February 10 2015 Psychology 202 Lecture Consciousness Sensation and Perception Exam is a week from today O Altered state of consciousness forms of experience that depart from the normal subjective experience of the world and the mind Hypnagogic pre sleep state and Hynopompic waking state Brain shows EEG changes in beta alpha theta and delta waves 5 stages of sleep stage 1 4 and REM REM sleep a stage of sleep characterized by rapid eye movement and a high level of brain activity dreaming occurs most often here body is paralyzed Electrooculograph EOG instrument that measures eye movements Awake Beta Drowsy Relaxed Alpha Stage 1 Theta Stage 2 Sleep spindles K complexes Stage 3 4 Delta REM Fast Random More REM sleep is achieved as sleep progresses after first 4 hours REM occurs more often Sleep and Sleeplessness The Current Scene Video today Americans average about 7 hours of sleep per night nobody is sure what the function of sleep is 42 of American adults don t get the sleep they say they need more than 80 different sleep disorders with the most common being insomnia trying to prove that lack of sleep affects our body as well as our mind look at effects of limited sleep on healthy young men hypertension and weakened immune system DANGEROUS Cephalon drug stimulant medafinil fools hypothalamus into staying awake treat narcolepsy by tricking body clock military is looking into using the drug to keep military pilots awake during combat killer whales can sleep with one side of the brain at a time Sleep is important in the learning process brain helps make connections and store info We need about one hour of sleep for every two awake memories deteriorate unless sleep occurs REM sleep deprivation has the most detrimental effects followed by slow wave sleep Micro sleeps inability to stay awake temporary can be 30 seconds episode of sleep Circadian rhythm naturally occurring 24 25 hour cycle Deactivation of prefrontal cortex during sleep Activation synthesis parts of your brain are just firing in a random way creating a story Hypnosis an altered state of consciousness characterized by suggestibility and the feeling that one s actions are occurring involuntarily the essence of hypnosis is in leading people to expect that certain things will happen that are outside their conscious will susceptibility varies greatly subject agreeableness evidence for pain control supports idea that hypnosis is an altered state of consciousness During hypnosis unique patterns of brain activity PET scan of subjects performing 3 tasks 1 perception heard a sentence 2 imagination imagined hearing something 3hallucination listened as hypnotist suggested sentence was said again Results Right Anterior Cingulate Cortex area involved in attention The area is just as active in participants hallucination and those actually hearing the sentence this is not found in people who are not highly hypnotizable Intro to Sensation and Perception Sensation and perception are related but different Sensation simple stimulation of a sense organ Perception interpretation of a sensation in order to form a mental representation Transduction what takes place when many sensors in the body convert physical signals from the environment into encoded neural signals sent to the central nervous system Basic processes of sensation 1 modification via accessory structure example ears lens of eyes 2 transduction 3 encoding 4 representation in cortex Transduction is converting energy in neural activity occurs at sensory receptors which respond especially to CHANGES in stimulus intensity Coding making sense of neural activity Thalamus is relay station for sensory information except smell Light cornea pupil lens retina photo transduction 2 types of photoreceptor cells in the retina contain light sensitive pignments that transduce light into neural impulses Cones detect color operate under normal daylight conditions and allow us to focus on fine detail Fovea an area of the retina where vision is the clearest and there are no rods at all only cones Rods become active under low light conditions for night vision Stars We have a blind spot within our eye Transduction structure and encoding structures Bundle of axons nerve Retina main transduction area Blue man group video Red green blue recognized by cones Proximal stimulus what is represented on the retina Distal stimulus what happens in the environment Perception involves construction of the world which involved selection of sensory input organization of sensory input and interpretation of sensory input Perceptual construction is influenced by attitudes preferences and social situational contexts of perception i e what I see is influenced by what I expect to see Eye witness testimony in the legal system unreliable fake robbery and ask people what did you see everyone sees different things Change blindness Curious Psychology 1 video they kept changing clothes changed the tablecloth and changed the curtain Visual attention video There s a Gorilla on the basketball Court
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