Bell Activity 3/1/2013 Learning Targets: At the end of class, you will be able to-Describe the importance of sensation and perception -Define: stimulus, signaldetection theory, Weber’s law -Create an experiment 1.) How do things look the way they do? 2.) What is this color? 3.) How do we know if everyone else is seeing the same color? 4.) How do we know we are moving and if we are, where we are going? Sensation & Perception School Tour 1. 2. Write down all of the places that you went (or think you went). How do you know that these are the places you went? Sensation & Perception Sensation: Occurs when a stimulus activates a receptor Ex: Changes in heat, light, sound, physical pressure, etc. Perception: The organization of sensory information into meaningful experiences. Ex: Vision incorporates colors, intensity of light, distance, etc Fraser’s Spiral Now, cover up half of the spiral So…How do we use sensation and perception together to understand our world? Combination of senses and past experiences Sensation & Perception Our knowledge of the world comes from chemical & electrical processes occurring in the brain. Stimulus: Any aspect of or change in the environment to which an organism responds. A stimulus can be measured by size, duration, intensity or wavelength. Sensation & Perception Sensation occurs anytime a stimulus activates a receptor Psychophysicists study the relationship between stimuli & sensory experience. Sensation & Perception Thresholds, Differences & Ratios Absolute Threshold: minimum amount of physical energy needed to produce a sensation 50% of the time. In general, the senses have very low absolute thresholds Ex: In a dark room, project low-intensity beam of light against the wall. Slowly increase the intensity of the light until it can be seen. Then, start with a bright light and lower it until the participant cannot see it any longer. Sensation & Perception Absolute Thresholds of the 5 Senses Vision: seeing a candle flame 30 miles away on a clear night. Hearing: hearing a watch ticking 20 ft. away. Taste: tasting 1 teaspoon of sugar dissolved in 2 gallons of water. Smell: smelling 1 drop of perfume in a 3 room house Touch: feeling a bee’s wing falling a distance of 1 centimeter onto your cheek. *In general, the senses have very low absolute thresholds. Sensation & Perception Difference threshold: the just noticeable difference, minimum amount of energy needed to produce a change in sensation. Sensory experiences depend more on changes in the stimulus than on size or amount of stimulus (3lb. into and empty backpack vs. 3 lbs in a 100 lb. backpack) Weber’s Law: The larger or stronger a stimulus, the larger the change required for an observer to notice. Sensation & Perception Sensory Adaptation: Senses respond to increases and decreases in stimulus. Example: Eyes adjusting to darkness in a room. Sensation & Perception Signal Detection Theory: (Abandons the idea of a true absolute threshold) based on the notion that a stimulus (signal) must be detected in the presence of competing stimuli. Ex: Being able to study in a room with a radio playing and a TV on, etc. Bell Activity 3/5/2013 Learning Targets: At the end of class, you will be able to-Create an experiment to find absolute threshold -Describe how vision works 1.) What is the relationship between sensations and perceptions? 2.) Eyes adjusting to light differences is referred to as ____. 3.) How do 3-D movies work? In the Computer Lab Go to Mr. P’s site: http://spetersopsych.wikispaces.com/ Click on the “Unit 4” link Play the “Eye Hop Game” and take the “Depth Perception Test.” Take the Color Blind Test; From this site, write down 10 things you learned about color blindness. Vision Most studied of all the senses How does vision occur? Light enters through the pupil & reaches the lens that focuses light on the retina. Vision The retina contains two types of receptor cells: rods and cones. Rods and cones are responsible for changing light energy into impulses which travel along the optic nerve to the occipital lobe. Vision Cones work best in daylight and are sensitive to color. Rods are used in night vision What Happened? Answer: The receptors for green, yellow and black became fatigued (neuron firing shifted) Vision The Electromagnetic Spectrum: Includes radio waves, microwaves, infrared radiation, X-Rays and gamma rays. Visible light represents a very small portion of the spectrum Vision Binocular Fusion- receiving 2 images but combining them into 1. We receive two images from our eyes and form one composite image of the two views. Vision Retinal Disparity- differences between the two images (closing one eye and looking at object). This is essential to creating our sense of depth perception. StereopsisPhenomena of seeing depth as a result of retinal disparity Vision When your eyeball is not perfectly shaped, your vision will be impaired because the focal point has been changed Nearsightedness: Eyeball is too long Farsightedness: Eyeball is too short Bell Activity 3/6/2013 Learning Targets: At the end of class, you will be able to-Describe the function of senses such as taste, touch, smell and hearing 1.) What are the receptor cells in the eyes called? 2.) How does retinal disparity help us with our vision? 3.)What songs remind you of important events in your life? Ex: http://www.youtube.com/wat ch?v=pIotIGFN2oc 4.) What smells do you associate with childhood? *Remember only water is allowed outside of the Commons-School Policy! Hearing Depends on vibrations of the air (sound waves) that pass through various bones & fluids until they reach the inner ear. Hair-like cells change sound vibrations into neuronal signals that travel along the auditory nerve to the brain. Hearing Loudness depends on the amplitude of vibrations; strength/soundpressure is measured in decibels. (0-14-, anything over 110 can damage) Pitch: the experience associated with a sound’s frequency: the “highness” or “lowness” of a sound. Hearing-Pathway of Sound The ear is designed to capture sound Outer ear receives sounds Earflap directs sounds down a short tube called the auditory canal to vibrate Causes the eardrum to vibrate Hearing Bones in the Middle Ear pickup vibrations and push against cochlea Cochlea: Sensory cells in the cochlea turn the vibrations into neuronal impulses Hearing 2 Types of Deafness Conduction: when anything hinders physical motion through the ear (hearing aides) Sensorineural: Damage to the cochlea (cochlea implant) Hearing http://www.youtube.com/watch?v=KGn9McP K7Qw Smell and Taste Chemical Senses: receptors are sensitive to chemicals rather than light or sound. Smell- molecules enter nose in vapors, the vapors come into contact with smell receptors in nose. Messages are sent to the brain by the olfactory nerve. Smell and Taste Taste- chemical stimulate receptors (buds) on tongue, messages sent to brain with data about texture & temp. 4 primary taste sensations: sour, salty, bitter & sweet. 