Ch 6 Sensation and Perception 09 26 2013 Sensing the world some basic principles Sensation the experience of having your sense organs stimulated having stimulation from outside world reach sense organs Perception interpreting the sensations that are experienced to recognize meaning ful objects and events o Knowing who your best friend is o Can smell coffee Ambiguous images images with multiple interpretations same sensations with different perception cube man with sax woman Prosopagnosia inability to perceive faces even though vision is fine specific to faces who it is o Can see the face and see the properties of it but cannot tell o Sensation without perception o Caused by damage to FFA area of brain with face recognition Bottom up processing analysis beginning with sensory receptors and works up to brain s integration of sensory info o Stimulus driven processing o Image constrains your interpretation Top down processing info processing guided by higher level mental processes experience expectations o Impose them on thing that s put object in front of you o Experience expectation drivem o Both bottom up and top down Thresholds o Psychophysiscs study of relationship between physical characteristics of stimuli and out psychological experiences of them o Absolute threshold minimum stimulation needed to detect particular stimulus 50 of the time o Signal detection If presented with stimulus 100 times will react to it 50 times Signal against background noise Ability to detect that against background noise will be affected by experience expectations motivation and fatigue o Subliminal stimulation Subliminal below your threshold or conscious awareness even though you don t detect it the first time it could effect you later on Priming activation of activations that you re often unaware of that activation can influence later behavior Exposure at time one influences what you do at Activates neurons at time 1 even though you re time two unaware of it o Difference threshold minimum difference a person can detect half of the time o Weber s law its not the amount of difference that matter but the proportion of difference that matters Vary by constant proportion not by constant amount When add a second pen to your hand you notice When add pen to your backpack you don t notice the weight difference the weight difference Sensory adaptation diminishing sensitivity to an unchanging stimulus o If stimulus remains constant you stop noticing it In stinky room get used to it Vision Stimulus input light energy o Transduction transforming one form of energy to another o Wavelengths determine hue Short wavelengths blue Long wavelengths red Higher amplitude brighter Lower amplitude dimmer o Amplitude height of waves determine how bright light is The eye o Pupil hole in eye allows light to enter o Iris muscle that surrounds pupil gives color regulates amount of light allows to enter constricts or expands Emotions drugs ambient light can influence how much light is allowed in your eyes Dim conditions pupils will dilate iris will expand Bright conditions pupils will be smaller iris will constrict o Cornea clear coating over the front of your eye focus the light protective mechanism o lens sits behind the pupil second thing responsible for focusing light o retina back of eye where all the light energy hits photo receptors located here detect light energy start process of transduction o fovea part of retina whatever it is your fixating on that s the image that falls directly on your fovea peripheral vision projected onto outer retina 2 degrees of 180 degree vision nearsighted shape of eye is too elongated image focused in front of fovea farsighted shape of eye is too squished together image focused beyond fovea o cone photoreceptor responsible for color vision work best in adequate lighting conditions help you see things in detail acuity highest concentration is right at fovea as you move out number of cones gets less and less and less o rod photoreceptor shading black and white active in nighttime conditions bigger shapes general shape and size of things more numerous in the periphery in your retina o light hits back of eye first then travels back forward cons rods first hit bipolar cells ganglion cells axons of these cells form together and form your optic nerve then optic nerve leaves to back of eye o blind spot part of eye where optic nerve exits no photoreceptors no senstation blind spot but don t see a black hole because of sensory adaptation each eye sees a little differently brain compiles two different images from each eye and fills the hole o optic chiasm where optic nerves from each eye cross passes through visual area of thalamus to the occipital lobe feature detectors nerve cells neurons that respond maximally to specific features of the stimulus o different types of feature detectors that respond to different types of stimulus shape angle movement o individual cells supercell clusters pick up on patterns in the environment parallel processing brain breaks down color motion form and depth color vision o processing all these aspects simultaneously o the wavelength determines what color hue you see o young helmholtz trichromatic theory have three different kinds of cones in retina red green blue any other colors are formed by combo of those three primary colors said that to see yellow combo of red and green but in some colorblind people they can see yellow and not red or green Cant be right Ch 7 Learning Learning vs innateness 09 26 2013 How do we learn Innate something that comes natural hard wired inside of you walking Learned relatively permanent behavior change due to experience o Riding a bike tying your shoe cooking ect o If don t use the behavior might forget how o And new behaviors might take place of old behaviors Aristototle Associationism when one event occurs so does the other o Contiguity mearness in time and space o Frequency how often two things co occur More often they occur together the stronger the association is going to be Rain and clouds occur more than rain and thunder o Similarity how alike things are Get associated with each other Cats dogs pets domestic animals four legs ect Association developing and understanding that events co occur o If study will get better grades Obeservation learning by someone else and imitating those actions for yourself Associative learning Behaviorism psychology should o Be an objective science if you take two independent observers and have them