Chapter 2 Flashcards Preview

Psychology 135 (Sensation and Perception) > Chapter 2 Flashcards > Flashcards

Flashcards in Chapter 2 Flashcards Deck (68):
1

What is the plot of the amount of light absorbed versus the wavelength of the light?

Absorption spectrum

2

A process of adjusting the shape and thickness of the lens. Done in order to produce sharp images even at different distances from the stimulus.

Accommodation

3

This denotes the signal which lasts about 1 millisecond w/c happens from resting potential at (-70 mV) --> (+40 mV) --> negative again --> resting potential again.

Action potential

4

Other than bipolar and ganglion cells, and receptors, what are the two types of neurons that connect neurons across the retina? (2)
Signals traveling between bipolar and ganglion cells use this.

Amacrine cells

5

Eyeball is too long; images of faraway objects are not focused sharply.

Axial myopia

6

_____ is filled with fluid that conducts electrical signals.

Axon

7

Where do signals generated in the receptors travel to first?

Bipolar cells

8

This is a spot where there are no receptors (receptors are missing).

Blind spot

9

This is the key component of neuron. This contains mechanisms to keep the cell alive.

Cell body

10

What do you call a curve that is produced when an observer looks directly at a test light so that it stimulates only the cones in the fovea?

Cone spectral sensitivity curve

11

This occurs when a number of neurons synapse onto a single neuron.

(Neural) Convergence

12

The process of increasing sensitivity to light in the dark

Dark adaptation

13

A function which relates sensitivity to light to time in the dark, beginning when the lights are extinguished.

Dark adaptation Curve

14

"This threshold, the minimum amount
of energy necessary to just barely see the light, is converted to sensitivity; it is measured while the eyes are adapted to the light; 100,000 times greater than the light-adapted sensitivity mea- sured before dark adaptation began"

Dark-adapted sensitivity

15

These parts of the neuron branch out from the cell body to receive electrical signals from other neurons

Dendrites

16

Process which shows the inside of the neuron becoming more positive; causes the charge to change in the direction that triggers an action potential; an excitatory response

Depolarization

17

detachment of retina to pigment epithelium can occur as a result of traumatic injuries of the eye or head, as when a baseball player is hit in the eye by a line drive.

T/F

18

This occurs when the inside of the neuron becomes more positive; one of the two types of responses by the receptor sites.

Excitatory response

19

_____ point is he distance at which light becomes focused on the retina.

Far point

20

It only contains cones. When we look directly at an object, the object’s image falls on this one.

Fovea

21

Where do signals generated in the receptors travel to after the bipolar cells?

Ganglion cells

22

Other than bipolar and ganglion cells, and receptors, what are the two types of neurons that connect neurons across the retina? (2)
Signals travel between receptors through here.

Horizontal cells

23

This condition happens when the focus point for parallel rays of light is located behind the retina, usually because the eyeball is too short.

Hyperopia

24

They are molecules that carry an electrical charge; present in the liquid solution of neurons.

Ions

25

What happens in isomeization?

Retinal changes shape from being bent to straight and detaches from the opsin.

26

These signals (from receptors transported to neurons w/in retina) are transmitted out of the back of the eye in the optic nerve to a group of neurons

Lateral geniculate nucleus

27

20% of the focusing power goes here.

Lens

28

A condition most common in older people, destroys the cone- rich fovea and a small area that surrounds it. This creates a blind region in central vision, so when a person looks directly at something, he or she loses sight of it

Macular degeneration

29

Light of a single wavelength used when measuring one wavelength at a time and the observer's sensitivity to each wavelength

Monochromatic light

30

An inability to see distant objects clearly. The system of this condition brings parallel rays of light into focus at a point in front of the retina, so the image that reaches the retina is blurred.

Myopia

31

This distance at which the lens can no longer accommodate to bring close objects into focus.

Near point

32

filled with fluid that conducts electrical signals

Nerve fiber

33

interconnected groups of neurons

Neural circuits

34

This occurs when one of more neuron synapse into a single neuron.

