Unit+3+Review+Page

Be sure to review all this stuff for your Sensation Perception Test!

__Sensation and Perception Study Guide:__ Be prepared to answer questions 1 - 5 for your test. Note that you will only be asked to answer question 3 or 4 but not both. All other questions will appear on the test. To participate in the review page add some useful notes, thoughts and examples for the questions/tasks below. __To make the Review Page clear make sure your notes are done in black so that they stand out from the questions__

**1.** Label the part and functions of the eye and then write a brief paragraph to describe how vision is processed by the brain. (Check out the slide show on Vision on the Unit 3 page) (worth 20 points) // Cornea: // Clear protective covering. Behind is fluid // Iris: // Colored part of eye. Muscles that regulate amount of light that is being absorbed. (i.e- in intense sunlight the muscle contracts to make the pupil smaller thus letting in less light) // Lens: // Clear muscle that focuses images on the back of the eye (retina). (Close range- lens becomes shorter and fatter. Long range- lens becomes longer and thinner.) // Blind Spot: // At the back of the eye where the optic nerve leaves eye so nothing is processed because there's no retina in this one spot. //Optic Nerve:// Connects the eye to the brain-It carries impulses formed by the retina to the brain. //Retina:// Back of eye, containing millions of receptors for light. This is where light is processed into chemical electrical energy (transduction) and sent to the optic nerve where they are then sent to the brain. //Pupil:// Space in which light passes through the eye.


 * light hits receptor cells at the back of the eye and perform transduction (physical to electrical-chemical energy)
 * two types of cells
 * **cones** - color (behind pupil is where most cones are densely packed)
 * **rod** - edges / shapes
 * eye's peripheral vision is black and white
 * biopolar cells take info from receptor cells and process feature detection
 * ganglion cells - are woven into optic nerve
 * finally sent to occipital lope in the brain
 * side note: eyeball split left and right, processed on opposite side

**2.** Choose any **two** from the list of senses below and address the parts A, B, and C (worth 30 points)
 * ==== Hearing ====
 * ==== Touch & Pain ====
 * ==== Smell and Taste the Chemical Senses ====
 * ==== Body Movement: Kinesthetic and Vestibular ====

A.What is the absolute threshold for humans and how does this compare to other animals? B.How is the sensory information processed and transmitted to the brain? C. What function does the sense serve for survival and how does it work with other senses?

a) The absolute threshold for hearing is the tick of a watch twenty feet away in a quiet room. The hearing sense is the first sense to detect changes in one's surroundings. Animals have a much higher hearing threshold than humans. Dolphins can hear 14 times better than humans. Animals' ability to hear sounds loud and from farther away allow them to be very conscious of their surroundings and to detect danger. b) Sound waves are processed when they collide with the eardrum, causing the hammer, anvil, and stirrup, known as the auditory ossicles, to vibrate. The ossicles are the smallest bones in the human body; all together they could fit on a penny. The auditory ossicles are attached to a drum head called the oval window, which oscillates to make waves of a fluid substance in the cochlea, a spiral shaped cavity of the inner ear. The sound waves in the fluid are detected by tiny hair cells which generate nerve impulses to be sent to the brain and process sound (Notebook). Over time, particular waveforms and frequencies create different patterns and are processed and recognized as different sounds. The process is similar to learning a visual pattern such as a face or object (Elsea).
 * Hearing **

When a noise is made vibrations are sent through the air and are funneled into the ear canal by the outer ear. The vibrations then travel into the middle ear and hit the eardrum, causing it to vibrate. There is a chain reaction of vibrations. The eardrum then vibrates three different bones in the body. These bones include the hammer, the anvil, and the stirrup. The stirrup then passes vibrations to the cochlea which is located in the inner ear. The cochlea contains 1,000 hair- life nerve endings called cicilia. Cicilia change the vibrations into messages that are sent to the brain via the auditory nerve. This nerve carries the messages from 25,000 receptors in the ear to the brain. The brain then makes sense of these noises or sounds.

