Study Guide 5 - Sensation And Perception Flashcards
Sensation
-detect stimuli from the environment
Perception
-interpret sensations
Ex) interpreting light as bright
Transduction
-receptors convert stimuli into signals through action potentials and neurotransmitters
Thalamus
-processes and relays sensory signals
Psychophysics
-study of relationship between physical stimuli and our psychological experience with them
Bottom-Up Processing
-looking at somethings parts and then perceiving it as a whole image
Top-down Processing
- seeing the big picture first
- draws on our experience and expectations
Parallel Processing
- understanding based on simultaneous operation of different parts of the brain
- ex) Processing the color, form and motion of a picture
Selective Attention
- ability to focus on only 1 thing
- ex) distracted driving: difficult and dangerous to drive while doing other things such as eating, texting etc.
Cocktail Party Phenomenon
-when you hear you name from across the room and begin listening to that conversation
Inattentional Blindness
- when you focus on 1 thing and miss something else
- ex) moonwalking bear video
Change blindness
- a type of inattentional blindness
- when you focus on 1 thing so you miss another stimulus change
- ex) asking for directions video
Signal Detection Theory
- predicts how and when someone detects the presence of a stimuli
- depends on experience, expectations, fatigue
- hit or miss grid: stimulus present/absent & respond absent/present
- ex) walking down and street and hearing someone walking behind you
Absolute Threshold
-minimum stimulation to detect a stimulus 50% of the time
Difference/JND Threshold
-minimum difference between 2 stimuli required for detection 50% of the time
Subliminal Threshold
-when stimuli are below one’s absolute threshold so you are not aware of them
Weber’s Law
- 2 stimuli must differ by a constant minimum % rather than an amount to be perceived as different
- ex) for one weight to be perceived as heavier it must weigh 2% more
Sensory Adaptation
- decreased sensitivity to a stimuli because it is constant
- ex) don’t feel our clothes on our bodies
Wavelength/Hue
- the wavelength determines the hue (name of color) we see
- short = blue long = red
Intensity
- brightness of color
- amplitude of the light wave
- big amplitude = bright small = dull
Visual Capture
-the tendency for vision to dominate the other senses
Visual Accommodation
- changing the light rays curvature on the retina
- the eye adjusting and focusing, producing a sharp image
Cornea
-transparent tissue where light enters the eye
Iris
-muscle that expands and contracts to change the size of the opening (pupil) for light
Lens
-focuses the light rays on the retina
Retina
- contains the rods and cones that process visual information and send it to the brain
- where transduction occurs
Fovea
- part of the eye with the most focus and clearest vision
- where cones cluster in the center of the retina
- damage leads to inability to see detail or color
Rods/Cones
- sensory receptor cells
- rods: black and white vision, why night is colorless (1 type)
- cones: function in light, detect color and detail (3 types)
Bipolar Cells
-neurons that connect rods and cones to the ganglion cells
Ganglion Cells
- neurons that connect to the bipolar Cells
- their axons form the optic nerve
Optic Nerve
-carry neural impulses from each eye to the visual cortex of the brain
Blind spot
-the optic disk, where the optic nerve leaves the eye and there are no rods or cones
Trichromatic Theory of Color Vision
- we have color visions because each type of cone responds best to either red, blue, or green wavelengths
- other colors are combinations of those three
Opponent Process Theory
-to account for complementary afterimages it was proposed that we have three sets of color opponent Cells:
Red-green
Blue-yellow
Black-white
-afterimages: if we view colored stimuli for a long time we see an afterimage in a complementary color
Color Blindness
- sex-linked trait on X chromosome
- mostly in males
- Dichromatic (lacking red/green cones is most common)
Pop-out Phenomenon
-when a unique visual target can be quickly seen among a set of similar looking targets
Photoreceptors
- nerve cells in the retina that code light energy into neural activity
- rods and cones
Photopigments
- in photoreceptors
- chemicals that respond to light
- when light stricken they break apart, changing the membrane potential of the photoreceptor cell -> signal that goes to the brain
Light/Dark Adaptation
- dark Adaptation is the increased ability to see in the dark as time passes
