Visual search strategies in lab and life

To what extent can our eye movement be thought of as efficient, that is, targeting locations where high resolution is needed to differentiate objects? Previous research reported conflicting conclusions: people are near-optimal, random, or even counter-optimal, according to different lines of evidence. Researchers tend to use the simplest possible environments to measure search efficiency, assuming these will minimize the individual differences in experience that could introduce unnecessary variation in behaviour. Here we measured the efficiency of 30 participants as they searched through simple line segment stimuli and through a set of complex icons. We observed a dramatic shift from highly variable strategies with the line segments, to uniformly efficient search with the icons. These results demonstrate that changing what may initially appear to be irrelevant, surface-level details of the task can lead to large changes in measured behaviour, and that visual primitives are not always representative of more complex objects.