Psy Chapter 3 Flashcards
Transduction
Converting outside stimuli (light) into neural activity
Sensation
When special receptors in the sense organs are activated; allowing various forms of outside stimuli to become neural signs in the brain
Sensory receptors
Specialized form of neurons; stimulated by different kinds of energy (e.g) light for eye, vibration for ear etc
Just noticeable difference (jnd or the difference threshold)
Smallest difference between two stimuli that is detectable 50% of the time
Absolute threshold
Lowest level of stimulation that a person can consciously detect 50% of the time the stimulation is present
(One drop of perfume diffuses through there rooms, tick of watch 20ft away in quiet room)
Signal detection theory
- Provides method for assessing accuracy of judgements/decisions under certain conditions;
- used in perception research and other areas
Habituation
Tendency of brain to stop attending to constant, unchanging information (heater)
Sensory adaption
Tendency of sensory receptor cells to become less responsive to a stimulus that is unchanging (food taste, smell)
Photons
“Wave packets” (light)
Brightness
How high/low wave is (the higher the wave, the brighter the light)
Color (hue)
- Determined by length of waves
- short waves: blue end of visible spectrum
- longer waves: red end
Saturation
- purity of color
Mixtures of wavelengths
How light enters eye
- light enters (sun)
- travels through structures of eye and ends on retina as single point
- light bends as it passes through substances of different densities (process known as refraction)
Cornea
- Clear membrane that covers surface of eye
- protects eye
- fixed curvature (camera without option to adjust focus)
- bends light waves so the image can be focused on retina
Aqueous humor
- Fluid that continually replenishes and supplies nourishment to eye
Pupil
- Iris opening that changes size depending on amount of light in environment
Iris
- Round muscle that controls size of pupil
- colored part of eye
- can change size of pupil, letting more or less light into eye
- this can help focus image (like squinting)
Lens
- behind iris
- changes shape to bring objects into focus
Visual accommodation
Change of thickness of lens as eye focuses on objects that are far away or close
Vitreous humor
Clear jelly-like fluid, nourishes/shapes eye
Retina
- contains photoreceptor cells
- light sensitive area of eye containing 3 layers: ganglion cells, bipolar cells, rods and cones, special receptor cells (photoreceptors)
Rods
Visual sensory receptors found at back of retina, responsible for non-color sensitivity to low levels of light
Cones
Visual sensory receptors found at back of retina, responsible for color vision/sharpness of vision
Blind spot
- where optic nerve leaves eye
- no photoreceptor cells
Dark adaption
The recovery of the eye’a sensitivity to visual stimuli in darkness after exposure to bright lights
Light adaption
The recovery of the eye’s sensitivity to visual stimuli in light after exposure to darkness
Trichromatic theory (three colors)
Red cones, blue cones, green cones
Original 3 corresponding colors
- short wavelength cones: blue violet (420nm)
- medium wavelength cones: green (530nm)
- long wavelength cones: green yellow (560nm)
Afterimages
Images that occur when a visual sensation persists for a brief time even after original stimulus is removed
Opponent-process theory
Visual neurons are stimulated by light of one color and inhibited by light of another color
Color blindness
Caused by defective cones in retina
Hertz (Hz)
Cycles or waves per second, a measurement of frequency
Humans limits: 20-20000
Pinna
Visible part of ear
Auditory canal
Short tunnel that runs from the pinna to the eardrum
Cochlea
Snail-shaped structure of inner ear that is filled with fluid
Auditory nerve
Bundle of axons from the hair cells in the inner ear
Pitch
Psychological experience of sound that corresponds to the frequency of the sound waves; higher frequencies are perceived as higher pitches
Place theory
Different pitches are experienced by the stimulation of hair cells in different locations on the organ of corti
Frequency theory
Pitch is related to speed of Vibrations the basilar membrane
Volley principle
Frequencies from about 400 hz to 4000 hz cause the hair cells to fire in volley pattern, or take turns in firing
Conduction hearing impairment
Problems with mechanics of outer or middle ear; sound vibrations cannot be passed from eardrum to cochlea
Nerve hearing impairment
Problem either in inner ear or or auditory pathways in cortical areas of brain; aging or loud noises can be cause
Gustation
Sensation of a taste
Taste buds
Taste receptor cells, special kinds of neurons found in mouth, responsible for gustation
Taste buds and papillae
