Final Exam

Question 1

Retina

Answer 1

Light-sensitive tissue at the back of the eye

Question 2

Fovea

Answer 2

Location of maximum visual acuity (aligned with center of cornea

Question 3

Optic Disk

Answer 3

Where optic nerve exits the eye (causes blindspot)

Question 4

Rods

Answer 4

-More numerous
-Low-light vision
-cannot distinguish colors
-do not respond to red

Question 5

Cones

Answer 5

-Color vision
-require more light
-Sensitive to red, blue, and green

Question 6

Rods Location

Answer 6

Outside fovea

Question 7

Cones Location

Answer 7

In fovea

Question 8

Photopic vision

Answer 8

Daylight vision (cone-based)

Question 9

Scotopic vision

Answer 9

Night-time vision (rod-based)

Question 10

Retinotopic maps

Answer 10

Parts of the visual field that are near each other are presented by neurons near each other

Question 11

V1

Answer 11

-Primary Visual cortex
-Responds to lines of a specific direction
-Neurons have different receptive fields which have to line up for excitation

Question 12

Ocular Dominance Columns

Answer 12

-There is still separation in the left and right eye in each hemisphere separating the same hemifield

-Combination of nature (genetic map) and nurture (experience)

-Born blind in one eye=no ocular dominance columns

-Born blind in both eyes=ocular dominance columns are present

Question 13

Purpose of Pain

Answer 13

A protective mechanism to warn us before permanent damage occurs

Question 14

Thermal nocieptors

Answer 14

-Activated by extreme cold (< 41degrees)
-Activated by extreme heat (>113 degrees)

Question 15

Mechanical nociceptors

Answer 15

Activated by strong pressure applied to skin

Question 16

Chemical nociceptors

Answer 16

Activated by certain chemicals

Question 17

Polymodal nociceptors

Answer 17

Activated by:
-Intense temperatures
-noxious chemicals
-intense mechanical signals

A range of different things; a more dull pain

Question 18

Myelination in pain pathways

Answer 18

-Thermal and mechanical nociceptors: Myelinated and non-myelinated

-Chemical and polymodal nociceptors: non-myelinated

Question 19

Why are some pain pathways non-myelinated?

Answer 19

Pain is one of the oldest systems and predates myelination

Question 20

How pain is mediated

Answer 20

-By pathways in the spinal cord
-Deep brain stimulation
-opiates as inhibitors
-Pain is sort of an illusion and can be modulated with different techniques

Question 21

NMDA receptors

Answer 21

-Cell needs to be sufficiently depolarized and a glutamate neurotransmitter needs to bind to the receptor

-Helps strengthen connections for memory

-Neurons that fire together wire together

Question 22

Semantic memories

Answer 22

Remembering facts that aren’t tied to an experience

Question 23

Procedural memories

Answer 23

-Like riding a bike or tying your shoe

-Requires repeated exposure

-Not necessarily tied to memories or describable

-Doesn’t use hippocampus

-Encoded in motor pathways

Question 24

Episodic memories

Answer 24

-Memory of events
-formed in hippocampus but stored in cortex

Question 25

Memory damage

Answer 25

-Semantic: can’t remember facts

-Procedural: can’t remember how to do things like put on a shirt

-Episodic: lose recent episodic memories and prevent you from forming new memories

Question 26

Hippocampus

Answer 26

-Involved in learning and memory

-Critical for formation of new memories, but not retention of old memories

-Old memories moved to cortical regions

Question 27

Amygdala

Answer 27

-Reciprocal connections with hippocampus

-involved in memory and emotional reactions, particularly fear

-strong emotional events tend to form very strong memories

Question 28

Role of forgetting

Answer 28

-Forgetting allows generalization

-Generalization allows you to recognize that two situations are similar

-Can transfer generalization from one situation to the next

Question 29

How neural prostheses work

Answer 29

-Electrical current stimulates or inhibits neural activity

-Work is being done on adding chemicals to encourage neurons to grow towards electrical devices

Question 30

Deep Brain Stimulation

Answer 30

-Stimulates the basal ganglia, stimulating the region that’s normally missing due to loss of dopaminergic neurons, stimulating more neurons in that pathway

-For Parkinson’s patients

Question 31

Retinal Implant

Answer 31

-Allows 20/1260 vision (legal blindness is 20/200)

-Patients learn to interpret visual patterns sent to the brain

-Retinal camera is mounted on glasses

-Patients move their head around to capture a visual scene

Question 32

Vestibular impalnt

Answer 32

-Skips normal process by directly stimulating the vestibular nerve

-For patients without a working vestibular system

-Not yet clinically available

Question 33

Cochlear Implant

Answer 33

-For those with lost or damaged inner hair cells

-Circumvents hair cells and directly stimulates auditory nerve

-Provides sensation of hearing; but not normal hearing

-You can measure electrically-evoked compound action potentials (corresponds to wave I of the ABR

-

Question 34

Evidence for place and temporal coding

Answer 34

-Location of electrode stimulated determined by the frequency of a sound

-You can stimulate place of electrode or rate in cochlear implant to increase pitch

Question 35

Limits of number of electrodes used in cochlear implants

Answer 35

-Current spread: Electrical fields will start interacting, even if electrodes give independent information.

-The more electrodes you put in, the closer together they get, the more you get a smearing effect.

-Distortion effect from electrical fields interacting between different electrodes, as well as what’s happening at the neural level