Psych 3: Sensation and Perception

Bottom-Up Processing: using individual parts to form a whole

Top-Down Processing: using the whole to fill in individual parts

Absolute Threshold: lowest level of stimulus that a person can detect at least 50% of the time, the flame 30 miles away

Just Noticeable Difference: the minimum difference a person can detect between 2 stimuli

Weber’s Law: a just noticeable difference is proportional to the intensity of the original stimulus

Signal-Detection Theory: expectations influence our ability to sense a stimulus

Sensory Adaptation: sensory receptors exposed to a particular stimulus for a long time will decrease in sensitivity to stimuli and make them less noticeable

Priming: exposure to previous stimuli unconsciously affects future responses

Perceptual Set: a specific form of top-down processing where expectations from previous experiences affect perception

Perceptual Constancy: tendency to see familiar objects as having standard shape, size, color, or location

Cornea: light enters here and it focuses light in the eye

Iris: a muscle that controls the pupil by changing size based on light to help you see clearly

Pupil: controls how much light goes into the back of the eye

Retina: captures light let into the eye and helps translate it into images we see

Fovea: helps focus the eye in sharp central vision

Optic Disc: round spot on the retina formed by the passage of axons to retinal ganglion cells to transfer signals from photoreceptors of eye to optic nerve, letting us see

Optic Nerve: a bundle of nerves that carry visual messages from eye to brain

Lens: works with the cornea to focus light correctly on the retina

Rods: responsible for black-and-white vision

Cones: responsible for color vision

Bipolar cells: provide main retinal interneurons and provide pathways from photoreceptors to ganglion cells: collect visual information from bipolar cells and output them to the brain

Dark Adaptation / Light Adaptation: a process where eyes become more or less sensitive when exposed to different levels of light

Color Vision: Cones translate light waves in the retina

Opponent-Process Theory: the eye has receptors that make agonistic responses to 3 pairs of colors, red/green yellow/blue black/white

Afterimage Effect: A flash of light prints a lingering image on your eye

Color-Blindness: inability to distinguish between certain colors, monochromat and dichromat

Gestalt Principles: The whole is more important than the individual parts, figure and ground, closure, similarity and proximity, continuity and connectedness, symmetry

Closure: filling in the blanks

Similarity and Proximity: grouping things into similar categories, grouping things based on closeness

Continuity: things viewed together not in parts

Figure & Ground: distinguishing between the main figure and background

Symmetry: the brain prefers symmetry

Simplicity: we are biased toward the simplest view of the world

Depth Perception - Monocular Cues: using one eye to perceive depth, relative size, overlap linear perspective, relative height, and texture gradient perspective

Linear Perspective: parallel lines appear to converge in the distance

Relative Size: things farther away appear smaller

Relative Height: things farther away appear higher up

Overlap/Interposition: things farther away are blocked by closer objects

Texture Gradient/ariel perspective: things farther away appear blurrier and less detailed

Depth Perception – Binocular Cues: using two eyes to perceive depth, retinal disparity

Retinal Disparity: difference in images seen by two eyes used to calculate distance and relative distance

Frequency: wavelength, shorter wavelengths are higher frequencies and high-pitched sounds, longer wavelengths are lower frequencies and low-pitched sounds

Amplitude: height, the taller amplitude is higher volume and louder, the smaller amplitude is lower volume and quieter

Waveform: the shape of a wave, amplitude and frequency patterns

Sound Localization: the ability to identify the position and changes in the position of sound sources based on acoustic information

Pinna: in the outer ear, gathers sound waves from the environment and directs them into the ear Ear canal: connects the outer ear to the eardrum and the middle ear

Eardrum/tympanic membrane: seperates the outer and middle ear, vibrates when hit with sound, and converts sound waves into electric impulses

Ossicles (hammer/malleus, anvil/incus, stirrup/stapes): the middle bones of the ear attached to the eardrum, they amplify sound

Cochlea: shell-shaped inner ear bone, that helps with auditory transduction, converting sound waves to electrical impulses

Semicircular Canals: 3 fluid-filled tubes in the inner ear that help us keep balance

Basilar Membrane: In the cochlea of the inner ear, it helps to distinguish different types of sounds and frequencies

Auditory Nerve: transforms vibrations into electrical impulses

Primary tastes (5): Sweet, salty, sour, bitter, umami

Olfactory Cilia: smell receptors, hairs in the nasal passage, sent to the forebrain not the thalamus

Supertasters & Non-tasters: more or less sensitive to taste based on different numbers of tastebuds

Nociceptors: unique pain receptors in the skin

Fast pathway: registers localized pain, relays to brain in a fraction of a second, ex → pricked finger

Slow pathway: conveys less localized, longer-lasting, aching pain after an injury, lags seconds behind other path

Pain Subjectivity: pain is dependent on individual psychological, cognitive, and emotional state, placebo effects, cultural pain expectations (childbirth), distraction by other stimuli

Pain: a touch sensation that is processed in the brain

Gate-Control Theory: spinal cord has a “gate” that blocks pain signals or allows them to pass on to brain, opened by pain signals traveling up small nerve fibers, closed by activity in larger fibers (rubbing) or by information coming from the pain (distracting thoughts)

Anterior Cingulate Cortex: part of the brain that processes pain

Kinesthetic System: monitors positions of various parts of the body, receptors in joints and muscles transmit to brain

Vestibular System: monitors position of the body in space, provides a sense of balance and equilibrium, located in the ear’s semicircular canals of ear

Evolutionary Explanation: parts of our being like our senses that help us survive

Innate vs. Learned theories: nature vs nurture, our biological perceptions and how our environment influences expectation