PSYC week 7

Question 1

Describe the basic functions of the four cerebral lobes: occipital, temporal, parietal, and frontal.

Answer 1

Occipital- responsible for vision
Temporal- auditory, multisensory integration, memory
Parietal- bodily sensations
frontal- motor cortex, motor planning, judgement

Question 2

Autonomic nervous system

Answer 2

A part of the peripheral nervous system that connects to glands and smooth muscles. Consists of sympathetic and parasympathetic divisions.

Question 3

Parasympathetic nervous system

Answer 3

A division of the autonomic nervous system that is slower than its counterpart—that is, the sympathetic nervous system—and works in opposition to it. Generally engaged in “rest and digest” functions.

Question 4

Somatic nervous system

Answer 4

A part of the peripheral nervous system that uses cranial and spinal nerves in volitional actions.

Question 5

Sympathetic nervous system

Answer 5

A division of the autonomic nervous system, that is faster than its counterpart that is the parasympathetic nervous system and works in opposition to it. Generally engaged in “fight or flight” functions.

Question 6

Differentiate the processes of sensation and perception.

Answer 6

-sensation: the physical processes to environmental stimuli
-perception: how sensory information is interpreted

Question 7

Explain the basic principles of sensation and perception.

Answer 7

-vision: light enters the eye through pupil, passes through lens which focuses light on the retina, in the retina light is transduced by photoreceptors, travels through the optic nerve to the primary visual cortex

-hearing: sound waves funnelled by pinna (outer ear), through auditory canal, to the eardrum which vibrates against ossicles (three tiny bones), which amplify sound waves before they reach the cochlea and auditory hair cells which transduce sound into electrical potentials, then to the auditory primary cortex

-touch: mechanoreceptors in skin respond to texture, information is sent to primary somatosensory cortex

-smell: odorants bind to receptors
-taste: tastants bind to taste receptor cells

-smell and taste combine to give flavour

Question 8

Apply knowledge of sensation and perception to real world examples.

Answer 8

see familiar objects, feel a person’s touch against your skin, smell the aroma of a home-cooked meal, or hear the sound of music playing in your neighbor’s apartment

Question 9

Explain the consequences of multimodal perception.

Answer 9

superadditive effect of multisensory integration: the response to many stimuli is greater than response to each stimuli on its own
-principle of inverse effectiveness: less likely to benefits from many stimuli if the response to a single stimulus is quite strong

Question 10

Primary visual cortex

Answer 10

Area of the cortex involved in processing visual stimuli.

Question 11

Retina

Answer 11

Cell layer in the back of the eye containing photoreceptors

Question 12

Shape theory of olfaction

Answer 12

Theory proposing that odorants of different size and shape correspond to different smells.

Question 13

Trichromatic theory

Answer 13

Theory proposing color vision as influenced by three different cones responding preferentially to red, green and blue.

Question 14

opponent-process theory

Answer 14

Theory proposing color vision as influenced by cells responsive to pairs of colors.

Question 15

Describe the basic auditory attributes of sound

Answer 15

-loudness: sound intensity or pressure, frequency and duration also have an effect

-pitch: repetition rate of waves, the faster the wave form repeats-the high the pitch

-timbre: quality of sound, sounds with higher frequency tend to sound brighter and lower frequencies as rich or dull

Question 16

Describe the structure and general function of the auditory pathways from the outer ear to the auditory cortex.

Answer 16

-hearing: sound waves funnelled by pinna (outer ear), through auditory canal, to the eardrum which vibrates against ossicles (three tiny bones), which amplify sound waves before they reach the cochlea (frequencies are broken up) and auditory hair cells which transduce sound into electrical potentials, then to the auditory primary cortex

Question 17

Discuss ways in which we are able to locate sounds in space.

Answer 17

-interaural time differences (ITD): differences in time and intensity between the two ears, something on the left will usually reach the left ear first, a fraction of a millisecond, best at lower frequencies
-interaural level differences (ILDs): at higher frequencies, the sound on the left side of the ear is heard as higher than the right (head shadow)

Question 18

Describe various acoustic cues that contribute to our ability to perceptually segregate simultaneously arriving sounds.

