Sensation and Perception

Question 1

What is the difference between sensation and perception ?

Answer 1

Sensation is the ability to take in physical, auditory, electromagnetic, and etc. info form the internal and external environment & convert this info into electrical signals in the nervous system. Perception would be processing this info in the nervous system in order to make sense of the significance of the info.

Question 2

Neurons that respond to sensory receptors by triggering electrical signals that carry info to the CNS is termed?

Answer 2

Sensory receptors

Question 3

How do proximal and distal stimulus’ work cooperatively?

Answer 3

Proximal stimuli affect sensory receptors and in turn inform the body of the presence of the distal stimuli

Question 4

Collections of neuron cell bodies found outside the CNS are ?

Answer 4

Ganglia

Question 5

What are the most essential receptors and their functions?

Answer 5

Photoreceptors: respond to electromagnetic waves in the visible spectrum (sight)
Mechanoreceptors: respond to pressure or movement (auditory)
Nociceptors: respond to painful or noxious stimuli (somatosensation)
Thermoreceptors: respond to changes in temp (thermosensation)
Osmoreceptors: respond to osmolarity of blood (H2O homeostasis)
Olfactory receptors: respond to volatile compounds: (smell)
Taste receptors: respond to dissolved compounds (taste)

Question 6

The min energy of a stimulus needed to activate a sensory system is termed ?

Answer 6

Absolute Threshold

-Threshold in sensation and not perception

Question 7

The level of intensity that a stimulus must have in order to be concisely perceived by the brain is the_____?

Answer 7

Threshold of conscious perception

-Info received by CNS but does not pass this threshold is termed subliminal perception

Question 8

What is the difference between absolute threshold and the threshold of conscious perception ?

Answer 8

A stimulus below the absolute threshold will not transduce (never reaches CNS), but a stimulus below the threshold of conscious perception will still arrive at CNS but will not be strong enough to reach the regions of the brain that will elicit a reaction/response

Question 9

The min change in magnitude required for an observer to perceive that 2 different stimuli are in fact different is the ______?

Answer 9

Difference threshold (just noticeable difference)
-Basis for discrimination testing (change in stimulus/magnitude of original stimulus)

Question 10

The idea that difference thresholds are proportional and must be computed as percentages is termed ?

Answer 10

Weber’s Law

Question 11

The study of how internal and external factors influence thresholds of sensation and perception is termed ?

Answer 11

Signal Detection Theory

Question 12

Trials in which the signal is presented are _____, and those where it’s not present are _______?

Answer 12

Noise trials and catch trials (respectively)

• Hit: signal presented and correctly detected
• Miss: signals presented but not detected
• False alarm: signal not presented but claimed to be detected
• Correct negative: no signal presented and correctly identified that it was not present

Question 13

Most of the exposed portion of the eye is covered by a thick structural layer known as the_____

Answer 13

Sclera (white of the eye)

Question 14

The eye is supplied w/ nutrients by 2 sets of blood vessels: _____ & ______

Answer 14

Choroidal vessels (between sclera and retina)
Retinal vessels

Question 15

The innermost layer of the eye that contains the photoreceptors that transduce light into chemical info the brain can process is the _____

Answer 15

Retina

Question 16

Light 1st passes through the _____ which gathers and focuses incoming light

Answer 16

Cornea

Question 17

The front of the eye is divided into the ______ & the _______

Answer 17

Anterior chamber (in front of the iris)
Posterior chamber (between the iris and the lens)

Question 18

The colored part of the eye (iris) is composed of which 2 muscles ?

Answer 18

Dilator pupillae (opens the pupil under sympathetic stimulation)
Constrictor pupillae (constricts the pupil under parasympathetic stimulation)

Question 19

The vascular layer of connective tissue that provides supports and nourishment to the retina is termed ?

Answer 19

Choroid

Question 20

What produces the aqueous humor of the eye and where does it drain ?

Answer 20

Ciliary body & Canal of Schlemm

Question 21

The ____ controls the refraction of incoming light.

Answer 21

Lens

Question 22

The transparent gel that lies behind the lens and supports the retina is termed ?

