Chapter 4

Question 1

what is sensation

Answer 1

the basic unit of conscious experience that we have detected but not assigned meaning to.

Question 2

what are examples of sensation

Answer 2

patterns,(visual), warm, sweet, bitter (taste)

Question 3

what is perception

Answer 3

the meaningful interpretations of the sensations we’ve detected

Question 4

what are examples of perception

Answer 4

what the patterns are making, what the food is we’re tasting

Question 5

what is sensory transduction

Answer 5

the process of changing external stimulation into signals in the brain

Question 6

what is light

Answer 6

a form of electromagnetic radiation that enables the human eye to see

Question 7

what are wavelengts

Answer 7

the distance from one energy peak to another

Question 8

what is amplitude/intensity

Answer 8

how much energy is transmitted (brightness) `

Question 9

how do wavelengths and amplitude of light relate to colour and brightness

Answer 9

electromagnetic radiation or wavelengths that are in the visible part of the spectrum are being absorbed by the object. depending on the object certain wavelengths are absorbed and some are reflected causing a sensation of colour

Question 10

how does is the amount of light that enters your eye controlled

Answer 10

muscles around the pupil are controlled by an unconscious reflex that is triggered depending on the amplitude/intensity of light.

Question 11

what happens when there is a high amplitude of light directed towards your eye

Answer 11

the muscles around your pupil make it shrink

Question 12

what happens when there is a low amplitude of light being directed towards your pupil

Answer 12

the muscles around your pupil make it dialate

Question 13

how is light focused on your retina

Answer 13

By the lens which changes shapes through the use of muscles depending on how close or far an object is

Question 14

what happens to your lens when an object is close

Answer 14

the lens gets shorter and fatter

Question 15

what happens to the lens when objects are far

Answer 15

it gets thinner and longer

Question 16

what is the word for when the muscles change the shape of your lens

Answer 16

accomadation

Question 17

what are the light-sensitive receptor cells called

Answer 17

photoreceptors

Question 18

what is the fovea

Answer 18

an area where photoreceptors are densely packed together

Question 19

what is the optic nerve

Answer 19

a place where there are no photoreceptors. where the axons of your cells come together and leave the back of your eye

Question 20

what is the cornea

Answer 20

the outer layer of your eye where light enters

Question 21

what is the pupil

Answer 21

where the light goes in

Question 22

how does light get translated into the electrochemical language of the brain using the rod and cone cells (photoreceptors)

Answer 22

1. Light passes through the cornea and lens, strikes the retina which is made up of rod cells, cone cells, ganglion cells, and bipolar cells.
2. Light goes past the ganglion and bipolar cells hits the rods and cones which contains photopigement.
3. photopigment absorbs the photons and breakdown
4. this causes depolarization in the cell and starts sending action potentials to the bipolar and ganglion cells
5. they pass the message through the optic nerve

Question 23

where are rod cells generally located

Answer 23

around the edges

Question 24

what are rod cells responsible for

Answer 24

your vision in low light conditions at night (peripheral vision)

Question 25

where are cone cells located

Answer 25

the centre of the fovea

Question 26

what are cone cells responsible for

Answer 26

fine details and seeing colour (central vision)

Question 27

explain the process of dark adaptation

Answer 27

1. when light is on the chemicals inside your photoreceptors (photopigment) are being depleted (bleached) and no longer able to send action potentials 2. photoreceptors are constantly replenishing the photopigment in them 3. when the lights are turned off as time goes on more and more photopigment replenishes 4. this gives your photoreceptors the ability to catch the few photons that are in the room

Question 28

how do bipolar and ganglion cells process the messages from the photoreceptors to detect edges in the visual field

Answer 28

multiple photoreceptors are connected to one bipolar cell. multiple bipolar cells are connected to one ganglion cell. If the ganglion cells receive messages from only a few bipolar cells that is how it detects edges

Question 29

describe where the blind spot is in our retina and what the visual system does about

Answer 29

the optic nerve is a large father of axons leaving no room for any photoreceptors. There is no means of detecting light making this the blind spot. because this is located in your peripheral vision when it hits one eye it does not hit the other allowing the vision from one eye to compensate for the blind spot in the other

