Object-based attention in the primary visual cortex of the macaque monkey

Nature. 1998 Sep 24;395(6700):376-81. doi: 10.1038/26475.


Typical natural visual scenes contain many objects, which need to be segregated from each other and from the background. Present theories subdivide the processes responsible for this segregation into a pre-attentive and attentive system. The pre-attentive system segregates image regions that 'pop out' rapidly and in parallel across the visual field. In the primary visual cortex, responses to pre-attentively selected image regions are enhanced. When objects do not segregate automatically from the rest of the image, the time-consuming attentive system is recruited. Here we investigate whether attentive selection is also associated with a modulation of firing rates in area V1 of the brain in monkeys trained to perform a curve-tracing task. Neuronal responses to the various segments of a target curve were simultaneously enhanced relative to responses evoked by a distractor curve, even if the two curves crossed each other. This indicates that object-based attention is associated with a response enhancement at the earliest level of the visual cortical processing hierarchy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Attention / physiology*
  • Fixation, Ocular
  • Macaca
  • Neurons / physiology
  • Visual Cortex / physiology*
  • Visual Perception / physiology*