PubMed HealthSearch

Biomedical subjects

B Earhard

Publications and source records attributed to B Earhard.

12 recordsLinked to original sources

The generality of outside-in processing routines in the analysis of form.

In a previous study, Earhard and Walker (1985) showed that outer details of forms were more accurately reported than inner details. Although they suggested that this pattern might reflect a routinely applied outside-in processing strategy, their ability to generalize was limited by a reliance on small, single forms which occupied a fixed position in the visual field. To provide a more adequate assessment of generality of outside-in processing, a series of five experiments examined the discriminability of inner- and outer-line detail under a wide variety of conditions. Support for a general outside-in processing routine was obtained. More accurate reporting of outer detail was evident with large as well as small forms, with long and short exposure durations, and with trial-by-trial variations in the size and orientation of forms. Outer lines were also reported more accurately when a number of forms were presented simultaneously for inspection and under circumstances where error rates were low and reaction time procedures were employed. Evidence was presented to support the view that the more accurate discrimination of outer detail reflected the deployment of an attentional strategy.

Attention

The object-line effect: is it attributable to intercontext differences or the structural properties of contexts and task demands?

Briefly presented target lines are reported more accurately when part of an object-like context than alone (Williams & Weisstein, 1978). Efforts to explain this effect have tended to focus on structural properties that contexts must possess in order to be effective in facilitating target-line discrimination (e.g., Weisstein, Williams, & Harris, 1982). Enns and Prinzmetal (1984) take issue with this approach. They propose that contexts differ more from one another than do target lines presented alone, and it is this fact, and not the general structural properties of contexts, that underlies their effectiveness. Two experiments examined intercontext differences and structural factors as determinants of context effectiveness. Subjects were found to use intercontext differences to narrow the range of possible alternatives, but when this factor was controlled, structural properties determined context effectiveness. The structural interpretation of context effectiveness was found not be as straightforward as generally assumed, however. A third experiment showed context effectiveness to be affected by the character of the discrimination task employed.

Attention