Claire O’Brien Student ID: 14376041 13/02/2015
PS124 Semester 2 Assignment
Essay title: A miniature toy car nearby (e.g., on a table near us) and a full-size car at a distance (e.g., down the street) may cause the same size image on our retinas. However, we are very unlikely to mistake one for the other. Use detail on binocular and monocular perception cues to explain how we can distinguish a small car nearby from a larger car at a distance.
Parvo cells and magno cells are two ganglion cells which are found in the retina. Parvo cells are sensitive to colour and they play a crucial role in our perception of pattern and form. Magno cells on the other hand, are sensitive to brightness and help to detect motion and a perception of depth …show more content…
The pathway carrying information to the temporal cortex is often called the “what” system, it plays a major role in the identification of visual objects, telling us whether the object is a cat, an apple, or whatever. The second pathway, which carries information to the parietal cortex, is often called the “where” system, it tells us where an object is located - above or below, to our right or left (Ungerleider & Haxby, 1994; Ungerleider & Mishkin, 1982). Information from the primary visual cortex at the back of the head is transmitted to the inferotemporal cortex (the so-called “what” system) and to the posterior parietal cortex (the “where” system) .
Depth perception is the ability to identify forms and also to locate those forms in space. It allows a person to see objects in three dimensions and to judge distance. Depth perception is the key element that allows us to establish that one car is a toy and the other car is a full-size real car although they both appear to be the same size. Depth perception judges how far away that the full-size car down the street is from the toy car nearby and then aids our visual system in distinguishing one from the other. Depth perception uses two cues, binocular and …show more content…
In this case the view of a miniature toy car which is located nearby is seen through the ability of binocular cues. There are two main types of binocular cues – retinal disparity also known as stereopsis and convergence. Retinal disparity is when images from both eyes are different and when the object is nearby, the disparity is larger, e.g.; if you cover your right eye and look straight ahead you won’t be able to see anything on the right peripheral area. In contrast, if you cover your left eye and look straight ahead you won’t be able to see anything on the left peripheral area. Convergence is a neuromuscular cue. It causes both eyes to move inward to view near objects. Convergence allows the eye to focus and therefore create a clear and precise image. Retinal disparity and convergence are the main providers of allows the eyes to differentiate between two objects which appear to be the same on our retinas. No matter what size, distance, colour, binocular cues permit us to observe when two objects are in fact not the same as they