Behavioral Sciences 2: Sensation and Perception

Question 1

sensation

Answer 1

the conversion/transduction of physical, electromagnetic, auditory, and other info from the internal and external environment into electrical signals in the nervous system

Question 2

perception

Answer 2

the processing of sensory info to make sense of its significance

Question 3

distal stimuli

Answer 3

stimuli that originate outside of the body

ex. campfire

Question 4

proximal stimuli

Answer 4

stimuli that interact directly with and affect the sensory receptors and inform the observer about distal stimuli

ex. light, heat

Question 5

absolute threshold

Answer 5

the minimum of stimulus energy that is needed to activate a sensory system

Question 6

threshold of conscious perception

Answer 6

the minimum of stimulus energy that will create a signal large enough in size and long enough in duration to be brought into awareness

stimulus does not reach higher-order brain region

Question 7

subliminal perception

Answer 7

the perception of a stimulus below a given threshold

Question 8

difference threshold / just-noticeable difference

Answer 8

the minimum difference in magnitude between two stimuli before one can perceive this difference

Question 9

Weber’s law

Answer 9

the jnd for a stimulus is proportional to the magnitude of the stimulus, and this ratio is constant over most of the range of possible stimuli

Question 10

signal detection theory

Answer 10

perception of stimuli can be affected by nonsensory factors like memory, motives, expectations

changes in our perception of the same stimuli depending on both internal and external context

Question 11

fusiform gyrus

Answer 11

a part of the visual system in the brain, and plays a role in high level visual processing and recognition

Question 12

response bias

Answer 12

the tendency of subjects to systematically respond to a stimulus in a particular way due to nonsensory factors

Question 13

adaption

Answer 13

decrease in response to a stimulus over time

Question 14

dilator pupillae

Answer 14

muscle in the iris which opens the pupil under sympathetic stimulation

Question 15

constrictor pupillae

Answer 15

muscle in the iris that constricts the pupil under parasympathetic stimulation

Question 16

accommodation

Answer 16

contraction of eye muscles that pulls on the suspensory ligaments and changes the shape of the lens

Question 17

duplexity/duplicity theory of vision

Answer 17

theory that states that the retina contains two kinds of photoreceptors: those for light-dark detection (rods) and those for color (cones)

Question 18

rhodopsin

Answer 18

pigment in rods that allows for sensation of light and dark

Question 19

visual pathway in eye

Answer 19

rods/cones -> bipolar cells -> ganglion cells -> horizontal cells -> amacrine cells -> optic nerve

the more convergence, the less details from the photoreceptor cells retained

less cones converge than rods, so color vision is more sensitive to fine detail

horizontal/amacrine cells accentuate slight differences in each bipolar cell - increase contrasts

Question 20

visual pathway from eye to brain

Answer 20

each eye’s right visual field projects onto left half of its retina

all fibers corresponding to right visual field from both eyes project into the left side of the brain

goes to visual cortex in occipital lobe and inputs at superior colliculus

eye -> optic nerve -> optic chiasm -> optic tracts -> LGN -> visual cortex

Question 21

optic chasm

Answer 21

location where fibers from the nasal retinas of both eyes cross paths

carry info from temporal fields

Question 22

lateral geniculate nucleus

Answer 22

nucleus in the thalamus that assess visual inputs

Question 23

parallel processing

Answer 23

the ability to simultaneously analyze and combine info regarding color, shape, motion and compare to our memories to determine what’s being seen

Question 24

parvocellular cells

Answer 24

cells that detect shape

high spatial resolution - allow fine detail

low temporal resolution - can only work with stationary/slow objects

Question 25

magnocellular cells

Answer 25

cells that detect **motion** low spatial resolution - **no fine detail** high temporal resolution - allow for **motion sensing**

Question 26

outer ear

Answer 26

pinna (auricle), external auditory canal, tympanic membrane

Question 27

tympanic membrane

Answer 27

part of the outer ear vibrates at a **higher rate for high frequency sounds** louder sounds have greater intensity; higher amplitude

Question 28

middle ear

Answer 28

malleus, incus, stapes connects to nasal cavity through **Eustachian tube**

Question 29

inner ear

Answer 29

bony labyrinth within a membranous labyrinth

Question 30

membranous labyrinth

Answer 30

consists of cochlea, utricle and saccule, semicircular canal filled with K+ - rich **endolymph**

Question 31

cochlea

Answer 31

part of the ear that detects sound divided into 3 parts that run the entire length - scala vestibuli, scala tympani middle filled with endolymph - has organ of Corti, basilar membrane, tectorial membrane top and bottom continuous with oval and round window, filled with perilymph

