Psychology exam #1

What is the process of sensation to perception? (4)

stimulus-> sensory reception -> neural impulses -> perception

what is sensation?

the process of detecting external events by the sense organs(eyes skin ears etc.) => collecting information from the external world

what is transduction?

The process in which physical or chemical stimulation is converted into a neural impulse which is relayed to the brain => converting sensory information into an electrical signal

what is perception?

involves attending to, organizing, and interpreting stimuli that we sense

what is the absolute threshold

Minimum amount of energy or quantity of stimulus (light sound etc) required for it to be reliably detected at least half of the time it is presented

what is difference threshold?

Minimum amount of change in a stimulus intensity that is required for a subject to detect => a just noticeable difference = a weber fraction

what is the webers law by gutav fechner?(2)

how much can change for us to notice a difference resulting from a change one of our senses detects - how sensitive are?

what is signal detection theory table? and what does it help us asses? (2+example)

A table comparing a subjects response with an actual stimulus condition

it helps us asses what we are most sensitive to, and make sure we detect things that are there. so if we are able to detect something in a different lighting that adjustment can be made (doctor example identifying tumors in different lightings)

what is the signal detection theory divided into? (4)

correct responses:

1) hit- detecting a present stimulus

2) correct rejection- not detecting a stimulus when absent

incorrect responses:

3) miss- not detecting a present stimulus

4) false alarm- detecting a stimulus that is absent

what is the signal detection theory(2)

decision making process under conditions of uncertainty

which can vary depending on the context or individual making the decision.

subliminal messaging + stimuli

something being shown fast and we subconsciously consume it

what is subliminal stimuli and their effects?

Subliminal stimuli: presented to a person below their conscious threshold => we detect it without conscious awareness => activates in certain regions in the brain

effects: are limited and should not make you do something that is unlike yourself

what is perceptual organization and how do we assess it? (3)

process when elements are organized to form perceptible objects = grouping information

– first you look at the image then your brain groups it and assesses the sensory like visual aspects

– maybe a blurry picture is a dog when you focus on it.

what is the gestalt principle?

organizing perception into something more meaningful

figure - ground principle (2)

• foreground - background princple → our brain always tries to figure out what is foreground (infront) and whats background.

• we are always trying to figure out our environment, the objects and figures that contrasts the background.

what is good continuation principle? (2)

• when we look at things that disappear our brain fills in that it actually continues

• when covered our brain assumes continuation since it knows how subjects behave (a rope going around a rod in an image we fill in that the rope continues on the other side

what is proximity (1+example)

• things close together seem to belong together as a unit

• ex. like a cube and then if we were to break it up to smaller groups they would be a unit

what is similarity? (1+ example)

• objects similar belong together for a larger image or object

• ex. people wearing colored shirts in a crowed creating an image like a flag etc. 

what is closure?

our brain tends to close things for us like if there were no lines we kind of just make an image by closing those lines ourselves

what is top down processing(2+ example)

• occurs when prior knowledge and expectations guide perception

• our expectations guide experience → Familiar processing and expectations

• example: looking at numbers and letters, if you were to look at 12 13 14 you are reading number but if it was A 13 C (13 would be closer) it would represent a B since you are expecting a letter.

what is bottom up processing? (1 + 3 of some examples and connections)

• constructing a whole stimulus or concept from bits of unfamiliar raw sensory information,

• looking from the bottom up you can construct one image but then given other information you can assess a diff image within (rat and old man example)→ you are more unaware and you put more effort into processing since you don’t have any expectations or prior knowledge → give info to guide perception to process something otherwise you would not have been able to perceive

what is selective attention?

devoting all of our attention to one task

what is divided attention and what is the result of it on the task at hand

• paying attention to multiple tasks at once (multitasking)

• trying to multitask actually shows worse performance on all of the tasks that are (like distracted driving)

what is inattentional blindness (2)

• failure to notice clearly visible events or objects because attention is directed somewhere else

