Abstract
Question: Does our representation of a learned object weigh all features equally or are diagnostic features given greater prominence? To find out, we conducted a visual search experiment based on the premise that search will be fastest when the features that are prominent in the observer's representation are also salient in the stimulus.
Methods: Observers were trained to associate names with three butterflies that had different types of texture on their upper and lower wings. For each observer, the texture sample on one set of wings varied (the diagnostic wings) while the texture sample on the other set of wings was fixed (the common wings). Soon after training, the observers were tested on a visual search task with the butterfly names as cues. Each search stimulus contained one butterfly on a textured background; the observer's task was to locate the butterfly. On some trials, the statistics of the background texture matched those of the common wings, causing the common features to be highly camouflaged and the diagnostic features to be salient. On other trials, the statistics of the background texture matched those of the diagnostic wings, causing the diagnostic features to be highly camouflaged and the common features to be salient.
Predictions: If diagnostic features are given special prominence in object representations, then search should be fastest when those features are salient in the image. If common features are given special prominence (possibly because they are seen most frequently), then search should be fastest when those features are salient in the image.
Results: Observers found butterflies faster on background textures that camouflaged the common wings rather than the diagnostic wings. Our internal representation of objects gives greater prominence to diagnostic features than to common features.