Chapter 10 Flashcards
Visual illusion
- a visual illusion is created by a misinterpretation (distortion or mistake) of the reality of a visual stimulis
- its unavoidable; even when we know were looking at an illusion, our perception is still confused
- for something to be a visual illusion, our perception of it must be consistently differ from the objective reality
Muller-Lyer illusion
- its the misinterpretation of two lines of equal length
(each with different shaped ends, 1-arrowheads 2-feathertails)
- explanations of the muller-lyer illusion point to social and biological factors
social explanation of muller-lyer illusion
- culture
- ‘carpentered-world hypothesis’
- grown up in cultures in which society is restricted by rectangular internal walls, (common with modern, western building design) = more likely to be tricked by the muller-lyer illusion
- grown up in cultures with non rectangular and right-angle dominated building designs, = less likely to be tricked by this illusion
biological explanation of muller-lyer illusion
- size constancy
‘apparent distance theory’
- states that if two objects cast the same size retinal image but one is perceived to be further away, our brain interprets the more distant objects as being larger
- our brain uses top-down processing to make sense of the discrepancy and determines that the more distant feathertail line can only project the same sized retinal image as the arrowhead line if it is longer in the first place
Ames room illusion
- designed to create a visual illusionn for an observer viewing the room through a peephole
- the dimensions of the room are not rectangular but is made to look rectangular
- the illusion is further enhanced by the addition of special flooring and wall decoration
- due to only being able to view the room using one eye only at a time, it prevents them from using their binocualr depth cues (e.g convergence and retinal disparity)
how does Ames room illusion work
- its explained with perceptual constancy
- the observer has no access to binocular depth cues and is forced to use one eye they therefore cannot perceive that the far left corner of the room is actually further away
- the shape is maintained in the observers brain by shape constancy
- the illusion is reinforced by top-down processing where the observer has been raised in a culture in which rooms tend to be rectangular - what they expect to see
Spinning dancer illusion
- an illusion in which a dancer can be percieved as spinning clockwise or anticlockwise, and the same viewer can alternate between percieving either
- the direction that you percieve depends on whether you interpret the dancer as standing on her left or right leg
Bistable perception
- the ability to spontaneously switch between different interpretations of the same ambiguous visual stimulus
Visual agnosia
- brain disorder that interferes with one’s ability to recognise or identify objects, people or sounds using one or more of the senses, despite the affected sensory systems being otherwise fully functioning
- the distortion of perception cannot be explained by memory, attention or language problems, or lack of familiarity with the stimuli
AGNOSIA- A meaning ‘without’ GNOS ‘knowledge’ IA signifies the term is a condition
Apperceptive visual agnosia
- an inability to recognise familiar visual stimuli due to problems with processing perceptions
- no perception has taken place, people with apperceptive visual agonsta cannot even copy a drawing of the stimulus
Factors that can affect our perception of taste
1- amount of papillae
2- judgement of flavour
3- external factors such as miraculin
1- papillae
- ‘bumps; that people have on their tounges. within these papille lie our taste buds, which help us percieve taste
- each person has a dufferent amount of papillae ‘supertasters’ are ablem to taste flavours more intensely than ‘non-tasters’
2- judgment of flavour
- judgement can be ‘tricked’ when our top-down and bottom-up processes get conflicted or confused (e.g you expect a dish to taste a certain way, whuich can influence how we actually taste it)
3- External factors such as miraculin
- a protein found in the pulp of the miracle berry that makes sour senses sweet
Synaethesia
- was first discovered in the 19th century
- active reasearch area since then, with new findings
- it is a perceptual distortion which is when sensory information is percieved differently then the neurotypical
