Understanding the visual world Flashcards
1
Q
what are the stages of visual info processing?
A
- retinal info processing sensation (EYE)
- feature discrimination early perception (optic cortex)
- higher order feature analyses late perception (cerebral cortex)
- object (world) knowledge cognition and thought (cerebral cortex)
- action (eye movement)
2
Q
what is low-level processing?
A
- Basic analysis of shapes, forms, colours, contours, contrasts and movement. These “primitives” are first processed in the eye and the electrical signals are then transmitted to the thalamus and the early visual cortex.
3
Q
what is mid-level processing?
A
- Primitive information is organized into fundamental forms, as these are the basis for higher-order processing, i.e. what do the forms represent and how they are perceived from a bottom-up perspective (no prior knowledge).
4
Q
what is higher-level processing?
A
- Fundamental forms are given meaning through connection/associations with our previous knowledge/experience of the world. This stage also directs our attention to specific parts of the visual scene, to areas of salient features (bottom-up) or of particular interest (top-down). The brain can sometimes also “supplement” information, e.g. blind spot.
5
Q
what did Gregory 1997 study?
A
- With the emergence of computers in the mid 20C, psychologists started to think of the mind as an information processer. This was a cognitive revolution.
- Bottom-up processing vs. top-down processing
6
Q
what are the stages of visual cognition?
A
- First two stages are referred to as bottom-up processing: visual experience is driven by piecing together information that is available.
- Last stage is top-down processing as your visual experience is driven by higher cognitive functions (e.g. Attention, Memory).
7
Q
what is the differences between Bottom-up vs Top-down?
A
- Objects can be perceived through two different processes:
- Bottom-up processing is stimulus-driven, i.e. exogenous.
- Top-down processing is goal- ,thought- and/or knowledge directed, i.e. endogenous.
8
Q
what does BU and TD processing say about Bruegel’s fall of Icarus?
A
- Bottom-up processing is stimulus-driven, i.e. exogenous. Your eyes are drawn to the red.
- Top-down processing is goal-, thought- and/or knowledge directed, i.e. endogenous. Your eyes are drawn to the legs in the water.
9
Q
what are the blind spots?
A
- corresponds to an area in your visual where there are no photoreceptors to encode visual information
- basically blind in this region
10
Q
how does the brain fill in the gaps?
A
- At the same time, the areas surrounding your blind spot are filled in so that you can have a coherent representation of the world.
- This is called filling-in and is a top-down process as it requires your brain to know what is around and what info to fill in.
11
Q
what is perceptual organisation?
A
- Gestalt psychologists, such as Max Wertheimer and Kurt Koffka, were interested in how the brain organises information.
- They believed that our sensory experiences are not driven by individual elemental features but are determined by all features as a whole.
- We therefore achieve an understanding of what we see based on the ensemble of visual features and it is this ensemble integrated together that generates the illusion of form (Wagemans et al., 2012).
- They proposed four key principles of Gestalt systems.
12
Q
what is emergence?
A
- The process by which the visual system first recognises the whole and then only after this stage are the individual features recognised.
13
Q
what is reification?
A
- Objects are perceived to contain more spatial information than what is actually present. Our knowledge and expectations fill in the gaps of what we think we should see.
- Important information can be left out as long as there is enough of it to allow for a close enough pattern match.
14
Q
what is multistability?
A
- Multi-stability is the phenomenon that describes ambiguous perceptual experiences that switch back and forth between alternative interpretations, e.g. reversible figures.
- Some objects can be perceived in more than one way, but both interpretations cannot be seen simultaneously. You perceived one of the (two) stable alternatives.
15
Q
what is invariance?
A
- Simple objects are recognized independent of the lighting conditions, their rotation, the translation and their scale.
- This relates to perceptual
- constancies
- Size
- Shape
- Brightness
- Colour
16
Q
what is Prägnanz?
A
- Tendency to interpret ambiguous and complex stimuli as the simplest forms possible.
- Our experiences are ordered in a manner that is regular, orderly, symmetric and simple. This is also known as the Law of simplicity and good figure.
- In Perception, the easiest shapes are assumed.
- In Reasoning/Cognition: If it looks like a duck and quacks like a duck…
- In social psychology, we sometimes attribute someone’s bad behaviour to their disposition (bad person). This is because it is easier to blame a person than to consider situational factors that are not always salient. This is the Fundamental Attribution Error.
17
Q
what are Gestalt laws?
A
- Gestalt psychologists have also defined additional laws that help describe how the perceptual system organises information. These include laws of:
- Closure,
- Proximity,
- Similarity,
- Continuity,
- Symmetry, and
- Common Fate
18
Q
what is closure ?
