Chapter 5

Question 1

what is sensation

Answer 1

brings information to the brain that arises in the reality outside our bodies
- upset stomach, etc
- begins with the interaction between a physical stimulus and our biological sensory systems

Question 2

what is perception

Answer 2

the process of interpreting sensory information
- individual differences
the gateway to perception is the process of attention of our narrow focus on consciousness

Question 3

what is synesthesia

Answer 3

a condition where the stimulation of one sensory pathway leads to the simultaneous automatic stimulation of another sensory pathway
- differences in perception
- may see letters as specific colours

Question 4

what is transduction

Answer 4

before you can use info from your senses, it must be translated into a form the nervous system can understand
- the process from translation from stimulus to neural signal = transduction

Question 5

what is sensory adaptation

Answer 5

the reduced response to an unchanging stimulus
- when the smell of food is barely noticeable after a while
- high intensity stimuli like bright lights or loud noises are things such as nearby explosions and have consequences for our safety

Question 6

what is bottom up processing

Answer 6

the brains use of incoming signals to construct perceptions
- visual reality from information about light that is sent from the eye to the brain
- when we read a sentence that is spelled wrong, we use this type of processing to bring the sensations of the letter shapes to our brain and we use our knowledge and previous knowledge to make sense of the individual worlds

Question 7

what is the top-down processing

Answer 7

we use knowledge gained from prior experience with stimuli to perceive them
- a skilled reader has no trouble reading the a jumbled sentence

Question 8

what is psychophysics

Answer 8

gustav fechner developed methods which was used for studying the relationships between stimuli and perception of those stimuli
- used to establish the limits of awareness or thresholds for each of our sensory systems

Question 9

what is the absolute threshold

Answer 9

the smallest possible stimulus that can be detected at least 50% of the time

Question 10

what is the difference threshold

Answer 10

the smallest difference between 2 stimuli that can be detected at least 50% of the time
- the amount of difference that can be detected depends on the size of the stimuli being compared
- larger stimuli = larger differences by the observer
EX: you are eating salty chips, friend is eating lightly salted chips but if we were to add equal amounts of salt to both bags, your friend would notice because it is passing their difference threshold since yours are already very salty
- being able to detect the difference between two different weights

Question 11

what is a signal detection

Answer 11

it is a two-step process involving the actual intensity of the stimulus - which influences the observes belief that the stimulus did occur, b) and the individual observers criteria for deciding whether the stimulus occurred
- EX: a jurys decision on whether a person is guilty - weighing their concerns

Question 12

define vision

Answer 12

the processing of light reflected from objects - is one of the most important sensory systems in humans
- cerebral cortex processes visual information

Question 13

light moves in ____

Answer 13

waves
wavelength = distance between each peak
amplitude = height of the wave
large amp = brighter light
humans can only see a small fraction of the electromagnetic spectrum

Question 14

what is the cornea - part of the eye

Answer 14

toward the front of the eye - outer layer covering becomes clear
- begins process of bending light to form an image on the back of the eye

Question 15

what is the pupil - part of the eye

Answer 15

the light that travels through the cornea and into the pupil which is surrounded by the iris (which can be coloured)
- the pupil opening can adjust in response to the amount of light present in the environment and to signal from the autonomic nervous system
- arousal = dilated, relax = constricted

Question 16

what is the lens - part of the eye

Answer 16

directly behind the pupil and iris is the main optical instrument of the eye
- muscle attached to the lens can change its shape, allowing us to accommodate or adjust our focus to see near or distant objects
- muscles relax = lens flatten = focus on distant objects
- muscles contract = lens becomes spherical = focus on near objects

Question 17

what is the retina

Answer 17

behind the lens - the main ball in your head
a thin but complex network of neurons specialized for processing light
- located in deep of the retina = specialized receptors - light is passed for information
- before it hits the receptor, it hits the vessels and neurons but we cannot see them
- the retina sees things upside down and reversed due to diffraction

