Object Recognition Flashcards
What is object recognition for humans?
Perception of familiar items
What is object recognition for computers?
Perception of familiar patterns
Between category discriminations
e.g. Is this a chair, is it not a chair?
Is this object recognition for humans or computers?
Computers
Within category discriminations
e.g. Whose face is this?
Is this object recognition for humans or computers?
Humans
Why is object recognition difficult?
Environment contains hundreds of overlapping objects
Yet perceptual experience is of structured coherent objects which we can recognise, use and usually name
True or False?
Apparent size and shape of an object does not change despite large variations in retinal image
True
Apparent ____ and ____ of an object does not change despite large variations in retinal image
- size
- shape
What are 5 examples of variability in object recognition?
- Translation invariance
- Rotation invariance
- Size invariance
- Colour
- Partial occlusion
and presence of other objects
Define translation invariance
Recognising an object when it is not in the same location as before
Recognising an object when it is not in the same location as before
This is known as…?
Translation invariance
Define rotation invariance
Recognising an object when it is not in the same rotation as before
Recognising an object when it is not in the same rotation as before
This is known as…?
Rotation invariance
Define size invariance
Recognising an object when it is not the same size as before
Recognising an object when it is not the same size as before
This is known as…?
Size invariance
Define colour (variability)
Recognising an object when it is not the same colour as before
Recognising an object when it is not the same colour as before
This is known as…?
Colour (variability)
Define partial occlusion
and presence of other objects
Where an object is blocked off partially by some other object/space
Where an object is blocked off partially by some other object/space
This is known as…?
Partial occlusion
and presence of other objects
What is intra-class variation?
Image variations occur between different images of one class
e.g. These objects are all chairs but they all look so different. (different shapes, structure, colour, height)
Image variations occur between different images of one class
e.g. These objects are all chairs but they all look so different. (different shapes, structure, colour, height)
This is known as…?
Intra-class variation
What are the 2 challenges of object recognition?
- Intra-class variation
- Viewpoint variation
What is viewpoint variation?
Being able to recognise an object even from different viewpoints
Being able to recognise an object even from different viewpoints
This is known as…?
Viewpoint variation
e.g. Recognising that the object is a coffee pot from the top view (looks like a square with a circle in the middle and a rectangle at the side)
This is an example of…?
Viewpoint variation
How do we recognise the letter ‘A’ according to template theories?
When you see your letter A, you match it to what you have stored in your LTM memory (mini copy or template in LTM of all known patterns) and when you get a good enough match, you can recognise that as a letter A
simply = Multiple templates are held in memory, we compare stimuli to templates in memory for one with the greatest overlap until a match is found
When you see your letter A, you match it to what you have stored in your LTM memory (mini copy or template in LTM of all known patterns) and when you get a good enough match, you can recognise that as a letter A
This is known as…?
Template theories on 2D Pattern matching
How do we engage in 2D Pattern matching?
List 4 points
- Template theories
- Prototype theories
- Feature theories
- Structural descriptions
What are the 2 implications of template theories?
- Does not consider normalisation
- How many mini copies or templates of the object do we store in the LTM? Is it infinite?
Give 2 examples of template theory 2D pattern matching
- Barcodes
- Fingerprints
Multiple templates are held in memory, we compare stimuli to templates in memory for one with the greatest overlap until a match is found
This is known as…?
Template theories on 2D Pattern matching
What are the 3 limitations of template theories?
- Problem of imperfect matches
- Cannot account for the flexibility of pattern recognition system
- Comparison requires identical orientation, size, position of template to stimuli
How do we recognise the letter ‘A’ according to prototype theories?
Rather than storing lots of different templates, we have an average template stored in memory. When you see your letter A, you match it to the average template (prototype) stored in your memory.
Simply = Modification of template matching (flexible templates), Possesses the average of each individual characteristic, No match is perfect; a criterion for matching is needed
Rather than storing lots of different templates, we have an average template stored in memory. When you see your letter A, you match it to the average template (prototype) stored in your memory.
