Sensation & Perception Notes

Sensation & Perception

Depth Perception

1. Binocular Depth Information

   • Binocular depth information is crucial for understanding depth perception through the use of two eyes.

   a. Binocular Disparity

   • Binocular disparity is the difference in the images seen by the left and right retinas due to their horizontal separation.

   • Each retina receives a slightly different view of the environment, which aids in depth perception.

     i. Comparing Images on Right and Left Retinas

     • The left retina and right retina have different images due to their positions, causing binocular disparity.

     ii. Corresponding Retinal Points

     • Corresponding retinal points are points on the left and right retinas that perceive the same point in space.

     • These points are crucial for depth perception to align visual input accurately.

     1. Horopter

        • The horopter is an imaginary circle that passes through the fovea of both eyes, indicating the location of corresponding points.

        • Objects that lie on the horopter will be seen in focus, appearing at roughly the same distance from the viewer.

     2. Focus on Objects on the Horopter

        • Everything that falls within the horopter is perceived clearly and is thought to be at a similar distance.

     iii. Non-corresponding (or Disparate) Points

     • Non-corresponding points refer to points that do not coincide between the left and right retinas.

     • They are critical for depth perception as they help to perceive depth through comparison of images.

     iv. Stereopsis

     • Stereopsis is the perception of depth that arises from binocular cues, particularly from binocular disparity.

     • It allows the brain to process the slight differences in image view from both eyes to create a three-dimensional perception of the environment.