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concept 6a Flashcards

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1
Q

sensation

A

transduction of physical stimuli into neurological signals

performed by receptors in the peripheral nervous system which forward stimuli to central nervous system

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2
Q

transduction

A

the conversion of physical, electromagnetic, auditory, and other info from our internal and external environment to electrical signals in the nervous system

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3
Q

perception

A

processing of this information to make sense of its significance
helps us make sense of the world

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4
Q

sensory receptors

A

neurons that respond to stimuli and trigger electrical signals
encode multiple aspects of a stimulus
differ from one sense to another

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5
Q

common sensory receptors

A 
photoreceptors 
hair cells 
nociceptors
thermoreceptors 
osmoreceptors 
olfactory receptors 
taste receptors
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6
Q

photoreceptors

A

respond to electromagnetic waves in the visible spectrum (sight)

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7
Q

hair cells

A

respond to movement of fluid in the inner ear structures

hearing, rotational and linear acceleration

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8
Q

nociceptors

A

respond to painful or noxious stimuli
somatosensation
sense pain

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9
Q

thermoreceptors

A

respond to change in temperature

somatosensation

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10
Q

osmoreceptors

A

respond to the osmolarity of the blood

water homeostasis

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11
Q

olfactory receptors

A

respond to volatile compounds

smell

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12
Q

taste receptors

A

respond to dissolved compounds

taste

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13
Q

ganglion

A

collection of neuron cell bodies found outside the central nervous system
receive the stimulus and transmit the data to the central nervous system

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14
Q

projection areas

A

areas in the brain that further analyze the information from the ganglia
once transduction occurs the electrochemical energy is sent to projection areas by neural pathways

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15
Q

threshold

A

the minimum amount of a stimulus that renders a difference in perception
3 types: absolute threshold, threshold of conscious perception, and the difference threshold

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16
Q

absolute threshold

A

the minimum of stimulus energy that is needed to activate a sensory system
threshold of sensation
determines if the sensation is enough to be converted into action potentials
*minimum intensity at which a stimulus will be transduced

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17
Q

threshold of conscious perception

A 
subliminal perception (limina means threshold)
perception of a stimulus below a given threshold 
stimulus arrives at the central nervous system but does not reach he higher-order brain regions that control attention and consciousness
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18
Q

difference threshold

A

just-noticeable difference (jnd)
minimum difference in magnitude b/w 2 stimuli before one can perceive this difference
if the difference b/w stimuli is small then they will be perceived as the same

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19
Q

Weber’s law

A

states that there is a constant ratio between the change in stimulus magnitude needed to produce a jnd and the magnitude of the original stimulus
(change needed/original stimulus) gives percent of jnd

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20
Q

signal detection theory

A

focuses on the changes in our perception of the same stimuli depending on both internal (psychological) and external (environmental) context
perception can be affected by non sensory factors, such as experiences (memory), motives, and expectations

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21
Q

response bias

A

refers to the tendency of subjects to systematically respond to a stimulus in a particular way due to non sensory factors

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22
Q

signal detection experiments

A

consists of many trials where a stimulus may or may not be presented
trials when signal is presented are called catch trials
when signal is not presented called noise trials
after each
subjects asked to indicated whether or not signals was given
leads to 4 different results

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23
Q

results of signal detection experiments

A

hits: subject correctly perceives the signal
misses: subject fails to perceive a given signal
false alarms: subject seems to perceive a signal when none was given
correct negatives: subject correctly identifies that no signal was given
proportion of misses and false alarms indicate response bias

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24
Q

adaptation

A

decrease in stimulus perception after a long duration of exposure
detection of a stimulus can change over time
have both a physiological (sensory) component and a psychological (perceptual) component

