Gregorys Theory Flashcards
What is Gregory’s theory known as?
Top down theory
How did Gregory define perception?
Perception involves going beyond the immediately given information of the senses
Briefly explain Gregory’s theory…
An active process
Past experiences, context, knowledge, expectations and motivations affect how we interpret information
Quick process, slowed down with ambiguous information
Make a best guess at what an object is and test it against evidence of our eyes
What affects how we perceive information?
Past experience Own knowledge Context Motivations Expectations
What ideas can be used to explain Gregory’s theory?
Perceptual set
Visual illusions
What is a perceptual set?
A bias to perceive somethings more readily than others
Why does a perceptual set occur?
The brain is pushed to perforce things in certain ways due to factors such as past experience, context, motivation, expectation, knowledge.
How does the idea of a perceptual set support Gregory’s theory?
It fits his idea that perception is motivated by experience and guess work
What is an example of a perceptual set?
Minturn and Bruner
What study is relevant to Gregory’s theory?
Minturn and Bruner
What were Minturn and Bruner’s findings?
The middle figure was more likely to be seen as the number 13 if presented with 12 and 14. It was more likely to be seen as B if presented with A and C
Draw Minturn and Bruner’s stimulus…
Add through Internet
A
12 B 15
C
How do Minturn and Bruner’s findings support Gregory’s theory?
They suggest perception is not just influenced by the sensory data but the persons interpretation of it due to context and knowledge. It is what the brain does with the information not just the information itself
What did Gregory believe about visual illusions?
That the brain creates a hypothesis to explain sensory data
What do visual illusions illustrate?
How we can be misled and dress the wrong conclusions about what we see
How do many illusions arise?
From our tendency to perceive three dimensional objects from two dimensional drawings
What is an example of a visual illusion?
Distortions
What is an example of a distortion?
The ponzo illusion
The Muller Lyer illusion
Draw the ponzo illusion
Draw
Explain what the ponzo illusion is?
Two horizontal lines are equal in length but the top one is perceived as being longer due to converging lines exciting a perception of depth
Help does Gregory explain the ponzo illusion?
We see this as a three dimensional object with the top line further away than the bottom line. As things feels further away than they are (size constancy) our brain interprets the top line as being longer.
Could add in Mu
B
How does the Muller alter illusion create an illusion?
We are lead to believe there is a perception of depth which leads us the perceive the vertical line of the left hand finger as being longer than the right
What affects how one interprets the Muller Lyer illusion?
Culture
How does culture affect how one perceives the Muller Lyer illusion?
Those who live in an industrialised country live in what is known as a ‘carpenter world’ can see the illusion, but those who live in pre-industrialised cultures and live in round huts do not fall for the illusion
What is a carpenter world?
An environment built with lots of square and rectangular objects
How does living in a carpenter world affect how the muller Lyer illusion is perceived?
Because we are used to living in a world full of rectangular and square objects so perceive the illusion, whereas those who live in preindustrialised cultures and live in round huts don’t
What evidence supports Gregory’s explanation of the muller Lyer illusion?
Cataracts patients who have had their eye sight restored see the lines as the same length digesting learning through visual experience is necessary to fall for the muller Lyer illusion. This further supports Gregory’s ideas that the environment, experience and learning affect our understanding.
How do Segall’s findings support Gregory’s explanation of the muller Lyer illusion?
European groups were more susceptible to the illusion suggesting Gregory is right and our past experiences, context and knowledge do affect how one perceives
What evidence contradicts Gregory’s explanation of the muller Lyer illusion?
Children are more susceptible to the muller Lyer illusion than adults, even though they have had less experience of the carpented environment digesting Gregory had placed to much of a stress on learning and experience and their effect on perception.
What were Eysenck and Keene’s findings?
That if the fins are replaced by circles we still fall for the illusion
Briefly, what are the strengths of Gregory’s theory?
It is very comprehensive.
Lots of research to support it
How is Gregory’s top down theory comprehensive?
In that it shows how perception is influenced by a number of cognitive, environmental, emotional and motivational factors. It explains why people perceive things differently from others.
Why is Gregory’s theory better than Gibson’s?
Because it explains why people can perceive differently, where as Gibson suggests that all people view the world in much of the same way.
Briefly, what are the weaknesses of Gregory’s theory?
Many of the studies lack validity
It ignored the importance of movement
Why does visual illusion studies lack validity?
They involve very artificial two dimensional stimuli which give little information about depth and context. They are often flashed on the screen for a second, it’s no wonder guess work comes into play.
Why is Gregory’s theory not as good as Gibson’s theory?
It ignored the importance of movement and is less good at explaining how vision is associated with rapid and accurate response often required in the natural environment.
Explain Eysenck and Keenes findings…
This means the muller Lyer illusion can no longer be related to a carpentered world