This is known as…?
Prototype theories on 2D Pattern matching
Modification of template matching (flexible templates), Possesses the average of each individual characteristic, No match is perfect; a criterion for matching is needed
This is known as…?
Prototype theories on 2D Pattern matching
Describe Franks & Bransford’s (1971) evidence for prototype theory
List 4 points
- Presented objects based on prototypes
- Prototype not shown
- Yet participants are confident they have seen the prototype
- Suggests the existence of prototypes
Simply = By seeing all these examples that all surround this prototype, you think as though you have seen the prototype even though you have not seen it at all
Which 2D pattern matching theory does this apply to?
Pattern consists of a set of features or attributes
a. Template theories
b. Prototype theories
c. Feature theories
d. Structural descriptions
c. Feature theories
Which 2D pattern matching theory does this apply to?
Modification of template matching (flexible templates)
a. Template theories
b. Prototype theories
c. Feature theories
d. Structural descriptions
b. Prototype theories
Which 2D pattern matching theory does this apply to?
Possesses the average of each individual characteristic
a. Template theories
b. Prototype theories
c. Feature theories
d. Structural descriptions
b. Prototype theories
Which 2D pattern matching theory does this apply to?
Mini copy or template in LTM of all known patterns
a. Template theories
b. Prototype theories
c. Feature theories
d. Structural descriptions
a. Template theories
Which 2D pattern matching theory does this apply to?
Multiple templates are held in memory
a. Template theories
b. Prototype theories
c. Feature theories
d. Structural descriptions
a. Template theories
Which 2D pattern matching theory does this apply to?
No match is perfect; a criterion for matching is needed
a. Template theories
b. Prototype theories
c. Feature theories
d. Structural descriptions
b. Prototype theories
Which 2D pattern matching theory does this apply to?
Compare stimuli to templates in memory for one with greatest overlap until a match is found
a. Template theories
b. Prototype theories
c. Feature theories
d. Structural descriptions
a. Template theories
Which 2D pattern matching theory does this apply to?
Problem of imperfect matches
a. Template theories
b. Prototype theories
c. Feature theories
d. Structural descriptions
a. Template theories
b. Prototype theories
Which 2D pattern matching theory does this apply to?
Cannot account for the flexibility of pattern recognition system
a. Template theories
b. Prototype theories
c. Feature theories
d. Structural descriptions
a. Template theories
Which 2D pattern matching theory does this apply to?
Comparison requires identical orientation, size, position of template to stimuli
a. Template theories
b. Prototype theories
c. Feature theories
d. Structural descriptions
a. Template theories
How do we recognise the letter ‘A’ according to feature theories?
- Pattern consists of a set of features or attributes
- A = 2 straight lines and a connecting crossbar.
- But also need to know the relationship between features
- Pattern consists of a set of features or attributes
- A = 2 straight lines and a connecting crossbar.
- But also need to know the relationship between features
This is known as…?
Feature theories on 2D pattern matching
How do we recognise the letter ‘A’ according to structural descriptions?
- Describe the nature of the components of a configuration and the structural arrangement of these parts” (Bruce & Green, 1990)
- Capital letter T = 2 parts; 1 horizontal; 1 vertical; vertical supports horizontal; vertical bisects horizontal
- Describe the nature of the components of a configuration and the structural arrangement of these parts” (Bruce & Green, 1990)
- Capital letter T = 2 parts; 1 horizontal; 1 vertical; vertical supports horizontal; vertical bisects horizontal
This is known as…?
Structural descriptions on 2D pattern matching
How do we recognise 3D objects?
List 2 steps
- Firstly we must interpret the input to the visual system as coherent structures, segregated from one another and from the background (early image processing)
simply = Must know how to segregate an object as being a distinct one object that goes together and is distinct from the background
- Must be processed to give a description– which can then be matched to the descriptions of visual objects stored in memory.
What does Marr’s Computational Approach aim to explain?