Question 18

what are rods and cones in the eye

Answer 18

responsible for different aspects of vision
rods = more sensitive to light than cones, they excel at seeing dimmed light
- your peripheral vision does a better job at viewing dim light than your central vision does
cones = red, blue, green
- function best under bright light and provide the ability to see both sharp images and colour

Question 19

what is the optic nerve

Answer 19

the nerve exiting the retina of the eye
- the axons from the final layer of the cells leave the back of the eye to form this nerve
- at the optic chiasm - the axon closest to the nose cross over to the other hemisphere
(focusing straight means that everything on the left side is processed by the right hemisphere) = helps seeing depth

Question 20

what are optic tracts

Answer 20

nerve pathways travelling from the optic chiasm to the thalamus, hypothalamus and midbrain
axons in the optic tract synapse in the thalamus - which sends info to the amygdala and the primary visual cortex and the occipital lobe
- the amygdala uses visual info to make quick emotional judgements - about harmful stimuli
- the rest of the optic tract fibres connect with the hypothalamus - where their input provides information about light needed to regulate sleep wake cycles

Question 21

what are the two major pathways radiating from the occipital cortex

Answer 21

1. dorsal stream - extends upward from the primary visual cortex - this is pathway that helps us process movement and localize objects in space
2. ventral system - extends downwards from the V1 in the occipital lobe to the temporal lobe - this is the pathway that responds to the shape and colour and contributes to our ability to recognize objects and faces

Question 22

what are the three primary colours in the world of light

Answer 22

red, blue, green - in the world of light
but the primary colours of paint = red, blue, yellow

Question 23

what is the trichromatic theory

Answer 23

a theory of colour vision based on the existence of different types of cones for the detection of short (blue), medium (green) and long wavelengths (red)
high wavelength = low freq

Question 24

what is the opponents process theory

Answer 24

the theory of colour vision does a better job than the trichromatic theory in explaining these colour afterimages. This theory proposes the existence of colour channels: a red–green channel and a blue–yellow channel. We cannot see a colour like reddish green or bluish yellow because the two colours share the same channel. The channels are “opponent” or competing. Activity in one colour group in a channel reduces activity in the other colour group.

Question 25

T/F males are more likely to have a form of red-green colour deficiency

Answer 25

true the genes for pigments used by red and green cones are located on the X chromosome - this makes the deficiency sex-linked

Question 26

which theory is better? the thrichomatic theory or the opponent process?

Answer 26

The trichromatic theory provides a helpful framework for the functioning of the three types of cones in the retina - However, as we move from the retina to higher levels of visual analysis... - the opponent process theory seems to fit observed phenomena neatly - Both theories help us understand colour vision but at different levels of the visual system.

Question 27

how can we recognize objects

Answer 27

the hierarchical model implies a reality built out of individual bars and edges the mathematical approach suggests that we analyze patterns of lines - grating van vary between freq and contract - high freq = bars in a given distance and provide fine detail - low freq = relatively few bars - high contract = large differences in intensity between adjacent vars like black being next to white - low contrast = gratings have subtler differences in intensity between cars like dark gray next to black

Question 28

what is the fusiform face area

Answer 28

- FFA - in adolescence, the visual processing of faces activates a particular area of the brain which is part of the ventral pathway located in the inferior temporal cortex - it becomes active during the processing of faces as opposed to other objects - faces carry special significance in the typically developing human visual system

Question 29

what are the 5 Gestalt principles

Answer 29

1. suggests that we spont divide a scene into a main figure and ground 2. proximity - objects that are close together tend to be grouped together - (same thing with stimuli, similar stimuli are grouped together) 3. principle of continuity - which shows that points that are close together are seen as smooth lines 4. principle of closure - when people see a complete unbroken image even if there are gaps in the lines - they fill in the blanks 5. principle of simplicity - suggests that we use the simplest solution to a perceptual problem

Question 30

what is the depth perception

Answer 30

the ability to use the 2D image projected on the retina to perceive 3D

Question 31

explain monocular cues vs binocular cues

Answer 31

mono = one eye - occulsion - or the blocking of images of distant objects by closer objects - to understand you need to be familiar with how big the real size of the object is bino = two eyes used to construct a 3D image to provide an illusion of depth in their 2D pieces

