Question

John has enrolled in an art class and is learning how to convey depth perception in his drawings. John had thought about Gestalt principles of vision perception. He claims that these principles are applicable only to textbook illustrations and therefore are not very useful.

• Describe the three things John can do in his drawings to convey depth convincingly.
• Explain how Gestalt principles can be applied to everyday and real-life vision perceptions.

Consider a community where most people have achromatopsia.

• Describe this vision disorder and its causes.
• Based on what you know about rod and cone vision, explain how the community could be modified to compensate for this vision disorder.

Answer 1

* Figure - ground perception

It is a type of perception in which a person sees the main objects as the figure, while considering the rest of the image as the background. In the image below, if a person focuses on white space, he may see it as a vase, so it will be the figure and the black areas will become the ground, whereas if the person focuses on the black areas he may see two faces which will be the figure and the white space will be the ground. Depending on which figure the person focuses, the rest would become the ground. John can use this figure ground perception in his drawings to show one part of the drawing to be the figure whereas the rest of the drawing will be the ground.  

  

* Closure

It is the ability of a person to see a complete figure even though some parts of the figure are missing or incomplete. In the image below, a person may say that a white star is placed on the top of 5 black circles, but the actual image does not have any star and only has 5 circles with some missing pieces. John can use this in his drawing by drawing images that are not completely filled but having some shadings or highlighting that will give a perception of a whole figure.

* Proximity

It is the ability of a person to perceive images or objects by looking at how close the images are to each other. The person focuses on the ways these elements are assembled and perceive them as a group based on their shape, color and size if they are closer. In the image below, a person would say the image on the left as a group of circles, whereas he may say the image on the right as three groups of circles because he had perceived the space between the set of lines and had grouped them as they are closer to each other. John can use this in his drawing to group similar objects.

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* Gestalt principles in everyday life

Gestalt principles are used in day to day life such as depth perception while walking on the road, using continuation while we look in to google maps as we navigate to find the route, using closure to interpret various signs, symbols or logos though they contain some missing parts, using proximity when solving dot puzzles or grouping objects, using figure and ground to interpret and understand pictures or images.

* Achromatopsia

People with achromatopsia have a total or a partial absence in their color vision. Individuals with complete achromatopsia can only see black, white and shades of grey. Whereas individuals with incomplete achromatopsia can only see some colors but not others. Between 4 and 10% of the people belonging to the Pingelapese island have complete achromatopsia. This disorder is caused by a type of gene mutation that is present in these people.

In people with achromatopsia, the cones are non-functional due to which they cannot have color vision. The cones are responsible to provide day light vision (vision in bright light), whereas the rods are responsible to provide night vision (vision in low light). Due to this mutation, the phototransduction is affected since the cones cannot react properly to the light., thus resulting in achromatopsia. Since achromatopsia is inherited by autosomal recessive pattern, if two individuals in which each of them is possessing the mutated copy of the gene mates, then their child, who will possess both their gene will have achromatopsia, if an individual with one copy of the mutated gene mates with an individual who does not have a mutated copy of the gene, then their children will not have achromatopsia as they will inherit only one copy of the mutated gene.