Week 7

Question 1

Sensation

Answer 1

The physical process during which our sensory organs-those involved with hearing and taste, for example-respond to external stimuli. our sense organs are engaging in transduction, the conversion of one form of energy into another

Question 2

Perception

Answer 2

After out brain receives the electrical signals, we make sense of all this stimulation and begin to appreciate the complex world around us

Question 3

Absolute threshold

Answer 3

The smallest amount of stimulation needed for detection by a sense

Question 4

signal detection

Answer 4

method for studying the ability to correctly identify sensory stimuli

Question 5

How do we measure absolute thresholds

Answer 5

using a method called signal detection. Involves presenting stimuli of varying intensities to a research participant in order to determine the level at which someone can reliably detect stimulation in a given sense

Question 6

differential threshold/ just noticeable difference

Answer 6

The smallest difference needed in order to differentiate two stimuli

Question 7

Weber’s law

Answer 7

States that just noticeable different is proportional to the magnitude of the initial stimulus

Question 7

How does experience influence hoe our brain processes things

Answer 7

stimuli we’ve experienced in our past will influence how we process new ones.

Question 8

Top-down processing

Answer 8

Experience influencing the perception of stimuli

Question 9

Why don’t we feel the weight of our clothing

Answer 9

When we experience a sensory stimulus that doesn’t change, we stop paying attention to it.

Question 10

Bottom up processing

Answer 10

Building up to perceptual experience from individual pieces

Question 11

Sensory adaptation

Answer 11

Decrease in sensitivity of a receptor to a stimulus after constant stimulation

Question 12

How vision works

Answer 12

▪ When we see an object, we are actually seeing light bounce off that object and into our eye
▪ Light enters the eye through the pupil, a tiny opening behind the cornea
▪ The pupil regulates the amount of light entering the eye by contracting in bright light and dilating in dimmer light
▪ Once past the pupil, light passes through the lens, which focuses an image on a thin layer of cells in the back of the eye, called the retina
▪ Because we have two eyes in different locations, the image focused on each retina is from a slightly different angle (binocular disparity), providing us with our perception of 3D space (binocular vision)
Light is transduced, or converted into electrical signals in the retina by specialized cells called photoreceptors
▪ Electrical signal is sent through a layer of cells in the retina, eventually travelling down the optic nerve
* After passing through the thalamus, this signal makes it to the primary visual cortex, where information about light orientation and movement begin to come together
* Information is sent to a variety of different areas of the cortex for more complex processing

Question 13

two types of photoreceptors in the retina

Answer 13

rods and cones

Question 14

Rods

Answer 14

primarily responsible for our ability to see in dim light conditions, such as during the night

Question 15

Cones

Answer 15

provide us with the ability to see colour and fine detail when the light is brighter

Question 16

how are rods and cones different

Answer 16

differ in their distribution across the retina, with the highest concentration of cones found in the fovea (central region of focus), and rods dominating the periphery

Question 17

Retina

Answer 17

Cell layer in the back of the eye containing photoreceptors

Question 18

Binocular disparity

Answer 18

Difference is images processed by left and right eyes

Question 19

Binocular vision

Answer 19

Our ability to perceive 3D and depth because of the difference between the images on each of our retinas

Question 20

Primary visual cortex

Answer 20

Area of the cortex involved in processing visual stimuli

Question 21

Ventral pathway

Answer 21

Pathway of visual processing. The “What pathway

Question 22

dorsal pathway

Answer 22

Pathway of visual processing. The “where” pathway

Question 23

Night vision

Answer 23

takes around 10 minutes to turn on, a process called dark adaption. Because our rods become bleached in normal light conditions and require time to recover

Question 24

dark adaptation

Answer 24

Adjustment of eye to low levels of light

Question 25

light adaptation

Answer 25

Adjustment of eye to high levels of light. Happens almost instantly compared to dark adaption

Question 26

colour vision

Answer 26

Cones allow us to see details in normal light conditions, as well as colour. Cones respond preferentially, not exclusively, for red, green and blue

