Chapter 4

Question 1

Sensation

Answer 1

simple stimulation of a sense organ; basic registration of light , sound, pressure, odor, or taste as parts of your body interact with the physical world.

Question 2

Perception

Answer 2

the organization, identification, and interpretation of as sensation in order to form a mental representation.

Question 3

Sensation and Perception are-

Answer 3

Actual components you experience; but are 2 distinct tests that work together for an experience.

Question 4

How do sensory receptors communicate through the brain?

Answer 4

Transduction

Question 5

Transduction (where does it happen ?)

Answer 5

• occurs when many sensors in the body convert physical signals from the environment into encoded neural signals sent to the central nervous system.
• the eyes and ears

Question 6

3 basic Tasks of Sensation and Perception ?

Answer 6

• Translate incoming info into neural impulses
• identify message components
• produce a stable interpretation

Question 7

The human perceptual system is better at detecting __ in stimulation than the simple onset or offset of stimulation.

Answer 7

• changes

Question 8

JND ( just noticeable difference)

Answer 8

• the smallest amount of change in a stimulus that can just barely be detected.
• Is CONSTANT
• not a fixed quantity
• proportional to the intensity of the stimulus.

Question 9

JND was noticed by __

Answer 9

• Ernst Weber

Question 10

What is “Weber’s law” ?

Answer 10

• The just noticeable difference of a stimulus is a constant proportion despite variations in intensity.
• Noticeable difference is the proportion of the size of the standard.

Question 11

Example of “Weber’s law”?

Answer 11

• if you picked up a 1 ounce envelope and a 2 ounce after, you would notice the difference between them. But if you picked up a 20 pound package- then a 20-pound 1 ounce package, you’d detect no difference at all between them.

Question 12

Sensory Adaptation

Answer 12

• Sensitivity to prolonged stimulation tends to decline over time as an organism adapts to current conditions.
• responds more strongly to changes in stimulation more so than constant

Question 13

Light waves vary in…

Answer 13

• height and wavelengths.

Question 14

3 physical properties of light waves

Answer 14

• Length ( determines what colors we see )
• Amplitude (how hight the peaks are, determines what we perceive as brightness)
• Purity (number of distinct wavelengths that make up light/ determines saturation or richness of the colors.)

Question 15

light

Answer 15

translated to neural impulse where transduction happens.

Question 16

Cornea

Answer 16

• Outer covering of the eye (light gray) (protective covering)
• clear smooth outer tissue where light first passes through

Question 17

Pupil

Answer 17

• dark center of the eye (dilates to let light in) (or constricts to keep light out)
• hole in the colored part of the eye

Question 18

iris

Answer 18

• colored part of the eye. (donut shaped muscle) ( controls constriction or dilation of the pupil)
• controls the amount of light that can enter your eye.

Question 19

lens

Answer 19

• (green portion) if you have vision problems this is where it comes from. uses [accommodation]

Question 20

accommodation

Answer 20

• process by which the eye maintains a clear image on the retina
• lens changes shape to focus nearby or faraway objects on the retina

Question 21

retina

Answer 21

• light sensitive tissue lining the back of the eyeball
• where transduction happens
• light is translated into that neural impulse
• made up of “rods and cones”

Question 22

myopia

Answer 22

• nearsightedness

- condition where eyeball is too long and images are focused in front of the retina

Question 23

hyperopia

Answer 23

• farsightedness

- if eyeball is too short , images are focused behind the retina

Question 24

2 types of photoreceptor cells

Answer 24

• rods

- cones

Question 25

cones

Answer 25

-detect color , operate under normal daylight conditions, and allow us to focus on fine detail.

Question 26

Rods

Answer 26

- become active under low-light conditions for night vision | - much more sensitive than cones

Question 27

fovea

Answer 27

-an area of the retina where vision is the clearest and there are no rods at all.

Question 28

similarity

Answer 28

- Regions that are similar in color, lightness, shape, or texture are perceived as belonging to the same object.

Question 29

closure

Answer 29

- we tend to fill in missing elements of a visual scene, allowing us to perceive edges that are separated by gaps as belonging to complete objects.

Question 30

continuation

Answer 30

- when edges or contours have the same orientation, we tend to group them together perceptually.

Question 31

frequency (wavelength of the ear)

Answer 31

- how often the peak in air pressure passes the ear or a microphone , measured in cycles per second (Hertz Hz) - perceived by humans as changes in (pitch)

Question 32

Pitch

Answer 32

- how high or low a sound is | - changes in the physical frequency of a sound wave are perceived

Question 33

amplitude (sound wave of the ear)

Answer 33

- refers to it's height, relative to the threshold for human hearing - corresponds to loudness - ex.) sound of leaves rustling in the breeze

Question 34

loudness

Answer 34

- corresponds to amplitude | - sound's intensity

Question 35

complexity (sound waves of the ear)

Answer 35

- mix of frequencies | - corresponds to timbre

Question 36

timbre

Answer 36

- listener's experience of sound quality or resonance - offers us information about the nature of sound. - same note played at the same loudness produces a perceptually different experience depending on whether out was played on a flute versus a trumpet

Question 37

Pinna of the ear

Answer 37

-airtight flap of skin that vibrates in response to sound waves gathered by the pinna and channeled through the canal

Question 38

Cochlea

Answer 38

- a fluid filled tube that is the organ of (auditory transduction)

Question 39

basilar membrane

Answer 39

- structure in the inner ear that undulated when vibrations from the ossicles reach the cochlear fluid.

Question 40

Haptic perception

Answer 40

active exploration of the environment by touching and grasping objects with our hands.

Question 41

Touch

Answer 41

- mechanical energy - different locations on the body project sensory signals to different locations in the somatosensory cortex in the parietal lobe. - has a powerful effect on our decisions and judgments.

Question 42

Smell / Olfaction

Answer 42

- least understood sense - only one directly connected to the forebrain with pathways into the frontal lobe, amygdala , and other forebrain structures. - smell has a close relationship with emotional and social behavior. - Olfactory receptor neurons (ORNs), receptor cells that initiate the sense of smell

Question 43

Taste / gustation

Answer 43

- hundreds of taste buds - organ of taste transduction - 5,000 to 10,000 taste buds fairly evenly distributed over the tongue, roof of the mouth , and upper throat.

Question 44

pain

Answer 44

- fast acting (A) delta fibers transmit initial sharp pain one might feel right away from a sudden injury - (C) fibers transmit longer-lasting, duller pain that persitis after initial injury. - if (A) and (C) delta fibers are impaired in cases of congenital insensitivity to pain, that can be life threatening.

Question 45

PAG ( periaqueductal gray)

Answer 45

- under high stress, naturally occurring endorphins can activate the PAG to send inhibitory signals to neurons in the spinal cord that then suppress pain signals to the brain - activated through the action of opiate drugs, such as morphine.

Question 46

absolute threshold

Answer 46

- the minimal intensity needed to just barely detect a stimulus in 50% of the trials. - it's a boundary between awareness and unawareness.