Re: What are visual searches?

Hi Christine,

      Visual searches, also called saccades or 'gaze shifts', are eye and head movements that allow you examine the world around you. They happen at a rate of roughly 3 every second. We don't really notice that we're making them, but we do it all the time!

      There is quite a lot of literature about the effect of distractors on visual search, both at the level of how well people do with increasing numbers of distractors, and at the level of figuring out what parts of the brain are involved. For finding psychology research, I would look up the terms "visual search" and "attention." For finding research on brain areas, I would look up terms like "attention," "saccades," "saccadic eye movements," and "gaze." Some details about the eye can be found here. And two parts of the brain that have been studied in the context of saccades and in interpreting scenes are the "visual cortex" and "superior colliculus."

      The visual cortex has the task of recreating the world inside our heads. The backs of our eyes are tiled with photoreceptors, which basically give the brain a pixelated version of the world (kind of like a computer screen). But then the brain has to figure out the details of the scene. This is the job of the visual cortex.

      The superior colliculus and frontal eye fields play a role in moving our eyes to a new spot - they send a signal of "move your eyes 20 degrees to the right" to the eye muscles, and the muscles just follow orders. But they also participate in interpreting visual stimuli to help make the decision of where to move your eyes and attention.

      I hope that provides a starting point for your research.

      cheers,
Alex