How do we sense perceive and see the world

Question 1

the only input our brain receives from the “real” world is a series of?

Answer 1

action potentials passed along the neurons of our various sensory pathways

Question 2

specialized cells that transduce (convert) sensory energy into neural activity

Answer 2

sensory receptors

Question 3

each sensory systems receptors are designed to respond to ? give 4 sensory systems and what they respond to

Answer 3

only a narrow band of energy

• vision: light energy produces chemical energy
• auditory: air pressure produces mechanical energy
• somatosensory: mechanical energy
• taste and olfaction: chemical molecules

Question 4

specific part of the world to which a sensory receptor organ responds

Answer 4

receptive field

Question 5

stream of visual stimuli that accompanies an observers forward movement through space

Answer 5

optic flow

Question 6

change in sound heard as a person and sound sources pass each other

Answer 6

auditory flow

Question 7

each photoreceptor has a unique___ that partially ___ with _____

Answer 7

receptive filed, overlaps, adjacent field

Question 8

by overlapping receptive fields we can?

Answer 8

check information against each other (more accurate)

Question 9

___ is important for determining the sensitivity of a sensory system
example?

Answer 9

density

–> ore tactile receptors on the fingers than on the arms

Question 10

differences in receptor ___ determine the special abilities of animals

Answer 10

-density

ex, olfactory ability of dogs

Question 11

explain a neural relay and what happens at different stages of a neural relay

Answer 11

• all receptors connect to the cortex through a sequence of 3 or 4 intervening neurons, information can be modified at various stages in the relay,
  (the info that reaches the primary cortex is not the same as the info that enters our receptors)

Question 12

what does information being modified at various stages of the neural relay allows the sensory system to do?

Answer 12

mediate different responses

Question 13

sensory neural relays are central to the hierarchy of>

Answer 13

motor responses in the CNS

Question 14

sensory info is encoded by ____ that travel along peripheral nerves to the __

Answer 14

action potentials, CNS

Question 15

different sensations are produced in ?

Answer 15

different areas of the cortex

Question 16

how do we learn to distinguish our senses

Answer 16

through experiences

Question 17

each system has distinct wiring set up at ___ of neural organization

Answer 17

all levels

Question 18

presence of a stimulus will ___ our potential for an AP

Answer 18

increase

Question 19

The ____represents the sensory field of each modality: vision, hearing, touch, smell, and taste—as a spatially organized neural representation of the external world

Answer 19

neocortex

Question 20

the ___ is a neural- spatial representation of the body or of the areas of the sensory world perceived by a sensory organ

Answer 20

topographic map
(more cortical area for different senses)

Question 21

Registration of physical stimuli from the environment by the sensory organs

Answer 21

Sensation

Question 22

Subjective interpretation of sensations by the brain

Answer 22

perception

Question 23

___ is our primary sensory experience

what does this mean for brain organization?

Answer 23

vision

- far more of the brain is dedicated to vision than to any other sense

Question 24

Light-sensitive surface at the back of the eye; consists of neurons and photoreceptor cell

Answer 24

retina

Question 25

3 functions of the retina

Answer 25

1. translates light into action potentials 2. discriminates wavelengths (colours) 3. works in a wide range of light intensities

Question 26

region of the center of the retina that is specialized for high acuity

Answer 26

fovea

Question 27

receptive field at the center of the eyes visual field

Answer 27

fovea

Question 28

where is vision the best

Answer 28

in the center of the visual field

Question 29

where is our blind spot

Answer 29

region of the retina (known as the optic disc) where axons forming the optic nerve leave the eye and where blood vessels enter and leave

Question 30

the blind spot has no?

Answer 30

photoreceptors

Question 31

swollen optic disc

Answer 31

papilledema

Question 32

papilledema may be due to?

Answer 32

hgih intracranial pressure (tumour in the brain or infection) or inflammation of the optic nerve (optic neuritis)

Question 33

can pailedema cause loss of vision

Answer 33

yes

Question 34

you optic disc is in ____ in each eye

Answer 34

a different spot

Question 35

where is the optic disc located relative tot eh fovea in the left and right eye?

Answer 35

- lateral to the fovea in each eye

Question 36

Rods: - ___numerous then cones - sensitive to ___ levels of light - used mainly for ? - __ types of pigment

Answer 36

- more - low levels (dim light) - night vision - 1

Question 37

cones: - highly responsive to ___ levels of light - specialized for ? - in the __ only - __ types of pigment

Answer 37

- bright light - colour and high visual acuity - fovea - 3

Question 38

responsible for colour and our ability to see fine detail

Answer 38

cones

Question 39

the 3 types of cone pigments absorb light over a range of frequencies, but their maximal absorptions are? for what colour?

Answer 39

1. 419nm short wavelengths (blue) 2. 531nm middle wavelengths (green) 3. 559nm long wavelength (red)

Question 40

are there equal numbers of all cones?

Answer 40

no. ~ equal amounts of red and green but less blue

Question 41

4 types of retinal neurons in order that light travels and what they do

Answer 41

1. Bipolar cell: recieves input from photoreceptors 2. Horizontal cell: links photoreceptors and bipolar cells 3. Amacrine cell: links bipolar and ganglion cells 4. Retinal ganglion cell: gives rise to the optic nerve

Question 42

light has to pass through all the layers of retinal neurons before reaching?

