Post on 16-Aug-2015
transcript
Perception
• Different people may experience the same sensory information in radically different ways because PERCPETION IS AN ACTIVE, CREATIVE PROCESS in which raw sensory data are organized & given meaning
Processing Functions to create Perception
• Bottom-up processing – the system takes in individual elements of the stimulus & then combines them into a unified perception
• Top-down processing – sensory info is interpreted in light of existing knowledge, concepts, ideas & expectations
Perception is Selective: The Role of Attention
• Attention involves 2 processes of selection: focusing on certain stimuli & filtering out other incoming info
• Shadowing
Perception is Selective: The Role of Attention
• Inattentional blindness – the failure of unattended stimuli to register in consciousness
• Environmental & Personal Factors in Attention– Intensity, novelty, movement, contrast &
repetition– Motives & interest– Stimuli that represent a threat to our well-being
Perception have Organization & Structure
• How do we organize the separate parts of our perceptual field into a unified & meaningful whole?
• Figure-ground relations – tendency to organize stimuli into a central or foreground figure & a background
• Gestalt principle of perceptual organization
Gestalt Laws of Perceptual Organization
• Law of similarity – says that when parts of configuration are perceived similar, they will be perceived as belonging together
• Law of proximity – elements that are near each other are likely to be perceived as part of the same configuration
• Law of closure – people tend to close the open edges of a figure or fill in gaps in an incomplete figure so that their identification of the form is more complete than what is actually there
• Law of continuity – people link individual elements together so they form continuous line or pattern that makes sense
Perception involves Hypothesis Testing
• Perceptual schema – a mental representation or image containing the critical & distinctive features of a person, object, event or other perceptual phenomenon
Perception is Influenced by Expectations: Perceptual Sets
• Perceptual set – a readiness to perceive stimuli in a particular way
Stimuli are Recognizable under Changing Conditions: Perceptual Constancies
• Perceptual constancies – allow us to recognize familiar stimuli under varying conditions– Shape constancy – allows us to recognize people &
other objects from many different angles– Brightness constancy – the relative brightness of
objects remains the same under different conditions of illumination
– Size constancy – the perception that the size of objects remains relatively constant even though images on our retina change in size with variations in distance
Depth & Distance Perception
• Retina receives info in 2D; brain translates it in 3D
• Monocular depth cues – require only one eye• Binocular depth cues – require both eyes
Monocular Depth Cues
• Patterns of light & shadow• Linear perspective – perception to that
parallel lines converge as they recede into the distance
• Interposition – in which objects closer to us may cut off part of our view of more distant objects
• Height in the horizontal plane
Monocular Depth Cues
• Texture• Clarity• Relative size• Motion parallax – nearby objects appear to
move faster in the opposite direction than do faraway ones
Binocular Depth Cues
• Binocular disparity – each eye sees a slightly different image
• Convergence – produced by feedback from the muscles that turn your eyes inward to view a close object
Perception of Movement
• Stroboscopic movement (phi phenomenon) – illusory movement when a light is briefly flashed in darkness & then a few milliseconds later, another light is flashed nearby (aka phi phenomenon)