Neuronal representation of disappearing and hidden objects in temporal cortex of the macaque

Neurons in the anterior regions of the banks of the superior temporal sulcu s (STSa) of the macaque monkey respond to the sight of biologically signifi cant stimuli such as faces, bodies and their motion. In this study the resp onses of STSa neurons were recorded during the gradual occlusion of the exp erimenter and other mobile objects behind screens at distances of 0.5-4 in from the monkeys. The experimenter or other object remained out of sight fo r 3-15 s before emerging back in to view. We describe a population of neuro ns (n=33) showing increased activity during the occlusion of objects that w as maintained for up to 11 s following complete occlusion (when only the oc cluder itself was visible). This increase in activity was selective for the position of the occlusion within the testing room. Many neurons showed lit tle or no change in activity prior to occlusion when the object or experime nter was completely in view. By coding for the presence and location of rec ently occluded objects, these responses may contribute to the perceptual ca pacity for object permanence.