3D Object recognition
3D Object recognition can be explained by which approach?
Marr’s Computational Approach
What are the 3 steps to Marr’s Computational Approach
- Primal Sketch
- 2 1⁄2-D Sketch
- 3-D Representation
What is a primal sketch in Marr’s Computational Approach?
2-D description includes changes in light intensity, edges, contours, blobs
What is a 2 1/2 D Sketch in Marr’s Computational Approach?
Includes information about depth, motion, shading. Representation is observer-centered.
What is a 3D representation in Marr’s Computational Approach?
A representation of objects and their relationships, observer-independent
2-D description includes changes in light intensity, edges, contours, blobs
This is known as…?
Primal sketch
Includes information about depth, motion, shading. Representation is observer-centered.
This is known as…?
2 1/2 D Sketch
A representation of objects and their relationships, observer-independent
This is known as…?
3D representation
What are the 4 questions asked when recognising objects?
- What elements are used in the description? (primitives)
- How is the relationship between these elements specified?
- How is the overall description invariant across views?
simply = How can you recognise objects from different viewpoints? How is it that we can create a description that works from different viewpoints
- What about viewpoint dependence?
simply = Does it depend on the task that you are doing?
What did Marr & Nishihara (1978) express about objects in relation to cylinders?
Every object can be broken down into a series of cylinders and we must specify the relationship between cylinders to create a structural description of the object
Every object can be broken down into a series of cylinders and we must specify the relationship between cylinders to create a structural description of the object
Who proposed this?
Marr & Nishihara (1978)
The relationship between these cylinders creates a structural description of the object
This works particularly well what kinds of objects?
Biological type objects
e.g. human body
Marr & Nishihara (1978) expressed structural relations by …?
A hierarchical organisation of cylinders
According to Marr & Nishihara (1978), structural relations are based on a hierarchical organisation of cylinders
What does this mean?
Each cylinder has an axis and the way in which others are joined is expressed as coordinates
The position of each cylinder is described relative to its own axis, resulting in a description which is invariant across viewpoints.
This is useful to determine what types of objects?
Argued to be useful in determining who is a human or gorilla, depending on the length of the arms, etc.
The position of each cylinder is described relative to its own axis, resulting in a description which is invariant across viewpoints.
This is not useful to determine what types of objects?
Other objects that are not biological/bodily types of objects
e.g. a piece of paper cannot be broken down into cylinders
Works well for biological objects but not other objects
Which model does this apply to?
Marr & Nishihara’s (1978) cylinder model
Who provided an alternative model to Marr & Nishihara (1978)?
Biederman (1987;1989)
Which theory proposes that objects are composed of basic shapes?
Biederman’s Recognition-by-components theory
What does Biederman’s Recognition-by-components theory propose about objects?
Objects composed of basic shapes
According to Biederman’s Recognition-by-components theory, objects are composed of basic shapes known as…?
GEONS
What are GEONS?
Geometrical ions
Basic shapes that make up an object
Give 4 examples of GEONS
- Blocks
- Cylinders
- Arcs
- Wedges
- Blocks
- Cylinders
- Arcs
- Wedges
These are examples of…?
GEONS
Approximately how many different volumetric shapes (GEONS) are there based on Biederman’s Recognition-by-components theory?
36
Which model/theory is viewpoint invariant?
Biederman’s Recognition-by-components theory
Which model/theory proposes that objects are made up of cylinders?
Marr & Nishihara (1978)
Which model/theory proposes that objects are made up of GEONS?
Biederman’s Recognition-by-components theory
Which model/theory proposes that there are small numbers of structural relationships?
Biederman’s Recognition-by-components theory
Biederman’s Recognition-by-components theory claims that there is a small number of structural relationship
Give 4 examples
- Relative size
- Verticality
- Centring
- Relative size of surfaces at join
Viewpoint-invariant theory of recognition is known as…?
