Myers’ PSYCHOLOGY (6th Ed) Perception Perception: A mental process that elaborates and assigns meaning to the incoming sensory patterns. Perception brings meaning to sensation. It produces an interpretation of the world, but it isn’t a perfect representation.

Perception Selective Attention focus of conscious awareness on a particular stimulus

Testing Selective Attention http://www.youtube.com/watch?v=vJG698U2Mvo

Bottom-Up and Top-Down Bottom-Up processing: Analysis that emphasizes the characteristics of the stimuli rather than our concepts and expectations. Top-Down perception: Analysis that emphasizes the perceiver’s expectations, rather than individual characteristics.

Describe This Picture

Describe This Picture The Forest Has Eyes by Bev Doolittle Bottom-Up: Lines, angles and colors…a guy riding a horse through the forest Top-Down: We consider the title and direct our attention to aspects that will give meaning to it.

Perceptual Constancy Perceptual Constancy perceiving objects as unchanging despite changes in retinal image color shape size

Perceptual Illusions

Perceptual Illusions

Perceptual Illusions

Perceptual Illusions

Perceptual Organization- Gestalt Visual Capture tendency for vision to dominate the other senses Grouping the perceptual tendency to organize stimuli into coherent groups

Perceptual Organization Figure and Ground organization of the visual field into objects (figures) that stand out from their surroundings (ground) Works for all senses

Perceptual Organization- Gestalt Gestalt- an organized whole tendency to integrate pieces of information into meaningful wholes 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

Perceptual Organization- Grouping Principles

What shapes do you see in each image?

Law of Perceptual Grouping Law of Common Fate: The Gestalt principle that we tend to group similar objects together that share a common motion or destination. Think a school of fish, a flock of seagulls, a murder of crows

Laws of Perceptual Grouping Law of Pragnanz: The Gestalt principle which states that the simplest organization, requiring the least cognitive effort, will emerge as the figure. What is wrong with this image?

Perceptual Organization- Grouping Principles Gestalt grouping principles are at work here.

Perceptual Organization-Depth Perception ability to see objects in three dimensions allows us to judge distance Binocular cues retinal disparity images from the two eyes differ closer the object, the larger the disparity convergence neuromuscular cue two eyes move inward for near objects

Perceptual Organization-Depth Perception http://www.youtube.com/watch?v=p6cqNhHrMJA Visual Cliff

Perceptual Organization-Depth Perception Monocular Cues relative size smaller image is more distant interposition closer object blocks distant object relative clarity hazy object seen as more distant texture coarse --> close fine --> distant

Perceptual Organization-Depth Perception Relative Size

Perceptual Organization-Depth Perception

Perceptual Organization-Depth Perception Monocular Cues (cont.) relative height higher objects seen as more distant relative motion closer objects seem to move faster linear perspective parallel lines converge with distance relative brightness closer objects appear brighter

Perceptual Organization-Depth Perception Perspective Techniques

Perceptual Organization

Perceptual Organization-Muller-Lyer Illusion

Perceptual Organization- Size-Distance Relationship

More Illusions at the Perceptual Level

Perceptual Organization-Brightness Contrast

Perceptual Interpretation Perceptual Adaptation (vision) ability to adjust to an artificially displaced visual field prism glasses Perceptual Set a mental predisposition to perceive one thing and not another

Perceptual Set- Schemas What you see in the center is influenced by perceptual set

Perceptual Set- Schemas Flying Saucers or Clouds?

Perception without Sensation? Extrasensory Perception controversial claim that perception can occur apart from sensory input telepathy clairvoyance precognition Parapsychology the study of paranormal phenomena ESP psychokinesis

The End If you assume your senses give you an accurate and undistorted picture of the world, you are probably wrong. If you don’t believe me, try this. Silently read the backwards statement below. Flip if over in your mind. What does it say? .rat eht saw tac ehT

Answer How many people saw this: The cat saw the rat. Look at it again: .rat eht saw tac ehT The cat was the rat. Answer: The cat was the tar. http://illusionoftheyear.com/