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25
sclera
thick structural layer covering exposed portion of the eye white of the eye doesn't cover the front of the eye
26
choroidal vessels
complex intermingling of blood vessels b/w the sclera and the retina along with the retinal vessels both sets of vessels supply eye with nutrients
27
retina
innermost layer of the eye contains photoreceptors that transduce light into electrical information the brain can process like a screen consisting of neural elements and blood vessels
28
cornea
clear, domelike window in the front of the eye | gathers and focuses incoming light
29
anterior chamber
lies behind the cornea in front of the iris
30
posterior chamber
between the iris and the lens | contains aqueous humor
31
iris
``` colored part of eye composed of 2 muscles: the dilator pupillae and the constrictor pupillae continuous with the ciliary body iris contracts--> enlarge pupil iris relaxes--> constricts pupil ```
32
dilator pupillae
opens the pupil under sympathetic stimulation
33
constrictor pupillae
constricts the pupil under parasympathetic stimulation
34
ciliary body
produces aqueous humor that bathes the front part of the eye before draining into the canal of Schlemm
35
lens
lies behind the iris helps control the refraction of incoming light connected to suspensory ligaments
36
suspensory ligaments
connected to the lens | when the ciliary muscle contracts it pulls on the ligaments and changes the shape of the lens
37
accommodation
the change shape of the lens from the suspensory ligaments and the ciliary body
38
vitreous humor
transparent gel that supports the retina | lies behind the lens
39
duplicity theory of vision
states that the retina consists of 2 kinds of photoreceptors: those specialized for light and dark detection those specialized for color detection
40
cones
photoreceptors used for color vision sense fine details 6 million in the retina most effective in bright light and comes in 3 forms: short or blue, medium or green, long or red
41
rods
``` photoreceptors used for light and dark vision contain small pigments called rhodopsin low sensitivity to detail permit light vision 120 million in the retina ```
42
fovea
central section of the retina (macula) | contains only cones
43
bipolar cells
connects rods and cones | highlight gradients b/w adjacent rods and cones
44
ganglion cells
synapse with bipolar cells | group together to form the optic nerve
45
amacrine and horizontal cells
receive input from multiple retinal cells in the same area before the information is passed on to ganglion cells accentuate slight difference b/w the visual info in each bipolar cell important for edge detection
46
visual pathway
right visual field goes to left hemisphere left visual field goes to right hemisphere through the optic nerve to the optic chiasm to the optic tract information goes to several different places in the brain: the lateral geniculate nucleus (LGN), visual cortex, and the superior colliculus
47
processing areas
lateral geniculate nucleus (LGN) in the thalamus visual cortex in the occipital lobe superior colliculus, which controls some responses to visual stimuli and reflexive eye movements
48
parallel processing
ability to simultaneously analyze and combine information regarding color, shape, and motion then they can be compared to our memories to determine what is being viewed
49
parvocellular cells
detects shape have high color spatial resolution work with stationary or slow-moving objects so they have low temporal resolution
50
magnocellular cells
detect motion high temporal resolution low spatial resolution provide blurry but moving images
51
pinna
or auricle where sound wave first reaches cartilaginous outside of ear channel sound waves not the external auditory canal which directs sound to the tympanic membrane
52
tympanic membrane
eardrum membrane vibrates in phase with the incoming sound frequency of wave determines pitch intensity corresponds to amplitude of vibration divides the outer ear and the middle ear
53
ossicles
housed in the inner ear 3 smallest bones in the body help transmit and amplify the vibrations from the tympanic membrane
54
middle ear
malleus (hammer) affixed to the tympanic membrane, and acts on the incus (anvil), which in turn acts on the stapes (stirrup) the base plate of the stapes rests in the oval window
55
Eustachian tube
connects the middle ear to the nasal cavity | helps equalize pressure b/w the middle ear and the environment
56
inner ear
sits within a bony labyrinth contains the cochlea, vestibule, and semicircular canals all continuous with each other and form the membranous labyrinth filled with endolymph also contains perilymph that transmits vibrations and cushions the inner ear structure
57
cochlea
spiral-shaped organ divided into 3 parts called scalae that run the entire length of the cochlea middle scala houses organ of corti and contains endolymph other 2 scalae filled with perilymph
58
organ of corti
actual hearing apparatus housed in the middle scala lies on a thin, flexible membrane called the basilar membrane composed of thousands of hair cells that are bathed in endolymph on top is immobile membrane called tectorial membrane