Answer 22

Vitreous humor

Question 23

The process of the ciliary muscles contracting and pulling the suspensory ligaments to change the shape of the lens to focus on an image is termed ?

Answer 23

Accommodation

Question 24

Which 2 photoreceptors compose the duplexity theory of light ?

Answer 24

Cones (detect color)

Rods (detect light and dark)

Question 25

The central section of the retina ____ has the highest conc of cones

Answer 25

Macula | -Centermost region (fovea) has cones only

Question 26

Rods and cones synapse directly w/ _____, which then synapse w/ _____

Answer 26

``` Bipolar cells (highlight gradients btwn adjacent rods or cones) Ganglion cells (axons group together to form optic nerve) ```

Question 27

What is the visual pathway from the eyes to the brain?

Answer 27

1. Optic chiasm: fibers from nasal half of each retina cross paths 2. Optic tracts: fibers corresponding to the left visual field from both eyes project into the right side of the brain (& vice versa) 3. (option 1) Lateral geniculate nucleus (LGN): synapse nerves that pass through radiations in temporal and parietal lobes to the visual cortex in the occipital lobe 3. (option 2) Superior colliculus: controls some reflexive responses to visual stimuli and reflexive eye movements

Question 28

The brain's ability to analyze info regarding color, form, motion, & depth simultaneously using independent pathways in the brain is termed ?

Answer 28

Parallel processing

Question 29

The shape of an object & our ability to discriminate an object of interest from the background by detecting its boundaries it termed ?

Answer 29

Form

Question 30

Parvocellular cells have very high color spatial resolution that allows us to do what ?

Answer 30

Detect fine detail when thoroughly examining an object | -Can only work with stationary or slow moving objects due to low temporal resolution

Question 31

In contrast to parvocellular cells, magnocellular cells have the ability do what ?

Answer 31

Detect motion of an object due to high temporal resolution (provide blurry but moving image of an object) -Don't really detect fin details once object is in motion due to low spatial resolution

Question 32

Our ability to discriminate the 3D shape of our environment & judge the distance of objects within it is based on ?

Answer 32

Depth perception | -Binocular neurons responsible for detecting differences in hemispheres

Question 33

Our ability to associate certain patterns of stimuli w/ expected behaviors/outcomes is assisted by specialized cells in the visual cortex known as ?

Answer 33

Feature detectors

Question 34

What are the parts and functions of the outer ear ?

Answer 34

1. Pinna (auricle): channel sound waves into EAC 2. External auditory canal: transmit sound waves to eardrum 3. Tympanic membrane (eardrum): vibrates in phase with incoming sound (louder sounds = higher intensity)

Question 35

What are the components and functions of the middle ear ?

Answer 35

1. Ossicles: Malleus (hammer)--->Incus (anvil)---> Stapes (stirrup) {transmit and amplify vibrations from TM to inner ear} 2. Connected to nasal cavity via eustachian tube: equalizes pressure between middle ear and environment

Question 36

The membranous labyrinth is filled by a K+ rich fluid called ?

Answer 36

Endolymph

Question 37

_____ simultaneously transmits vibrations from the outside world and cushions the inner ear structures.

Answer 37

Perilymph

Question 38

The spiral shaped organ that contains hearing receptors is termed ?

Answer 38

Cochlea -Composed of 3 parts known as scalae Organ of Corti: middle scalae that houses the hearing apparatus (rests on basilar membrane) Hair cells in O of C transduce physical stimuli into an electrical signal (carried to CNS by auditory [vestibulocochlear] nerve) -Other 2 scalae filled w/ perilymph

Question 39

A membrane covered hole in the cochlea that permits perilymph to move within the cochlea is termed ?

Answer 39

Round Window

Question 40

The vestibule is the portion of the bony labyrinth that contains which 2 structures ?

Answer 40

Utricle and Saccule - Sensitive to linear acceleration, in turn used as part of the balancing apparatus & to determine one's orientation in 3D space - Contain otoliths (modified hair cells) that resist acceleration of the body

Question 41

Semicircular canals are sensitive to ?

Answer 41

Rotational motion - End in ampulla (where hair cells are located) - Endolymph in SC resist motion when the head rotates

Question 42

