Perception Continued

Visual Capture tendency for vision to

dominate the other senses Movie theater – we perceive

sounds as coming from the screen in front of us, not from the projector behind us

Visual vs. Major Mistakes?

• https://www.youtube.com/watch?v=5oHIfeCB3z8

Perceptual Organization: Gestalt

• Gestalt: an organized whole– Gestalt Psychology: emphasizes our tendency to

integrate pieces of information into meaningful wholes

Perceptual Organization Figure and Ground--organization of the visual

field into objects (figures) that stand out from their surroundings (ground)

Perceptual Organization: GestaltGrouping: the perceptual tendency to organize stimuli into coherent groups

Grouping Principles proximity--group nearby

figures together similarity--group figures

that are similar continuity--perceive

continuous patterns closure--fill in gaps connectedness--spots,

lines, and areas are seen as unit when connected

closure

Perceptual Organization: Grouping Principles

Gestalt grouping principles are at work here

What do you see?

Reification (Gestalt Property)

• object is perceived as having more spatial information than is actually present in the original stimulus

Depth Perception

FACT: Objects presented to our retinae in 2-D, yet we perceive them in 3-D

How? Depth perception – we estimate distances from us using various strategies

Visual Cliffs & Cues

Visual Cliff – lab device testing depth perception in infants and young animals. • Monocular Cues – available to each eye separately • Binocular Cues – require both eyes

Binocular Cues – help perceive depth • Retinal disparity –the greater the difference

between two images the retina receives of an object, the closer the object is to the viewer

• Convergence –extent to which the eyes converge inward when looking at an object

Monocular Cues • Relative size • Relative clarity • Texture gradient• Relative height• Interposition:

• Relative motion (motion parallax)

• Light & Shadow• Linear Perspective

Perceiving Motion

• Motion pictures– Really just consecutive images – Super quick slide show we perceive motion

• Phi phenomenon – Illusion of movement created with two or more

adjacent lights blink on an off in succession • “moving” Christmas lights

• Perceptual constancy – perceiving objects as unchanging even as retinal images change– We recognize objects/people at different angles,

distances, lights, etc.• Shape & Size constancy- different angles/distances

change shape and size, we are still able to recognize objects – Ex.

Size- Distance Relationship

Lightness Constancy • Lightness constancy (aka

brightness constancy– We perceive an object as having

a constant lightness – Actual: lightness varies

• Relative lumanance – comparison to lightness of objects surrounding it

Sensory Deprivation & Restored Vision

• “I once was blind, but now I see…”– Cortical pathways don’t form correctly– Can distinguish color, figure/ground – Can’t recognize objects they learned through

touch

Perceptual Adaptation

• - when visual input changes, we adapt (i.e. new glasses)

• - shifted reality (for whatever reason) we adapt quickly with assistance and without - we can adapt (not all species can)

• - we can even adapt to upside down shifts!

Perceptual set

• - mental disposition to perceive one thing and not the other

• ex. if we are told what to expect, we see it or confirm it (subliminal messages, misleading photos)

• Context effects- we make assumptions based on experience, previous interactions, etc.

ESP - extrasensory perception• - controversial claim that perception can occur apart from

sensory input. – - parapsychology - the study of paranormal phenomena,

including ESP and psychokinesis – telepathy - mind to mind communication – clairvoyance - perceiving remote events (sensing something bad

is occurring right now) – precognition - perceiving future events (game bets, etc)– psychokinesis - the idea of mind over matter (levitating a table,

etc) • when put to the experimentation phase - no ESP has been

proven (remember our first video we watched?)