Ap Psych Notes (Unit 4) PDF

Ap Psych Notes (Unit 4) Sensation What is the difference between sensation and perception? - Sensation: process of our sensory receptors receive information from stimuli - Perception: the process that organizes those sensory images into meaningful images What is the difference between bottom...

Ap Psych Notes (Unit 4) Sensation What is the difference between sensation and perception? - Sensation: process of our sensory receptors receive information from stimuli - Perception: the process that organizes those sensory images into meaningful images What is the difference between bottom up and top down processing? Give an example of each Top Down (Schema driven)- we use past experience and expectations to process ad scenario Bottom Up (Data driven)- focus on sensory analysis of smaller elements of a figure to understand what it is Thresholds What is Psychophysics and how do they relate to sensation? - Psychophysics is the study of how the intensity of a stimulus relates to the experience of that stimulus What is absolute threshold? - The minimum stimulation necessary to detect a sensation 50 percent of the time Why fifty percent? - Takes into account individual sensitivity and interference What is signal detection theory and what role does iti play in perception? - Signal detection theory predicts how and when we detect the presence of a faint stimulus amidst noise (based on experience, motivation, expectation) What might influence our ability to detect a stimulus? - Our motivation and our expectations (response criteria) - False positive: when we think we see something that is not there - False negative; when we fail to see something that is there Difference Thresholds How does difference threshold affect perception? - The minimum difference between two stimuli required for detection 50 percent of the time (just noticeable difference) Weber’s Law: the principle that to be perceived as different, two stimuli by a constant minimum percentage (not an amount) Why does Weber’s Law use percentages not a constant amount? Subliminal Messages What is a subliminal message? - Anything that occurs below the threshold of conscious awareness but influences behavior Why do many people not believe in the power of subliminal messages?  - How can something influence our behavior if we do not know it exists What psychological phenomenon shows that subliminal messages can work? - Priming is when something briefly flashed on a screen can impact our perceptions to a later question - We process things around us all the time automatically and without thinking Greenwald (1991) preformed an experiment which showed that subliminal effect was very minimal and in fact the placebo effect was behind the actions Sensory Adaption Explain the principle of sensory adaptation? - Ability for the senses to adjust to an unchanging stimulus over time Explain what is shown in the above illustration? - Our eyes always move but with this divide the eye remains still the result is that images fade into fragments - Interestingly our mind attempts to creature meaning out of the fragments - Explains times our mind plays tricks on us Vision What does transduction mean? - The process in which our body converts stimulus energies into neural messages What are the elements that dictate the colors we see? Wavelength- this is the distance from one peak to the next and this determines hue (the color we see) Amplitude- is the height of the wave, this determines the intensity (brightness) based on the amount of energy Frequency- is the amount of times compete wavelengths pass by a point in a given time - Shorter the wavelength the higher the frequency What are the roles for the different parts of the eye? Cornea: outermost layer of the eye that protects it from particles Pupil: adjustable opening in the center of the eye through which light enters (construction/dilation) Iris: a ring of muscle tissue that forms the colored portion of the eye around the pupil, controls size of pupil opening Lens: adjustable opening that changes shape to help focus image Retina: light sensitive inner surface of the eye that contains the receptors Visual Distortions What is the difference between nearsightedness and farsightedness? Nearsightedness: inability for the eye to focus on objects that are far away from the eye because the image is focused on the entire retina Farsightedness: light rays from nearby images come into focus behind the retina Astigmatism: cornea is abnormally curved causing the image to be blurry when it reaches the retina Cataracts: One or both lenses often become cloudy as one ages. Does eye color matter? 20/20 vision If you have 20/20 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 How light triggers vision 1) Light triggers a photochemical reaction in the rods and cones 2) The rods and cones activate the bipolar cells in a chemical reaction 3) Bipolar cells trigger ganglion cells 4) Ganglion cells send a message via the optic nerve 5) The optic nerve sends the message to the thalamus 6) The thalamus sends the massage to the occipital lobe What is the difference between rods and cones? Rods Cones (color, center) 120 million 6 million Located in the periphery of the retina Located in the center of the retina Highly sensitive in low light Low sensitivity in dim light Cannot see color or detail but see motion Sees color and detail What is a blind spot? - The location on the retina where there are no receptors - Place where optic nerve leaves retina for thalamus Nocturnal animals would have more rods or cones? Why? - Rods because they are more sensitive in lower light levels When we enter a dark room our pupils dilate, Why? - They adjust to let more light in Explain accommodation - The process by which the lens changes shape to focus images on the retina Dashboard lights are red for a reason, rods don’t see Red!!! Foveal Vision- used for reading or driving - No rods, all cones Feature Detection Hubel and Wiesel (1979): found that visual cortex has feature detector neurons which responds only to specific features in a scene Lateral Inhibition- the excitation of one neuron leads to shutting down of neighboring neurons Parallel Processing Explain parallel processing and compare it to serial