Flashcards
Sensory systems L3
Cards in this deck (50)
- 1what is comparative neuroscienceusing how the brain works in models and how it goes wrong to imply how brain may work in humans
- 2what are mechanoreceptorsa sense organ or cell that responds to mechanical stimuli such as touch
- 3where can mechanoreceptors be foundthe skin (and ears)
- 4T or F: the retina is part of the PNSF its part of the CNS
- 5sensors for which senses are in the CNSVision
- 6Sensors for which senses are in the PNSall scenes but vision
- 7T or F: the retina evolves from the same tissue in the embryo as what creates the rest of the CNST
- 8what part of the retina has the most cone visual receptorsthe fovea
- 9the optic nerve leaves the eye at the (3 names)optic disk, blind spot, optic nerve head
- 10the area of the eye that provides the sharpest vision is?the fovea
- 11the centre of the retina is?the fovea
- 12why is the optic disk also called the blind spothear the nerves are so tightly wrapped together they leave no room for photoreceptors as such no light detection can occur at this point ant therefore the area can be classed as blind
- 13what is the major source of synaptic input into the LGNthe striate cortex
- 14what is the LGN? and what does LGN stand forlateral geniculate nucleus is the visual relay nucleus of the thalamus
- 15what is the striate cortexthe part of the occipital cortex that receives the fibers of the optic radiation from the lateral geniculate body and is the primary receptive area for vision
- 16what are the functions of the striate cortex (3)1. tells you where to look
2. focuses attention
3. filters out unnecessary information - 17if an axon originates from the same side as the side of the brain it goes into (e.g. out the left eye into left side of brain) it is calledipsilateral
- 18if an axon originates from the opposite side as the side of the brain it goes into (e.g. out the left eye into right side of brain) it is calledcontilateral
- 19higher pitch means the sound waves arehigher frequency
- 20early on the auditory becomes bilateral. what is meant by thisthat there are inputs from each side to both side of brain. i.e. the right ear innervates the auditory centres in both the right and left hemisphere same for left ear
- 21why is the fact the auditory system is bilateral helpfulunilateral lesions don't cause deafness in either ear (and bilateral lesions at same points are less common)
- 22what is: aphasiageneral defect in communication/speaking
- 23what is anomiathe inability to find words for something
- 24name two regions of the brain better adapted to locate sounds then to hear its pitchsuper parietal
superior frontal gyrus - 25name two regions of the brain better adapted to hear pitch than to localise soundauditory cortex
inferior frontal gyrus - 26action potentials were first discovered in which neuronssquids giant axon
- 27what are Russell and birches 3 Rs1. Replacement: all possible alternatives must be considered first
2. reduction: minimise the number of animals involved
3. refinement: eliminate or minimise pain and distress to the animal - 28T or F: we are still finding new neurological conditions at a notable paset
- 29how much does alzheimers cost the US a yearroughly 100 billion dollars
- 30name two invasive methods used in neurological studies, and outline each1. neuronal electrophysiology: using electrodes to directly measure electrical activity from a bunch of neurons
2. optical imaging: using voltage sensitive dyes thats injected into the neurons and changes colour when the neuron becomes excited - 31name 3 non-invasive neurological study technies1. phycophysics
functional imaging
3. structural imaging - 32what is a CAT scan'computerized axial tomography. its the same thing as a CT
- 33what is psychophysicsPsychophysics quantitatively investigates the relationship between physical stimuli and the sensations and perceptions they produce.
- 34the first recorded use of psychophysics was when? by who? title of paper?1860
GT fletcher
elementa der psychopysik - 35what is absolute sensory thresholdthe smallest amount of stimulus energy needed to produce a sensation
- 36absolute sensory threshold for light test. outlinesit someone in a pitch dark room and flash lights at people. these lights will be at varied levels of brightness (stimulus level). after each flash ask the person if they saw it. from this data create a curve where you plot the brightness against the percentage of the times that brightness was flashed the individual saw the brightness
- 37for a stimulus threshold test what sort of graph would you expect to prodyuce? draw it for a light example
- 38at what point is absolute sensory threshold placed? why?the stimulus level where the person perceived it 50% of the time. this accounts for random chance (say they were guessing ach time 50% of the time they would get it right you would expect)
- 39what is sensory difference threshold? use an example to explainthe difference required between two stimuli to detect a difference. e.g. how different (In brightness do two light flashes have to be before someone can say yes they are different)
- 40what is webers law (hint its a formula)ΔI/I=C
where ΔI is intensity difference
I is intesnity - 41what is the meaning of webers lawthat the difference required to determine between two stimuli depends on the intensity of those two stimuli. like we can discern between our tv screen and phone screen easily but at already exceptionally bright levels that difference would mean nothing
- 42what is fechners lawS=k(log(I))
where S is sensation
k is a constant - 43what is k in fechners lawweber constant
- 44sensation and stimulus intensity relate in a what manner ? meaning doubling the stimulus intensity ......logarithmic
does not double the sensation felt
hence a 60W light bulb does not feel twice as bright as a 30W - 45draw a stimulus intensity (X) vs sensation (y) felt graph
- 46contrast =brightness(max)-brightness(min)/ brightness(max)+brightness(min)
- 47when does webers law failat really low intensity signal
- 48functional brain scans? (6)fMRI, PET, MEG, SPECT, EEG, fNIR
- 49depression is expected to be how prevalent by 2020second largest disease burden
- 50animal welfare vs animal rightswelfare is just being as nice as possible to the animal don't cause it undue discomfort, rights is more about putting it on equal footing with humans