Perception

Inattentional Blindness Challenge: Count the number of passes the white shirts pass! Video (2mins) Type of selective attention Failing to see visible objects when your attention is directed elsewhere

Focusing on the task (relevant), not the person (irrelevant)! Change Blindness You fail to notice a difference in a stimulus (ex. the person) from just a moment ago Focusing on the task (relevant), not the person (irrelevant)! British video (4 mins) Daniel Simons (4 mins) © 1998 Psychonomic Society Inc. Image provided courtesy of Daniel J. Simmons.

Do you see what I see? Gestalt: German meaning “whole” or “form” When given a cluster of sensations, we tend to organize them using gestalt Constantly filtering info in ways that make sense to us

Figure-ground relationship: Define the figure (focused object) from the ground (its surroundings) Relationship is continuously reversible The same stimulus can trigger more than one perception

Does this most closely resemble 6 lines or 3 groups of 2? Proximity: We group nearby figures together

Do you see vertical or horizontal lines? Similarity: group similar objects together http://deadspin.com/stupid-nike-uniforms-wreaking-havoc-on-colorblind-nfl-f- 1742272136

How do you draw an X? Continuity: perceive smooth, continuous patterns rather than discontinuous

How many? Connectedness: if uniformed and linked, we perceive each set of two dots and lines as a single unit

This is a _______?? Closure: we fill in gaps to create a complete whole object We assume the circles are complete and just blocked by a triangle

Binocular Cues cues that depend on using BOTH eyes Retinal disparity You see two angles of every object Convergence When objects get closer to your face, you cross your eyes to continue using your fovea

Monocular Cues Relative size Interposition Relative motion Texture gradient Relative height Linear perspective Shadowing Depth cues that DO NOT require both eyes

Which letter is the closest? Monocular Cues Which pencil is closer? Relative Size: if we assume two objects are the same size, we perceive the smaller retinal image as farther away Which letter is the closest? Interposition: objects that block the view of other objects must be the closest Relative Motion: distant objects seems to move with you while nearby objects go by rapidly Smaller objects appear to go faster than larger objects moving at the same speed OBJECTIVE 7| Explain how monocular cues differ from binocular cues, and describe several monocular cues for perceiving depth.

Monocular Cues Texture Gradient Relative Height Surface quality of an object; we see less texture on something that is farther away. Distant objects appear relatively higher in your field of vision than close objects.

Monocular Cues Linear Perspective Shadowing Distance cue; parallel lines converge, as they move away from us Given two identical objects, the dimmer one will seem farther away Gives clues about depth Gives clues about movement (1:01-2:50)

Motion Perception Stroboscopic effect (flip book effect) Film is not motion! At 24 slides per second we perceive as motion When the information is limited, the brain often makes assumptions based on what it knows. In the case of spinning rims, the relative position of the individual spokes and the light source which makes them visible can combine to create an optical illusion of backwards motion. forza motorsport 5 (2:15)

Perceptual Illusions Julian Beever (3:00)

Motion Perception Phi Phenomenon: blinking lights make it look like light is jumping from one point to another creating the illusion of motion.

Which is a darker shade of gray? A or B? Perceptual Interpretation OBJECTIVE 11| Discuss lightness constancy and its similarity to color constancy. Perceived color depends on the amount of light an object reflects relative to its surroundings. Lightness Constancy

Size-Distance Relationship Perceptual Interpretation When we are unfamiliar with the size of an object, monocular cues (linear perspective) tricks us in perceiving the false size of the object. The monster farther away is larger, right? Size-Distance Relationship

Perceptual Interpretation The moon looks huge when it’s near the horizon, but it’s actually always the same size! We have no perspective of how far away the moon is in high sky since we don’t have a horizon to compare it to. Moon Illusion

Perception Highlights Start at 8:00-15:00