Biederman’s Recognition-by-components theory
Recognition using 3D component parts (e.g. 36 GEONS), with structural relations between the parts
Which model/theory proposes this?
Biederman’s Recognition-by-components theory
Define viewpoint-invariant
The object can be identified from any angle
The object can be identified from any angle
This is known as…?
Viewpoint-invariant
According to Biederman (1987; 1989), what is helpful in segmenting visual image into parts?
Concave parts of an object’s contour
According to Biederman (1987; 1989), concave parts of an object’s contour is helpful in…?
Segmenting visual image into parts
Geons are specified in terms of…?
‘Non-accidental’ properties
Are specified in terms of ‘non-accidental’ properties
This is known as…?
GEONS
GEONS are specified in terms of ‘non-accidental’ properties
What are they? List 5
- Curvature
- Parallel
- Co-termination
- Symmetry
- Co-linearity
- Curvature
- Parallel
- Co-termination
- Symmetry
- Co-linearity
These are properties of…?
GEONS
How do we recognise an object using GEONS?
List 4 points
- Pick out one GEON from another in terms of points of concavity
- Look at the relationships between the GEONS, which gives you structural descriptions of an object
- Once you have created that structural description, you try to match it to all of the structural descriptions you have stored in your memory
- Once you find a good enough match, you recognise it as an object (e.g. lamp)
How do we recognise a cylinder using GEONS?
List 2 points
- Cylinder posses curved edges & two parallel edges connecting the curved edges
- Regularities in the visual image thought to reflect actual (non-accidental) regularities in the world
e.g. 2D symmetry in the visual image indicates symmetry in 3D object.
GEONS are specified in terms of ‘non-accidental’ properties such as curvature
What is curvature?
Points on a curve
GEONS are specified in terms of ‘non-accidental’ properties such as parallel
What is Parallel?
Set of points in parallel
GEONS are specified in terms of ‘non-accidental’ properties such as co-termination
What is co-termination?
Edges terminating in a common point
GEONS are specified in terms of ‘non-accidental’ properties such as symmetry
What is Symmetry?
Versus asymmetry
GEONS are specified in terms of ‘non-accidental’ properties such as co-linearity
What is co-linearity?
Points in a straight line
List these steps of recognising object using GEONS in the correct order, according to Biederman (1987)
DETERMINATION OF COMPONENTS
EDGE EXTRACTION
DETECTION OF NON-ACCIDENTAL PROPERTIES
MATCHING OF COMPONENTS TO OBJECT REPRESENTATIONS
PARSING OF REGIONS OF CONCAVITY
- EDGE EXTRACTION
- DETECTION OF NON-ACCIDENTAL PROPERTIES
and
PARSING OF REGIONS OF CONCAVITY
- DETERMINATION OF COMPONENTS
- MATCHING OF COMPONENTS TO OBJECT REPRESENTATIONS
According to Biederman’s (1987; 1989) model, what makes objects more difficult to recognise?
Forms of degradation which disrupt the basis for identifying geons
According to Biederman’s (1987; 1989) model, what effect do forms of degradation which disrupt the basis for identifying geons have on object recognition?
It makes objects more difficult to recognise
According to Biederman’s (1987; 1989) model, why do forms of degradation lead to difficulty in recognising objects?
They disrupt the basis for identifying geons
According to Biederman’s (1987; 1989) model, what disrupt the basis for identifying geons?
Forms of degradation
Describe Biederman’s (1987) study on forms of degradation
List 2 points
- Biederman (1987) deleted edges at points where easily reinstated or difficult to determine
- Stimuli was presented for 100, 200 or 750 msec with 25%, 45% or 65% contours removed
Describe the results of Biederman’s (1987) study on forms of degradation
List 2 points
- Ps were relatively good at recognising objects with deleted edges at points where easily reinstated or recognisable objects (partial degradation)
- Ps were slow and inaccurate at recognising objects with deleted edges at points where it was difficult to determine or non-recognisable objects
Ps were relatively good at recognising objects with deleted edges at points where …?
a. Easily reinstated
b. Difficult to determine
a. Easily reinstated
Ps were slow and inaccurate at recognising objects with deleted edges at points where …?
a. Easily reinstated
b. Difficult to determine
b. Difficult to determine
According to Biederman (1987), what does deletion of component affect?