Question 32

what is the retinal disparity

Answer 32

the most effective depth cues - requires both eyes - binocular cue - they provide infor about the relative distance between 2 objects in the visual field

Question 33

how is binocular depth system an advantage to predators

Answer 33

prey are good at hiding esp if they blend into the environment - retinal disparity allows us to spot tiny variations in the depth of objects in the visual field - makes animals stand out against the background

Question 34

what is astigmatism

Answer 34

the surface of the cornea is uneven

Question 35

what is audition

Answer 35

sense of hearing

Question 36

ultrasounds and infrasounds

Answer 36

ultra = above the range of the human hearing infra = below the range of the human hearing

Question 37

explain the outer ear

Answer 37

structures that are visible outside the body - the pinna = collects and focuses on sounds like a funnel - helps to localize sounds as being above or below the head - the sounds are chanelled through the auditory canal

Question 38

explain the middle ear

Answer 38

the boundary between the middle and inner ear is formed by another membrane - the oval window this gap between these 2 membranes is bridged by a series of tiny bones - the purpose of these bones is to transfer sound energy from the air of the outer and middle ear to the fluid found in the inner ear

Question 39

explain the inner ear

Answer 39

contains 2 sets of fluid filled cavities embedded in the bone of the skull one set = vestibular system other set = the cochlea - specialized receptor cells that respond to vibrations transmitted to the inner ear

Question 40

what is the cochlea

Answer 40

inner ear structure that has receptors - 1. vestibular canal - 2. tympanic canal - vibrations transmitted by the bones of the middle ear to the oval window produce waves in the fluid of the vestibular canal that travels around the apex and back through the tympanic canal between the 2 canal = cochlear duct

Question 41

what is the basilar membrane

Answer 41

a membrane in the cochlea on which the organ of corti is located

Question 42

what is the organ of corti

Answer 42

resting on top of the basilar membrane - contains many rows of hair cells that transduce sound energy into neural signals

Question 43

what is the auditory nerve

Answer 43

bending the hair cells stimulates the release of neurotransmitters onto the cells of the auditory nerve - the basiliar membrane needs to move very little before the hair cells are stimulated - the branches of the nerve cell can make contact with the haircells and the medulla which sound information is then sent to the midbrain - midbrain --> thalamus which sends info to the --> primary auditory cortex

Question 44

T/F the freq of sound interacts with our perception of its loudness

Answer 44

true

Question 45

how can we tell where the sound is coming from

Answer 45

we localize sound to the left and right by comparing the differences between the arrival times of the sounds to our two ears

Question 46

T/F our ability to localize sounds is influenced by interactions with vision and audition

Answer 46

true

Question 47

how do we group sounds together

Answer 47

sounds from one location are grouped together bc we think it all came from the same source - when we know its from diff locations we know its from diff sources - sounds that start and stop at the same time are perceived as being the same source

Question 48

what is somatosensation

Answer 48

provides us with information about the position and movement of our bodies along with touch, skin temp and pain

Question 49

t/f having a high pain tolerance cant lead to premature death

Answer 49

true because the impaired pain reception affect our ability to respond to injury and assess our circumstances

Question 50

how does somatosensory stimuli arise

Answer 50

within the body or making contact with its surface - these stimuli provide an organism with little time to react somatosenses provide essential feedback needed for movement, speech, safety

Question 51

what is the vestibular system

Answer 51

the system in the inner ear that provides information about body position and movement contain sensitive hair cells that are bent back and forth within their surrounding fluids when the head moves and when the movement stops the fluids can reverse the movement of the hair cells result in the production of a signals in the auditory nerve - the same nerve that carries info about sound the axons form connections in the medulla and in the cerebellum the medulla receives input from the visual system, the cerebellum and other somatosenses - vestibular information travels from the medulla to the thalamus, the primary somatosensory cortex or the parietal lobe and then the primary motor cortex

Question 52

what is the sensory homunculus

Answer 52

demonstrates the areas of the body that are represented based on their sensitivity rather than their size - how the human body is represented in the brain

