2.1b - perception: visual organization and interpretation

sensation

Process where sensory receptors detect info in our env

Perception

Process where brain interprets, organizes, and processes sensory info

Feature detectors

Specialized nerve cells in the occipital lobe's visual cortex

Parallel processing

Processing several aspects of a visual stimulus simultaneously

Figure-ground

Organizing visual field into objects (figure) that stand out from their surroundings (ground)

Grouping rules

• Proximity: group things close together

• Similarity: group things that are similar

• law of closure: eye fills in gaps

• continuity: seeing continuous, smooth flowing lines

Visual cliff

Lab device testing depth perception in infants

Binocular depth cues

Depend on movement of both eyes

Retinal disparity

Eyes compare & combine 2 images to judge depth

- decreases with distance

Convergence

Eyes turn inwards to look at nearby objects

Relative size

If similar in shape, smaller size is farther away

Relative height

Objects higher in field of vision are farther

Linear perspective

Parallel lines appear to converge in the distance

Interposition

Objects that block other objects are closer

Relative clarity

Sharpness provide depth cue

• closer = clear

• distant = hazy

Texture gradient

When textured surface recedes, its texture becomes less sharp

Relative motion (motion parallax)

Objects closer to a fixed point more faster & in opposing direction to objects that are farther from the point, moving slower & in same direction

Perceptual constancy

Perceiving objects as unchanging

Size constancy

Perceiving objects with the same size even as distance varies

Motion perception

• Shrinking objects are retreating

• enlarging objects are approaching

Illusions

Perceptual cues are distorted

Apparent motion

Brain interprets static movements as continuous movement

Phi phenomenon

Illusion of movement when lights blink

Relative luminance

The amount of light an object reflects relative to its surroundingS

Blindsight

Visual info bypasses the damaged primary visual cortex

• person responds to visual stimuli w/o having conscious awareness of seeing it

Prosopagnasia affected brain region

Right fusiform gyros in temporal lobe