- photoreceptors build up more photopigments, takes time
Visual Acuity
- visual clarity greatest in fovea
- variations in the density of cones accounts for differences in visual acuity
Lateral Inhibition
- process in which lateral connections allow one photoreceptor to inhibit its neighbor, enhancing the visual contrast
- receptor that receives more light inhibits one that receives less, brain gets the impression that that Area is even darker
Feature Detectors
-specialized neurons in visual cortex that respond to specific stimuli
Ex) lines and dots
Motion Detectors
-neurons the detect motion
Primary Visual Cortex
- optic nerve connects to a region of the thalamus called the lateral geniculate nucleus
- neurons in the LGN send visual info to this cortex in the occipital lobe
Frequency
- number of complete cycles during each second
- measures in hertz
- longer wavelength = lower frequency
- pitch! High frequency = high pitch
Loudness
- determined by amplitude of sound wave
- greater amp = louder
- decibels
Outer Ear
- sound waves collected
- begins with pinna -> ear canal
Eardrum
- at the end of the ear canal
- sound waves -> matching vibrations in the eardrum
Three bones
- vibrations in eardrum are passed onto the MALLEUS(hammer) -> INCUS(anvil) -> STAPES(stirrup)
- bones amplify changes in pressure produced by sound waves by focusing vibrations onto smaller OVAL WINDOW
Cochlea
- after sound vibrations pass through oval window they enter cochlea
- fluid filled spiral in which transduction occurs!
Basilar Membrane
- forms the floor of the tube in the cochlea
- when a sound wave passes through tube, it moves basilar membrane -> bends hair cells of ORGAN OF CORTI
Auditory Nerve
- hair cells connect to this nerve, which is a bundle of axons that go to the brain
- when hair cells bend they stimulate neurons in auditory Nerve to fire sending brain a message about the sound
Conduction Deafness
-when three bones of middle ear fuse so vibrations can’t be reproduced
Cochlear Implants
-an artificial cochlea that can stimulate the auditory nerve
Auditory Cortex
- auditory nerve conveys info -> brainstem -> thalamus -> auditory cortex
- in temporal lobe
- where sound is subjected to analysis
Place Theory
-hair Cells at a particular place on basilar membrane respond most to a certain frequency of sound
Frequency Theory
- place Theory does not account for coding of very low frequencies
- firing rate of neuron in auditory nerve can match frequency of a sound wave
Olfactory Bulb
- brain structure that receives messages about smell instead of thalamus
- axons from neurons in nose extend into brain and synapse with this bulb
Pheromones
- dogs/snakes
- chemicals that are released by an animal and shape another animals behavior
- role in humans not clear
Synesthesia
-an unusual mixing of senses
Ex) feel colors, sense certain colors when they hear sounds
-occurs partly because brain areas the process color near those that process letters/#s and connections extensive
-combined activation of brain regions that process dif types of sensory info
Papillae
-contain groups of taste buds (receptors within buds)
5 basic tastes
- sweet, sour, bitter, salty, umami
- each taste bud responds best to only 1/2 categories
Supertaster
- 25% of the population
- especially large number of papillae
- more sensitive to bitterness
Flavor
- smell and taste and temperature interact
- most of the properties that make food taste good are actually smells
- in flavor Cortex neurons also respond to sight, texture, fullness
- variations in nutritional state can affect taste and flavor of food
- spicy foods actually stimulate pain receptors
Kinesthesis
- somatic sense
- tells the brain where the parts of the body are
- depend on to guide movements and improve motor skills
- info comes from joints and muscles
Vestibular Sense
- tells the brain about the position and movements of the head (sense of balance)
- semicircular canals: fluid filled tubes in the inner ear with hairs that extend into the fluid, when your head moves so does the fluid, stimulating the hairs -> activates neurons, signaling about head movement
- has connects to cerebellum, ANS (nausea) and Eyes (eyes fixed on a point even when head is moving)
Temperature “Hot”
- some of the skins sensory neurons respond to changes in temp
- warm fibers: inc firing rates 95-115
- cold fibers: respond to cool temps
- many of the fibers that respond to temp also respond to touch ex) warm and cold objects feel heavier
- receptors for cold and warm firing at same time, warning
How do we experience pain?
