the results for space and object-based attentional selection are discussed.

Adolescent↗
PubMed1994

The cost-effectiveness of prenatal carrier screening for cystic fibrosis.

OBJECTIVE: To evaluate the economic consequences of routinely offering cystic fibrosis-carrier screening to pregnant white women under 35 years of age. METHODS: Decision analysis was used to evaluate the health outcomes and medical costs of a screening program from the health care payer's perspective. Probabilities were taken from the literature; cost data were based on consultations with laboratory and hospital administrators. Sensitivity analysis was performed for key assumptions. RESULTS: If the test acceptance rate were 78% and the screening test identified 85% of carriers, a prenatal cystic fibrosis-carrier screening program would identify slightly more than half of the high-risk pregnancies in the population. For a cohort of one million pregnant women, it would cost $83 million. If the proportion of couples choosing abortion were 30% and the lifetime cost of medical care for cystic fibrosis were $243,650, the program would save $12 million in averted costs of medical care for cystic fibrosis, for a net cost of $71 million. Even after accounting for the savings in averted medical care for cystic fibrosis, the cost per high-risk pregnancy identified would be $82,000; the cost per unwanted cystic fibrosis birth averted would be $1.4 million. Results were sensitive to the cost and sensitivity of the screening test, but relatively insensitive to the test acceptance rate and therapeutic abortion rates between 50-100% among pregnancies identified with cystic fibrosis. CONCLUSION: A prenatal cystic fibrosis-carrier screening program would not save the health care payer money under most assumptions, but may be justified if the benefit of the early information provided to expectant parents is judged worth the cost.

Abortion, Induced↗