Post Midterm 3 Flashcards

Question

object perception

Answer 1

somatosensory cortex shows cells that respond maximally to orientations and directions of movement selectivity for different features, just like in the visual system spaciotemporal receptive field direction selective etc have basic features but also more complicated

Answer 2

specific reaching and tactile inputs this selectivity is expressed in differetial response in somatosensory cortex to grasping different objects so same graspoing movement but different objects = fifring for one object but not another from a particular single cell

Answer 3

-Center-surround receptive fields • Receptive fields of different sizes • Acuity (as measured with the two-point threshold) varies with location on the body • Sensitive to movement • Selective with respect to edge orientation and direction of motion.

Answer 4

mole system for sensory cortex does not see has a bunch of fingers it uses to see the world around - nasal rays taken notion of having notion of having lots of small and dense receptors sensory substitution thumps table alot = makes image of world around blows bubbles to smell world around him

Answer 5

signals imdending damage to the skin types of nocioceptors respond to heat, chemicals, severe pressure and cold info carried back to nervous system carried by two routes A-delta fibres C-fibres

Answer 6

– A-delta fibers –myelinated, fast conduction times (~20meters/s), sharp initial response to mechanical or thermal input

Answer 7

C-fibers – non-myelinated, slow conduction times (~2meters/s), dull slow response to most mechanical, thermal or chemical input eg sensation of itch - slow buring feeling

Answer 8

thermal - activated by noxious heat/ cold (via different receptors) chemical - selective response to different compounds mechanical - response to excess pressure or to incisions that break skin

Answer 9

``` caused by damage to tissue and joints that releases chemicals that indirectly activate nociorecpetors why legs hurt the day after running why advil (anti inflamatries) work to alleviate pain ```

Answer 10

cause by damage to the central nervous system, such as brain damage caused by stroke, and repetitive movements which cause conditions like capal tunnel syndrome (or disease like diabetes) really hard to treat as can't go in and fix it

Answer 11

– Participants watched a computer game – Then were asked to play with two other “players” who did not exist but were part of the program – The “players” excluded the participant – fMRI data showed increased activity in the anterior cingulate cortex and insular areas when participants reported feeling ignored and distressed = consistent with areas associated with actual pain idea = physical pain of ostracisation like damaging physical pain arguments against solitary confinement

Answer 12

protective - posions, ability to identify foods that were previously associated with bad outcomes more subtle = cant taste salt / sugar because you smkoe or drink = problems with diet on the other extreme, the destruction of taste buds can make life miserable. Following the radiationf for ENT cancers, subjects often report that everything tastes metallic and totaly unappetizing - can contribute to severe weight loss

Answer 13

having a keen sense of smell that is necessary for survival | eg dogs

Answer 14

a less keen sense of smell that is not crucial to survival | eg humans

Answer 15

number of receptors not sensitivity humans = 6-10 million dogs = 300 million to 10 billion also additional adaptations some dogs: Spent air exits through the slits in the sides of dogs’ noses. The exhaled air swirls out to help usher new odors into the dog's nose. University of Oslo in Norway: a hunting dog holding its head high into the wind sniffed in a continuous stream of air for 40 seconds, spanning at least 30 respiratory cycles. in humans, unlike some other animals, olfaction consists of a series of highly discrete "snapshots"

Answer 16

Underarm secretions were collected from 9 donor women • These were wiped on the upper lips of recipient women • Results showed that menstrual synchrony occurred since: – Secretions from the donors taken at the beginning of their cycles led to a shortened length of the recipients’ cycles – Secretions from the ovulatory phase lengthened recipients’ cycles • Pheromones in the secretions led to the changes, even though the women did not report smelling them • Women do not synchronize their menstrual cycle… suggests humans sensitive to pheromones etc... fialure to replicate etc but not managed Yang and Schank, 2006, Human Nature replicated (in large samples) and didn't get these results

Answer 17

forced-choice = two trials are given, one with odorant and one without particiaptn indicates which smells strongest just like with visual / auditory experiments big hose hooked up to nose must be done carefully controlled conc using an olfactometer olfaction follow webers law of approx 11%

Answer 18

methanol = not super sensitive but mercaptin (what they add to gas to know leak) = super sensitive

Answer 19

Humans can discriminate ~trillion odors but they cannot label them accurately. • For example, humans can accurately discriminate their t-shirt from >100 other identical t-shirts worn by other people (Lord and Kasprzak 1989) • This appears to be caused mostly by an inability to retrieve the name from memory, not from a lack of sensitivity. no accurate labelling so no accurate encoding to memory

Answer 20

Good localization when interacting with smells, poor localization when passively perceiving (just above chance to discriminate left/right for most odorants) Sobel insititue, Israel = series of exp. presented odorant on left and right and determine whether came from right or left = we are bad at this, no better than chance =person in body suit so only get odor senses and nothing else, line on grass with oderant. subjects try to sniff through environment using odor alone = humans actually good at it. so when all other sense taken away can rely on it also have to actively engage with info --people can get better at this over subsequent trials

Answer 21

For example, adding color to an odorless solution increased the probability of assigning an odor to the solution (Engen 1972). Coloring a cherry-flavored drink in orange rendered it as having an orange or apricot flavor, and also, coloring the same drink in green rendered it as lime or lemon flavor (Dubose et al. 1980). Even “olfactory experts” are not immune to visual dominance in olfactory decisions: A panel of 54 students of Oenology (wine experts) shifted to assigning red wine descriptors to white wine that was colored with an odorless red (Morrot et al. 2001).

Answer 22

researchers have found it difficult to map perceptual experience onto physical attributes of odors

Answer 23

6 corners with the qualities putrid, ethereal, resinous, spicy, fragrant, and burned – Other odors located in reference to their perceptual relation to the corner qualities – Unfortunately, Henning’s prism has proven of little use in olfactory research. these dimensions are not anchored in reality. we dont know how to quantify the psych space attempt to define analgous space to HSV

Answer 24

no principled means of characterizeding sensory space initial attempts showed difficulties since -some molecules with similar shapes have very different smells some similar smells come from molecules with different shapes

Answer 25

Olfactory mucosa is located at the top of the nasal cavity – Odorants are carried along the mucosa coming in contact with the sensory neurons – Cilia of these neurons contain the receptors that bind with different odorants, triggering action potentials – Humans have about 350 types of receptors – Receptors project to Glomeruli in olfactory bulb – Run through Cribriform plate (bone) - ANOSMIA = shearing of fibres through bone so no receptor relys = no info to glomeruli so no sense of smell

Answer 26

lateral inhibition (like horizontal connections in the retina

Answer 27

mitral and tufted cells

Answer 28

regenerate throughout the lifespan, with new olfactory receptor cells arising from underlying basal (stem) cells. This process likely occurs over a period of weeks. =constant recyling of receptors

Answer 29

in periform cortex prominant structure large bundle of axons right above your eyes

Answer 30

olfactory mucosa is divided into 4 zones -each zone contains many types of receptors -however specific types of receptors in only one zone (eg 1-10 in zone 1, 11-20 in zone 2) specific types of receptor neurons synapse with only one or two glomeruli, so bulb also arranged in zones so olfactory bulb inherits olfactory mucosa structural organisation

Answer 31

so olfactory bulb (containing glomeruli) inherits olfactory mucosa structural organisation so one smell = lots of activity in one spot if given another odorant will have two diff patterns

Answer 32

proposed by Malnic etr al from results of calcium imaging experiments -odorants are coded by combination of olfactory neurons called recognition profiles specific receptors may be part of the code for multiple odorants sort of like a fingerprint for each odorant

Answer 33

activating the olfactory bulb 2DG contains glucose, ingested by animal (rat MRI) mouse is exposed to different chemicals neural activation is measured by amount of radioactivity present this technique is used with behavioural testing shows patterns of neural activation is related to perception diff smell = diff activation same smell = same activation

Answer 34

receptors olfactory bulb primary olfactory cortex (priform cortex) indirect routing through thalamus orbitofrontal cortex (both direct and indirect projections) -two ways into orbitofrontal cortex -purpose of this wiring

Answer 35

very much analogous to olfactory bulb distributed codes smiliarity of activity patterns seems to encode odor identity

Answer 36

