Chapter 14-olfaction

Question 1

Odor

Answer 1

The translation of a chemical stimulus into a smell sensation

Question 2

Odorant

Answer 2

A molecule that is defined by its physiochemical characteristics, which are capable of being translated by the nervous system into the perception of smell; physical thing you smell

Question 3

In order to be smelled, odorants must b

Answer 3

Volatile, small, hydrophobic

Question 4

Human olfactory apparatus contains

Answer 4

Olfactory clefts and olfactory epithelium

Question 5

Olfactory cleft

Answer 5

Narrow space at the back of the nose into which air flows

Question 6

Olfactory epithelium

Answer 6

Mucous membrane in the human nose whose primary function is to detect odorants

Question 7

Primary function of the nose

Answer 7

Breathe; filter, warm and humidify air that you breathe

Question 8

Odor receptors sites are located where

Answer 8

On the cilia of olfactory sensory neurons where odorant molecules bind

Question 9

Odor receptors are what kind of receptors

Answer 9

Chemoreceptors; receptive sites bind with molecules

Question 10

Mitral cells receive projections from how many and what type of receptors

Answer 10

About 200, same type of receptor; convergent, lose spatial information

Question 11

How many different receptor types are ther

Answer 11

About 1000, respond to distinct chemical molecules or parts of molecules

Question 12

How many molecules are needed to activate odor receptors

Answer 12

7-8

Question 13

Humans have how many receptors

Answer 13

6 million

Question 14

Olfactory pathway

Answer 14

Olfactory bulb, Piriform cortex, entorhinal cortex, limbic system, orbitofrontal

Question 15

Olfactory bulb

Answer 15

Olfactory info first processed here, 1 in each hemisphere that corresponds ipsilaterally to each nostril

Question 16

Primary olfactory cortex also known as

Answer 16

Piriform cortex

Question 17

Entorhinal cortex

Answer 17

Old, sensory association area, connect to the limbic system

Question 18

Limbic system

Answer 18

Emotion (fear) and memory, base survival learning

Question 19

Orbitofrontal cortex

Answer 19

Conscious perception and hedonics (liking)

Question 20

Shape pattern theory

Answer 20

Dominant biochemical theory for how chemicals come to be perceived as specific odors. Contends that different scents-as a function of odorant-shape to OR shape fit-activate different arrays of olfactory receptors in the olfactory epithelium. Population coding

Question 21

Population coding

Answer 21

Part of shape pattern theory; the various arrays produce specific firing patterns of neurons in the olfactory bulb, which then determine the scent we perceive

Question 22

Shape of odor molecule

Answer 22

Physical molecule

Question 23

Pattern of odor molecule

Answer 23

Which scent of odor receptor and to what degree, combination processing

Question 24

Chemical aromas

Answer 24

Smell odors that are not physically present; activate odor receptors, smell is an epiphenomenon (not directly representing physical world)

Question 25

How does population coding work

Answer 25

Odorants have different physical shapes that matter the most, and different colors (content) that also matter; receptors are selective to the shape and content of odorants

Question 26

Stereoisomers

Answer 26

Similar chemical compound but a different shape; result in different perceptual states-shape matters

Question 27

Odorant and receptor table: a given odorant will excite several receptors due to what

Answer 27

Its chemical composition

Question 28

Odorant and receptor table: a given receptor will respond to several odors, but the ___ of activity represents the composition of any given odor

Answer 28

Pattern

Question 29

Intensity

Answer 29

Certain receptors are more sensitive to aspects; can influence which receptors are active, due to relative amounts of different components of the odorant

Question 30

Because we rarely smell pure odorants, we smell mixtures; how do we process the components

Answer 30

Analysis and synthesis

Question 31

Analysis

Answer 31

Separate into parts

Question 32

Synthesis

Answer 32

Combine into a new whole

Question 33

Binaral rivalry

Answer 33

Competition between the two nostrils for odor perception; when a differen scent is presented to each nostril, we experience one scent at a time, not a combination of the two scents together

Question 34

What we smell can affect what we

Answer 34

See

Question 35

Adaptation

Answer 35

Sense of smell is a change detector; allows for responses to new smells and/or important information

Question 36

Bottom up receptor adaptation

Answer 36

Receptors stop responding to the odorant and detection stops; firing rate

Question 37

Top down influence of adaptation

Answer 37

Conscious thought can influence time course of adaptation

Question 38

Negative bias of smell makes it

Answer 38

Stronger for longer, more important

Question 39

Positive bias to a smell makes it

Answer 39

Decrease over time more than the neutral smell

Question 40

Odor hedonics

Answer 40

The liking dimension of odor perception, typically measured with scales pertaining to an odorants perceive pleasantness, familiarity and intensity

Question 41

Familiarity of smells

Answer 41

We like odors that we have smelled before

Question 42

Intensity of smells

Answer 42

Good smells: neutral for less intense smells, unpleasant for very intense Bad smells: dislike increases the more intense the smell gets

Question 43

Hedonic responds are most likely from nurture

Answer 43

Odor preferences of infants vary from adults, cross cultural data supports associative learning

Question 44

2 aspects to support nature of hedonics

Answer 44

Pain response to irritating odors and variability in receptor types and amounts

Question 45

Sniffing sticks

Answer 45

Pre-determined set of odorant sin distinct performance for discrimination

Question 46

Triangle test

Answer 46

Participant is given 3 odors to smell, two are the same and 1 is different; identity the odd odor; used for detection and discrimination