-pain is increased intensity of a stimulation
-pain provides info and has emotional content
-receptors are free nerve endings
-painful stimuli -> chemical released that fit into pain receptors -> fire
-nerve fibers carry pain signals to spinal chord -> thalamus -> other parts of brain (cerebral cortex)
-different nerve fibers for sharp and dull pain
and activate dif brain regions
-dif pain neurons activated by dif degrees of pain
Gate-control Theory of pain
- “gate” in the spinal chord that stops pain impulses from traveling to the beau
- input from other skin senses can take over the pathways that the pain impulses would have used
- messages from the brain can block incoming pain signals
Endorphins/Substance P
- endorphins are the brains natural opiates
- act as neurotransmitters where they block synapses of pain-carrying fibers
- substance P allows us to feel pain
Pain - BIOPSYCHOSOCIAL
- biological: nerve fibers carry pain signals to the brain
- psychological: pain carries information and emotion - pathways carry emotion component to hindbrain and reticular formation, depends on how we think about them
- social: presence of others, empathy, cultural expectations
Priming
- unconscious activation of perception or memory
- good news before bad news
Sound Localization Theory
- sound reaches the ear quickly when it is coming from the side and you can tell where it is coming from
- harder to locate sound when coming from the top or bottom
Basic Skin Receptor Types
-pressure
-warmth
-cold
-pain
All touch sensation are a mix of these
Nasal Cilia
-small hairs that keep airways clean by removing mucus
Perceptual set
- influence of prior assumptions on your perceptions
- ex) clouds or UFOs picture
Gestalt
- according to his theory when we look at something we organize it into a shape rather than seeing it as a bunch of smaller shapes
- while greater than parts
Figure Ground Gestalt Principle
- figure in the front that pops out and background
- can see both parts but NOT at the same time
Proximity
-group things that are close together
Similarity
-group things that look alike
Continuity
- lines are seen as following the smoothest path
- flowing smoothly without breaking lines up
Connectedness
-we organize as 1 unit those parts that appear connected
Closure
-brain “finishes” images
Monocular Cues Shadow and Light
- objects cast a shadow
- object covered by a shadow is perceived to be further away than the object in the light
Monocular Cues Linear Perspective
-2 parallel lines seem to come together in horizon
Monocular Cues Interposition
-an object that partly blocks another object is perceived as being closer
Monocular Cues
-if two objects are about the same size then the object that looks the largest will be judged as closer
Binocular Cues
-need two eyes for depth perception
Monocular Cues
-depth Cues detected with 1 eye
Retinal Disparity
-each eye perceives an object in a slightly different location
Retinal Convergence
- how much your eyes must rotate to see an object
- closer an object gets the more your eyes must rotate
Visual Cliff
- device for testing depth perception in infants (ability to judge distance)
- in experiments, it was found that depth perception is partly innate
- deep end covered in glass, babies wouldn’t crawl over
Stroboscopic Motion
- illusion in which we see motion from a series of still images
- ex) flip book
Phi Phenomenon
- POMS!