6 smell experiences: flowery, fruity, spicy, resinous, putrid & burned. Much of taste is also produced by smell, temp and texture. Smell and taste play a much more important role in “lower animals” “Hey Bud!” Results Touch Skin provides brain w/ info. about environment: pressure, warmth, cold & pain Pressure varies from place to place (fingertips v. calf) serve as protection/warning. Pain makes it possible to prevent damage (emergency system) Touch Pain -Sharp localized pain immediately after an injury -Dull, generalized pain you feel afterward -Gate Control Theory of Pain: You can lesson pain by shifting attention away -Referred Pain: Pain in area away from the actual source. Balance and Body Senses Regulated by the vestibular system (inside inner ear) The vestibular system contains the semicircular canals with contain moveable fluid. Over stimulation can result in dizziness. Kinesthesis: Sense of movement & body position Cooperates with the vestibular system and visual senses to maintain posture and balance. Balance and Body Senses Without kinesthesis, your movements would be jerky and uncoordinated. Other body sensations come from receptors that monitor internal body conditions. Referred pain-pain in an area that is actually away from the actual source. Bell Activity 3/7/2013 Learning Target: At the end of class, you will be able to-Find taste locators on the tongue -Describe the senses -Explain the Gestalt Principle of Perception Remember, water is the only drink allowed outside of the Commons area-School Policy! 1.) What serves to protect the body from outside harm? 2.) What are the two types of deafness? 3.) What relays messages about smell to the brain? 4.) In your mind, what do teachers do? Bell Activity 3/8/2013 Learning Targets: At the end of class, you will be able to -Describe the five principles of Gestalt -Describe how we develop perceptions -Explain the importance of subliminal messaging 1.) Which system regulates our balance? 2.) What are the 2 types of pain? 3.) What makes our movements fluid as opposed to jerky and uncoordinated? *Test on Tuesday! *Vocab due on Monday. Perception The process of the brain receiving information from the senses, organizing it and then interpreting it into meaningful experiences. Principles of Perception The brain receives information from the senses and organizes/interprets it into meaningful experiences unconsciously. Gestalt: (whole experience) the experience that comes from organizing bits and pieces of information into meaningful objects and patterns. The whole is greater than the sum of parts (ex. music). If the elements of a pattern are close to one another or similar they are perceived as belonging to each other. Gestalt Principles: Proximity, Similarity, Closure, Continuity, Simplicity 5 Principles of Gestalt Principles of Perception Figure-Ground Perception: The ability to discriminate between figure (object) and ground (background); 3-D v. 2-D Principles of Perception Perceptual Inference Perceptions that are not based on current sensory information. Otherwise known as “filling in the gaps”. We use learned information to help us draw conclusions. Often depends upon previous experiences-but not always (babies won’t fall off of the “cliff”). People and animals must be actively involved in their environments to develop perception Learning to Perceive Perceiving is something we learn to do. Involvement with one’s environment is important for accurate perception. (Ex: Blind patients who gain sight do not know difference between squares an circles Perception is based on our needs, beliefs, and expectations. You see what you want to see. (Ex: Bias in politics, stereotypes, etc) Computer Activity Go to Mr. P’s Web Site: http://spetersopsych.wikispaces.com/hom e Click on the Unit 4 link Go to the “illusions” and “more illusions” links Click on the different optical illusions Pick 15 of the optical illusions and explain how they work Subliminal Perception Brief auditory or visual messages presented below the absolute threshold Ability to detect stimuli that only affect the subconscious mind Controversial Bell Activity 3/11/2013 Learning targets: At the end of class, you will be able to-Identify examples of subliminal messages -Discuss factors that shape our perceptions -Review for the sensation and perception test How would a Psychophysicist (someone who studies the relationship between sensation and perception) answer the following question? If a tree falls in the forest and no one is around to hear it, does it make a sound? Bell Activity Answer A Psychophysicist would say that the answer is…. NO! Why? From a scientific point of view the physical event happens (there is sound waves created) but, the psychological event cannot happen unless an organism is present to experience the event (turn sound waves into impulses sent to the brain to be interpreted) Subliminal Political Ad? http://www.youtube.com/watch?v=QKAWB u_GOoA Subliminal Messages in Fast Food http://www.youtube.com/watch?v=YoIIkTs 2j3Q Other Factors That Shape our Perceptions Monocular Depth Cues: Cues that can be detected with just one eye (bigger=closer) Binocular Depth Cues: Cues that depend on the cooperation of both eyes (retinal disparity) Motion Parallax: Apparent movement of objects in relation to other objects as you move Linear Perspective: Parallel lines converge in the distance Relative Motion: How other objects move in relation to your movements Constancy: We perceive things to be unchanged regardless of light, distance, angle, etc.