Matching stage
simply = It reduces the number of components to match to
What reduces the number of components to match to?
Deletion of components of an object
According to Biederman (1987), what type of deletion makes it more difficult to determine components?
Midsegment deletion
True or False?
At brief exposures
(65ms) partial objects are better recognised
True
At brief exposures
(65ms) _____ objects better recognised
Partial objects
True or False?
At longer exposures (200ms) midsegment deletion led to
more errors
False
At longer exposures (200ms) midsegment deletion led to
less errors
At longer exposures (200ms) ____ led to less errors
Midsegment deletion
Describe Vogel et al.’s (2001) results supporting Biederman’s model
List 3 points
- Found some cortical neurons in monkeys sensitive to geons.
- Assessed response of individual neurons in the inferior temporal cortex to change in geon or change in size of object
- Some neurons responded more to geon changes, providing support for geons
According to Vogel et al. (2001), what neurons in monkeys are sensitive to geons?
Cortical neurons
According to Vogel et al. (2001), some neurons responded more to…?
a. Change in size of object
b. Change in geons
b. Change in geons
According to Vogel et al. (2001), some neurons responded more to geon changes
What claim does this support?
Support for the existence of geons
What are the 3 evaluations of Biederman’s (1987; 1989) model?
- Why 36 geons?
- Experimental results were consistent with the model but doesn’t provide critical test
- It doesn’t explain how descriptions are matched to those stored in memory
What are 2 advantages of Biederman’s (1987; 1989) model?
- Recognises the importance of the arrangement of the parts
simply = It is not just the components that are important but also the relationships between the components
- Parsimonious: Small set of primitive shapes
It is a flexible and comprehensive system for describing objects
This applies to which theory/model?
Biederman’s (1987; 1989) model
It doesn’t explain how descriptions are matched to those stored in memory
This applies to which theory/model?
Biederman’s (1987; 1989) model
Experimental results were consistent with the model but doesn’t provide critical test
This applies to which theory/model?
Biederman’s (1987; 1989) model
Only tells us about how we create structural descs of the object and not how we match it to the descs stored in our memory
This applies to which theory/model?
Biederman’s (1987; 1989) model
Recognises the importance of the arrangement of the parts
simply = It is not just the components that are important but also the relationships between the components
This applies to which theory/model?
Biederman’s (1987; 1989) model
Parsimonious: Small set of primitive shapes
This applies to which theory/model?
Biederman’s (1987; 1989) model
What are the 5 disadvantages of Biederman’s (1987; 1989) model?
- Structure is not always key to recognition: Peach vs. Nectarine
simply = Basing object recognition on edges (point of concavity)
They both have the same edge, so how do we discriminate between them?
- Which geons?
simply = Does not explain which geons are used for recognising different objects
- Does not explain within category discrimination (which chair?)
- De-emphasise the role played by context in object recognition (affects later stages of object recognition)
- Simplifies the contribution of viewpoint- dependence
simply = It is easier to recognise objects from one viewpoint to another but this perspective does not take this into account
Structure is not always key to recognition: Peach vs. Nectarine
simply = Basing object recognition on edges (point of concavity)
They both have the same edge, so how do we discriminate between them?
This applies to which theory/model?
Biederman’s (1987; 1989) model
Does not explain which geons are used for recognising different objects
This applies to which theory/model?
Biederman’s (1987; 1989) model
Does not explain within category discrimination (which chair?)
This applies to which theory/model?
Biederman’s (1987; 1989) model
De-emphasise the role played by context in object recognition (affects later stages of object recognition)
This applies to which theory/model?