Question 32

utricle and saccule

Answer 32

part of the inner ear that detects **linear acceleration** within the vestibule contain modified hair cells covered with **otoliths** as body accelerates, otoliths resist motion, stimulate underlying hair cells

Question 33

semicircular canals

Answer 33

part of the inner ear that detects **rotational acceleration** arranged perpendicularly, ending in **ampulla** where hair cells are head rotates, endolymph resists motion, bending hair cells

Question 34

auditory pathway

Answer 34

**cochlea** -\> **vestibulocochlear nerve** -\> **MGN** -\> **auditory** also projects to **superior olive** for sound localization or to **inferior colliculus**

Question 35

medial geniculate nucleus

Answer 35

nucleus in the **thalamus** that assesses **auditory input**

Question 36

hair cells

Answer 36

cells that respond to **mechanical stimulus** have tufts of **stereocilia** on top surface that move with vibrations in endolymph movement opens ion channels -\> receptor potential

Question 37

place theory

Answer 37

the **locations** of a hair cell on basilar membrane **determine the perception of a pitch** when the hair cell is vibrated **high frequency pitch** - vibrations very close to oval window (base) **low frequency pitch** - vibrations away from oval (apex) cochlea is **tonotopically** organized - where hair cells vibrate indicate pitch of sound

Question 38

olfactory pathway

Answer 38

**nasal passage** -\> **olfactory nerve** -\> **olfactory epithelium** -\> **olfactory bulb** -\> **olfactory tract** -\> **brain**

Question 39

somatosensation

Answer 39

pressure, vibration, pain, temperature

Question 40

Pacinian corpuscles

Answer 40

receptors that respond to **deep pressure and vibration**

Question 41

meissner corpuscles

Answer 41

receptors that respond to **light touch**

Question 42

merkle cells/disc

Answer 42

receptors that respond to **deep pressure and texture**

Question 43

ruffini endings

Answer 43

receptors that respond to **stretch**

Question 44

free nerve endings

Answer 44

receptors that respond to **pain and temperature**

Question 45

pathway of somatosensation

Answer 45

**receptors** -\> **CNS** -\> **somatosensory cortex** in parietal lobe

Question 46

two point thresholds

Answer 46

the **minimum distance** necessary between **two points of stimulation on the skin** such that the points will be felt as **two distinct stimuli** depends on **nerve density**

Question 47

physiological zero

Answer 47

**normal temperature of the skin** to which objects are compared to determine if they feel "warm" or "cold"

Question 48

gate theory of pain

Answer 48

pain sensation is **reduced** when **other somatosensory signals are present**

Question 49

proprioception

Answer 49

kinesthetic sense the ability to tell **where one's body is in 3D space** depends on **receptors in muscles/joints** provides **hand-eye coordination, balance, mobility**

Question 50

bottom-up (data-driven) processing

Answer 50

recognition by **parallel processing and feature detection** **slower**, less prone to mistakes takes individual sensory stimuli and **combines it** to make a cohesive image

Question 51

top-down (conceptually-driven) processing

Answer 51

recognition by **memories and expectations** recognition of **whole objects and its components** **quicker**, more prone to mistakes

Question 52

perceptual organization

Answer 52

our ability to use **top-down and bottom-up processing in tandem** with all other sensory clues about an object to **complete a picture/idea**

Question 53

monocular depth perception

Answer 53

perception that reveals **relative size, partial obscuring, the convergence of parallel lines at a distance, lighting, shadowing**

Question 54

binocular depth perception

Answer 54

perception that reveals **slight differences projected** on the retinas

Question 55

gestalt principles

Answer 55

tools that the brain uses to **infer missing parts of a picture** when a picture is incomplete

Question 56

law of proximity

Answer 56

Gestalt principle that states that elements **close to one another** tend to be perceived as a **unit**

Question 57

law of similarity

Answer 57

Gestalt principle that states that objects that are **similar are grouped together**

Question 58

law of good continuation

Answer 58

Gestalt principle that states that **elements that appear to follow the same pathway tend to be grouped together**

Question 59

subjective contours

Answer 59

Gestalt principle that refers to the **perception of nonexistent edges** in figures, based on surrounding visual cues

Question 60

law of closure

Answer 60

Gestalt principle that states that when a **space is enclosed by a group of lines**, it is perceived as a **complete or closed line**

Question 61

law of Pragnanz

Answer 61

Gestalt principle that states that **perceptual organization** will always be **as regular, simple, symmetric** as possible