Unit Two: Biopsychology Domain Chapter 3: Senation and Perception Module 7: Sensation; Module 8: Perception
SENSORY PROCESSES: How Do We Perceive The World?
ThEcOwgAvecOla..rat eht saw tac eht The quick brown fox jumped over the lazy dog. The quick brown fox jumped over the lazy dog.
How many squares do you see?
Sensation receiving information from the environment Perception organizing sensory information to make it meaningful Interference conflicting old and new stimuli Habituation brain stops attending to constant unchanging information Adaptation gradual loss of unneeded or unwanted sensory information
Perception Perceptual Constancies: The world around us is in constant motion; our brain must work to hold size, color, shape, brightness and space steady to be able to make sense of it.
Size Constancy Space Constancy Color Constancy Brightness Constancy Shape Constancy
How can expectations and experiences influence our perception? Perceptual Set (Expectancy): perceiving stimuli due to previous experiences or expectations. MAC DONALD MAC HENRY MAC MAHON MAC HINERY machinery
Top-down processing: using preexisting knowledge to organize individual features into a unified whole. Bottom-up processing: analysis of smaller features to build up to a complete perception. Top-down v. Bottom-up
Organizing Information Gestalt Principles Gestalt An organized whole, shape, or form; the sum is greater than it s parts.
Depth Perception ability to see the relation of objects in space Binocular (retinal) disparity difference between the images provided by the two retinas Texture gradient How rough or smooth objects appear; used in depth perception
Depth Perception The two work together allowing us to see depth; each sends a slightly different message to the brain for processing Are we born with depth perception? visual cliff experiment 1960s Gibson and Walk Visual Cliff Visual Cliff and Development Over Time
Grand Canyon Skywalk
A Few Famous Illusions Muller-Lyer Illusion Size and Shading Reversible Images Moon Illusion
Kurt Wenner Sidewalk Art
So what can we learn from illusions? Illusions: an inaccurate perception 1. How our brain organizes the world around us. 2. Our environment/culture (experience) can influence how we perceive information. 3. That our sense of vision.
Sensation: Vision dominates the senses. What made the green eggs and ham so unpalatable?
Rods: see black and white for night vision Seeing Color Cones: see color for day vision; vision sharpness Trichromatic Theory: eyes contain red, blue and green cones each for primary colors of light. ability to perceive certain colors Colorblindness: inability to perceive certain colors
Opponent Process Theory: proposes that color vision has four primary colors with cones arranged in pairs: red and green; blue and yellow. Afterimages: image that remains after retina stimulation ends; cones fire back to balance
Vision s Psychological Characteristics vision dominates human senses iris: colored muscle focus of lovers pupil: opening for light smaller if disgusted, larger if we see something (or someone) we like; wide for heightened emotions including danger.
Sensation: Hearing hearing is energy from sound waves; measured in decibels
Tinnitus: ringing in your ears
Hearing s Psychological Characteristics animals rely on sound more than humans Music and human behavior has a long history some hair cells recognize specific sound patterns: a mother s voice; newborn babies relax at sound of mother s heartbeat a loud noise can disturb sleep; but a constant sound of 50 decibels can help sleep music genre, mood and behavior: Earworms: the musical itch we can t scratch
curing earworms
Sensation: Cutaneous Nerve receptors respond to pressure, temperature or pain
Touch and its Psychological Characteristics contact comfort Satisfaction from soft, physical stimulation Harlow s Monkeys Palmer Grasp Harry Harlow 1906-1981
Sensation: Olfaction Olfactory bulbs receive odor molecules and communicate their nature to the brain food detection and taste
Smell and its Psychological Characteristics our most animal-like sense stimulating or craving healing emotions memory recall Pheromones odor chemical that communicate a message
Sensation: Taste Taste receptors on the tongue decode molecules of food or drink: detect sweet, sour, salty and bitter Salt for body chemistry balance Sugar for energy Sour and bitter detect poisons and spoiled food