processing? - Parallel processing allows our brain to do several things at once, while serial processing does things in a step by step fashion (computer) - This is done automatically an even for people with disorders who might not think they can see certain things Color vision - We see color due to reflection - A tomato is red because absorbs every color but red - The world is not colored, our brain creates color How does the Young-Helmholtz Trichromatic theory explain color vision? - Our brians have receptors for three colors (red, green and blue) - Leave question as to how we see yellow as pure color? - Or how do RG colors blinded people see yellow Young Helmholtz Theory- Addictive Color Mixing - Missing lights is addictive because wavelengths from each light add to each other Explain the opponent-process theory? - Explains that we see color in terms of opposing retinal processes (red-green, yellow-blue, white-black) Subjective Colors- sometimes when our brain sees black and white moving lines colors are seen that are not really there - These patterns mimic the temporal stipulation we get when viewing color so our brain creates the illusion of color even though its not there Why does our own voice sound different when we hear it on tape recorder?  - When we speak we hear sound conducted by air waves to the outer ear and those carried directly to auditory nerve (bone conduction) - When we use a tape recorder we only use sound waves conducted by the outer ear Audition - Loudness of sound is determined by a sound waves amplitude or strength - The pitch (tone) is determined by the frequency - High pitched tones have high frequencies and short waves - A decibel is used to measure sound energy - Our auditory system is far moe sensitive than our visual system Why are some sounds pleasant and some irritating? How the Ear Works What are the three regions of the ear? - Outer ear, middle ear, inner ear How do they work to convert sound waves into neural activity? - Sound is funneled into the middle ear from the outer year - The middle ear amplifies sounds and sends it to the inner ear - Hair cells in the inner ear move which sends messages to brain Middle Ear- chamber between eardrum and cochlea which contains the hammer, anvil, and stirrup; responsible for concentration the vibration into cochlea Cochlea- a coiled fluid filled tube in the inner ear Hair cells- line the basilar membrane and are used to detect movement Theories on Pitch Detection Identify and describe the two theories on how we perceive pitch? Place theory- we hear different pitches based on the place where the cochlea’s membrane is stimulated Frequency Theory- the sound wave traveling up the auditory nerve matches the frequency of the tone - Since individual neurons can only fire at 1000 times per second alternative firing between cells accounted for frequences above 1000 (volley principle) - Best explaining low pitched sounds Which do you think is the most likely explanation? Why? - Vesicular membrane doesn’t localize low pitched sounds Hearing Loss What is the difference between conduction hearing loss and Sensorineural hearing loss?  - Conduction- refers to the damage to the eardrum or bones in the middle ear which impact our ears ability to conduct vibrations - Occurs when eardrum is punctured or bone are damaged - Sensorineural results from mange to the hair receptors or auditory nerves - Occurs from prolonged loud music, aging or genetics - Elderly people often struggle to hear high pitched sounds due to nerve degeneration in the beginning of the basilar membrane Which theory of pitch detection does this support? Place theory - A hearing aid is a device that can amplify the vibrations of the frequencies hardest to hear in the person (sensorineural) - Deaf people can still hear sound through bone conduction Cochlear Implants What is a cochlear implant? - An electronic device that converts sounds into electrical signals and then triggers the auditory nerve Which biological area is the cochlear implant replacing? - Hair cells Why would there be resistance to the use of this device? How might the age of the onset of deafness impact one’s feelings on cochlear implants? Sensory Compensation (“super senses”) How do we use other senes to perceive the world around us? Touch What four senes can our skin detect? - Warmth - Cold - Pain - Pressure Rubber Hand Illusion- sensation of touch is a top-down process based on expectation - Soccer leg break What is phantom sensations and what is the theory behind it? - When the brain interprets pain in the absence of normal sensory input - People that are blind and deaf report seeing and hearing - We sense the world with our brain even without working senses - Capgras syndrome What is Gate Control Theory? - Spinal cord contains an neurological gate that blocks plain signals from reaching the brain  - Pain is exhibited in many ways (warmth, cold, sharp, etc…) Taste Like touch, taste has several different sensations. What are the different sensations? - Sweet which detects sugar - Satly which detects sodium - Sourness detects acidity - Umami detects meaty and savory flavors - Bitter detects sharp, unpleasant flavors Why are the senses detecting specific flavors so important? - Umami, sweet and salty are all appealing flavors which tell us to eat more - Bitter and sour foods are aversive and they warn us against harmful foods Lollipop Taste Demonstration (no vision, no smell, no vision/smell, all senses) Sensory interaction- the idea that senses sometimes combine to provide sensations (Rubber Hand Illusion) Synesthesia- rare case when senses become joined McGurk effect- when our bain blends what it hears and seeds (sight overrides sound) Smell When smell is referred to as a chemical sense what does that mean? - Like taste, olfactory receptors are triggered by scent molecules - Smell cannot be separated into categories nor is there a part of the olfactory system like the retina How do we know that there is a connection between odors and emotions/memories? - Women are shown to have a stronger sense of smell when identifying gender (hands, breath, t-shirt) Pheromones: chemical smells released from the nose to attract the opposite sex Body Position and Movement What sense allows us