Form Perception Flashcards
What did the Gestalt psychologists believe?
With respect to perception, believed that the “whole is greater than the sum of it’s parts”
(Ppl percieve whole stimulus rather than just putting together a collection of its parts)
The Gestalt movement was in response to the Structuralist movement. What did the structuralist movement believe?
That everything could be reduced to its basic elements
Motion is an ______ property of the sequence of _______
Emergent
Pictures
What are the Gestalt principles? (broad translation, don’t list them)
Laws that describe how we organize visual input
We either are born with them, or we acquire them very rapidly
What is the first/most fundamental Gestalt principle?
Figure Ground
- the ability to distinguish an object from its background
What properties of figures and backgrounds help us distinguish the two?
Figures have distinct borders that:
- give it form over the background
- helps it be perceived as being in front of the background
Backgrounds are either formless or made up of multiple forms
What does the Gestalt principle of Proximity state?
Objects that are close together in space tend to belong together
Why will you naturally see regions of high density as one group?
Because of their proximity together (according to the principle of proximity)
XX XXX XXXXXXXX
Which X’s are you more likely to group together according to the principle of proximity?
The Xs that are close together rather than the ones that are farther apart
What does the Gestalt principle of Closure state?
If there are gaps in the contour of a shape, we’ll tend to fill in those gaps and perceive a whole object
If a telephone pole is in front of part of a truck, and blocking some of its contour, what will we see? Why?
According to the principle of Closure, we will see the fill in the parts that are blocked by the telephone pole and end up seeing the whole truck as a whole object rather than parts of an object
What does the Gestalt principle of Similarity state?
That we tend to grp together elements that are physically similar
XOXOXOXO
XOXOXOXO
XOXOXOXO
XOXOXOXO
Why would you see the columns of the same elements (either all Xs or all Os) as belonging together, rather than grouping together a row of XOXO?
Bc we tend to grp together elements that are physically similar (Gestalt principle)
What does the Gestalt principle of Continuity state?
The ability to perceive a simple, continuous form, rather than a combination of awkward forms
According to the principle of continuity, how would we perceive an X?
a) as two crossing lines
b) as two v’s stack on top of each other
a) as two crossing lines
What does the Gestalt principle of Common Fate state?
Things that change in the same way should be grouped together
Why would we perceive school fish moving together, not as a group of elements, but as an object on its own?
Because the tendency to group together things that change/move in the same way is very strong
How does the principle of Common Fate help explain why we can suddenly see a camouflaged animal once it moves?
When it’s still, it’s grouped together with the (nonmoving) background, so we can’t see it
As the animal moves, there are elements within its pattern that are moving in the same direction and at the same time—> these elements allow the contour of the animal’s shape to be seen
What are the first two steps of figure recognition?
1) identifying what aspect of the scene is the figure and what is the background
2) parts of the figure are identified and grouped together into a single object
Object recognition is a combination of two processes. What are these processes (in their respective orders)?
Bottom Up
Top Down
What is Bottom-Up processing?
Features that are present in the stimulus itself guides object recognition
(you recognize what you see by analyzing the individ features and comparing those features to things with similar features that you have in memory)
According to bottom-up processing, how do you recognize a cow as being a cow?
You look at the animal, and then analyze the features (the four legs, the udders, the spots). When you compare it to what you’ve seen before, it matches with the image of a cow that you have in your mind.
What is top-down processing?
Your own beliefs or expectations are the primary influence for det what you’re seeing
Describe a typical priming experiment
Experimenter measures how fast a participant can read a word that is flashed on a screen
If the experimenter tells the participant that the next word is an animal, the participant will recognize it much faster
Priming experiments test which sort of processing?
a) bottom-up
b) top-down
b) top-down
Why can’t you just use top-down processing alone to describe object recognition?
You need some input from the stimulus itself before your expectations about that stimulus can influence your recognition of it
Why can’t you just use bottom-up processing alone to describe object recognition?
Bc it’s not JUST the stimulus that guides object recognition, your expectations also do
What are the theories of object recognition?
Biederman’s Geon
Template
Prototype
What does Biederman’s Geon theory of object recognition suggest?
That we have 36 diff simple geometrical forms (geons) stored in our memory (i.e. cone, sphere, cylinder)
Using these geons, it’s possible to recognize over 150 mill diff objects
What are two problems with the geon theory?
1) Certain stimuli (i.e. faces, crumpled pieces of paper) are diff to det what geon should be used, yet we have no problem recognizing these stimuli
2) Some forms of brain damage lead to very specific deficits (ie. only has difficulty recognizing diff types of fruit). If geons were involved, you would expect deficits in recognizing objects based on shape, not category.
What does the Template theory of object recognition suggest?
That we store many diff (specific) templates in memory and when we come across an object, we compare it to all diff templates in memory
If match found, we name it by activating connections to other language areas in the brain
Why isn’t the Template theory very compelling?
We’d have to store MANY templates to recognize all of the diff objects that we encounter
What does the Prototype theory of object recognition suggest?
That we store the most typical (not specific) example of an object + all of the ones that we are personally familiar with (i.e. ideal dog + all dogs we’re personally familiar with)
