06. Important information Flashcards

1
Q

Why have sensory systems evolved in animals?

A

In order to guide their behaviour and provide specific kind of information the animal needs to survive and reproduce

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define sensation

A

The psychological experience associated with sound, light, or other simple stimuli and the initial information-processing steps by which sense organs and neural pathways take in stimulus information from the environment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define perception

A

The recognition, organisation, and meaningful interpretation of sensory stimuli.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the steps in the process of sensation

A

physical stimulus- physiological response- sensory experience

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

True or false: each sense has distinct sensory receptors and neural pathways to and within the brain?

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are sensory receptors?

A

Specialised biological structures—which in some cases are separate cells and in other cases are the sensitive tips of sensory neurons—that respond to physical stimuli by producing electrical changes that can initiate neural impulses (action potentials) in sensory neurons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are sensory areas?

A

Areas of the brain’s cerebral cortex that receive and analyse input from the body’s senses. Separate sensory areas exist for each distinct sense.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is sensory coding?

A

The process by which information about the quality and quantity of a stimulus is preserved in the pattern of action potentials sent through sensory neurons to the central nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is transduction?

A

The process by which a receptor cell produces an electrical change in response to physical stimulation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are receptor potentials?

A

Electrical changes in neurons that can trigger action potentials in sensory neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does the coding of stimulus quality occur?

A

Qualitatively different stimuli optimally activate different sets of neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is sensory adaptation?

A

The temporary decrease in sensitivity to sensory stimulation that occurs when a sensory system is stimulated for a period of time, and the temporary increase in sensitivity that occurs when a sensory system is not stimulated for a period of time.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is pyschophysics?

A

The scientific study of the relationship between physical characteristics of stimuli and the psychological (sensory) experiences that the stimuli produce.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the absolute threshold?

A

In psychophysics, the faintest (lowest-intensity) stimulus of a given sensation (such as sound or light) that an individual can detect.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the difference threshold?

A

In psychophysics, the minimal difference that must exist between two otherwise similar stimuli for an individual to detect them as different; also called the just-noticeable difference (jnd).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is Weber’s law?

A

The idea that, within a given sensory modality (such as vision), the difference threshold (amount that the stimulus must be changed in magnitude to be perceived as different) is a constant proportion of the magnitude of the original stimulus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is signal detection theory?

A

Proposes that the detection of a sensory stimulus is dependent upon both the physical intensity of the stimulus and the psychological state (including expectations, motivation, and alertness) of the perceiver.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Why are smell and tase called chemical senses?

A

Because the stimuli for them are chemical molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Define olfaction

A

Sense of smell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How many different types of sensory neurons are contained in the olfactory nerve and where are their terminals located?

A

roughly 400 different types, the olfactory epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where do the glomeruli in the olfactory bulb send most of their output and what effect might this account for

A

Most output goes to structures in the limbic system and the hypothalamus which are involved in basic drives and emotions. These connections account for the strong and often unconscious effects that smell can have on our motivational and emotional states

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Where are the primary and secondary olfactory areas located?

A

Primary- underside of the temporal lobe
Secondary- orbitofrontal cortex located at the underside of the frontal lobe
Areas are crucial for the conscious understanding of and identifying of odors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Odourants can reach the olfactory epithelium via two different routes which are…

A

The nostrils and an opening in the mouth called the nasal pharynx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Where does flavour come from?

A

Taste and smell triggered through the nasal pharynx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Which gender is more sensitive to odor?

A

Women

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

When does the sense of smell decline?

A

With age

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is one finding that helps to substantiate the theory that olfaction serves one or more special functions related to reproduction?

A

Women of child bearing age have smell sensitivity which is not present in prepubescent girls or post-menopausal women

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Odour figures into the complex stimuli that are involved in attachment between human infants and their mothers. True or false

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Why would mice choose mates that have the most different smell from them?

A
  1. This indicates that the are not likely to be close relatives
  2. This will add new genetic variation to the mix of disease-fighting cells that develop in offspring
    (their smell is associated with genes that determine some cells in the immune system)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How does smell play a role in incest avoidance?

A

By creating a natural aversion. Those pairings most likely to suffer negative consequences of incest (father-daughter, siblings) have a natural aversion to each others body odour.

31
Q

What is a pheromone?

A

A chemical that is released by an animal and that acts on other members of the species to promote some specific behavioural or physiological response.

32
Q

What is the vomeronasal organ?

A

A structure found in the nasal cavity of most mammals designed to respond to specific pheromones

33
Q

Where do human taste receptors exist?

A

Only in the mouth

34
Q

Where are receptors for taste found?

A

In special taste receptor cells (not directly on sensory neurons) which are located on taste buds which are in turn located in spherical structures called fungiform papillae

35
Q

How many taste buds do most people have?

A

Between 2000- 10000, located on the tongue, roof of the mouth, and opening to the throat

36
Q

How is a chemical tasted?

A

First, it must be dissolved in saliva, then come into contact with the appropriate receptor cell, then, via transduction (action potential) the taste information is carried to the sensory neurons that run to the brain

37
Q

What are the six primary tastes?

A

sweet, salty, bitter, sour, umami and fat

38
Q

Where is the primary taste area located?

A

In the insula- buried in the central fissure that separates the temporal and parietal lobes

39
Q

Where does the primary taste area send output to create flavour?

A

The orbitofrontal cortex

40
Q

Pain is a somatosense, true or false?