Biederman’s (1987; 1989) model
Simplifies the contribution of viewpoint- dependence
simply = It is easier to recognise objects from one viewpoint to another but this perspective does not take this into account
This applies to which theory/model?
Biederman’s (1987; 1989) model
What do viewpoint invariance theories argue?
The ease of object recognition is not affected by the observer’s viewpoint
simply = being able to recognise an object is not affected by viewpoint
What do viewpoint dependent theories argue?
Assume changes in viewpoint reduce the speed and / or accuracy of object recognition
Assume changes in viewpoint reduce the speed and / or accuracy of object recognition
a. view point invariance theories
b. view point-dependent theories
b. view point-dependent theories
The ease of object recognition if not affected by the observer’s viewpoint
simply = being able to recognise an object is not affected by viewpoint
a. view point invariance theories
b. view point-dependent theories
a. view point invariance theories
According to view point invariance theories (Biederman, 1987) ease of object recognition if not affected by the observer’s viewpoint
Why?
Because you are creating an invariant desc which is invariant across views
Give one example of viewpoint invariance theories
Biederman (1987
Give two examples of viewpoint invariance theories
- Tarr (1995)
- Tarr & Bulthoff (1995; 1998)
e.g. you normally see a bowl as being upright but if you see it being tilted to the side on it’s back, you might take longer to recognise it as a bowl
a. view point invariance theories
b. view point-dependent theories
b. view point-dependent theories
According to viewpoint dependent theories, object representations are…?
Collections of views that depict the appearance of objects from specific viewpoints
Object representations are collections of views that depict the appearance of objects from specific viewpoints
a. view point invariance theories
b. view point-dependent theories
b. view point-dependent theories
Evidence suggests that viewpoint invariant mechanisms are used sometimes in
a. object recognition
b. other times other than object recognition
a. object recognition
Evidence suggests that viewpoint dependent mechanisms used at…?
a. object recognition
b. other times other than object recognition
b. other times other than object recognition
Evidence suggests that ____ used sometimes in object recognition
a. viewpoint dependent mechanisms
b. viewpoint invariant mechanisms
b. viewpoint invariant mechanisms
Evidence suggests that ____ used used at other times other than object recognition
a. viewpoint dependent mechanisms
b. viewpoint invariant mechanisms
a. viewpoint dependent mechanisms
Which mechanism is better for within category discriminations (e.g. different kinds of car)?
a. viewpoint dependent mechanisms
b. viewpoint invariant mechanisms
a. viewpoint dependent mechanisms
Viewpoint dependent are more important for _____ discriminations
a. Within category
b. Different category
c. None of the above
a. Within category
True or False?
The key question is no longer if object recognition is viewpoint-dependent or viewpoint independent, but rather when, i.e. under which circumstances
True
Which mechanism is more useful for complex within category decisions?
a. viewpoint dependent mechanisms
b. viewpoint invariant mechanisms
a. viewpoint dependent mechanisms
Which mechanism is more useful for easy categorical decisions?
a. viewpoint dependent mechanisms
b. viewpoint invariant mechanisms
b. viewpoint invariant mechanisms
Which mechanism is more useful for this task:
e.g. This is my laptop, this is your laptop
a. viewpoint dependent mechanisms
b. viewpoint invariant mechanisms
a. viewpoint dependent mechanisms
Which mechanism is more useful for this task:
e.g. Is it a chair, is it a table?
a. viewpoint dependent mechanisms
b. viewpoint invariant mechanisms
b. viewpoint invariant mechanisms
True or False?
Object representations are only viewpoint-dependent
False
Object representations are neither viewpoint-dependent nor viewpoint- invariant
There is a middle ground where both of those things play a role
What are the issues with object recognition theories?
List 2 points
- Any theory of object recognition must address the binding problem = how do we integrate different kinds of information to produce object recognition?
- When presented with several objects how do we decide which features or geons belong to which object?
What should happen once structural description of an object is formed?
It must be matched to stored representations
If there is a match between stored representations and structural description of an object, then the object is …?