``` 10 odorants presented 1 taken away very similar representation 1 added very different representations shows is not one cell for an orange, one for a banana, is a pattern of activation ```

Answer 37

bumps = where taste buds are - circumvallate papillae = big back ones - foliate = side bumps/ ridges - filiform papillae = top - fungiform = top and side

Answer 38

more developed in other animals eg rough cat tongue not taste buds, shaped like cones and located over entire surface - move stuff around (cleaning, circulating salavia etc) usually stay pretty short in humans but can grow = yuck

Answer 39

shaped like mushrooms and found on the sides and tip of your tongue

Answer 40

series of folds on back and sides

Answer 41

shaped like flat mounds in a trench located at the back | found right infront of the tounsils

Answer 42

taste buds are located in papallae - tongue contains 10,000 taste buds - each taste bud (little cilia) has taste cells with tips that extend into taste pore - transduction occurs when chemicals (eg sweet, sour etc) contact the receptors sites on the tips

Answer 43

salty sour sweet bitter umami = meaty, buttery or savoury and associated with MSG sort of forgotten word but not entirely real / based in clear same experience for everyone but better contrar to popular belief, sensations of diff qualities are not strictly localized to specific parts of the tongue

Answer 44

some differential distributions for receptors of diff taste | but very much overlapping

Answer 45

facial nerve glossopharylgeal nerve vagus nerve superfirical petronasal nerve

Answer 46

relays from anterior two thirds of tongue

Answer 47

from back of tongue (circumvillate + folliate)

Answer 48

from mouth anf throat

Answer 49

from soft palate

Answer 50

cranial nerve solitary nucleus of meduall oblongata (brain stem) crosses into contralateral cortex, medial lemniscus (also brain stem) relays to thalamus primary gustatory cortex in insula

Answer 51

taste + smell

Answer 52

reaches olfactory mucosa through retronasal route

Answer 53

MSG related to umami all other flavours perception changes if nose closed / clamped

Answer 54

35% women, 15% man tasters = more taste buds than nontasters tasters have specialised receptors for these compunds supertasters appear more sensistive to bitter substances than tasters can affect diet (dislike bitter veggies) and susceptinility to pain (burning mouth syndrome)

Answer 55

``` whole punch bue food dye on tongue -taste buds dont absord die circle on tongue count number of papilliae (and so number of taste buds) more than 35 = supertaster 15-35 is normal taster ```

Answer 56

distributed coding - similar to olfaction -different taste stimuli were presented to rats and recording were made from the chorda tympani (branch of facial nerve) across-fibre patterns showed that two substances (ammonium chloride and potassium chloride) are similar to each other basically measuring relative activity in each fibre in bundle of nerves carrying info into the brain then -rate trained by shocking them when they drank potassium chloride -when given the choice they owuld hen subsequently avoid ammonium chloride experiment provides physiological and behavioural evidence for distributed coding