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72 Cards in this Set
- Front
- Back
Sensation
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the chain of biochemical and neurological events that begins with the impinging of a stimulus upon the receptor cells of a sensory organ.
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perception
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the mental state that entails symbolic representation of the external world
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qualia
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basic perceptual symbols such as 'red', 'hot', 'smooth', 'loud'.
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the law of specific nerve energies
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this term expresses the fact that we are aware only of the activity of our nervous systems. For this reason, what matters is which nerves are stimulated, not how they are stimulated.
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mind-body problem
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the nature of perception
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dualism
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idea that mental states are non-physical substances interacting with the physical brain
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materialism
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idea that mental states are physical, emerging from the brain activity as a whole.
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Finding neural correlates of perception is hard, but...
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...understanding why we need perception at all is even harder,
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the two basic schemes of information processing
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the basic schemes of <this> are bottom up and top down (knowledge based)
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All the senses (9)
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sight, hearing, touch, taste, smell, temperature, pain, balance, body sense
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sensory receptor
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a structure that recognizes a stimulus in the internal or external environment of an organism
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sensory transduction
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initiated by sensory receptor in response to stimuli, creates action potentials in the same cell or an adjacent one
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G protein-coupled receptors
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a family or protein receptors that transduce and extracellular signal into an intracellular signal by means of G protein activation
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neuron
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main cells in the nervous system, they process and transmit information
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soma
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cell body of a neuron
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axon
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transport output lane of a neuron
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denritic tree (dendrites)
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where a neuron receives inputs
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action potential
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electrical signal spike generated and propagated by neurons
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graded potential
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smooth sloped electric signal generated by neurons
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nerve impulses
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electrochemical; voltages change along axon as electrically charged ions (sodium and potassium) pass in and out of the membranes of nerve cells
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neurotransmitters
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molecules that cross the synapse from the axon of one neuron to the dendrite of the next.
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human brain
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main part of central nervous system, controls lower (heart) and higher (thought) activities.
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cerebrum
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contains cerebral cortex, lots of the forebrain. Does movement, sensory processing, learning, memory, language.
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cerebral cortex
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outermost layer of cerebral cortex, contains sensory processing area (among others)
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cerebellum
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small circle brain thing in the back, mostly motor control
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thalamus
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relays sensation, spatial sense, and motor signals to cerebral cortext
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brain stem
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all information going to brain passes through brain stem. contains sensation carrying pathways.
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corpos callosum
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connects the two brain cortexes
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gray matter
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neurons (10%) and supporting glia cells (90%)
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white matter
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neuronal projections (axons) which interconnect neurons
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cranial nerves
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12 pairs of paths(left &right) which transmit sensory information
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PET
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positron emission tomography
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MRI
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functional magnetic resonance imaging
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EEG/MEG
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elelectro/magnetic encephalogram
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Fechner
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founder of psychophysics. discovered relationship of psychological sensation and the physical intensity of a stimulus via the formula: "S = K Log I". also developed threshold measurements, reaction time measurements, and magnitude estimation
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threshold measurement
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measuring the minimum detectable stimulus change.
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magnitude estimation
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people are asked to assign numbers in proportion to the magnitude of the stimulus
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somatosensory system
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the neural system connected to skin receptors that senses touch, temperature, pain, proprioception
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Meissner Corpuscle
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transient local stimulation
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Pacinian corpuscle
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transient global stimulation
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merkel disks
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sense steady pressure of a small object
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ruffini endings
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sense steady pressure and stretching
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somatosensory cortex
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receives different signals from receptors via nerves (different nerves for different receptors). Located in parietal lobe
Hands, face, and lips have the most material dedicated to them in the somato-cortex |
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homunculus
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little representation of human (can be used to demonstrate how much of the brain is dedicated to sensing stimuli on different areas)
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receptive field
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the area of skin that excites a touch receptor.Neurons in the somatosensory cortex have center-surround receptive fields: excitatory center, inhibitory surround, or vice versa.
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vibrotactile stimulation
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measures sensitivity for touch, which is highest for lips, and lowest for soles of feet
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touch spacial acuity
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can be measured by two point threshold test(highest for index fingers, lowest for calves)
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phantom limb pain
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50-80% of amputees suffer from it, which demonstrates the perceptual nature of touch. Explained by an incomplete cortical reorganization following amputation
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anticipatory inhibition mechanism
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explains how we distinguish events in the environment from self-induced events. tickling sensation occurs when the touch simulation was not anticipated
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olfaction
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smelling, one of the two chemical senses (other is tatste)
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olfactory epithelium
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specialized tissue inside nasal cavity containing 10 million olfactory sensory neurons
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olfactory sensory neuron
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cell inside nose regenerated every 40 days from basal stem cells. Contain olfactory receptors. Sends signal to olfactory bulb
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olfactory receptor
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g protein-coupled receptor, there are as many as a 1000 different olfactory receptors.
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theories of olfaction:
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molecular shape theory: (lock and key)
molecular vibrations theory: vibration of an oderant determines smell |
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olfactory bulb
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receives signal from OSN (olfactory sensory neuron). Enhances sensitivity and discrimination of odor detection. Projects to olfactory cortex.
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distributed coding (olfaction)
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belief that neurons in the olfactory cortex identify odors as activity patterns distributed across many OSNs.
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olfactory sensitivity
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varies from odor to odor, some are easily discriminated, others are hard to recognize even if they are familiar odors.
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odors become associated with...
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...events and can serve as potent memory cues. They also affect emotional state.
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familiar odors also seem more...
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...pleasant. Pleasant odors seem more familiar.
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n cordon
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A cordon is a line or ring of police, soldiers, or vehicles preventing people from entering or leaving an area.
Police formed a cordon between the two crowds. |
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the last line of defense for preventing unwanted chemicals from entering the body.
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taste
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papillae
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bumpy structures on tongue
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taste buds
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found on the papillae and roof of the mouth which contain taste receptor cells.
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fungiform papillae
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front of the tongue
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foliate papillae
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rear edges of the tongue
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circumvallate papillae
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rear center of the tongue
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supertaster
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person with more than normal number of fungiform papillae, very sensitive to bitter foods.
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taste receptor cell
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contains microvilli studded with taste receptors, supporting cells, and basal stem cells, which regenerate every 10 days.
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where do taste signals go?
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ipsilateral (no crossover) - brainstem, thalamas, gustatory cortex
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what taste are humans most sensitive to?
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bitter (poisons are bitter)
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emotional response to taste is wired...
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at a subcortical level (low level)
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adaptation
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pleasure reversal effect occurs.
in tasting, sweet/salty foods create a sour/bitter aftertaste. |