‘Recognised’
If there is a match between ____ and ____, then the object is recognised
- Stored representations
- Structural description of an object
What are the 5 stages of the recognition process, according to Humphreys et al (1988)?
- OBJECT
- STRUCTURAL DESCRIPTION
- SEMANTIC REPRESENTATION
- NAME REPRESENTATION
- NAME
What patients may struggle to create a structural description of an object?
Agnosic patients
Agnosic patients may struggle to create a structural description of an object
What are the consequences of this?
They can’t match the structural descriptions to the representations stored in memory and the objects don’t seem familiar to them
What is the main limitation of Humphreys et al.’s (1988) stages of object recognition?
Oversimplification
‘Later’ processes may start before earlier ones have been completed
What is the main advantage of Humphreys et al.’s (1988) stages of object recognition process?
Provides general support for model from patients with object recognition difficulties
e.g. Associative agnosia
Patient HJA; Patient JB
Provides general support for model from patients with object recognition difficulties
e.g. Associative agnosia
Patient HJA; Patient JB
Which theory/model does this apply to?
Humphreys et al.’s (1988) stages of object recognition process
Oversimplification
‘Later’ processes may start before earlier ones have been completed
Which theory/model does this apply to?
Humphreys et al.’s (1988) stages of object recognition process
What are the 4 stages of object recognition process, according to Humphreys et al.’s (1988) alternative model (‘Cascade’ model’)
- STRUCTURAL DESCRIPTION SYSTEM
- SEMANTIC REPRESENTATIONS
- NAME REPRESENTATIONS
- NAME
According to Humphreys et al.’s (1988) alternative model (‘Cascade’ model’) of object recognition, ____, ____ and ____ interact
- Structural
- Semantic
- Name stages
What are the 3 characteristics of Humphreys et. al.’s (1988) ‘Cascade’ model’?
- Structural, semantic and name stages interact
- Both within and between stages
- Makes different predictions about how subjects will perform in object naming task.
Problems at one stage will have ‘knock on’ effect
Which theory/model does this apply to?
Makes different predictions about how subjects will perform in object naming task.
Problems at one stage will have ‘knock on’ effect
Humphreys et al.’s (1988) ‘Cascade’ model
Which theory/model does this apply to?
Structural, semantic and name stages interact both within and between stages
Humphreys et al.’s (1988) ‘Cascade’ model
List these stages in the correct order, according to Humphreys et al.’s (1988) ‘Cascade’ model
(Apple) edible crunchy sweet
Apple
(Apple) round stalk
Object = ‘Apple’
- (Apple) round stalk
- (Apple) edible crunchy sweet
- Apple
- Object = ‘Apple’
There are ___ and ___ evidence for a separation of structural, semantic and naming processes in recognition
- Anecdotal
- Empirical
Anecdotal and empirical evidence for a separation of ____, _____ and ____ in recognition
- Structural
- Semantic
- Naming processes
_____ propose processing across these stages operates in cascade rather than independently
Humphreys et. al. (1988)
Humphreys et. al. (1988) propose processing across these stages operates in ____ rather than independently
Cascade
simply = Interaction between the different stages
Humphreys et. al. (1988) propose processing across these stages operates in cascade rather than independently
Give an example of this
e.g. Patient JB.
Naming visually confusable objects (birds, animals) had knock on effects, making it more difficult to identify their category
simply = If you get stuck on one stage, you can’t move on to later stages
e.g. Patient JB.
Naming visually confusable objects (birds, animals) had knock on effects, making it more difficult to identify their category
simply = If you get stuck on one stage, you can’t move on to later stages
Which theory/model supports this?
Humphreys et. al. (1988) cascade model
Define agnosia
Failure of knowledge or recognition
Failure of knowledge or recognition
This is known as…?
Agnosia
In visual agnosias, ___ and ___ remain intact
- Feature processing
- Memory
When feature processing and memory remain intact, and recognition deficits are limited to the visual modality
This is known as…?
