February 10, 2015 Psychology 202 LectureConsciousness 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 andweakened 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 feelingthat one’s actions are occurring involuntarily; the essence of hypnosis is in leading peopleto 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); 3-hallucination (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- Tr ansduction: 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)- Lightcorneapupillensretina (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]
View Full Document