Non-retinotopic visual search

Abstract

At the heart of feature integration theory there is a master map that operates on the various features maps. Explicitly or implicitly, it is assumed that these feature maps are organized retinotopically. If in conjunction search, for example, a horizontal green line must be found, the master map would look at the retinotopic position (x,y) in both the colour and the orientation maps to determine whether there is a “green” and a “horizontal” entry, respectively. Here, using a Ternus-Pikler display, we provide evidence that the master map operates on non retinotopic feature maps. We presented a typical Ternus-Pikler display where three squares appeared to move back and forth (group motion). Each square contained a different conjunction search display. The task of the observers was to search for a green horizontal line in the central square only. Retinotopically organized feature maps predict poor search performance because the central display changed position from frame to frame. In contrast to this expectation, we found a remarkably strong performance. Perceptually, only one central square with one search display was perceived for which search is easy. This indicates that efficient search results from the ability to integrate non-retinotopically across the two positions of the central square.

Footnotes

 This research was supported by the Pro*Doc