• we can only pay attention to so many things at once

what is wavelength and amplitude in light

• Wavelength: distance between waves → psychological effect of the color

• Amplitude: height of the waves → intensity of the color

How do we see light waves as colors?

light waves in the visible light spectrum generate a perception of color but do not have one.

what is the sclera?

white of the eyes which gives structure and shape

what is the cornea?

clear outer surface of the eye to collect outside light and focus it

what is the pupil?

hole in the eye to allow the light into the eye – controlled by the iris

what is the iris?

round muscle that adjusts the size of the pupil – the color around the eye

what is the lens in the eye?

clear structure that focuses light onto the back of the eye – final refinement

what is myopia? (3)

• near sightedness

• blurry sight far distance wise

• the shape of the eye ball is stretched out so the point of focus is focused on the retina making it blurry

what is hyperopia? (3)

• far sightedness

• blurry close distance

• eye is squished and too short of an eyeball focusing light behind the eyeball

what is the retina?

• back side of the eyeball

• where all the light is directed towards since it has all the light detecting cells

what are the two types of photoreceptors? (1 meaning + 2 kinds)

the two types of light cells are:

Cones: concentrated on the fovea (middle) to produce high detail color vision at our point of visual focus – point of focus

Rods: on outer regions of retina provide peripheral vision and are specialized for low light conditions - not as much detailed

what do rods and cones do? or what can we compare them to?

interpreters translate light energy into an impulse

what is dark adaption?

• the process by which rods and cones gain sensitivity to low light levels

• vision is first depended on cones then rods provide more details over time

Why are the nerves all the way to the back of the eye?

the rods and cones are in the back to access the blood for nutrients and oxygen supply and for protection and cushion

the process of light to nerve? (5)

• When light reaches rods and cones ->

• Transduction occurs at the back of the eye and where action potential begins

• then sent to bipolar neurons

• then sent to the ganglion cells which are all axon fibers

• those axon fibers then connecting to optic nerve passing info to the brain

what are bipolar neurons?

• they synapse onto photoreceptors (cones and rods)

• relaying and speeding it along to ganglion cells

what are ganglion cells?

• transmits the signals from bipolar neurons to the brain –

• almost like a super highway bringing information fast to the brain

what is the optic disc? and what does our brain do to this area?

area on retina lacking rods and cones – blind spot -> brain goes into completion and patches up the blind spot in the area where the optic nerve is

what is the optic nerve?

axon tracts from ganglion cells leading to the brain

what is trichromatic theory

color vision is determined by three diff cone types that are sensitive to short medium and long wavelength light

Long: red

Medium: green

Short: blue

how do we have other colors other then red blue and green if those are the only cones we have?

The combined activity of all three cone types generates a unique signature associated with each perceived color even colors without a corresponding wavelength

what does TRIchromatic mean Vs Di or even tetrachromatic?

tri just means we have three cones active for the colors we interpret for example birds see UV light waves

what is the opponent process theory of color?

• this process suggests that we perceive colors through opposing pair receptors provided by ganglion cells

• so when one functions the other one is suppressed

• red and green are opposing pairs, they can not light up together therefore there’s no reddish greens

can we choose trichromatic theory over opponent process theory? 2)

• no, we are able to explain vision of color by combining the two,

• TC - at the photoreceptor level while OPT is explaining it at the ganglion level

what are negative afterimages plus one example(2)

• opponent process theory supported by evidence

• the constant green in the Canadian flag example is exhausting that neuron(red - green opposing receptor) and so the inhibitory signal starts firing causing the red to pop up when switching to a white background

why is opponent process necessary? (2)

• additional analysis of the ratio of cone responses allows for more fine color perception

• this helps explain why we can not see certain color combinations, something that trichromatic theory can not explain

what is lateral inhibition ?

helps us see contrast in images like blocks of a color getting deeper and deeper

what are horizontal cells

• inhibitory interneurons (GABA releasing) that connect between photoreceptors-> prevent activation in surrounding neurons

• at the edge there is a slightly more intense region since to the right is a dimmer light and the inhibition process causes that edge to appear

what is the optic chiasm?

