Visual perception Flashcards
How is visual perception influenced?
By biological, psychological and social factors
How does visual perception occur?
Through the interaction of numerous factors, many of which automatically influence and assist the interpretation of what we are looking at
Numerous factors interact, assisting and influencing how we interpret.
an image
What is reception?
When receptors in the eye detect and respond to light
What is transduction?
When light is converted from electromagnetic energy in the form of action potentials
neural impulses.
What are the two main depth cues?
Binocuar and monocular depth cues
What are binoclar depth cues?
The use of both eyes to provide information about depth and distance
Especially important for objects that are close.
What are monocular depth cues?
Only require one eye to distinguish depth,
- Linear perspective, interposition, texture gradient, relative size, height in visual field
What are the two cues for binocular depth cues?
Retinal disparity and convergence.
Binocular depth
What is retinal disparity?
Difference or ‘disparity’ between different retinal images received by either eye.
- closer object is, greater disparity.
- when perceiving object, use combination of images
- brain takes note of differing images and creates combined, cohesive image
Binocular depth
What is convergence?
When the brain detects depth and distance from the change in tension to eye muscles that occurs when eyes turn inwards
Monocular depth:
What is accomodation?
Involves automatic adjustment of the shape of lens to focus on an object in response to how far away it is.
How shape of lens adjusts to focus on how far away an object is
What happens to the lenses of the eyes for accomodation?
Lens bulges to focus on light from a nearby object, and elongates (flattens) to focus on light for a further away object.
What are pictoral depth cues?
Linear perspective, interposition, texture gradient, relative size, height in visual field
What is linear perspective?
convergence of paralell lines as they recede into distance
paralell lines look like they get closer, the further away they are.
e.g train tracks
What is interposition?
Occurs when one object partially covers, overlaps or blocks another object, and therefore the one behind is further away
e.g if apple overlaps orange, apple looks like it is infront
What is texture gradient?
Reduction of detail in a surface as it recedes into distance
Further away something is, less detail it has.
What is relative size
Tendency to visually perceive object that produces larger image on retina as being closer
if something is bigger, it is closer.
Height in visual field
Refers to location of object in fov, where objects closer to horizon are further away
close to horizon, far away. Far from horizon, closer.
What do the Gestalt principles of vision refer to?
Define
Refers to the way we organise features of an image by grouping them to perceive them as a whole
What are the four Gestalt principles?
- Figure-ground
- Proximity
- Closure
- Similarity
Gestalt principles:
What is figure-ground?
Ability to recognise objects (figures) by distinguishing them from the background (ground)
Gestalt principles: Figure-ground
What does figure-ground involve?
Automatically focusing on some objects at the exclusion of others
- what we focus on - figure
- everythig else fades into background
Perceptions are in the eyes of the beholder.
Gestalt principles:
What is proximity?
Parts of an image that are near one another tend to be grouped together.
Closer objects are together, more likely to be perceived as a unit.
Gestalt principles:
What is closure?
Tendency to fill gaps in a figure
Allow us to mentally fill gaps of an image.
Gestalt principles:
What is similarity?
Parts of an image that look alike tend to be grouped together.
What is a perceptual set?
Readiness (predisposition) to percieve something how we expect it to be.
How does perceptual set affect how something is interpreted?
Expectations of what object or event will be make us more likely to interpret object or event in a predetermined way.
Perceptual set:
What are the 5 factors influencing perceptual set?
- Context
- Motivation
- Past experience
- Memory
- Culture
Perceptual set:
What is context?
Refers to setting or environment to which perception is made
Perceptual set:
How does context effect perceptual set?
Context has ‘focusing’ role, assists in making quick and accurate interpretation of what you look at.
e.g light in sky may be perceived as different things depending on setting. In battle, could be a flare; at NYE, a firework.
Perceptual set:
What is motivation?
Refers to internal processes which activate behaviour we use to achieve a goal.
Perceptual set: Motivation
How does motivation influence perceptual set?
Motives influenced by biopsychosocial factors. Visual perception is influenced by motives when we see what we WANT to see, rather than what is actually there.
Perceptual set:
What are past experiences?
Personal experiences throughout our lives.
- everything learnt both intentionally and unintentionally.
Perceptual set: Past experience
How does past experience influence perceptual set?
Unique combination of past experiences can lead to individual differences in perception.
Perceptual set:
What is memory?
Knowledge and past experiences stored in long-term memory, and can remain relatively intact for lifetime.
- things stored in long-term memory, used to identify, interpret and understand meaning of new visual information.
Perceptual set: Memory
How does memory influence perceptual set?
example
When seeing something using top-down processing, sensory information compared with pre-existing information. When match found, enables us to recognise what we at looking at.
If memory of something is negative, can cause us to perceive something negatively.
Perceptual set:
What is culture?
Way of life of a particular community or group that sets it apart from other communities or groups.
customs beliefs, traditions, values, etc.
Gestalt principles:
Who do gestalt principles affect?
Psychologists argue gestalt principles only relevant to people who have studied geometrical concepts in formal education system
Contemporary psychologists suggest experience with two-dimensional drawings on sheet of paper may also be factor that explains results.