c) Hearing is very important in human survival because it is the first sense to detect new things coming into our surroundings. It allows us to be able to sense danger before our other sense kick in and react to the danger. After something is heard, body movement can take places, and the human or animal in danger can move out of danger

a) For smell, a human’s absolute threshold is one drop of perfume diffused into a three room apartment. For taste, a human’s absolute threshold is one teaspoon of sugar diffused into two gallons of water. In comparison to humans, dogs have a better sense of smell and insects have the most highly developed sense of taste. b) The process of smelling and tasting begins first when when molecules released by the substances around us stimulate special nerve cells found in the nose, mouth, or throat. These cells then transmit messages to the brain, where specific smells or tastes are identified. In order to smell something, volatile chemical substances enter the nose. The molecules stimulate olfactory receptors in the upper nasal passage. Neurons from the receptors group together to form the olfactory nerve, which travels to the olfactory bulb in the brain where the information is processed. In terms of tasting, the Gustatory or taste nerve cells are clustered in the taste buds of the mouth and throat. The chemicals are initially processed by some of the 10,000 taste buds that are located on the bumps of the tongue, known as papillae. The taste buds send information through sensory nerves to the thalamus and other areas of the cortex.These surface cells send taste information to nearby nerve fibers, which send messages to the brain.
 * Touch & Pain **
 * a.) The absolute threshold for touch is the wing of a bee falling onto one's cheek. **
 * Smell and Taste **

c)Smell and taste are vital for survival. Flavors and aromas often work together and according to scientists, “most of what we call flavor actually comes from the odors that reach nerves via nasal passages at the back of the throat.” Both of these senses are directly connected to certain brain areas that help control emotions, regulate food and water intake, and even form memories. Interestingly, your sense of smell is the sense most directly connected to your memory.


 * Body Movement **

Smell
-The absolute threshold for smell is a drop of perfume in a three room apartment

Taste -The absolute threshold for taste is one tsp of sugar diffused in two gallons of water.


 * NOTE: On the test you will only be assigned either question 3 or 4. **

**3**. Review the images from the Perception Slide Show embedded on the wiki. Be ready to define **any 3** the following terms and explain how they apply to one of the slides (worth 20 points ):


 * Top-Down Processing- background knowledge and past experiences are used to fill in gaps in what we sense
 * Law of Pragnanz- (Law of Simplicity)- perceiving things in the simplest way possible
 * Law of Closure - Objects that make up a recognizable image are more likely to be perceived as belonging in the same group, even if the image contains gaps that the mind needs to fill in. The brain has the tendency to fill in the missing information from the perceptual array by closing in gaps. People mentally fill in the gaps to see it as a whole.
 * Law of Continuity - Tendency to prefer to see fluid or continuous forms rather than jagged or irregular ones.
 * shadowing- by seeing the shadow, we can tell where the light source is coming from
 * linear perspective- vanishing point and far away things. Think railroad tracks in the distance
 * perceptual set- people tend to see what they are looking for, its a predisposition to perceive something in a certain way
 * Schemata- mental representations of how we expect the world to be
 * perceptual constancy- people perceive objects in the same way even if there's a change in angle, distance or lighting
 * framing- the context in which something is viewed. Think how people react to someone swearing in class vs. someone swearing when they're just with their friends
 * template matching theory- match new complex patterns against prototypes in our mind

**4.** Check out the Illusion of Movement videos on the Unit 3 page. Be prepared to explain which of the following types of illusion of movement applies and then explain how one other term from the Trail Guide applies. (worth 20 points)

Illusions of Movement:
 * stroboscopic movement :a series of still pictures presented in rapid succession to produce the illusion of movement.
 * phi phenomenon: A series of stationary, flashing lights that produce an illusion of movement. Las Vegas Neon lights.
 * induced movement: an object that encloses another tends to act as a frame which is seen as stationary. When reversed, person will experience perceived movement.
 * autokinetic effect: spots of light in a dark room that may seem to be moving due to lack of context cues

**5.** Explain the concept of Gestalt Psychology and using specific examples from the unit to explain how our various senses are integrated into meaningful perceptual whole for each individual. (worth 30 points) Gestalt Psychology: Total is more than the sum of its parts. We perceive things other than the information our senses give us. Why we all perceive the same event differenly


 * __Trail Guide Terms:__**


 * Perceptual Organization**- (perceptual grouping)- processes which group smaller units of the perceptual world into larger units.


