3.3 Smell and TASTE

Question 1

smell

Answer 1

impression formation
chemical sense
guides eating behaviour
more close to emotions than others

Question 2

smell stimulus

Answer 2

chemical doors in gas

latest work suggests 4-10 primaries

Question 3

Henning classification

Answer 3

prism classification
simple doors on outside
problem: odors are subjective, and the dimensions in the model are arbitrary

Putrid, fruity, fragrant, spicy, resinous – burnt

Question 4

stereochemical theory of classification

Answer 4

by amour
based on chemical structures

camphoraceous (mothballs) 
pungent (vinegar) 
floral (Roses) 
ethereal (fruity) 
minty (peppermint) 
musty (musk) 
putrid (rott) 

each onerous molecule has specific shape and aligns with specific receptor (not supported by evidence)

Question 5

olfactory system

Answer 5

odours come from nostrils
olfactory epithelium: contains smell receptors

olfactory bulb: actual brain component, where epithelium go

Goes to thalamus, frontal cortex, hypothalamus
and amygdala

connection between motivation, emotion, memory, and smell

Question 6

smell receptors

Answer 6

1 receptor type (humans have 5 million)
each have cilia (location of reception)

DIRECT contact between stimulus and receptors

Question 7

absolute threshold of smell

Answer 7

depends on substance and amount of substance
doesn’t equate identification ability
individual differences exist

ID: results of vocabulary processes, not familiarity

Question 8

difference threshold of smell

Answer 8

20-30 percent (very large) for difference to be noticed

Question 9

adaptation of smell

Answer 9

super quick (within a second) can go lower than detection threshold
only for faint odors

Question 10

taste primaries

Answer 10

sweet, bitter, salty, sour (and maybe umami)

Question 11

receptors of taste:

Answer 11

taste buds (little bumps: papillae) 
types: foliate, village, fungiform, filiform) 
tip of buds are in the pit of the papillae 

humans have 10,000 taste buds that last 10 days `

Question 12

areas of tongue to perceive primary

Answer 12

bitter: roof of mouth
sour: sides of mouth
sweet: tip of mouth
salty: front of mouth

Question 13

taste coding

Answer 13

all receptors react at varying levels

the code is the relative activation of each type

Question 14

taste pathway

Answer 14

mouth - hypothalamus - thalamus - prefrontal cortex - insulation - amygdala

Question 15

thresholds for taste

Answer 15

low sensitivity in salty and sweet, high with bitter
depends on vocabulary as well
difference: 15-25% (salt is adaptive)

Question 16

factors that affect taste and smell

Answer 16

taste-smell interaction = flavour
smell = more door if coloured
taste = red sugar = sweeter

temp = more sensitivity at room temperature