Answer 18

A
-because different frequencies are broken up in the cochlea, we are able to hear different sounds based on these frequencies
-when frequencies overlap, a sound could mask another sound
-low-frequency sounds are likely to mask high-frequency sounds and vice versa

Question 19

Tympanic membrane

Answer 19

Ear drum, which separates the outer ear from the middle ear.

Question 20

Pinna

Answer 20

Visible part of the outer ear.

Question 21

Interaural differences

Answer 21

Differences (usually in time or intensity) between the two ears.

Question 22

Cochlea

Answer 22

Snail-shell-shaped organ that transduces mechanical vibrations into neural signals.

Question 23

Describe the transduction of somatosensory signals: The properties of the receptor types as well as the difference in the properties of C-afferents and A-afferents and what functions these are thought to have.

Answer 23

-nociceptors: respond specifically to potentially tissue damaging stimuli, high threshold
-A-fibres: fast conducted response to the somatosensory cortex (allows us to distinguish the pain)
-C-pain: convey noxious, thermal, and heat signals, let us know that what we did was harmful, goes to the insular cortex and other areas of the brain involved in processing
-C tactical fibres: respond to gentle tough and light stroking

Question 24

Describe the social touch hypothesis and the role of affective touch in development and bonding.

Answer 24

-social touch hypothesis: c tactile fibres form a system for touch perception that supports social bonding
-firing of c tactile fibres corresponds with how pleasant the touch feels
-when babies are not touched they suffer from cognitive and neural development delay
-soothing touch of a mother reduces stress in a baby
-sense of touch is the first one to develop in the womb

Question 25

Explain the motivation–decision model and descending modulation of pain, and give examples on how this circuitry can promote survival.

Answer 25

-descending pain modulatory system: top down system where different parts of the brain and brain stem inhibit pain in order to attend to more important tasks, dependent on opioid signalling and pain relief (analgesics)
-motivation-decision model: the brain constantly weighs the pros and cons of every situation
-in situations facing our survival this can help one to overcome the pain and prevail

Question 26

Explain how expectations and context affect pain and touch experiences.

Answer 26

-placebo effect:where pain relief is due at least partly to your brain’s descending modulation circuit, and such relief depends on the brain’s own opioid system

-eg. when heterosexual men are told that a male will be stoking their leg, they do not enjoy the touch when in reality it is actually a woman

Question 27

Describe the concept of chronic pain and why treatment is so difficult.

Answer 27

Describe the concept of chronic pain and why treatment is so difficult:
-allodynia: neural disease or injury makes normally pleasant things feel painful, causes a-afferants which don’t normally respond to pain, to be painful in the brain
-often begin with injury to peripheral nervous system or tissue around it releasing hormones and inflammatory molecules that sensitize nociceptors so that uninjured nerves become more excitable and constantly contribute to pain

Question 28

Chronic pain

Answer 28

Persistent or recurrent pain, beyond usual course of acute illness or injury; sometimes present without observable tissue damage or clear cause.

Question 29

C-fibers

Answer 29

C-fibers: Slow-conducting unmyelinated thin sensory afferents with a diameter of 1 μm and a conduction velocity of approximately 1 m/s. C-pain fibers convey noxious, thermal, and heat signals; C-tactile fibers convey gentle touch, light stroking.

Question 30

A-fibers

Answer 30

Sensory nerves with myelinated axons conduct fast-conducting signals with larger diameters and thicker myelin sheaths. Aβ-fibers conduct touch signals at 80 m/s, Aδ-fibers conduct cold, noxious, and thermal signals at 12 m/s, and Aα conducts proprioceptive information.

Question 31

C-pain or Aδ-fibers

Answer 31

C-pain fibers convey noxious, thermal, and heat signals

Question 32

C-tactile fibers

Answer 32

C-tactile fibers convey gentle touch, light stroking