it is the crossover point for the optic nerve at the midpoint of the brain where everything from both sides gets communicated (left visual field communicated to the right side of the brain vice verse), and is communicated to the thalamus

what is the lateral geniculate nucleus(2)

• region within the thalamus that directs visual information throughout the brain

• receives 90% of visual signals from the optic nerve → after that to the primal visual cortex

what does the primary visual cortex do?

it takes raw visuals and break it down

what are feature detection cells? (2+ 1 example)

• neurons that respond selectively based on specific aspects of a stimulus like angles and edges as well as to specific regions of the visual field

• all possible angles are accounted for at any location in our vision

• ex. Computer screen is our visual field – every pixel is monitored by many cells to view the angle and perception changes

what is the ventral stream? just the simple definition and where is it?

it is the what? stream

visual stream underside of the brain which extends to temporal lobe

what is the ventral stream responsible for?

responsible for object and face recognition, fusiform face area in the brain to detect faces

what is pareidolia phenomenon?

seeing faces where they don’t exist

what is prosopagnosia phenomenon?

face blindness when they have the areas of face recognition damaged, cant recognize faces

whar is the dorsal stream? just the simple definition and where is it?

the where and how stream

extends from visual cortex to the paritral lobe(up through the back and through the brain)

what is the dorsal streams job(2)

• guides interaction with objects and is responsible for depth and motion perception.

• Where objects are and how can we interact with them

what is holistic face processing? (1+ example)

• we are not looking for details we just recognize the face,

• like flipping obama’s face upside down with his face deformed, when we flip it we realize the features and the holistic image is seen to be distorted

what is the fusiform face area?

said to be responsible for visual expertise but not specific to only faces

what is perceptual constancy? (1+ example)

• ability to maintain perception to objects within our frame of vision as having a constant shape size and color even with a difference in perspective

• like looking at trees from a different distance, we know the trees are same size but we are further

what is size constancy? (1+ 2 examples)

• illusions relying on contextual depth cues to achieve deception (someone further away might appear smaller)

• ex. Ames room: perceiving someone on the right bigger on the left because they are touching the ceiling

what is color constancy?

fundamental properties like color do not change by the change of perception they just have shading and light is hitting on it a certain amount what underlying assumptions are we making

what is the topdown influence we have with color? (1+ example)

• expectations we have for an image with a distortion like a filter on it we still see the original color under neath or perceive it that way, in reality its a diff color

• ex. strawberries with filter on them, to us seem red but in reality pink with filter on

what is lightness constancy?(1+example)

• being able to maintain perception under uneven illumination

• ex. here we see so many colors even though we divide into two colors, we just assume they are shadows and that the color is constant within the two colored blocks.

what are depth perception binocular cues? (2)

• both eyes must work together

• comparing the images between both eyes which allows the brain to perceive depth and distance

what is convergence ?

occurs when the eye muscles contract so that both eyes focus on a single subject

what is retinal disparity (1+1 example)

• the difference in perspective provided by each eye

• ex. you can notice this when you put a thumb infront of you and change between both eyes as the thumb slightly moves position.

what is stereopsis? (2)

• it is the sense of depth using the alignment of the eyes (iris)

• when the vision of one eye overlaps with the other to make the depth comparison

what is strabismus? (2)

• This is when the eyes do not align properly when looking at objects

• lazy eye, no overlap can not make a comparison and see depth and 3D correctly

why does the placement of the eye matter? (lateral vs frontal)

Eye placement depends on evolutionary demands of a species

Cats frontal – lots of overlap, birds: lateral not lots of overlap more of a view all around though

What is monocular depth cues (1+ example)

• these are depth cues that we can perceive with only one eye, we do not need the overlap of the other one to perceive them

• Ex. moving on a train (motion parallax)

What is the accommodation in the eye? (2+ result of it)

• curving of lens to focus on nearby objects

• muscles in the eye are changing the shape of the lens

• this results in seeing things in different distances

what is motion parallex?

it is a perception that as we move objects are moving the opposite direction

what is pitch and loudness?