to recognize our body position in the world? Kinesthesis- the system which sense the position and movement of individual body parts What other sense makes kinesthesis possible? - Vision, think about how much harder it would be to walk in a straight line with your eyes closed What is the vestibular sense? - This allows our body to detect head positions and movement How does the vestibular sense work? - Inside our ears the semicircular canals contain fluid which moves when our head moves - The movement triggers receptors which send a message to our cerebellum to adjust for movement and maintain balance Explain the feeling of dizziness after spinning in a circle? - The fluid in your semicircular canals has not stopped moving tricking your brain into feeling movement even after you stopped spinning - Nausea and poor balance What is the difference between sensation and perception? - Sensation: a bottom up process in which we detect energy from the environment and encode them into neural messages - Perception: a top down process in which we select, organize, and interpret our sensations Selective Attention - At any given moment our consciousness focuses on a limited aspect of what we experience (necker cube) - Our vibe senses take 11,000,000 bits of info per second but we only consciously process 40 What is the cocktail party effect? - Wen at a party you can attend to only one voice among many - Will automatically respond to your name What is the theory of inattentional blindness? - When our mind famils to see visible objects when our attention is diverted elsewhere Change Blindness and Deafness: two principles that relate to inattentional blindness - When focusing on a stimulus sometimes we do not notice changes in sound or appearance Motion perception - We perceive motion, even when its not there, based on two assumptions - Shrinking objects are retreating and enlarging objects are nearing - Large objects appear to move slower than smaller objects at the same speed Phi Phenomenon- illusion of movement when two or more adjacent lights blink on and off in succession (christmas lights) - Think of the way movies work by flashing several still pictures each second our mind sees motion that is not really there Grouping- we organize like stimuli together into coherent groups - Proximity- we group nearby figures together - Similarity- we group together figures that are similar to each other - Continuity- we perceive smooth continuous patterns rather than discontinuous ones - Connectedness- we link connected, uniform figures - Closure- our mind fills the gap to create complete objects Depth Perception- the ability to see objects in three dimensions even though the object might be two dimensional (allows us to judge distance) - Visual cliff experiment- most babies would not walk across glass indicating they had depth perception Binocular cues- these are depth cues that rely on the use of two eyes - Retinal disparity- the difference in images the two eyes see because of their distance (how 3-d works) Monocular cues- depth cues that are available to either eye alone - Relative size- if objects are the same size the one that is smaller is father away - Interposition- if one objects blocks the view of another we see it as closer - Relative clarity- because light must pas through the atmosphere clear objects are closer and hazy ones further away - Texture gradient- objects father away appear less detailed, smaller and denser - Relative height- we perceive objects higher in our field of vision as further way - Since lower objects are perceived as closer we perceive them as the figure - Relative motion (motion parallax)- as we move objects that appear stable seem to move - Objects beyond the fixation point appear to move forward and further objects are faster - Linear perspective- parallel lines appear to converge in the distance - Light and shadow- nearby objects reflect more light (assume light comes from above) Perceptual consistency- we perceive objects as unchanging despite changes in retinal images and illumination Size Consistency- principle that allows us to perceive the size of an object no matter the distance or angel How do disabilities and human factors influence perception - Studies showed color vision and ability to distinguish figure ground is innate - We are born with depth perception but learn to link size of girls with distance - Some believe sensation is innate and we learn to perceive the world Restored vision - When vision is restored to formerly blind people facial recognition is done in a very different manner - we top down process faces as people we know  - Those with restored vision look for distinct features to detect a face - Sensory deprivation for a short period does no permanent harm if it occurs later in life - If you derive the sense during an infant’s critical period you can permanently damage them Why does this make sense? - Without stimulation during the critical period the rain does not make the proper neural connections Why do some people struggle living with restored vision later in life? - Area of brain that was devoted to vision has taken on new roles - Difficult to transition life when used to being blind Perceptual adaptation Explain the idea of perceptual adaptation - When our visual input is changed by corrective lenses or another device our brain can adapt rather quickly When our vision is distorted our brains readjust to view the world the way it was before the change? - No. We just adapted our body movements based on the experience we had with these goggles What practical importance might this have in modern medicine? - Depending on when the vision impairment occurs certain visual perceptual cues might not be restored or recovered Perceptual set What is a schema? - A concept or framework that organizes/interprets information What is a perceptual set? - A mental predisposition to perceive one thing over another - They can be visual or auditory Give an example of a perceptual set? What impacts our perceptual set? - The context in which it was given - Also when contrasted with something else the perception might change (college letter) Give an example of how perceptions can differ based on the context? - Context effects - Violinist in the metro