Question 27

Trichromatic theory

Answer 27

theory proposing colour vision as influenced by three different cones responding preferentially to red, green and blue. Does not explain the odd effect that occurs when we look at a white wall after staring at a picture for 30 seconds

Question 28

Opponent process theory

Answer 28

theory proposing colour vision as influenced by cells responsive to pairs of colours

Question 29

Sound waves

Answer 29

changes in air pressure. The physical stimulus for audition

Question 30

amplitude/ intensity of a sound wave

Answer 30

cods for the loudness of a stimulus; higher amplitude sound waves result in louder sounds

Question 31

pitch of a stimulus

Answer 31

coded in the frequency of a sound wave

Question 32

timbre

Answer 32

quality of a sound

Question 33

How we sense sound waves from our environment

Answer 33

Sound waves are funneled by your pinna into your auditory canal. Sound waves eventually reach a thin, stretched membrane called the tympanic membrane, which vibrates against the three smallest bones in the body- the malleus, the incus, and the stapes- collectively called the ossicles. Both the tympanic membrane and the ossicles amplify the sound waves before they enter the fluid-filled cochlea, a snail-shell like bone structure containing auditory hair cells arranged on the basilar membrane After being processed by auditory hair cells, electrical nerves are sent through the cochlear nerve to the thalamus, and then the primary auditory cortex of the temporal lobe

Question 34

vestibular system

Answer 34

Parts of the inner ear involved in balance. comprised of three semicircular canals-fluid filled bone structures containing cells that respond to changes in the head's orientation in space

Question 35

How are we able to maintain our gaze on an object while we are in motion?

Answer 35

Information from the vestibular system is sent through the vestibular nerve to muscles involved in the movement of our eyes, neck, and other parts of our body

Question 36

Somatosensation

Answer 36

Ability to sense touch, pain, and temperature

Question 37

Tactile sensation

Answer 37

associated with texture, transduced by special receptors in the skin

Question 38

mechanoreceptors

Answer 38

Mechanical sensory receptors in the skin that response to tactile stimulation. Allow for the conversion of one kind of energy the brain can understand

Question 39

how tactile sensation works

Answer 39

Information is sent through the thalamus to the primary somatosensory cortex for further processing. This region of the cortex is organized in a somatotopic map, where different regions are sized based on the sensitivity of specific parts on the opposite side of the body. Various areas of the skin, such as lips and fingertips, are more sensitive than others, such as shoulders or ankles

Question 40

noiception

Answer 40

Our ability to sense pain

Question 41

Pain

Answer 41

An unpleasant sensation, appears to not have obvious value. Perception of pain is our body's way of sending us a signal that something is wrong and needs attention

Question 42

Phantom limbs

Answer 42

Sensations such as itching seemingly coming from the missing limb A phantom limb can also involve phantom limb pain, sometimes described as the muscles of the missing limb uncomfortably clenching Evidence to support that the damaged nerved from the amputation site are still sending information to the brain and that the brain is reacting to this information

Question 43

Chemical senses

Answer 43

Our ability to process the environmental stimuli of smell and taste

Question 44

Olfaction

Answer 44

Ability to process olfactory stimuli. Also called smell

Question 45

Gustation

Answer 45

Ability to process gustatory stimuli. Also called taste

Question 46

How olfaction works

Answer 46

Receptors involved in our perception of both smell and taste bind directly with the stimuli they transduce Odorants in our environment, very often mixtures of them, bind with olfactory receptors found in the olfactory epithelium The binding of odorants to receptors is through to be similar to how a lock and key operates, with different odorants binding to different specialized receptors based on their shape Olfactory receptors send projections to the brain through the cribriform plate of the skull, head trauma has the potential to cause anosmia, due to the severing of these connections

Question 47

Shape theory of olfaction

Answer 47

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

Question 48

Anosmia

Answer 48

loss of ability to smell

Question 49

Gustation

Answer 49

Receptors found in the taste buds of the tongue, called taste receptor cells Located in small divots around the bumps on your tongue Responds to chemicals from the outside environment, except these chemicals, called tastants, are contained in the foods we eat Binding of these chemicals with taste receptor cells results in our perception of the five basic tastes: sweet, sour, bitter, salty, and umami (savory)-although some scientists argue that there are more