A

true. It can originate from multiple places throughout they body

41
Q

Pain is not only a sense but also…

A

a perception, an emotion, and a drive

42
Q

What is one example of the evolutionary value of pain?

A

People born with a genetic condition which prevents them from feeling pain often die young due to tissue deterioration or wound infections

43
Q

What are the primary neural pathways for pain?

A

receptor cells are located in sensory neurons, pain neurons are thinner than other neurons from the skin and their sensitive terminals (free nerve endings) can be found in all body tissues from which pain is sensed

44
Q

What are the two types of pain sensory neurons

A
  1. C fibres- thin unmyelinated, slow conducting (respond to all types of pain)
  2. A-delta fibres- thicker, myelinated, faster-conducting (respond to strong pressue (pin prick) or temperature)
45
Q

What are the three psychological components of pain?

A
  1. Sensory component- (somatosensory cortex) perceive pain and locate it
  2. Primary emotional and motivational component- (cingulate and insular cortexes) desire to escape pain
  3. secondary emotional and motivational component- (prefrontal lobe) suffering that derives from worrying about the future and meaning of pain
46
Q

List one example of pain which does not derive from stimulation of pain receptors

A

phantom limb pain

47
Q

What is the gate-control theory of pain?

A

Melzack and Wall’s theory proposing that pain will be experienced only if the input from peripheral pain neurons passes through a “gate” located at the point that the pain-carrying neurons enter the spinal cord or lower brainstem.

48
Q

What are two possible evolutionary explanations for pain enhancement?

A
  1. to motivate ill individuals to rest rather than move around in order to conserve energy needed to heal/ fight disease
  2. to motivate individuals to protect damaged areas of their bodies
49
Q

What is the neural centre for pain inhibition in the midbrain called?

A

periaqueductal gray (PAG)

50
Q

Where are endorphins produced in the body

A

The brain, spinal cord, pituitary and adrenal glands

51
Q

What is stress-induced analgesia?

A

The reduced sensitivity to pain that occurs when one is subjected to highly arousing (stressful) conditions (depends partly if not entirely on the release of endorphins)

52
Q

Which mammals have the keenest hearing?

A

bats

53
Q

What is sound?

A

the vibration of air or some other medium produced by an object

54
Q

What is amplitude?

A

The amount of physical energy or force exerted by a physical stimulus at any given moment. For sound, this physical measure is related to the psychological experience of loudness. (decibels- dB)

55
Q

What is frequency?

A

For any form of energy that changes in a cyclic or wave-like way, the number of cycles or waves that occur during a standard unit of time. For sound, this physical measure is related to the psychological experience of pitch (Hertz- Hz)

56
Q

What is pitch?

A

The quality of the psychological experience (sensation) of a sound that is most related to the frequency of the physical sound stimulus.

57
Q

What is the frequency range of sounds audible to humans?

A

20- 20,000 Hz

58
Q

Hearing evolved out of which other sense?

A

Touch

59
Q

What is the outer ear?

A

The pinna (the visible, external portion of the ear) and the auditory canal (the air-filled opening that extends inward from the pinna to the middle ear).

60
Q

What is the middle ear?

A

The air-filled cavity separated from the outer ear by the eardrum; its main structures are three ossicles (tiny bones) that vibrate in response to sound waves and stimulate the inner ear.

61
Q

What is the inner ear?

A

The portion of the ear lying farthest inward in the head; it contains the cochlea (for hearing) and the vestibular apparatus (for the sense of balance).

62
Q

What is the cochlea?

A

A coiled structure in the inner ear in which the receptor cells for hearing are located.

63
Q

What is the basilar membrane?

A

A flexible membrane in the cochlea of the inner ear; the wave-like movement of this structure in response to sound stimulates the receptor cells for hearing.

64
Q

What are hair cells?

A

The receptor cells for hearing, which are arranged in rows along the basilar membrane of the cochlea in the inner ear.

65
Q

What are the two general categories of deafness?

A
  1. conduction deafness (ossicles become rigid, helped by conventional hearing aid)
  2. sensorineural deafness (damage to the hair cell/ auditory neurons, can be helped by cochlear implant if damage is to hair cells)
66
Q

Where are low, medium, and high frequency sounds perceived along the (uncoiled) cochlea?

A

High- peak near the oval window (shortest distance)
Medium- peak near the middle of cochlea
Low- peak near distal end (near round window, longest distance)

67
Q

How do modern cochlear implants code sound frequency and perception of pitch?

A

By using place (location along cochlea) and timing (frequency of action potentials- higher/ lower pitch).

68
Q

What does it mean that neurons in the primary auditory cortex are tonotopically organised?

A

neurons are systematically arranged such that high frequency tones activate neurons at one end of the cortical area and low-frequency tones activate neurons at the other end

69
Q

How do heredity and experience play a role in hearing?

A

Heredity determines the general form of the tonotopic map and experience determines the specific amount of cortex devoted to any particular range or frequencies

70
Q

What other area does the brain use to distinguish pitch?

A

An area in the parietal lobe of the primary auditory cortex called the intraparietal sulcus (it involves both music perception and visual space perception)

71
Q

What is a key factor in sound location?

A

The time at which each sound wave reaches one ear compared to the other

72
Q

What are phonemes?

A

The various vowel and consonant sounds that provide the basis for a spoken language

73
Q

What is phonemic restoration?

A

An illusion in which people hear phonemes that have been deleted from words or sentences as if they were still there (gap must be filled with noise, cannot be silent)