A
- Any missing information is filled in to generate a complete figure
19
Q
what is similarity?
A
- Elements that are similar in low-level features such as colour, size and brightness will be grouped together.
20
Q
what is proximity?
A
- Spatially or temporally proximate elements will be grouped together.
21
Q
what is continuity?
A
- Lines are perceived as being continuous.
22
Q
what is symmetry?
A
- Symmetrical features are grouped together and create a sense of harmony and balance.
23
Q
what is common fate?
A
- Features that undergo similar changes (in colour, brightness, size or direction) are grouped together.
24
Q
what is global vs local processing?
A
- Navon (1977) presented participants with large characters made out of small ones.
- Participants had to recognize either just the large characters or just the small ones.
- Navon (1977) found that the identity of the small characters had no effect on recognition of the large ones.
- But global cues which conflicted with the local ones did inhibit the responses to the local level.
- Local vs holistic processing of visual information.
25
Q
what is seeing sets?
A
- Ariely (2001) presented participants with a set of circles of different sizes.
- In the first experiment, he asked participants to identify whether a test patch was a member of the set.
- Participants were not very good at discriminating between member or non-member of the set.
- In the second experiment, he asked participants to estimate whether the test patch was larger or smaller than the mean of the set.
- Participants were very accurate in estimating the mean of the set.
26
Q
what is ensemble coding?
A
- When we are presented with a set of objects, we are very good at extracting a general representation of what we see, but we are not so good at remember the individual elements.
- This ability to encode the overall mean of a set is also referred to as ensemble coding, because you are coding the ensemble, rather than individual elements.
- This is similar to how we remember things in general:
- We remember the gist of events, not the details.
27
Q
what is sensation and perception?
A
- This is one of the first steps in Cognition.
- You first process external information via your senses and your perceptual system.
- sophisticated mechanisms of filling-in, ensemble coding, etc etc.
- Although I have presented these mechanisms in the perceptual level, they can also apply to other things in our lives.
28
Q
what is ensemble coding?
A
- The visual system processes sets of objects as a whole and can extract an average representation of the set. It does not process each individual items on its own.
- When we meet people from different groups, we also make a judgement about the groups, not always recognizing that each individual is different.
- For example in Tangled, you would group the individuals at the pub as thugs. But in fact, they each have dreams:
28
Q
what is filling in?
A
- The visual system fills in the blind spot based on its surroundings
- At a social level, we tend to assuming that individuals are equal to the group they belong to:
- Prejudice in thinking ”birds of a feather flock together” when you do not really know someone.
- You just fill in who they are based on what you know about their family/country/religion/ethnicity/class/etc.
29
Q
what is similarity and proximity?
A
- Objects that are similar and close are grouped together
- We tend to act and dress similar to our friends and we are also close to them in terms of values, beliefs, location, etc.
30
Q
what is top-down processing?
A
- What you see can be led by your goals, thoughts and/or knowledge.
- Our beliefs can influence what we focus on and process.
- Confirmation bias: Tendency to search for and recall information that confirms and supports your goals, beliefs and values.
31
Q
what is the importance of surroundings?
A
- In cognition, you have the framing effect which is acognitive biasin which people decide between options based on how they are presented.
- Individuals have a tendency to make risk-avoidant choices when options are positively framed, while selecting more loss-avoidant options when presented with a negative frame.
- Appropriate behaviour is also dependent on the situation.
32
Q
what are edges and delimitations?
A
- The visual system is highly sensitive to edges.
- At a higher level, sometimes we take categories and delimitations, in-group vs out-group, very seriously
- “Over-stepping a line”
- Cliques
- Racial segregation
- Borders
33
Q
what are the importances of differences?
A
- At another level, you might focus on how you are different from others, sometimes focusing on how you may be lacking in some respects.
- FOMO (Fear of Missing Out): Marketing uses this to their advantage (TKMaxx, Limited Editions, Time-Limited deals or banners, etc)
- Imposter Syndrome: People often engage in social comparison, but sometimes they focus on their perceived shortcomings. This may occur even if they are very successful. They will not focus on their achievements and success, but on how they are lacking.
34
Q
why is change good?
A
- The visual system has evolved to adapt and process change, e.g. microsaccades.
- The Coolidge Effect in social psychology postulates that individuals demonstrate heightened interest in new mates after being with a previous one for a prolonged period.
35
Q
how do we balance the costs and gains?
A
- The peripheral visual field is not processed in high resolution because there is less primary visual cortex encoding it.
- Whichever decision you take, it will be accompanied by a cost. YES to X is NO to Y. Example:
- Resources (time, money) are limited, so whichever decision you make will have a consequence.