Question 50

Taste receptor cells

Answer 50

receptors that transduce gustatory information

Question 51

tastants

Answer 51

Chemicals transduced by taste receptor cells

Question 52

multimodal perception

Answer 52

The effects that concurrent stimulation in more than one sensory modality has on the perception of evetns and objects in the world

Question 53

Superadditive effect of multi sensory integration

Answer 53

The finding that responses to multimodal stimuli are typically greater than the sum of the independent responses to each unimodal component if it were presented on its own

Question 54

Principle of Inverse effectiveness

Answer 54

The finding that, in general, for a multimodal stimulus, if the response for each unimodal component is weak, then the opportunity for multisensory enhancement is very large. However, if one component-by itself- is sufficient to evoke a strong response, then the effect on the response gained by simultaneously processing the other components of the stimulus will be relatively small

Question 55

Mcgurk effect

Answer 55

Visuals override what we hear

Question 56

loudness

Answer 56

Most direct physical correlate of loudness is sound intensity measured close to the eardrum. Many other factors also influence the loudness of a sound, including its frequency content, its duration, and the context in which is it presented

Question 56

Pitch

Answer 56

Plays a crucial role is acoustic communication Variations over time provide the basis of melody for most types of music; pitch contours in speech provide us with important prosodic information in non-tone languages, such as English, and help define the meaning of words in tone languages, such as Mandarin Chinese Most common pitch-evoking sounds are known as harmonic complex tones

Question 57

Timbre

Answer 57

Refers to the quality of sound, and is often described using words such as bright, dull, harsh, and hollow Includes anything that allows us to distinguish two sounds that have the same loudness, pitch, and duration. Important aspect includes the temporal envelope of the sound, especially how it begins and ends

Question 58

Pinna

Answer 58

The filtering produced by the pinnae helps us localize sounds and resolve potential front-back and up-down confusions The folds and bumps of the pinna produce distinct peaks and dips in the frequency response that depend on the location of the sound source Due to the small size of the pinna, these kinds of acoustic cues are only found is basically unchanged whether it comes from above, in front, or below

Question 59

Ear canal (auditory meatus) and the tympanic membrane

Answer 59

Thin, stretched membrane in the middle ear that vibrates in response to sound. Also called the eardrum

Question 60

Inner ear

Answer 60

Includes the cochlea, encased int eh temporal bone of the skull, in which the mechanical vibrations of sound are transduced into neural signals that are processed by the brain

Question 60

Middle ear

Answer 60

Consists of an air-filled cavity, which contains the middle-ear bones, known as the incus, malleus, and stapes, or anvil, hammer, and stirrup, because of their respective shapes Distinction of being the smallest bones in the body Primary function is to transmit the vibrations form the tympanic membrane to the oval window of the cochlea and, via a form of lever action, to better match the impendence of the air surrounding the tympanic membrane with that of the fluid within the cochlea

Question 61

cohclea

Answer 61

a spiral shaped structure that is filled with fluid

Question 62

basilar membrane

Answer 62

vibrates in response to the pressure differences produced by vibrations of the oval window

Question 63

Organ of Corti

Answer 63

runs the entire length of the basilar membrane from the base to the apex Organ of Corti includes three rows of outer hair cells and one row of inner hair cells The hair cells sense the vibrations by way of their tiny hairs, or stereocilia Outer hair cells seem to function to mechanically amplify the sound-induced vibrations, whereas the inner hair cells form synapses with the auditory nerve and transduce those vibrations into action potentials, or neural spikes, which are transmitted along the auditory nerve to higher centers of the auditory pathways

Question 63

Ways in which we are able to locate sounds in space

Answer 63

We have a 360 degree field of hearing Our auditory acuity is, at least an order of magnitude poorer than vision in locating an object in space Our auditory localization abilities are most useful in alerting us and allowing us to orient towards sources, with our visual sense generally providing the finer-grained analysis Our ability to locate sound sources in space is an impressive feat of neural computation

