Unit Two: Chapter Four Sensation and Perception

Warm up 02/17 ●How do your senses (sight, hearing, smelling, etc.) influence your behavior and mental processes?

The Basics ●Absolute Threshold ○ weakest amount of stimulus that can be sensed ○ dog’s absolute threshold for hearing is lower than humans ○ App that only young people can hear ○ differs from person to person

The Basics ●Differences in Threshold ○ minimum difference between 2 stimuli ●Signal Detection Theory ○ distinguishing sensory info ■ setting ■ your physical state ■ your mood ■ your attitudes ○ focus on what you consider important ○ different people find different things important

The Basics ●Sensory Adaptation ○ sense change to adapt to an environment ○ more sensitive to weak stimuli & less sensitive to unchanging stimuli ■ eyes adjusting to the dark ■ People in cities adjusting to sound of traffic

Vision ●Light ○ wavelengths - not all visible to humans

Vision ●The Eye ○ light enters the eye and then is projected onto a surface ○ pupil - determines the amount of light that is let in ■ sensitive to light and emotions ○ lens - adjusts to keep objects in focus ○ retina - consists of neurons ■ photoceptors - sends visual input to the brain

Vision ●blind spot - places in the eye that lack photoceptors ●rods and cones - types of photoceptors ○ rods- brightness of light ○ cones - color vision ●Visual Acuity ○ sharpness of vision

Vision ●Color Vision ○ color circle - complementary colors ○ afterimages - you perceive the afterimage of a color once you view it for a while ■ complementary pair

Vision ●Color Blindness ○ not normal color vision ○ unable to distinguish colors ○ missing or malfunctioning cones ○ total color blindness is rare

Activity ●Create your own color wheel. There is also an example in the book. ○ complementary colors are across from one another ●Create your own afterimage. ○ Remember the afterimage includes the complementary color.

Chapter 4 Vocabulary ●sensation ●perception ●absolute threshold ●difference threshold ●signal-detection theory ●sensory adaptation ●pupil ●lens ●retina ●gate theory ●vestibular sense ●similarity ●continuity ●stroboscopic motion ●photoreceptors ●blind spot ●visual activity ●afterimage ●cochlea ●auditory nerve ●conductive deafness ●sensorineural deafness ●olfactory nerve ●kinesthesis ●closure ●proximity ●monocular cues ●binocular cues ●retinal disparity

Warm Up 10/10 ●When was the last time you had a vision test? ●Do you require glasses or contacts?

READ! ~10 minutes

Warm Up 02/18 ●Do you rely more on your hearing or your sight? ●Why?

Hearing ●Pitch ○ how high or low a sound is ○ depends on the # of cycles per second ○ we can hear things between 20 and 20,000 cycles per second ●Loudness ○ depends on the height (amplitude) of sound waves

Hearing ●The Ear ○ outer, middle, and inner ear ○ eardrum separates outer and middle ear ■ vibration transmits sound to the hammer, the anvil, and the stirrup ○ cochlea - converts vibrations into neural impulses that are transmitted to the brain

Hearing ●Deafness ○ conducive deafness ■ damage to middle ear ■ prevents people from hearing quieter sounds ■ hearing aids can help ○ senisorineural deafness ■ unable to perceive sounds of certain frequencies ■ neurons in cochlea are destroyed ■ disease or prolonged exposure to loud sounds ● ipod deafness is real!

Hearing ●Deafness ○ deafness in the world today ■ American Sign Language taught in schools ■ “closed captioning” ■ research on repairing ear damage

Warm Up 02/19 ●Have you ever had a food craving? ●What food?

Other Senses ●Smell ○ closely connected to taste ○ receptor neurons deep in each nostril ○ sends info through the olfactory nerve ○ adapt to scents quickly

Other Senses ●Taste ○ primary - sweet, sour, salty, and bitter ○ umami - “savory” ○ receptor neurons on taste buds on tongue ■ you can have low sensitivity to certain tastes ○ taste cells can re grow in a week

Other Senses ●Skin Senses ○ pressure ■ sensory receptors in root of hair cells ■ different parts of body more sensitive to pressure than others ○ temperature ■ neurons just beneath the skin ■ different receptors for warmth and cool

Other Senses ●Skin Senses ○ pain ■ pain receptors send message to spinal cord and thalamus ■ pain chemical = prostaglandin ■ Gate theory = brain can only process so many messages at a time ● if you rub a sore spot on the body it distracts brain from pain ■ phantom limb pains in amputees ● neural impulse in stump left by missing limb

Other Senses ●Body Senses ○ Vestibular ■ tells you if you are standing upright without using eyes ■ keep balance ○ Kinesthesis ■ position and motion of the body ■ info comes from joints, tendons, and muscles

Grab a partner ●First, one of you demonstrate a complex set of movements ○ dance, sports, yoga ●Second, the other member of the pair repeat the movement back. ○ write down what the movement was and if it was easy or difficult ●Switch Roles and repeat

Sensation Walks ●You’ll need to create something to block out your vision for our sensation walks… ●I have paper in the front.

Activity ●Smell/Taste Log ○ write down over the course of today everything you smell or taste ○ was there a pattern?

Warm up 02/20 ●What is perception? ●How could it be different from a sensation?

Perception ●Perceptual Organization ○ closure ■ Gestalt psychology ■ perceive object with gaps as whole ○ figure-ground perception ■ figures against a background ○ other ■ proximity (nearness) ■ similarity (similar objects belong together) ■ continuity (continuous patterns)

Perception ●Movement ○ is hard to discern with only your eyes ●Stroboscopic Motion ○ rapid progression of images - looks like motion

Perception ➔ Depth Perception ◆ monocular cues ● only need one eye to perceive them ● some objects seem more distant ◆ binocular cues ● both eyes required to perceive ● retinal disparity

monocular cues

Perception ➔ Perceptual Constancies ◆ size constancy ● you maintain the ability to distinguish the size of something no matter what distance away it is ◆ color constancy ● things keep their color even in different lighting ◆ shape constancy ● same shape no matter the angle you view it

Perception ➔ Visual Illusions ◆ Muller-Lyer illusion ◆ Ponzo illusion ● example

Other Visual Illusions

other Visual illusions

Create your own Visual Illusions ●It can be a recreation of one we’ve talked about...or you can create something completely original