Taste buds are located inside papillae of tongue, composed of small cells that send signals to brain when stimulated by molecules of food
The five basic tastes
Sweet, sour, salty, bitter, “brothy”/umami (from glutamate)
Olfaction
Sensation of smell
Gustatory cortex
Found in front part of insula/Frontal Opercultum; involved in conscious perception of taste
Olfactory bulbs
Two bulb-like projections of brain located just above the sinus cavity and just below Frontal lobes that receive information from olfactory receptor cells
Somesthetic senses
The body senses consisting of the skin senses, the kinesthetic and proprioceptive senses and the vestibular senses
Pacinian corpuscles
Just beneath skin, respond to changes in pressure
Gate-control theory
Pain signals must pass through “gate” located in spinal cord
Kinesthesia
Awareness of body movement
Proprioception
Awareness of where body and body parts are located in relation to each other in space and to the ground
Vestibular sense
The awareness of the balance, position and movement of the head and body through space in relation to gravity’s pull
Sensory conflict theory
Explanation of motion sickness min which information from eyes conflicts with information of vestibular senses, resulting in dizziness, nausea, and other physical discomfort
Perception
Method by which experienced sensations are interpreted and organized in meaningful fashion
Size consistency
Tendency to interpret an object as always being same actual size, regardless of distance
Shape consistency
Tendency to interpret the shape of an object as being constant, even when it’s shape changes on retina
Brightness consistency
The tendency to perceive the apparent brightness of an object as the same, even when the Light conditions change
Figure-ground relationships
Tendency to perceive objects or figures as existing on a background
Proximity
A gestalt principle if perception; the tendency to perceive objects that are close to each other as part of the same grouping; physical or geographical nearness
Similarity
Gestalt principle of perception; tendency to perceive things that look similar to each other as being part of the same group
Closure
Gestalt principle; tendency to complete figures that are incomplete
Continuity
Gestalt principle; tendency to perceive things as simply as possible with a continuous pattern rather than with a complex, broken-up pattern
Contiguity
Gestalt principle, tendency to perceive two things that happen close together in time as being related
Depth perception
Ability to perceive works in three dimensions
Monocular cues
Cues for perceiving depth based on one eye only
Fovea
Central area of retina, greatest density of photoreceptors
Optic nerve
Sends visual information to the brain
Subliminal stimuli
Stimuli just below level of conscious awareness
Olfaction (olfactory sense)
Sensation of smell
Somesthetic senses
body senses consisting of skin senses, kinesthetic and proprioceptive senses and vestibular senses
Binocular cues
Cues for perceiving depth based on both eyes
Linear perspective
Monocular depth perception cue; tendency for parallel lines to appear to converge on each other
Relative size
Monocular depth perception clue; perception that occurs in her objects that a person expects to be a certain size appear to be small and are, therefore, assumed to be much further away
Overlap (interposition)
Monocular depth perception cue; The assumption that an object that appears to be blocking part of another object is in front of the second object and closer to the viewer
Aerial (atmospheric) perspective
Monocular depth perception cue; the haziness that surrounds objects that are farther away from viewer, causing distance to be perceived as greater
Monocular cues
Often referred to as pictorial depth cues, can be used to to give illusion of depth to paintings and drawings
Texture gradient
Tendency for textured surfaces to appear to become smaller and diner as distance from viewer increases
Motion parallax
Perception of motion of objects in which close objects appear to move more quickly than objects that are farther away
Accommodation
Brain’s use of information about the changing thickness of lens of eye in response to looking at objects that are close or far away
Convergence
Binocular depth perception cue; the rotation of the two eyes in their sockets to focus on a single object
Binocular disparity
Difference in images between the two eyes, which is greater for objects that are close and smaller for distant objects
Müller-Lyer Illusion
2 lines that appear to be different lengths
Perceptual sag
Tendency to perceive things a certain way because previous experiences or expectations influence those perceptions
Top-down Processing
Use of preexisting knowledge to Organize individual features into an unfinished whole
Bottom-up Processing
Analysis of smaller features to build up to a complete perception