Answer 42

cones and rods

Question 43

2 types of ganglion cells and what they do

Answer 43

1. Magnocellular cell: LARGE - -> receive input from primarily rods, sensitive to light and moving stimulus 2. Parvocellular cell: small - -> receives input from primarily cones, sensitive to colour

Question 44

what layers of the thalamus are for the magnocellular layers? and what layers are the parvocellular layers

Answer 44

Mcells: 1-2 Pcells: 3-6

Question 45

what thalamus layer has high acuity

Answer 45

parvo

Question 46

junction of the optic nerves from each eye

Answer 46

optic chiasm

Question 47

axons from the nasal side (inside) of the each retina go to ____ sides of brain axons from temporal (outside) half of each retina go to ___ sides of brain

Answer 47

- contralateral | - ipsilateral

Question 48

light that falls on the right half of each eye comes from the ___ visual field so it goes to the ___ hemisphere of brain

Answer 48

- left , right

Question 49

3 routes to the visual brain

Answer 49

1. geniculostriate system 2. tectopulvinar system 3. retinohypothalamic tract

Question 50

describe route or geniculostriate system

Answer 50

Projections from the retina to the lateral geniculate nucleus to the visual cortex

Question 51

describe the route of the tectopulvinar system

Answer 51

Projections from the retina to the superior colliculus to the pulvinar (thalamus) to the parietal and temporal visual area

Question 52

describe the route of the retinohypothalamic tract

Answer 52

synapses in the tiny suprachiasmatic nucleus in the hypothalamus

Question 53

the retinohypothalamic tract play a role in?

Answer 53

regulating circadian rhythms and in the pupillary reflex

Question 54

most information flows through what 2 tracts

Answer 54

geniculostriate and tectopulvinar

Question 55

2 paths originate form the striate cortex (region V1) : where do these routes go?

Answer 55

- one goes to the vision-related regions of the parietal lobe - one goes to the vision related regions of the temporal lobe

Question 56

- Pathway that originates in the occipital cortex and projects to the parietal cortex - Pathway that originates in the occipital cortex and projects to the temporal cortex

Answer 56

- dorsal | - ventral

Question 57

- the right LGN receives input from the ___ half of each retina - the left LGN receives info from the __ half of each retina

Answer 57

- right | - left

Question 58

``` 6 layers of the LGN (thalamus) : layers 1, 4, 6: layers 2,3, 5: layers 1-2: layers 3-6: ```

Answer 58

- input from contralateral retina - input from ipsilateral retina - input from magnocellular cells - input from parvocellular cells

Question 59

P and M retinal ganglion send ___ pathways to the thalamus as well as right and left eyes send ___ pathways to the thalamus

Answer 59

- separate

Question 60

the cortical column of the geniculostriate pathway is organization that represents a ?

Answer 60

functional unit of 6 cortical layers deep and approx 0.5mm square; perpendicular to the cortical surface

Question 61

From each lateral geniculate nucleus, information from each retina is sent to ____cortical columns, thus maintaining the separation of information from each retina

Answer 61

adjacent

Question 62

the cortical columns are in?

Answer 62

V1

Question 63

in the tectnopulvinar pathway, magnocellular cells from retina project to the superior colliculus whcih send info to the pulvinar (thalamus) - the medial pulvinar sends connections to? - and the lateral pulvinar sends info to?

Answer 63

medial --> parietal | lateral--> temporal

Question 64

occipital cortex is composed of at least how many visual regions

Answer 64

6.

Question 65

Striate cortex receives input from the lateral geniculate nucleus

Answer 65

primary visual cortex (V1)

Question 66

Visual cortical areas outside the striate cortex

Answer 66

secondary visual cortex (V2-V5)

Question 67

tectopulvinar pathway goes to what visual cortex

Answer 67

secondary visual cortex and areas

Question 68

heterogeneous layering in V1 is divided into ? and ?

Answer 68

blobs and interblobs

Question 69

Region in the visual cortex V1 that contains color-sensitive neurons

Answer 69

blobs

Question 70

region in visual cortex V1 that participates in perception fo form and motion

Answer 70

interblobs (region that separates blobs)

Question 71

blobs were revealed by staining for

Answer 71

cytochrome oxidase

Question 72

in V2 heterogenuous layering is divided into ?

Answer 72

thick stripes, thin stripes and pale zones

Question 73

in V2, receive information from movement-sensitive neurons

Answer 73

thick stripes

Question 74

in V2, receive information from color-sensitive neurons

Answer 74

thin stripes

Question 75

in V2, receive information from form-sensitive neurons

Answer 75

pale zones

Question 76

``` fusiform face area: parahippocampal place area: lateral intraparietal area: anterior intraparietal area: parietal reach region: ```

Answer 76

- faces - scenes - eye movements - visual control of grasping - visually guided grasping

Question 77

facial agnosia and prospagnosia

Answer 77

unable to recognize faces