 * Selective Attention**- the focusing of mental resources on only part of the stimulus field (the cocktail party phenomenon)


 * Signal Detection Theory**- tries to predict what we will perceive among competing stimuli. Includes motvation and expectations (response criteria)


 * Top-Down Processing**- we use our background knowledge to fill in gaps in what we sense schemata- mental repreentations of how we expect the world to be. These influence how we actually see the world. Schemata create a perceptual set- a predisposition to perceive something in a certain way. Seeing certain images in the clouds. Gestalt is top-down theory.


 * Bottom-Up Processing (Feature Analysis)**- instead of using our experience to perceive an object, we use only the features of the object itself to build a complete perception. An automatic process- hard to conceive of. More accurate, but more time-consuming than top-down.

we need for perception. We are hard-wired to make sense of sensory input
 * Theory of Constructive Perception**- relies on prior learning as an important component in perception Vs. Direct Perception- Our sensations and sensory context are all


 * Proximity**- tendency to group things on the basis of how near they are to one another; objects that are close together are likely to be perceived as belonging in the same goup.


 * Similarity**- tendency to group things on the basis of how similar they are to one another; elements are seen as belonging together because they share certain characteristics; objects that are similar in appearance are likely to be perceived as belonging in the same goup.

irregular ones. Objects that form a continuous form (such as a trail or a geometric figure) are more likely to be perceived as belonging in the same group; tendency to see continuation.... things maintaining their original course. camouflage
 * Symmetry**- tendency to perceive preferentially forms that make up mirror images continuity- tendency to prefer to see fluid or continuous forms rather than jagged or


 * Closure**- objects that make up a recognizable image are more likely to be perceived as belonging in the same group, even if the image contains gaps that the mind needs to fill in. Tendency to fill in missing information from the perceptual array by closing in gaps. When people see a figure that is disconnected or incomplete, they mentally fill in the gaps and view it as a whole. Similar to top-down processing.

figures- those things that stand out ground- the field against which the figures stand out
 * Figure-Ground Perception**- these relationships characterize most perceptual stimuli. tendency to organize the visual field into objects (figures) that stand apart from surroundings (ground). Often these are reversible. One image can be seen as 2 different things, but not at the same time.
 * Reversible Figures**- either of two figure-ground organizations is possible


 * Law of Pragnanz (Law of Simplicity)**- people perceive things in the simplest way possible


 * Visual Cliff Observation (Eleanor and James Gibson)**- infants old enough to crawl did NOT crawl across the visual cliff. Depth perception develops at about 3 months of age.


 * Depth Cues**- features of the stimulus situation that indicate how far the object is from the observer or from other objects in the world

indistringuishable from a single line. Railroad track lines converge at top of paper to show distance
 * Monocular (Depth) Cues**- clues provided by one eye, used by artistis to suggest depth in their drawings linear perspective- vanishing point- place where 2 lines become


 * Aerial Perspective**- based on observation that atmospheric moisture and dust tend to obscure objects in the distance more than they do nearby objects. Driving in the fog- a far-off building looks more distant than it really is


 * Interposition Cue**- objects that block the view to other objects must be closer; nearby objects sometimes obscure parts of objects that are farther away

changes in clarity, blurring at further distances. We can see details in texture close to us, but not far away. The patterns of distribution of objects appear to grow more dense as distance increases
 * Texture Gradient**- depth cue that enables us to know the more detail or texture we can see in something, the closer it is. The texture of a surface receding in the distance


 * Shadowing**- by looking at shadows, a person can figure where a light source is, and infer depth and position of objects


 * Linear Perspective and Relative Size**- the more distant an object, the smaller its image; produced by apparent converging of parallel lines in the distance


 * Looming**- rapid magnification of a form in the visual field that generally signals an impending impact; as person approaches, his image on the retina gets larger, but the brain knows that the person is not getting larger

objects seem to move faster than faraway ones. A phenomenon where near objects are seen as moving more rapidly and greater distances than far objects when the viewerʼs head is moving. Riding on the T-- see distant objects out the window as moving slowly in the same direction as the train see nearby objects as moving quickly and in the opposite direction to the movement of the train requires motion and cannot be reprsented as a 2-dimensional image
 * Motion Parallax**- difference in the apparent movement of objects at different distances when the observer is in motion. Depth cue that lets us know that closer