Question 52

T/F different receptors in the skin help us sense pressure, vibration, stretch or pain

Answer 52

true

Question 52

t/f those with autism have different sensory worlds

Answer 52

true - oversensitive touch

Question 53

t/f some pain receptors respond to mechanical damage only

Answer 53

false some can do mechanical damage and respond to temperature or chemicals

Question 54

what are the two types of fibers that bring info about pain to the brain

Answer 54

1. fast, myelinated axons - for sharp ouch sensations 2. slower, unmyelinated axons that are responsible for dull, aching sensations

Question 55

where does the pain info get sent to in the brain

Answer 55

pain fibres form synapses with the spinal cord cells, send message to thalamus, send message to the anterior cingulate cortex and the insula (which manage the emotional qualities of pain) and to the somatosensory cortex in the parietal lobe (intensity of pain)

Question 56

what is the gate control theory

Answer 56

helps explain the various psychological and physical factors that contribute to pain perception by proposing that rather than pain signals being automatically sent to the brain - these signals must first pass through neurological gates at the spinal cord. If the gate is open, pain signals travel to the brain and are perceived; if the gate is closed, it’s possible that the pain may not be perceived at all (child too excited at a bday party to let an injury bother them)

Question 57

why does the forebrain structure form connections with the periaqueductal grey of the midbrain

Answer 57

this area is rich in receptors for our natural opioids, the endorphins. The periaqueductal grey is a major target for opioid painkillers, such as morphine. Electrical stimulation of the periaqueductal gray produces a significant reduction in the experience of pain.

Question 58

t/f even when people are told they're receiving a placebo the pain relief can occur as long as they are told that placebo effects can be powerful

Answer 58

true

Question 59

what is olfaction

Answer 59

the sense of smell - provides information from a distance - taken in thru the nostrils and circulated within the nasal cavities where it interacts with the olfactory receptors - receptors are located in a thin layer of cells within the nasal cavity = olfactory epthelium

Question 60

what is gustation

Answer 60

the sense of taste - involves info from contact with the body - the tongue has receptors for carbohydrates and capsaicin (equally distributed)

Question 61

what is the olfactory nerve

Answer 61

a nerve carrying olfactory information from the olfactory receptors to the olfactory bulbs

Question 62

what is the olfactory bulbs

Answer 62

information is brought from the olfactory nerves - the nerve fibres synapses in one of the two bulbs which is located just below the mass of the frontal lobes these bulbs proceed to the olfactory cortex and to the amygdala - the cortex makes connections with the thalamus which sends info to the conscious awareness of odours

Question 63

what is a papillae

Answer 63

small bumps on the tongue that contain taste buds

Question 64

what are taste buds

Answer 64

a structure found in papillae that contains taste receptor cells - in each taste bud = receptor cells which extend like tiny hairlike cilia into the saliva that interact with dissolved taste stimuli - info travels from the mouth/tongue to the medulla which turns communication with the thalamus and to the other places, ending up in the orbitofrontal cortext where emotional pleasantness/unpleasantness in stimuli is processed

Question 65

T/F chemical senses interact to provide the perception of flavour

Answer 65

true - having a reduced sense of smell = blocked nose = less taste

Question 66

T/F as we age, out sensitivity to smell decreases

Answer 66

true - bc olfaction and taste interact to form the flavour of foods, decreased sensitivity in both senses might overal affect appetite as we age

Question 67

T/F the loss of olfaction may contribute to deficits in other senses

Answer 67

true like gustation and input from tthe trigeminal nerve

Question 68

T/F females are more sensitive to smell than makes

Answer 68

true

Question 69

how does olfaction and PTSD relate

Answer 69

close association between olfaction and memory allows certain smells to trigger ptsd

Question 70

how does the sense of smell/taste related to different cultures

Answer 70

different cultures may relates scents for religious, medicial or personal purposes - body odour in some countries is not harmful or offensive - everyone has different taste preferences

Question 71

T/F the loss of one sense gives us the greater ability to interact with other senses

Answer 71

true - loss of hearing = responds highly to touch, visual info