Ch. 2: Sensation and Perception

Question 1

What are sensory receptors?

Answer 1

neurons that respond to stimuli by triggering electrical signals that carry information to the central nervous system
ganglia are collections of neron bodys outside of CNS and will send input to projection areas into the brain

Question 2

What is absolute threshold?

Answer 2

minimum stimulus energy needed to activate a sensory system

Question 3

What is the threshold of conscious perception?

Answer 3

level of intensity of a stimulus for te brain to fully process the information

Question 4

What is a difference threshold?

Answer 4

mimimum difference between two stimli to be percieved as difference

Question 5

What is Weber’s Law?

Answer 5

the difference threshold for a simulus is proportional to the magnitude of stimulus and proportional to the range of possible stimuli

applying a ratio

Question 6

What is signal detection theory?

Answer 6

effects of nonsensory factors (experiences, motives, expectations) on peception of stimuli

Question 7

What is adaptation?

Answer 7

ability to detect a stimulus can change over time

Question 8

Explain the process of light entering the eye.

Answer 8

1. cornea: gathers and focuses light
2. anterior chamer
3. iris
4. posterior chamber
5. iris: contains dilator and constrictor pupillae to adjust pupuil, the iris is conitious with the choroid (conective tissue for nutrients) and the ciliary body
6. lens: controls refaction of incoming light (ciliary muscle changes lens shape)
7. vitereous humor: transparent gel supporting the retina
8. retina: converts incoming light to electrical signals

Question 9

What is accomodation?

Answer 9

ciliary muscpes contract and pull on suspensory ligaments to change to shape of the lens so that it may focus

Question 10

What is the ciliary body?

Answer 10

produces aqueous humor that drains through the canal of Schlemm

Question 11

What is the difference between rods and cones?

Answer 11

rods detect light and dark
cones detect color

both are located in the retina

Question 12

What is the macula and the fovea?

Answer 12

the macula is the central visual field in the retina which has mostly cones with the fovea being the center of the macula which only has cones

Question 13

What are bipolar cells?

Answer 13

send signals from rods and cones to ganglion cells

Question 14

What are ganglion cells?

Answer 14

recieve signals form bipolar cells and their axons form the optic nerve

Question 15

What are nasal/temporal visual fields and retinal fibers?

Answer 15

nasal is inside, nose side and temporal is outside
if the object is in that field, it is detected by the opposite retinal fibers

Question 16

Explain the visual pathway from the eye to the visual cortex.

Answer 16

1. optic nerves
2. optic chiasm - nasal fibers from left and right cross paths
3. optic tracts
4. lateral geniculate nucleus (LGN) in thalamus
5. visual cortex in occipital lobe

Question 17

What is parallel processing?

Answer 17

brain’s ability to analyze information about color, form, motionm=, depth simulatneously

Question 18

What are parvocellular cells?

Answer 18

detects form

Question 19

What are magnocellular cells?

Answer 19

detects motion

Question 20

What are binocular neurons?

Answer 20

detect depth

Question 21

What is the outer ear?

Answer 21

contains the auricle (outside part of ear) and directs sound waves to tympanic membrane (eardrum) to bibrate at thefrequency of the incoming sound

Question 22

What is the middle ear?

Answer 22

the middle ear has three small bones called ossicles that transmit and amplify the vibrations to the inner ear

malleus, incus, stapes

Question 23

What is the inner ear?

Answer 23

the inner ear is a bony labyrinth that has the cochlea, vestibule, and semicircular canals
it is filled tubes and chambers called the membranous layrinth
it is filled with a fluid called the endolympth
there is also a thin layer of fluid called perilymph that transmits vibrations from the outside and cusions inner ear

Question 24

What does the cochlea do?

Answer 24

detects sound

Question 25

What does the vestiule do?

Answer 25

utricle and saccule
detect linear acceleration

Question 26

What do the semicircular canals do?

Answer 26

detect rotational acceleration

Question 27

Explain the auditory pathways.

Answer 27

sounds starts at the cochlea and travels through the vestibulocochlear nerve and medial geniculate nucleus (MGN in the thalamus to reach the auditory cortex in the temporal nerve

Question 28

What do olfactory chemoreceptors do?

Answer 28

bind to chemical stimuli and cause a signal to the oftactory bul and tract to the brain

Question 29

How do we taste?

Answer 29

dissolved compounds are detected ny chemoreceptors (taste buds which take the for of papillae) they then transmit the information to the taste center in the thalamus and further into the brain

Question 30

What is somatosensation?

Answer 30

pressure, vibration, pain (nociceptors), temperature

Question 31

What is proprioception?

Answer 31

Ability to tell where your body is in space

Question 32

What is bottom-up processing?

Answer 32

Slower recognition of parallel processing and feature detection

Question 33

What is top-down processing?

Answer 33

Recognition by memories and expectations, little attention to detail and more prone to error

Question 34

What is perceptual organization?

Answer 34

Ability to create a complex picture or idea by combining both top-down and bottom-up. Integrates depth, form, motion, and constancy

Question 35

What is the law of proximity?

Answer 35

Elements close together tend to be perceived as a unit

Question 36

What is the law of similarity?

Answer 36

Objects similar in appearance tend to be grouped together

Question 37

What is the law of good continuation?

Answer 37

Elements that appear to follow the same pathway tend to be grouped together

Question 38

What is the law of closure?

Answer 38

When a space is enclosed by a group of lines it is perceived as a complete or closed line

Question 39

What is the law of pragnanz?

Answer 39

Perceptual organization will always be regular, simple, and as symmetric as possible