Shifting resources to recognize a forming object: Dependencies involving object properties

These experiments indicate that when the eyes and attention are allowed to shift to identify a newly appearing object, the success of the shift depend s on properties of the object. Observers attempted to identify a parafoveal target that was followed by a mask. On many trials a prime (cue) was prese nted immediately before the target. The prime was a group of elements (vert ices) that could trigger ocular or attentional shifts. Success of the shift s was measured by increases in identification accuracy relative to a no-pri me condition (facilitation effects). Facilitation was high for many primes, but decreased systematically toward zero when the prime-elements were not easily related to form a convex object and were located outside the boundar ies of the subsequent target.