Psychology Chapter 16 Flashcards
For Exams/Sacs
What is a visual illusion?
A visual illusion occurs when perception consistently differs from objective reality
It is consistent from person to person and from time to time
What is an illusion?
Illusions are caused by psychological factors, as opposed to other distortions of perception that can be caused by biological factors
Define the Ponzo Illusion, and why it works
- The upper horizontal line is perceived to be longer
/ \
/ - . Than the lower horizontal line
We mistakenly perceive this because of the depth cues of linear perspective and height in the visual field- both of which make the upper line appear further from us
Define the Müller-Lyer illusion
/. \/. Consists of two lines of equal length, each having
| . |. opposite-shaped patterns on the ends. One line has
| |. regular arrowheads; the other has inverted
arrowheads
\/. /. (feather-tails). The line with the feather-tails is perceived
as being longer than the arrow-headed line
What are the two theories that could explain the Müller-Lyer illusion?
The carpeted world hypothesis and the perceptual compromise theory
Define the carpeted world hypothesis
In a 3D world, we maintain a constant perception of the size of a familiar object by considering its distance from us. The carpeted world hypothesis argues that we mentally make a 3D form of each figure, using familiar features of buildings to do so.
How does the carpeted world hypothesis explain the Müller-Lyer illusion?
The observer perceives the arrow-headed line as the leading vertical edge of a buildings outer wall (closest to the viewer) and the line with the feather-tails is perceived as being further away (the inside corner of the room). Because the feather-tailed line is perceived as being the more distant of the two, we interpret the line with feather tails to be longer
What is the perceptual compromise theory and how does it it explain the Müller-Lyer illusion?
Both parallel lines cast identical-sized images on the retina, The arrowhead or feather tail lines at the ends of the figures create ‘open’ figures that cause us to apply the gestalt principle of closure, This creates a more ‘solid’ figure, Because of the perceptual compromise made we perceive each figure to be the length of the average between the internal and imagined external lines, As a result of this the feather tails are perceived as being longer than the arrowheads
What is the Ames room illusion?
The Ames Room illusion shows that we maintain shape constancy (of a room) at the expense of size constancy
It consists of a room built on a trapezoid shape and with a sloping floor not parallel to the ceiling but made to appear square when viewed through a peephole
When a person walks from the left corner to the right corner, the observer maintains shape constancy, but cannot also maintain size constancy - so the person appears to be growing rapidly in size
What is a Motion After-Effect Illusion?
M.A.E refers to the apparent motion of a stationary stimulus (object) following the extended viewing of a continuously moving stimulus
What is perceptual set in relation to gustatory perception?
a tendency to perceive or notice some aspects of the available sensory data and ignore others
Our expectations can influence the way we perceive different flavors. Visual cues can play a large role in the way we perceive flavor by allowing us to make predictions about whether or not we should eat something
What is colour intensity in relation to gustatory perception?
Colour intensity plays an important role, not just in assessment of food but in our prediction of flavor
Foods colored in certain ways could be expected to have certain tastes (e.g.- pink and purple are associated with sweet flavors)
While colour is often perceived to correspond with flavor, more intensely colored foods are often expected to have more intensive flavors
What is texture in relation to gustatory perception?
The way food and drink feels in our mouth also plays a role in our perception of flavor. The impact of texture also works on our expectations, and variation on texture can also give us different experiences of flavor
Describe synesthesia
The presentation of a stimulus from one sensory system automatically triggers a perception in a second sensory system or cognitive process
Such as seeing a certain colour when hearing certain sounds, or associating flavors with certain words
Bruner + Minturn
Context in Perceptual set
illustrated how expectation could influence set by showing participants an ambiguous figure ‘13’ set in the context of letters or numbers e.g. The physical stimulus ‘13’ is the same in each case but is perceived differently because of the influence of the context in which it appears.