- looks like continuous motion based on location
Motion Parallax
-Phenomenon in which near objects seem to move faster
Priming
- unconscious activation of perception or memory
- good news before bad news
Sound Localization Theory
- sound reaches the ear quickly when it is coming from the side and you can tell where it is coming from
- harder to locate sound when coming from the top or bottom
Basic Skin Receptor Types
-pressure
-warmth
-cold
-pain
All touch sensation are a mix of these
Nasal Cilia
-small hairs that keep airways clean by removing mucus
Perceptual set
- influence of prior assumptions on your perceptions
- ex) clouds or UFOs picture
Gestalt
- according to his theory when we look at something we organize it into a shape rather than seeing it as a bunch of smaller shapes
- while greater than parts
Figure Ground Gestalt Principle
- figure in the front that pops out and background
- can see both parts but NOT at the same time
Proximity
-group things that are close together
Similarity
-group things that look alike
Continuity
- lines are seen as following the smoothest path
- flowing smoothly without breaking lines up
Connectedness
-we organize as 1 unit those parts that appear connected
Closure
-brain “finishes” images
Monocular Cues Shadow and Light
- objects cast a shadow
- object covered by a shadow is perceived to be further away than the object in the light
- dimmer is farther away
Monocular Cues Linear Perspective
-2 parallel lines seem to come together in horizon
Monocular Cues Interposition
-an object that partly blocks another object is perceived as being closer
Monocular Cues Relative size
-if two objects are about the same size then the object that looks the largest will be judged as closer
Binocular Cues
-need two eyes for depth perception
Monocular Cues
-depth Cues detected with 1 eye
Retinal Disparity
-each eye perceives an object in a slightly different location
Retinal Convergence
- how much your eyes must rotate to see an object
- closer an object gets the more your eyes must rotate
Visual Cliff
- device for testing depth perception in infants (ability to judge distance)
- in experiments, it was found that depth perception is partly innate
- deep end covered in glass, babies wouldn’t crawl over
Stroboscopic Motion
- illusion in which we see motion from a series of still images
- ex) flip book
Phi Phenomenon
- POMS!
- looks like continuous motion based on location
Motion Parallax
-Phenomenon in which near objects seem to move faster
Sensorimotor Hearing Loss
-damage to cochlea/hair cells
Perceptual Constancy
-retinal image changes even if object remains the same
Shape Constancy
-an objects shape remains constant
Size Constancy
- objects size stays the same even if it looks dif
- ex) person walking away
ESP/Parapsychology
- not able to replicate
- perception without sensation
- parapsychology: Study of abnormal phenomenon
Precognition
-perceive future events
Clairvoyance
- perceive remote events aka events that are going on at the same time as the present
- ex) sensing a friend’s house is on fire
Telepathy
-mind to mind communication
Necker Cube
- an illusion
- blue and yellow parts of the box and unclear which is the front and which is the back
Monocular Cues Relative Height
-we perceive objects that are high in our visual field as farther away
Monocular Cues Relative motion
- objects beyond fixation point appear to move with you
- objects in front of the fixation point appear to move backward
Color Constancy
-perceiving familiar objects as having consistent color even when changing illumination alters wavelengths reflected by the object
Ames Room
- demonstrate the size distance illusion
- both girls in the room are of similar height but we perceive them as different heights because they’re standing in two corners of the room
- looks like they’re standing in the same location
Moon Illusion
- “horizon moon” appear larger than the moon in the night sky
- moon in the sky surrounded by lots of empty space making it look smaller
Context Effects and Perception
- context Cues can change our perception of size
- ex) horizon moon
- perceived size of an object depends on size of nearby objects
Prosopagnosia
- cannot consciously recognize faces
- when see a familiar face there are changes in brain/ANS activity but unavailable to conscious experience
Scheme and Culture
- schema is a mental representation of what we know and expect about the world
- can bias our perception
- generalizations based on experience which is influenced by our culture
Perceptual Adaptation
- ability to adjust to an altered perceptual reality
- in vision ability to adjust to an artificially displaced or inverted visual field
Blindness/Regaining Sight
- surgeries can give people sight again
- but much of vision is learned
- how much the brain adapts after surgery depends on the circumstances
Hyperopia V. Myopia
- hyperopia = farsighted, light focuses behind retina, hard to see things close by
- myopia = nearsighted, light focuses in front of retina, hard to see things far away
Path Sound Waves Take
-pinna, canal, eardrum, hammer, anvil, stirrup, oval, cochlea, semicircular canals, basilar membrane, hair cells, nerve, thalamus, auditory cortex
Path Light Waves Take
-cornea, iris, pupil, lens, fovea, retina, rods/cones, bipolar, ganglion, optic nerve, thalamus, visual cortex
