June 26, 2004 Sensation, and Perception (Don't worry about Tongue) Nose: Ol-factory bulbs Smell is a very salient cue to location etc... One of the primary things your sensory systems do is adapt to sensation that is not changing. Ex: Smells strong at first then weaker later on. If odor level remains the same we start to not notice it as much. Touch: its perceieved by pansinian corpusuls - they are neurons that come and end near the skin. Should a finger or some other object touch the skin the bending of the membrane around the corpusuls causes an opening in sodium channels - action potentials. Ex: Sock chart... Pressure I Wearing your sock. on on I .________._ Foot I .I. .I. I .I . .I . # of I .I . .I . Neuron I.....I . .I ...... firings off I_____I ....I_________ I_________________________ Time The feeling of having the sock on goes away after a short period of time. Also the nerve impulses of off and on are the same so it is the perception that tells us which it is. Perception if different than sensation: Adaptation. Pain - Is perceived by free nerve endings in the skin. Form synapses in spinal cord. Where they release "substance p" in the spinal cord. Whenever p is present in the spinal cord; you perceive pain in a location that is localized in the area of stimulus. Dermatones - areas of skin projecting to different parts of the spinal cord. Ex: Shingles Pain can be gates = Ex: Natural childbirth, runners, flaming monk, fire walker. Endorphins can be resonsible for this - the release of these blocks the release of substance "p." Ex: perception= no pain ; sensation = bulletwound Endogenous Opiates: made inside the body. States of Consciousness. The holy grail for psych. In the last 20 yrs. theories as to what consciousness is have been generated. They are best described as difficult to prove experimentaly. Consciousness working definition -- Aware of outside world. Enebriation -- Degraded form of consciousness? Problem with consciousness: we all agree we have it; its hard to define and decide what it is and who does and doesn't have it. Ex: Wife's Uncle Vs. Great Ape. Good research suggests repressed memory is manipulated by the individuals. A good way to look at states of consciousness is SLEEP You will die if you don't get enough sleep -- we don't know why. Sleep Stages... The one where your body is least active; the brain is the most active. Cercadium Rhythm; Natural fluctuations of some even across time. Ex: Sleeping; Eating; Body Temp. Ex: Sleeping in a dark room for extended periods of time will throw rythms off of natural cycle. External stimuli resets cercadium rythm; sun helps for sleep. Superchiosmatic Nucleus - processes cercadium rythm. Ex: Two breeds of hamsters have a rythm that is different by 4 hours. if the S.N. of the 20 hr. Breed is put into the location of the 24 hr. breed the 24 will become the 20. P. 229 EEGs - sumated electrical current across the head. Awake individual - EEG is generally flat (THe avergae of all the waves indicates the brain is doing different things.) Frequency and Amplitude are characteristics. Amplitude: High - brain doing same things; Low - brain doing different things Frequency: HIgh - lots of activity; Low - low activity Close your eyes on the couch.... Sleep Stages Stage 1 of sleep lasts about 10 minutes... - You are dancing along the lines of sleep. - You can respond to other people and certain situations - Alpha waves begin to add theta wave. - Activity in the brain is becoming more synchronized. Stage 2 sleep... - Much deeper sleep - sleep spindles can occur; three at a time is a K Complex - Dras less active; Dris more active - they fight for control - K complexes can wake you up. Stage 3 sleep... - Biggest difference is no more K complex - lower freq. high amplitude Stage 4 sleep... - lower freq. still; higher amplitude Stage 5 sleep... R.E.M. Sleep - Rem episodes occur here. - Dreams occur in this stage. - EEG - highest freq, lowest amp - The brain paterns look like someone is awake. - Its actually the deepest sleep. - Dris has won out over Dras. R.E.M Rapid Eye Movement - Eye is moving like crazy. If you R.E.M. deprive an animal it will die. If you wake an animal before R.E.M. a large amount. It will go straight into R.E.M. sleep upon subsequent sleeping trials. Studies also show impaired learning by animals deprived of REM sleep. The study was executed by putting an animal on an "island" in the middle of a kiddy pool when the animal hit REM sleep it would fall into the pool waking it self up. The control animal was woken up as well but not during REM sleep to make the control equal. Sleep Disorders... Insomnia - Wake up alot; or can't go to sleep. Apnia - can't breath during sleep Sleep Paralysis - can't move for first seconds while waking up. --- Almost to REM sleep and wake up; the DRIS shuts down too slowly --- and DRAS has to kick (it takes a couple seconds.) Dreams, NightMares - We all know about these Night Terrors - in REM sleep that is bad; you "wake up" but dream continues. Short term sleep deprivation - is one of the best immediate depression remedies. Pharmacology - drugs will often inhibit REM sleep. R.E.M. rebound - making up for R.E.M. missed for whatever reason. Don't forget exam on WEDS!!