Chapter Five Flashcards
- What is perceptual organization? Explain grouping and segregation. (pp. 100)
How we process elements (objects) of an environment in our visual system
Involves 2 components:
-Grouping –objects belonging together – Dalmatian picture
-Segregation – objects separate from each other – building pictures
- What are the Gestalt and structuralist approaches?
How are they different? (pp. 100-101)
Structuralist Approach
o Build up simple sensory parts (sensations) first and awareness (perception) will occur
o Past experiences can influence building sensation to form perception –pointillism lady face-
Gestalt Approach
o Gestalt = German for “configuration”
o Past experience play a minor role
o The “whole is different than the sum of its parts”
• Meaning: perception does not always require adding up sensations first
sensation
perception
Sensation - info we processed in the environment
Perception - Awareness of our senses perception has its way of organizing info, o Gestalt examples: • Apparent motion • Illusory contours
- Define the Gestalt organizing principles: good continuation, pragnanz, similarity, proximity, common fate, common region, uniform connectedness (pp. 102-104)
Gestalt Organization Principles
• How elements in a scene become grouped together
• Perception occurs through Gestalt principles
• 7 Principles
1. Good Continuation
• Connected points resulting in straight or smooth curves belong together
o i.e. curled rope is connected
2. Pragnanz
• German – “good figure”
• Pattern is interpreted the simplest way possible
o i.e. Olympic symbol
3. Similarity
• Similar things are grouped together
4. Proximity
• Things near to each other are grouped together
5. Common Fate
• Things moving in same direction are grouped together
o i.e. traffic moving on two sides of the freeway
6. Common Region
• Elements in the same region (area) are grouped together
o i.e. west US, Midwest US, etc.
7. Uniform Connectedness
• Connected region (area) are perceived as a single unit
o Trumps over proximity
o i.e. connect the dots
- What is perceptual segregation?
Explain the figure-ground segregation,
reversible figure-ground, border ownership,
Perceptual Segregation
-How an element can be separated from another element
-Figure-ground segregation
o Figure – the part that stands out
o Ground – the background of your figure
Properties of Figure and Ground
-Reversible figure-ground - alternating what you see as the figure and ground
-Properties
o Figure stands out as an object – more memorable
o Figure – seen in front of ground
o Ground – lacks a specific shape behind figure
o Border ownership – contour (border) separating figure and ground belongs to the figure
- Contrary to what Gestalt psychologists proposed about not requiring past experience to recognize a stimulus, what other possibility might influence recognizing patterns? (Hint: the Gibson and Peterson experiment) (pp. 107)
Recognizing Patterns
Gestalt psychologists believed that perceptual organization can override past experiences to recognize objects
Gibson and Peterson:
o Proposed that meaningfulness can play an important role in recognizing objects
Familiarity allows people to recognize patterns of an object (i.e. detecting a woman as a figure)
- Why is masking a stimulus presentation important? (pp. 109)
So that persistence of vision does not occur
- How do we perceive the gist of a scene? What are the five global image features? (pp. 109-110)
• The Gist of a Scene: how we generally describe our rapid awareness (gist) of the environment
- People can perceive the gist of a scene when presented ¼ second (250 milliseconds [ms])
- We perceive the overall gist first, followed by details
⇒ How do we know? Visual masking experiment
• Perceiving the Gist of a Scene:
- Global Image Features: characteristics we use to rapidly perceive specific types of scenes
• 5 Features (all happen simultaneously)
1) Degree of Naturalness
- Natural scenes → contain textured zones & wavy contours
- Man-made scenes → contain more straight lines
2) Degree of Openness
- Spacious & contains few objects
- E.g. ocean
3) Degree of Roughness
- How smooth looking the environment looks
4) Degree of Expansion
- Focuses on the convergence of parallel lines – distance can show how environment can expand
5) Color
- Colors can depict a certain type of scene
- Describe the two types of regularities in the environment of perceiving information. (pp. 110-112)
- Describe the two types of regularities in the environment of perceiving information. (pp. 110-112)
2 types: physical and semantic
• Physical Regularities: Regularly occurring physical properties
- Oblique effect → people perceive horizontal and vertical more easily than other orientations
- Similar colors or texture
- Light-from-above assumption → light in natural environment comes from above us
• Semantic Regularities: Our knowledge of regular things in context to a scene
- What is inference? What is the theory of unconscious inference? What is the likelihood principle? (pp. 112-114)
- Inference: how we make assumptions about our environment
- Theory of Unconscious Inference: our unawareness of our ability to interpret a stimulus in more than one way in the environment
- Likelihood Principle: objects are perceived based on what is most likely to have caused the pattern
- What is the Harrison Ford study? (pp. 114-115)
• People had to identify whether they saw Harrison Ford, another face, or nothing
• Fusiform Face Area → brain activates to specific faces
- Goal: to identify Harrison Ford (more neural firing)
- Detecting other faces (some neural firing)
- Detecting non-faces (no neural firing)
- What is binocular rivalry? (pp. 115-116)
• Each eye sees a different picture at the same time
• One eye shown a house; another shown a face
• Both eyes activated separate areas of the brain:
- Parahippocampal place area – places (house)
- FFA - face
- How do we recognize faces? What parts of the brain are involved in face recognition? (pp. 119-120)
• Fusiform Face Area (FFA) - Responds to faces only • Amygdala (AG) - Activated by emotional aspects of faces • Superior Temporal Sulcus (STS) - Responds to where a person is looking and to mouth movement • Frontal Cortex (FC) - Evaluate facial attractiveness
Apparent Movement
Apparent Movement
• An illusion of movement when nothing is moving
• Structuralist – cannot explain building up sensations to form the perception movement
• i.e. Pantomime movement
Illusory Contours
Illusory Contours
• An appearance of a shape without actual physical edges present
• Structuralists – cannot explain how sensations are built up without physical edges to perceive shapes
o Pacman triangle
