Object and face recognition Flashcards
(30 cards)
Explain Hubel and Wiesel’s theory of feature detectors
- we use pattern recognition to process objects
- scenes are pulled apart into features
- simple feature detector neurons in the visual cortex responsed to features such as lines , dots and colours etc.
- we recognise and understand objects regardless of different viewing angles , lighting and distance.
What does the dorsal visual stream tell us about an object
Where it is
What does the ventral visual stream tell us about an object
what it is
What does Navon propose?
We often perceive the whole before the finer details. Big letter made up of different smaller letters. Performance speed was slowed down when the big letter was bigger than the small. This suggests the larger scene is processed first?
Summarise Gestalt psychology
A reaction to reductionist theories proposing that when we view a group of objects together, we first automatically gather the images together
- a) the law of proximity.
- b) the law of similarity - similar elements are usually grouped together
- c) the law of good continuation , fewest changes and disruptions.
- d) law of closure, missing parts of a figure are filled.
What is the key principle of Gestalt psychology?
The importance of figure-ground segregation in perception
What is the Law of Pragnaz?
We typically perceive the simplest possible organisation of the visual field .
What evidence opposes the Gestaltists’ assumption that figure-ground segregation is innate?
Amnesic patients show no different identifying the background between familiar and unfamiliar stimuli
Explain Hedge’s spatial frequency theory
Different neurons in the visual cortex respond to high vs low spatial frequencies
- we process low spatial frequency quickly (processed by fast magnocellular pathway)
- then we process HSF milliseconds layer (processed in parvocellular pathway)
What did Livingstone (2000) argue in relation to Hedge’s spatial frequency theory?
Livingstone (2000) argued focus on spatial frequencies can help explain why the Mona Lisa has an elusive smile
Explain David Marr’s theory of object recognition
Stimulus then primal sketch (edges and contours) very quickly and then develop a 2.5D sketch (depth and orientation) where we begin to understand depth and then quickly after we understand the object is 3D and we can ‘go around it’ then we understand the object wholly.
What do some people argue against David Marr’s theory?
❌some argue the model is too focussed on bottom-up processing
Explain Irving Biederman’s recognition by components theory
viewing from every angle would still lead to similar object recognition . edges are important
- edge extraction , object resembling a line drawing
- then the object is segmented into neons
- there are five invariant properties of edges
Strength of Irving Biederman’s recognition by components theory
✅Vogel et al (2001) macaques responded to geons regardless of angle
Limitations of Irving Biederman’s recognition by components theory
❌some say Bierdman emphasised importance of edges too much
❌colours could be just as important too?
❌focussing on bottom up processes
Explain Goolkasian and Woodberry’s top down findings ?
Eskimo/Indian - eskimo, or indian? ppts saw ambiguous figures preceded by primes which systematically biased the interpretation of the figures
Explain Barr et al’s top down findings ?
concluded that top-down processes in orbitofrontal cortex are more important when recognition is difficult than when it is easy . there was less involvement of orbitofrontal cortex in object recognition when recognition was easy.
What did Lupyan and Ward propose? What was their procedure?
expectations affect object recognition
ppts were told the suppressed stimulus would be a circle, or square or no cue performance was better when valid cues were used so top down processes triggered by verbal labels activated shape information and influenced basic visual detection.
Explain Baruch et al’s interactive-iterative framework
top-down processes influences the allocation of attention and the allocation of attention influences subsequent bottom-up processing
How do humans recognise faces?
- holistically - whole face
- rapid
- parallel processing of features into a whole
- more reliable than object recognition
Explain evidence of holistic processing (FR)
We are worst and slower at identifying faces when inverted - evidence of holistic processing
However evidence is mixed - can this be for complex objects as well?
What did Diamond and Carey show?
Diamond and Carey, dog experts showed an inversion effect for dog breeds and faces
What were were Rossion and Curran’s findings ?
Rossion and Curran found car experts had a much smaller inversion effect for cars than for faces . But those with the greatest expertise showed a greater conversion effect for cars than did those with less expertise
Explain Prosopagnosia
severely impaired face processing, however there is some evidence of covert recognition . One theory why this may be the case is that it is only specific to faces, another is that maybe people with face blindness are just bad at identifying complex stimuli