Visual agnosias
Inability to recognise objects from seeing that object
This is known as…?
Visual agnosias
Define visual agnosia
Inability to recognise objects from seeing that object
In visual agnosias, recognition deficits are limited to …?
The visual modality
True or False?
In visual agnosia, alertness, attention, intelligence and language are affected
False
In visual agnosia, alertness, attention, intelligence and language are unaffected
In visual agnosia, what may substitute for vision in allowing objects to be recognised?
Other sensory modalities (touch, smell)
Define Apperceptive agnosia
Problems with early processing (shape extraction)
Problems with early processing (shape extraction)
This is known as…?
Apperceptive agnosia
All objects look similar, unable to tell the difference, low level perceptual deficit
This is an example of…?
Apperceptive agnosia
What causes Apperceptive agnosia?
Perceptual deficit
Describe how perceptual deficit causes Apperceptive agnosia
List 4 points
- Perceptual deficit affects visual representations directly
- Components of visual percept are picked up, but can’t be integrated
- Effects may be graded, often affected
- Results in unusual views of objects
- Perceptual deficit affects visual representations directly
- Components of visual percept are picked up, but can’t be integrated
- Effects may be graded, often affected
- Results in unusual views of objects
What type of agnosia is this?
Apperceptive agnosia
Define Associative agnosia
Problems with later processing (recognition)
Problems with later processing (recognition)
Associative agnosia
What causes Associative agnosia?
Lack of information about the percept
simply = lack of info, high level perceptual deficit
Visual representations are intact, but cannot be accessed or used in recognition. Lack of information about the percept.
What type of agnosia is this?
Associative agnosia
Feature processing and memory remain intact
a. Associative agnosia
b. Visual agnosias
c. Apperceptive agnosia
d. None of the above
b. Visual agnosias
Perceptual deficit, affects visual representations directly
a. Associative agnosia
b. Visual agnosias
c. Apperceptive agnosia
d. None of the above
c. Apperceptive agnosia
Visual representations are intact, but cannot be accessed or used in recognition
a. Associative agnosia
b. Visual agnosias
c. Apperceptive agnosia
d. None of the above
a. Associative agnosia
Recognition deficits are limited to the visual modality
a. Associative agnosia
b. Visual agnosias
c. Apperceptive agnosia
d. None of the above
b. Visual agnosias
Lack of information about the percept
a. Associative agnosia
b. Visual agnosias
c. Apperceptive agnosia
d. None of the above
a. Associative agnosia
Other sensory modalities (touch, smell) may substitute for vision in allowing objects to be recognised
a. Associative agnosia
b. Visual agnosias
c. Apperceptive agnosia
d. None of the above
b. Visual agnosias
Components of visual percept are picked up, but can’t be integrated
a. Associative agnosia
b. Visual agnosias
c. Apperceptive agnosia
d. None of the above
c. Apperceptive agnosia
Alertness, attention, intelligence and language are unaffected
a. Associative agnosia
b. Visual agnosias
c. Apperceptive agnosia
d. None of the above
b. Visual agnosias
Effects may be graded, often affected: unusual views of objects
a. Associative agnosia
b. Visual agnosias
c. Apperceptive agnosia
d. None of the above
c. Apperceptive agnosia
Inability to recognise objects from seeing that object
a. Associative agnosia
b. Visual agnosias
c. Apperceptive agnosia
d. None of the above
b. Visual agnosias
Lack of info, high level perceptual deficit
a. Associative agnosia
b. Visual agnosias
c. Apperceptive agnosia
d. None of the above
a. Associative agnosia
All objects look similar, unable to tell the difference, low level perceptual deficit
a. Associative agnosia
b. Visual agnosias
c. Apperceptive agnosia
d. None of the above
c. Apperceptive agnosia
Agnosia is useful for studying …?
Object recognition
True or False?
Agnosia may be restricted to specific categories
True
True or False?
Agnosia can only be found alone
False
Agnosia may be found alone or with problems with faces.