Sensation
The process of taking in information from the environment
Perception
The way we recognize, interpret, and organize our sensations
Psychophysics
Branch of psychology that deals with the effects of physical stimuli on sensory response
Absolute threshold
minimum amount of stimulus required to detect a stimulus over 50 percent of the time
Gustav Fechner
The founder of psychophysics; discovered the absolute threshold
Signal Detection Theory(SDT)
The idea that there are four possible outcomes for a detection experiment: yes, no, false yes, and false no
Discrimination Threshold
Point in which somebody can distinguish between two stimuli
Difference threshold or just noticeable difference(JND)
Minimum amount of distance between two stimuli that can be detected
Ernest Weber
Discovered Weber's law; just noticeable difference is proportional to intensity of stimulus
Weber's law
The larger the stimuli, the more difference needed to be noticeable and vice versa
Subliminal perception
When we are presented with something so fast, we cannot consciously recognize it
Priming
The processing of presented stimuli
Tip-of-the-tongue phenomenon
When we try to recall preconscious information that is not easily accessible, causing it to take longer to figure out
Receptor Cells
Cells of the sensory organs that are designed to detect specific types of energy
Receptive field
The area in which our receptor cells receive input
Transduction
When our receptor cells convert stimuli into neural impulses
Contralateral Shift
When sensory information travels from one side of the brain to the other
Sensory coding
how receptors convey a range of information to the brain
Qualitative dimension
What a stimulus is
Quantitative dimension
how much of a stimulus there is
Single-cell recording
Firing rate and pattern of a single receptor cell can be measured in response to varying sensory input
Visual Sensation
when the eye receives light input from the outside world
Distal stimulus
an object as it exists in the environment
proximal stimulus
image of an object on the retina
Cornea
protective layer outside the eye
Lens
Transparent structure behind the cornea that can change its curvature to account for distance
Accommodations
When the lens changes its curvature to account for distance
Retina
Screen in which the proximal stimulus is projected on, back of the eye; covered in rods and cones
Rods
Located on outside of retina, sensitive to low light
Cones
Located on the center of the retina(fovea), are sensitive to bright light and color vision
Fovea
the center of the retina, where cones are densely packed
bipolar and amacrine cells
Provide pathway for visual input to the retina which then relays it to the optic nerve
optic nerve
ganglion cells that send visual sensory input to the brain, cross at the optic chasm
optic chasm
where the optic nerve crosses, explains why the left hemisphere controls right eye and vice versa
Serial processing
When brain computes information step by step in a methodical and linear manner
Parallel processing
when brain computes multiple pieces of information at the same time
feature detectors
nerve cells that notice specific things, see and respond to just one piece of the puzzle.
convergence
the process by which sensory info becomes more complex and integrated
David Hube
Discovered feature detectors and that mammals will develop normal vision so long as errors are corrected in the critical period
Critical period
An optimal time for development shortly after birth that if missed, can lead to extreme developmental issues
Young Hemholtz's theory
Cones in the eye are activated by red, blue, and green light waves and all other colors are just a result of the mixture of said light waves
Opponent process theory
Thalamus responds to opponent pairs of receptor sets; black and white, red and green, etc.