Pitch: perceptual experience of sound wave frequencies

Loudness perceptual experience of amplitude

what is the outer ear made out of? and what does each thing do?(2)

Pinna: collects sounds funnel

Auditory canal amplifies frequencies between 1000-5000 hertz

what is in the middle ear? what are their jobs?(2)

Malleus incus and stapes, three bones that vibrate in your ear

Vibrations of tympanic membrane get amplifies by ossicles(3 bones) to convert wave in air to wave in fluid of inner ear

what is in the inner ear?

Cochlear fluid being that is being vibrated to create waves in order for us to hear

what is the basilar membrane (snail like structure)?

surrounds the cochlea, the vibrations from the ossicles shake the fluid inside

what is on the basilar membrane?

a bunch of tiny hair cells along it, this is the point of transduction (movement of those hairs)

what is a tonotopic map? +which frequency travels further?

Narrow thick base in the front used for high frequencies and wide thing apex(end) for low frequencies.

Low frequencies travel further so they go further through the cochlea

what is the place theory in the ear?

certain parts vibrate according to frequency to reveal the pitch (tonotopic map)

what is the frequency theory? (4)

• the hair cells fire synchronously with rising pressure phase of a sound stimulus

• at each top of the crest of each wave the hair moves and transduction occurs(action potential),

• but there is a refractory period that limits frequency that individual nerve fibers can signal,

• to get around that we do the volley principle

what is the volley principle?(2)

• summed activity of groups of cells (group of neurons) one neuron firing at a time then a next one during the first neurons refractory period etc.

• then the activity is added up as a community of neurons so it can provide a more accurate representation of frequency

what is the cochlear nucleus?

where the dorsal and ventral nucleuses crossover of auditory signals to contralateral hemisphere(the right ear to left side of brain and vice versa)

what is the medial geniculate nucleus?

it is the structure within the thalamus that is responsible for routing of auditory information

what is the auditory pathway? (6 steps so sorry)

1) as sound goes in and vibrates the cochlear fluid in the inner ear the hair cells start moving which then causes them to send signals (transductions)

2) those signals are then collected in the auditory nerve

3) The auditory nerve then moves these signals to the cochlear nucleus

4) in the cochlear nucleus there is the opportunity to be crossed over and shared with both hemispheres then to the thalamus

5) then to the (medial geniculate nucleus) traffic operator and then the major destination is the primary auditory cortex

6) which is then sending it to the speech and response area of the brain

function of primary auditory cortex? (2)

• break down of raw auditory information of frequencies

• is also organized in tonotopic map

what is a sound shadow and how does it help us? (2)

• Sound shadows help the brain build an “acoustic map” of the environment, supporting spatial awareness and navigation

• an area of reduced sound intensity created when an object—most importantly the human head—blocks sound waves, and this acoustic difference helps the brain localize where sounds come from.

what is the process of sound localization

• process of identifying where the origin of the sound comes from and it is achieved by sound shadow and interaural time differences => slight difference in time where a sound reaches our ear

how do we determine elevation with our ears? (2)

• by using the folds of the pinna if sound waves hit in a certain angle (elevation) against the pinna it affects the intensity of the wave

• so we can detect if we are listening to something higher up or lower down

what is multimodal integration (sensations)? +example (2)

• the brain combining sensations from different modalities into a single integrated perception, dependent on spatial (space)and temporal(time) association, 

• ex. someone’s mouth moves and a sound comes out we associate it with one another and conclude they are talking

what is the mcgurk effect?

when changing the sound to the spatial movement of like a mouth we are trying to understand this so we are actually able to create a whole new sound

what is the Somatosensory system?

system that controls our sense of touch- provided by the skin

what is skin made out of? (3)

two layers,

dermis: inside skin and embedded in it are pressure, touch warmth and pain sensitive neurons

epidermis: regenerated and protective barrier of skin (dead skin cells)

what are the two types of nerve endings in the skin?

Mechanoreceptors: detect pressure and touch

Nociceptors: detect heat and pain