| |
Abstract:
Abstract: A unique target (singleton) pops out of a display
of homogeneous non-targets. Irrelevant (distractor) singletons are
known to interfere with search for a target singleton. We
investigated the feature-specificity of such interference. Subjects
viewed homogeneous displays of bars, searching for a singleton
target distinguished by orientation, brightness, color or shape.
Reaction time was measured. Search for an orientation target was
delayed by orientation, length and shape distractors while color,
brightness and flickering distractors were relatively ineffective.
Thus, irrelevant singletons distinguished by a feature similar to
the target feature were the most effective distractors. Search for
brightness and color targets failed to show any effect of
irrelevant distractors, regardless of feature (including brightness
and color distractors). In search for a shape target, only a shape
distractor highly similar to the target shape was effective. Other
shape distractors as well as distractors distinguished by other
features (orientation, length, and color) were ineffective.
Together, these findings point to a high degree of
feature-specificity in visual search. It appears that the
attentional template is quite specific, based on the requirements
for search. The extent of feature-specificity in matching candidate
targets to the template, however, seems to vary depending on the
nature of the search target: distractors on related dimensions are
effective in some cases while distractors on the same dimension as
the target are ineffective in other cases. Supported by Emory
University Research Committee
|
