Y. Zhang and P.H. Schiller, 2005
Soc Neurosci. Abstr., 165.14.
Abstract
This study examined how performance accuracy and response latency for a visual
search task are affected by three factors: (1) The number of objects presented
in the scene, (2) the difference in luminance contrast between the target and
distractors, and (3) the difference in size between the target and the distractors.
Two rhesus monkeys were trained on the visual search task to select a target
object that was larger or had a higher luminance contrast than the distractors.
Each trial began with a central fixation spot that, when fixated by the animal,
was followed by the appearance of the visual display. This display consisted
of multiple circular objects that were evenly distributed at an eccentricity
of 3 degrees from a central fixation spot. One of these objects, the target,
was larger or brighter by various amounts than the distractors, which were identical
and were held constant through different trials. To obtain a drop of apple juice
as a reward, the animals were required to discriminate the target object from
the distractors and to make a single saccadic eye movement towards the target.
In each block of trials, the number of objects in the display remained the same
while the differences in luminance contrast or size between the target and the
distractors was systematically varied. The number of objects in the display
varied between different blocks of trials; the target was presented with 1,
3, 5, or 7 distractors. Our data show that with increasing number of distractor
elements in the display, accuracy in performance declined and response latency
increased.
Support Contributed By: EY14750 and EY014884
Citation: Y. Zhang, P.H. Schiller. THE EFFECT OF THE NUMBER OF VISUAL OBJECTS IN VISUAL SEARCH TASKS IN NON-HUMAN PRIMATES Program No. 165.14. 2005 Abstract Viewer/Itinerary Planner. Washington, DC: Society for Neuroscience, 2005. Online.