What is the auditory pathway of sound to the brain ?

Answer 42

Vestibulocochlear nerve-->brainstem-->medial geniculate nucleus (MGN) of thalamus--> nerve fibers project to auditory cortex--> some info sent to superior olive (localizes sound) or inferior colliculus (startle reflex & helps keep eyes fixated when head is turned)

Question 43

Which theory states that the location of a hair cell on the basilar membrane determines the perception of pitch when that hair cell is vibrated ?

Answer 43

Place theory

Question 44

What is the olfactory pathway of smell to the brain ?

Answer 44

Odor inhaled to nasal passages--> olfactory nerves in olfactory epithelium--> olfactory bulb---> relayed via olfactory tract to higher regions in the brain

Question 45

Tastes are detected by _____, which are sensitive to dissolved compounds.

Answer 45

Chemoreceptors

Question 46

The 5 different types of receptors that receive tactile info are:___?

Answer 46

Pacinian corpuscles: respond to deep pressure & vibration Meissner corpuscles: respond to light touch Merkel cells (discs): respond to deep pressure & texture Ruffini endings: respond to stretch Free nerve endings: respond to pain and temp

Question 47

The min distance necessary between 2 points of stimulation on the skin such that the points will be felt as 2 distinct stimuli is known as ?

Answer 47

A 2 point threshold

Question 48

The theory that proposes that a special "gating" mechanism can turn pain signals on or off to affect whether we receive pain or not is termed ?

Answer 48

Gate theory of pain | -Superseded by other theories but still helpful

Question 49

The ability to tell where one's body is in space is termed ?

Answer 49

Proprioception (kinesthetic sense) | -Proprioceptors found mostly in muscles and joints & play critical roles in hand-eye coordination, balance, & mobility

Question 50

Object recognition by parallel processing & feature detection is known as ?

Answer 50

Bottom-up processing (data-driven) -Brain takes the individual sensory stimuli & combines them together to create a cohesive image before determining what the object is

Question 51

Memories and expectations that allow the brain to recognize the whole object & then recognize the components based on the expectations is based on which theory ?

Answer 51

Top-down processing (conceptually driven) | -Allows us to quickly recognize objects w/o needing to analyze their specific parts

Question 52

The ability to create a complete picture/idea by combining top-down & bottom-up processing w/ all other sensory clues gathered from an object is ?

Answer 52

Perceptual organization

Question 53

The visual cue that requires only 1 eye & include relative size, interposition, motion parallax, linear perspective, & other minor cues is known as ?

Answer 53

Monocular cues - relative size: objects appear larger the closer they are - interposition: when 2 objects overlap, the 1 in front is closer - linear perspective: convergence of parallel lines @ a distance - motion parallax: perception that objects closer to us seem to move faster when we change our field of vision

Question 54

Which visual cue primarily involves retinal disparity (slight difference in images projected on the 2 retinas)?

Answer 54

Binocular cues | -convergence: brain detects the angle between the two eyes required to bring an object into focus

Question 55

Our ability to perceive that certain characteristics of objects remain the same, despite changes in the environment is known as ?

Answer 55

Constancy

Question 56

A set of general rules that account for the fact that the brain tends to view incomplete stimuli in organized. patterned ways is termed ?

Answer 56

Gestalt principles

Question 57

"Elements close to one another tend to be perceived as a unit" is which law ?

Answer 57

Law of proximity

Question 58

"Objects that are similar tend to be grouped together" is which law?

Answer 58

Law of similarity

Question 59

"Elements that appear to follow in the same pathway tend to be grouped together" is which law?

Answer 59

Law of good continuation

Question 60

Perceiving contours or shapes that are not actually present in the stimulus is termed?

Answer 60

Subjective contours

Question 61

"When a space is enclosed by a contour, the space tends to be perceived as a complete figure" is which law ?

Answer 61

Law of closure

Question 62

Altogether, Gestalt principles are governed by which law ?

Answer 62

Law of pragnanz: perceptual organization will always be as regular, simple, & symmetric as possible