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

Webers 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

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 and Ground

distinguishing between the main figure and background

Symmetry

the brain prefers symmetry

Simplicity

we are biased toward the simplest view of the world

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 / aerial perspective

things farther away appear blurrier and less detailed

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

Eardrum / tympanic membrane

seperates the outer and middle ear, vibrates when hit with sound, and converts sound waves into electric impulses

Ossicles

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

Sweet, salty, sour, bitter, umami

Olfactory Cilia

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

Super-tasters and 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

Order of light through the eye

Rods and cones, bipolar cells, ganglion cells, optic nerve

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

The muller lyer effect

the apparent difference in the length of a line as the result of arrowheads or arrow tails

The mcgurk effect

demonstrates an interaction between hearing and vision in speech perception