Question 64

Interaural time differences

Answer 64

differences between the two ears

Question 65

Interaural level differences

Answer 65

the difference in sound pressure level between the left and right ear

Question 66

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

Answer 66

Auditory system is able to break down, or decompose, complex waveforms and allow us to make sense of our acoustic environment by forming separate auditory "objects" or "streams", which we can follow as the sounds unfold over time Sounds that are in close proximity, in time or frequency, tend to be grouped together Sounds that begin and end at the same time tend to form single auditory object Spatial location is not always a strong or reliable grouping cue, perhaps because the location from individual frequency components if often ambiguous due to the effects of reverberation

Question 67

interoception

Answer 67

The sense of physiological state of the body. Hunger, thirst, temperature, pain, and other sensations relevant to homeostasis.

Question 68

exeroception

Answer 68

The sense of the external world, of all stimulation originating from outside our own bodies

Question 69

Cutaneous senses

Answer 69

The senses of the skin: tactile, thermal, pruritic (itchy), painful, and pleasant

Question 70

noiciception

Answer 70

our ability to sense pain

Question 71

Transduction

Answer 71

A process in which physical energy converts into neural energy

Question 72

mechanoreceptors

Answer 72

responds to mechanical stimuli, such as stroking, stretching, or vibration of the skin. High threshold for activation

Question 73

Thermoreceptors

Answer 73

responds to hot or cold temperatures

Question 74

Chemoreceptors

Answer 74

responds to certain types of chemicals, either applied externally or released within the skin

Question 75

nociceptors

Answer 75

receptors that fire specifically to potentially tissue damaging stimuli. Most are subtypes of either chemoreceptors or mechanoreceptors

Question 76

A-fibers

Answer 76

Fast conducting sensory nerves with myelinated axons. Larger diameter and thicker myelin sheaths increases conduction speed

Question 77

C-pain/ A delta fibers

Answer 77

convey noxious, thermal, and heat signals

Question 78

How pain is signalled

Answer 78

Sharp pain is signalled via fast conducting A-fibers, which project to the somatosensory cortex. This part of the cortex is somatopically organized-sensory signals are represented along to where in the body they stem from The unpleasant ache after a sharp pain is a simultaneous signal sent from the nociceptors in your foot via thin C-pain or A delta fibers to the insular cortex and other brain regions involved in processing of emotion and interoception

Question 79

Social touch hypothesis

Answer 79

propose that C-tactile fibers form a system for touch perception that supports social bonding

Question 80

what does the discovery of C-tactile system suggest

Answer 80

That touch is organized in a similar way to pain; fast conducting A fibres contribute to sensory discriminatory aspects, while thin C-fibers contribute to affective-motivational aspects

Question 81

Motivation-decision model

Answer 81

The brian automatically and continuously evaluates the pros and cons of any situation-weighting impending threats and available rewards.

Question 82

The brain's descending pain modulatory system

Answer 82

A top down system involving several parts of the brain and brainstem, which inhibits nociceptive signalling so that the more important actions can be attended to

Question 83

How the promise of a reward can be enough to relive pain

Answer 83

Expecting pain relief from a medical treatment contributes to the placebo effect- where pain relief is due at least partly to your brain's descending modulation in circuit, and such relief depends on the brain's own opioid system. Our brain can modulate the perception of how unpleasant pain is, while still retaining the ability to experience the intensity of sensation

Question 84

allodynia

Answer 84

Pain due to a stimulus that does not normally provoke pain, e.g, when a light, stoking touch feels painful

Question 85

noxious stimuli

Answer 85

a stimulus that is damaging or threatens damage to normal tissues

Question 86

Chronic pain

Answer 86

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

Question 87

Annual economic cost associated with chronic pain

Answer 87

560-635 billiion dollars

Question 88

why is it difficult to treat chronic pain

Answer 88

Chronic pain conditions are highly diverse, and they can involve changes on peripheral, spinal, central, and psychological levels. The mechanisms are far from fully understood, and developing appropriate treatment remains a huge challenge for pain researchers.

Question 89

Sensitization

Answer 89

Occurs when the response to a stimulus increases with exposure