Question 30

describe how studying brain damage can tell us how information is processed

Answer 30

Ex 1: If someone has brain damage and is no longer able to recognize and identify faces but able to identify objects we know that there is a part of the brain dedicated to facial processing ex 2: if someone is able can see someone/ something while stationary but not while in motion we know that there is a part of the brain dedicated to processing objects in motion

Question 31

what is it called when someone does not have facial recognition

Answer 31

prospagnosia

Question 32

what is it called when someone is unable to see objects/people when in motion

Answer 32

akinetopsia

Question 33

explain opponent-process to colour vision

Answer 33

some cell will increase their firing rate when they’re getting messages that red (560nm)is present and will decrease when there is blue (420nm) and increase again when green is (530nm) Part of your experience of colour is created by your visual system paying attention the difference in the firing rate in the opposing cells.

Question 34

what is the bottom-up processing

Answer 34

taking sensory input and building up recognizable images from the combination of lines corners and colours

Question 35

what is top-down processing

Answer 35

taking our knowledge, beliefs and expectations about the visual scene and using them to help construct a meaningful image

Question 36

describe the five of the Gestalt principles of top-down organization in perception

Answer 36

1. The law of proximity- thing that are close together are grouped together. Ex: columns vs rows 2. The law of similarity- things that share the same form (shape) are grouped together ex: different shapes 3. The law of closure- there is a tendency to perceive things as complete objects (whole not parts) if you can 4. The law of good continuation- we prefer to think of objects as having smooth continuous contours (gradually changing outlines), rather than outlines that abruptly change 5. The law of common fate- objects that move together are grouped together

Question 37

describe the variety of monocular cues to depth

Answer 37

- Linear perspective- parallel lines converge as they get further away - Atmospheric perspective- far away objects are bluish and hazy - Texture gradients- the texture of closer objects is coarser and rougher (you can see more of the details) than the texture of objects that are further away - Relative height- objects that are higher up in the visual field tend to be further away (at least, below the horizon) - Motion parallax- in front of the focal point, closer objects appear to move faster than ones further away

Question 38

describe the variety of binocular cues to depth

Answer 38

- Retinal disparity- the image from your right eye differs slightly from the image from your left eye. This can be used to judge depth The more different information about there the object is on your left and right retina, then the visual system assumes that the object is quite close to you - Convergence – your eyes turn inwards to focus on objects that are closer to you If you have to turn your eyes in closer together your visual system knows that the object is quite close and vice versa

Question 39

explain how size perception is based on both bottom-up and top-down processing and how this explains many visual illusions

Answer 39

the size that you perceive something as being depends on a combination of retinal size (bottom-up) and how far away you perceive it as being (top-down) by manipulating various depth cues, we can create illusions that fool your system into 'seeing' objects as larger than they really are

Question 40

explain what sound is

Answer 40

sound is a form of physical energy caused by vibrations causing waves of molecules in some substances or medium (usually in air or water)

Question 41

how are physical soundwaves translated into the electrochemical language of the brain

Answer 41

1. the outer ear (pinna) focuses sound into the auditory canal 2. the sound reaches the eardrum (tympanic membrane) and causes it to vibrate 3. the vibrations are transferred to the three bones in the middle of the ear (hammer, anvil and stapes) 4. when the state vibrates it passes the vibration onto the cochlea and causes fluid to move which also causes the basilar membrane to move 5. the hairs cells in the basilar membrane are the auditory sensory neurons which turn the physical waves into the electrochemical messages

Question 42

describe how our sense of pitch is created

Answer 42

the frequency of a sound is determined by the vibrations of the object. This is experienced as pitch. your brain creates high, medium low pitched sounds depending on which auditory sensory neurons are sending on the

Question 43

give examples that show how what we hear or perceive is a combination of bottom-up and top-down processing

Answer 43

there are cells in the auditory cortex that respond best to complex sounds. sometimes our top-down expectations influence what we hear. (think about when we hear lyrics but we read something that sounds the same)