Psychology- Chapter 4 Perception test Sensation and Perception Sensation Simulation of sensory receptors and transmission of sensory information to the central nervous system Interpret sensory stimulation *Perception is our reaction to sensation http://www.michaelbach.de/ot/ http://kids.niehs.nih.gov/games/illusions/index.htm http://www.123opticalillusions.com/ http://www.echalk.co.uk/amusements/opticalillusions/ill usions.htm http://www.moillusions.com/ http://www.sandlotscience.com/ Thresholds Absolute threshold Weakest amount of stimulus that can be detected Difference thresholds minimum amount of difference between two stimuli Signal detection theory distinguishing sensory stimuli by strengths and also physical setting, mood, attitudes Sensory adaptation More sensitive to weak stimuli and less sensitive to unchanging stimuli Optical illusions Walking into a dark theatre your eyes will adjust Hear a train every day you will not notice it very much Vision Light- electromagnetic energy Wavelengths Roy G. Biv Colors of rainbow- red, orange, yellow, green, blue, indigo, violet Ultraviolet and Infrared The Eye Pupil- (Black circle) lets in light and is sensitive to emotions Lens- (Blue oval) focuses image on retina Cornea- (Outer blue) protection Iris- (Dark blue lines) muscle that controls pupil Optic nerve- (Back pink) takes image to brain Retina- (Back pink) picks up image and relays to brain More parts to the eye Photoreceptors Blind spot- everyone has one in each eye Rods (shades) and cones (colors)- 100 million rods, 5 million cones Brain fixes images for us even if we don’t really see that Visual acuity 20/20 vision 20/20 vision is a term used to express normal visual acuity (the clarity or sharpness of vision) measured at a distance of 20 feet. If you have 20/20 vision, you can see clearly at 20 feet what should normally be seen at that distance. If you have 20/100 vision, it means that you must be as close as 20 feet to see what a person with normal vision can see at 100 feet. 20/20 vision does not mean perfect vision. It only indicates the sharpness or clarity of vision at a distance. There are other important vision skills, among them peripheral awareness or side vision, eye coordination, depth perception, focusing ability and color vision that contribute to one's overall vision ability. Color vision Complementary colors Afterimage Color blindness http://www.grand-illusions.com/opticalillusions/hollow_face/ http://www.grand-illusions.com/opticalillusions/dragon_illusion/ http://www.at-bristol.org.uk/Optical/DancingLights_main.htm http://www.coolopticalillusions.com/ http://mightyillusions.blogspot.com/2006/04/scary-optical-illusionno4.html Seeing Facts Most people blink every 2-10 seconds. Each time you blink, you shut your eyes for 0.3 seconds, which means your eyes are closed at least 30 minutes a day just from blinking. If you only had one eye, everything would appear twodimensional. (This does not work just by closing one eye.) Owls can see a mouse moving over 150 feet away with light no brighter than a candle. The reason cat's and dog's eyes glow at night is because of silver mirrors in the back of their eyes called the tapetum. This makes it easier for them to see at night. An ostrich has eyes that are two inches across. Each eye weighs more than the brain. A chameleon's eyes can look in opposite directions at the same time. A newborn baby sees the world upside down because it takes some time for the baby's brain to learn to turn the picture right-side up. One in every twelve males is color blind. Hearing Pitch- frequency of sound waves Loudness- amplitude of sound waves Timbre- a distinctive sound The ear Cochlea Hammer Anvil Stirrup Eardrum Ear canal Eustachian tube Auditory nerve Deafness Conductive deafness- middle ear, deals with the bones; cure- hearing aids Sensorineural deafness- inner ear, no cure Stimulation deafness Hearing Facts When you go up to high elevations, the change in pressure causes your ears to pop. Children have more sensitive ears than adults. They can recognize a wider variety of noises. Mosquito ringtone Dolphins have the best sense of hearing among animals. They are able to hear 14 times better than humans. Animals hear more sounds than humans. An earache is caused by too much fluid putting pressure on your eardrum. Earaches are often the result of an infection, allergies or a virus. Smell Olfactory nerve Taste and smell video http://www.youtube.com/watch?v=WavjbJ hiRAE&feature=related Take a deep breath. Air is sucked up into your nostrils over bony ridges called turbinates, which add more surface area to your sniffer. The air travels over millions of olfactory receptor neurons that sit on a stamp-size sheet, the olfactory epithelium, on the roof of the nasal cavity. Odor molecules in the air stimulate and inhibit the receptors. Each aroma sets off a signal made by the receptors that travels along the olfactory nerve to the olfactory bulb. The olfactory bulb sits underneath the front of your brain. Signals from the bulb tell your brain what reeks. Humans can recognize 10,000 different odors. However, no two people sense anything the same. Smelly Facts Dogs have 1 million smell cells per nostril and their smell cells are 100 times larger than humans! Humans use insect warning chemicals, called pheromones, to keep away pesky insects! People who cannot smell have a condition called Anosmia. If your nose is at its best, you can tell the difference between 4000-10,000 smells! As you get older, your sense of smell gets worse. Children are more likely to have better senses of smell than their parents or grandparents. Taste Taste buds Bitter Sweet Sour Salty Taste We have almost 10,000 taste buds inside our mouths; even on the roofs of our mouths. Insects have the most highly developed sense of taste. They have taste organs on their feet, antennae, and mouthparts. Fish can taste with their fins and tail as well as their mouth. In general, girls have more taste buds than boys. Taste is the weakest of the five senses Skin senses Pressure Temperature Pain Touch Body Senses Vestibular sense Kinesthesis Arms through the floor Arms raise above the head Touch your finger- hands wrapped. The Pinocchio experiment with body image * Find 2 willing (and good) friends * Sit on a chair blind-folded, and ask your friend (let’s call her Sam) to sit on a chair in front of you, with her back to you. * Ask your other friend to take your right hand and put it on Sam’s nose * Tap and stroke her nose in a gentle random manner, making exactly identical movements with your other hand, on your own nose. * Continue this for 60 seconds About 50% of people will have the extremely odd sensation that their nose is 3 feet long, or somehow their nose is elsewhere! http://www.youtube.com/watch?v=U8JSgp _NM90 freaky body illusions http://www.youtube.com/watch?v=0EP09p QJwow broom through body vestibular sense The vestibular sense is also connected to parts of the brain that tell you when it is time to vomit. This is the cause of motion sickness. If you spin hard enough and then suddenly stop, the tiny current keeps going for a little bit, and gives you the sensation that you are still spinning, but in the opposite direction. Your brain may try to compensate for this, and cause you to fall or at very least feel dizzy. You can also confuse these canals when you take a shower and allow hot or cold water into your ear. The temperature changes can cause currents to develop that wind up feeling just like spinning, and you may get dizzy. Perception http://www.youtube.com/watch?v=URLRd cnU6Hk 10 in 2 minutes Closure Perceive whole objects when gaps are present Figure ground perception What we see as background and what we perceive as figure influence our perception Escher Power point or word Place optical illusions in a power point Things that express consistancy, perspective, continuity, similarity, contrast, figure ground, ect…… no limit. But there will be expectations of high quality….. Proximity Things that are near each other influence each other http://www.youtube.com/watch?v=8wRcN wPmjmw Proximity and elation Similarity Group objects that are similar to each other Continuity We like to see a smooth continuous pattern rather than individual parts Common fate See things moving together you perceive them as belonging to each other Perception of movement Stroboscopic motion Depth perception Monocular cues Perspective Clearness Overlapping Shadow Texture Gradient Binocular cues Retinal disparity- floating finger Perceptual constancy’s Size Color Brightness Shape Speed Visual illusions