Detection of objects in natural scenes with minimal or no attention

Abstract

Attention plays a critical role in modulating visual information that eventually reaches our visual awareness. What can we see when we do not pay attention? Change-blindness experiments have demonstrated that one can be “blind” even to changes in major aspects of a natural scene. The only tasks that need minimal or no attention appear to be those carried out in the early stages of the visual system. Contrary to this common belief, we report that subjects can rapidly detect highly variable objects (e.g. animals or vehicles) in briefly presented novel natural scenes while simultaneously performing another attentionally demanding task (a five-letter form discrimination task). By comparison, they are unable to discriminate large ‘T's from ‘L's or a bisected two-color disk from its mirror image under the same condition. This ability does not depend on the fact that our subjects are extensively trained on this type of categorization task. Some of the subjects learn to perform a dual-task involving a given target category (e.g. “animal” or “vehicle”) and are subsequently tested using another target category. The pattern of results obtained in that case is comparable. We conclude that some visual tasks associated with “high-level” cortical areas may proceed in the near absence of attention.

Footnotes

 (This research is supported by NSF, NIH, the Kech Foundation and McDonnell Foundation.)