After image
When a specific visual receptor is fatigued, its opponent pair will take its place in order to create a lasting inverse image
Dichromats
People who cannot distinguish red and green or blue and yellow
Monochromats
People who only see in black and white, totally color blind
Auditory input
Sensory input in the form of sound waves
Tympanic membrane
What first vibrates due to auditory input; the eardrum
Ossicles
Transfer vibrations from the tympanic membrane to the inner ear; made up of three small bones called the malleus, incus, stapes
Cochlea
Inside of the inner ear, has hairs that vibrate causing energy to be produced and sent to the auditory nerve
Vestibular sacs and
Give information to the body about position and balance, located in the inner ear
Place theory
Sound waves generate activity at different places along the basilar membrane
Frequency theory
We sense pitch because rate of neural impulses is equal to frequency of a particular sound
Conductive deafness
Deafness caused by injury to outer or middle ear structures
Sensorineural deafness
Deafness caused by impairment to structures between the cochlea and auditory cortex, inner ear deafness
Olfaction
The chemical sense of smell caused by sensory input to receptor cells that travels to the olfactory cortex and then the limbic system
Gustation
Chemical sense of tastes created by five basic tastes: sweet, salty, sour, bitter, and umami
Cutaneous and tacti
Receptor cells on the skin that relay information about temperature, pressure, and pain
Gate theory of pain
Pain slowly decreases due to a signal that is sent to opiate receptors in the spinal cord from the brain
Vestibular sense
Sensation of balance controlled by semicircular canals of inner ear
Kinesthesis
One's sense of body position and motion
Synesthesia
When one sensory neuron is stimulated which leads to another being stimulated simultaneously
Habituation
When we become accustomed to a stimulus and notice it less over time
Dishabituation
When a stimulus we had not noticed or barely noticed changes and causes us to notice it once more
Selective Attention
Focusing on one thing while ignoring another
Cocktail Party Phenomenon
When your attention automatically switches during deep attention; like somebody saying your name
Shadowing
an experimental method that requires people to repeat the attended message out loud; helps to study the cocktail party phenomenon
Filter Theories
Stimuli must pass through a sort of screen to enter our attention
Attentional resource theories
We only have a fixed amount of attention and it can be distributed depending on what is required in certain situations
Divided attention
Trying to focus on more than one task at a time
Inattentional Blindness
When we focus too much on one thing causing us to miss something else
Bottom-up processing
Recognizing and analyzing an object by finding the features that make up a whole
Top-down processing
When the brain labels a particular stimulus
Monocular depth cues
Cues to interpret a scene using just one eye; they include relative size, texture gradient, interposition, linear perspective, vanishing point, aerial perspective, relative clarity, and motion parallax
Relative size
Farther images project smaller images onto our retinas
Texture gradient
Father objects appear smoother, closer object rounder and more defined
Interposition
An object blocking something else is perceived as closer to us
Linear Perspective
parallel lines converge at a vanishing point
Aerial perspective
Closer objects appear more clear than farther objects due to the atmospheric haziness and debris that exists
Relative clarity
Clearer images are closer to us, fuzzy images are farther
Motion parallax
Farther objects appear to move slower than closer objects while we are moving
Binocular depth cues
Rely on both eyes to interpret a scene; include retinal disparity, and retinal convergence
Retinal dispaarity
Difference between what each eye sees and the angles they see it at
Retinal convergence
When both eyes move inward to focus on a specific object
Stereoptic image
Image created from a fusion of the images in each retina
Elanor Gibson and Richard Walk
Developed the visual cliff test in order to study depth perception
Visual Cliff
A lab device that is half see through and half not, meant to test whether infants and young animals have depth perception
Binocular disparity
The closer an object is, the more different the image each eye has
Gestalt approach
based on top-down processing by labeling a figure based on the background it sits in
Proximity
The tendency to see objects near each other as forming groups
Similarity
The tendency to prefer grouping like objects together
Symmetry
Tendency to perceive forms that make up mirror images
Closure
The tendency to see closed objects rather than incomplete ones
Continuity
Tendency to perceive fluid and continuous forms rather than jagged and irregular ones
Law of pr
We tends to see objects in their simplest forms
Feature detector theory
People respond to specific aspects of a particular stimulus
Constancy
We know something is unchanged even though it appears different
Motion detection
Done in two ways: recording the changing position of an object and how much we move our heads
Apparent motion
Something that appears to move but doesn't
Phi phenomenon
A sign that blinks in one direction causing apparent motion even though the sign is unchanged
Stereoscopic effects
Still pictures that move at a fast enough rate to imply motion