perception how we organize and interpret sensory information
TRANSCRIPT
Inattentional Blindness
When focusing on one thing, we often miss or ignore other stimuli (no matter how exaggerated or crazy the stimuli may be… for example the gorilla in the basketball game).
Selective attention - we can only focus awareness on a limited part of what we are sensing.
Cocktail party effect – type of selective attention in which you can attend to only one voice at a time
Cell phones and driving? Listening to music and studying?
Visual Capture
The tendency for vision to dominate your senses.
At an IMAX movie, it feels like you are moving because it looks like you are moving. Your vision dominates over your vestibular system.
Parallel processing – processing many things at once
Man who mistook his wife for a hat – could see form but not the big picture
Colorblindness with functional conesMotion blindnessBlindsight
Depth Perception (seeing in 3D)Depth Perception (seeing in 3D)
Binocular cues – require both eyes
Retinal disparity – cue for relative distance of
different objects (greater the disparity, the
closer the object)
Convergence – extent to which eyes converge
inward when looking at something (greater
inward strain, the closer it is)
Depth Perception (cont’d)Depth Perception (cont’d)Monocular cues (available to each eye separately)
Relative size – assuming two objects are the same size, the one casting a smaller retinal image is farther away
Interposition – object partially blocking view of another perceived as closer
Relative clarity – hazy objects perceived as farther away than sharp, clear objects
Texture gradient – gradual change from coarse, distinct texture to a fine, indistinct texture signals increasing distance
Depth Perception (cont’d)Depth Perception (cont’d)Monocular cues (cont’d)
Relative motion (motion parallax) – as we move, objects that are stable appear to move. The nearer the object, the faster it appears to move. Objects beyond fixation appear to move with you.
Linear perspective – parallel lines appear to converge with distance.
Light and shadow – Nearby objects reflect more light on our eyes. Dimmer ones seem farther away. (Janus’ mask… assume light comes from above, so location of shadow indicates whether objects are concave or convex)
Motion PerceptionHow does the brain recognize an object is moving? How does it interpret the direction of
movement?
Brain interprets shrinking objects as receding and enlarging objects as approaching
Stroboscopic Effectthe perception of motion produced by a rapid succession of slightly varying images (animation, movies)
Phi phenomenonan illusion created when two or more adjacent lights blink on and off in succession, creating the perception of movement (lighted signs, illusions)
Motion Perception
Objects that are farther away appear to be moving more slowly. Think of a plane in the sky or a truck in the distance
Perceptual Constancy - the ability to perceive an object is the same even as the illumination and retinal image changes.
Shape Constancy – perception that shape of an object doesn’t change just because image on the retina does.
Perceptual Constancy
Size constancy – perception that an object’s size remain the same even as the retinal image changes.
Color Constancy – the perception that familiar objects have a consistent color, even if changing illuminations alter the wavelength reflected.
Perceptual Constancy
Lightness constancy – the perception that familiar objects have a constant lightness, even while illumination varies.
Size-distance relationshipWhen other monocular cues tell us an image is further away, it actually appears larger.
Moon illusion
Imagine you are outside on a clear night in which there are no clouds and that is a bright full moon. Pretend that you are going to pick up one of the following objects that when held at arm’s length just covers up the moon.
Moon Illusion Objects Imagine the moon is straight overhead.
BB
Pea
Dime
Penny
Nickel
Quarter
Golf ball
Baseball
Softball
Small Salad Plate
Large Salad Plate
Frisbee
Basketball
Beach ball
Moon IllusionNow imagine the horizon moon.
Softball
Small Salad Plate
Large Salad Plate
Frisbee
Basketball
Beach ball
BB
Pea
Dime
Penny
Nickel
Quarter
Golf ball
Baseball
Perceptual Adaptation
What happens if you wear goggles that distort your world? Could you shake hands? Catch a ball?
Let’s try!!
Perceptual Set – like a mental predisposition
Looking at either the left or the right-hand image first is likely to cloud your perspective of the center, ambiguous figure.
Perceptual Set ExamplesPunctuate the following so it makes sense:
TIME FLIES I CANT THEYRE TOO FAST
Read the following words out loud as they appear:MacDonaldMacHenryMacMurrayMachinery
Now let’s try some more…
Unscramble in order.
List A List B
LULB
CALEM
NUKKS
SEUMO
BAZER
EAP
NORC
NOONI
MATOOT
PREPPE
TEBE
EAP
In the next slide you will see a picture of two people. Name the person standing on the left (slightly behind the other person).