59
round window
membrane covered hole in the cochlea | permits perilymph to actually move within the cochlea
60
vestibule
portion of the bony labyrinth the contains the utricle and saccule sensitive to linear acceleration part of balancing apparatus
61
semicircular canals
sensitive to rotational acceleration (x,y, and z planes) arranged perpendicularly to each other ends in a swelling called an ampulla, where hair cells are located
62
auditory pathways
most info passes through the vestibulocochlear nerve to the brainstem auditory input --> middle ear--> cochlea--> auditory nerve--> superior olive--> inferior colliculus (thalamus)--> medial geniculate nucleus--> temporal cortex
63
tonotopically organized
the cochlea is organized this way | when the hair cells vibrate it gives the brain an indication of the pitch of the sound
64
smell
considered a chemical sense | respond to the incoming chemicals from the outside word via olfactory chemoreceptors
65
olfactory chemoreceptors
olfactory nerves located in olfactory epithelium in the upper part of the nasal cavity chemical signals bind to these receptors to cause a signal
66
olfactory pathway
chemicals bind to the olfactory receptors in the olfactory epithelium signal sent to the olfactory bulb then sent to higher regions of the brain
67
pheromeones
smell that carries interpersonal information bind to olfactory receptors play a role in animals social, foraging, and sexual behavior
68
5 basic tastes
``` sweet sour salty bitter umami (savory) ```
69
taste chemoreceptors
detect taste can sense dissolved compounds (salts) and specific molecules binding to receptors receptors are groups of cells called taste buds
70
papillae
little bumps found on the tongue | this is where taste buds are found
71
taste pathway
chemoreceptors on tongue (taste buds on papillae) detect taste sent to the brain stem ascend to the taste centers in the thalamus before traveling to higher brain regions
72
somatosensation
the sense of touch complex has many different receptors
73
4 sensations of touch
pressure vibration temperature pain
74
5 receptors
``` Pacinian corpuscles Meissner corpuscles Merkle discs Ruffini endings Free nerve endings ```
75
Pacinian corpuscles
respond to deep pressure and vibration
76
Meissner corpuscles
respond to light touch
77
Merkle discs
respond to deep pressure and texture
78
Ruffini endings
respond to stretch
79
Free nerve endings
respond to pain and temperature
80
somatosensation pathway
transduction occurs in the receptors | then sent to the central nervous system and eventually to the somatosensory cortex in the parietal lobe
81
two-point threshold
minimum distance necessary between 2 points of stimulation on the skin such that the 2 points will be felt as 2 different stimuli size of threshold depends on the density of nerves in the particular area of skin being tested
82
physiological zero
how temperature is judged the normal temperature of the skin, b/w 86-97 degrees F object feels cold bc it is under the physiological zero object feels hot bc it is above the physiological zero
83
gate theory of pain
proposes that there is a special "gating" mechanism that can turn pain signals on or off this affects whether or not we perceive pain spinal cord is able to preferentially forward the signals from other modalities of touch to the brain reducing the sensation of pain
84
kinesthetic sense
proprioception ability to tell where one's body is in space knowing where limbs are in space receptors are found mostly in muscles and joints play role in hand-eye coordination, balance, and mobility
85
bottom-up processing
data driven refers to object recognition by parallel processing and feature detection brain takes the individual sensory stimuli and combines them together to create a cohesive image before determining what the object is
86
top-down processing
conceptually driven driven by memories and expectations that allow the brain to recognize the whole object and then recognize the components based on expectations brain quickly recognize objects without needing to analyze specific parts
87
perceptual organization
ability to use these processes to create a complete picture or idea
88
Gestalt principles
``` ways for the brain to infer missing parts of a picture when a picture is incomplete law of proximity law of similarity law of good continuation subjective contours law of closure ```
89
law of proximity
elements close to one another tend to be perceived as a unit
90
law of similarity
objects that are similar tend to be group together
91
law of good continuation
elements that appear to follow the same pathway tend to be grouped together
92
subjective contours
perceiving contours and shapes that are not actually present in the stimulus may arise from the law of good continuation
93
law of closure
when a space is enclosed by a contour it tends to be perceived as more complete (or closed) than they really are
94
law of prägnanz
perceptual organization will always be as regular, simple, and symmetric as possible governs the Gestalt principles

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