Neural convergence

35

Electrical signals occur in structures

Neuron

36

These are chemicals released at the end of the neuron

Neurotransmitter

37

This contains both rods and cones and all of the retina outside of the fovea.

Peripheral retina

38

The ease with which a molecule can pass through the membrane; can be seen through the opening of channels (i.e. Na) and can be highly selective to a specific type of molecule.

Permeability

39

a layer that contains enzymes necessary for pigment regeneration.

Pigment epithelium

40

The increasing of distance of the near point as a person gets older.

Presbyopia

41

This is an important property of action potential; once the response is triggered, it travels all the way down the axon without decreasing in size.

Propagated response

42

A hole in the iris from which light passes through. Controls dilation or constriction of the pupil.

Pupil

43

Enhanced perception of short wavelengths during dark adaptation

Purkinje shift (p. 33)

44

These are small areas on the receiving neuron after the synapse; specific to neurotransmitters.

Receptor sites (p. 39)

45

A condition in which the cornea and/or the lens bends the light too much; images of faraway objects are not focused sharply

Refractive myopia (p. 25)

46

The interval between the time one nerve impulse occurs and the next one can be generated in the axon.

Refractory period (p. 37)

47

______ potential is when the axon or nerve fiber is at rest and the difference in potential between the tips of two electrodes is -70 mV, which stays the same as long as there are no signals in the neuron.

Resting potential (p. 36)

48

This condition first attacks the peripheral rod receptors and results in poor vision in the peripheral visual field; it is also generational.

Retinitis pigmentosa (p. 29)


49

A condition wherein there are no cones due to a rare genetic defect.

Rod monochromat (p. 31)

50

A process where cones are more sensitive to light at the beginning of dark adaptation, they control our vision during the early stages of adaptation, so we can’t see what the rods are doing.

Rod adaptation

51

To measure this curve, we measure the sensitivity after the eye is dark adapted (so the rods control vision because they are the most sensitive receptors) and present test ashes in the peripheral retina.

Rod spectral sensitivity curve (p. 33)

52

The place where the rods begin to determine the dark adaptation curve.

Rod–cone break (p. 31)


53

This can be measured by getting 1/threshold. High threshold (i.e. takes a high amt of light to be at the lower level of sensitivity).

Sensitivity

54

neurons specialized to respond to environmental stimuli

Sensory receptor (p. 35)


55

eye’s sensitivity to light as a function of the light’s wavelength.

Spectral sensitivity (p. 32)


56

relationship between wavelength and sensitivity; to see diff wavelengths in the visible spectrum

Spectral sensitivity curve (p. 32)


57

action potentials that occur in absence of stimuli from environment

Spontaneous activity (p. 38)

58

very small space between neurons

Synapse (p. 39)

59

minimum amount of energy necessary to just barely see the light

Threshold

60

transformation of one form of energy into another form of energy; transformation of light energy into electrical energy—occurs in the receptors for vision: the rods and cones

Transduction (p. 26)


61

Ability to see details clearly.

Visual acuity (p. 43)


62

These are molecules which absorb light and found in the outer segments of visual receptors.

Visual pigment (p. 23)


63

A process w/c accounts for change in shape and separation from the opsin causing the molecule to become lighter.

Visual pigment bleaching (p. 31)

64

A process which occurs more rapidly in the cones than in the rods; rods take about 20 to 30 minutes to reach their maximum sensitivity (point R on the curve), compared to only 3 to 4 minutes for the cones (point C) because of this.

Visual pigment regeneration (p. 32)

65

what are the two types of responses that occur at the receptor sites?

excitatory and inhibitory responses

66

When electrical signal reaches the synapse, it triggers a chemical process that causes a new electrical signal in the receiving neuron. Where do the nature of these signals depend on?

type of transmitter released and nature of receptor site in the receiving neuron

67

What increases the chance that a neuron will generate action potentials and is associated with increasing rates of nerve firing?

Excitation

68

What decreases the chance that a neuron will generate action potentials and is associated with lowering rates of nerve firing?

Inhibition