PSYCH01X - Sensation and Perception (Finals)

sensation

is the process by which our sensory organs (like the eyes, ears, nose, tongue, and skin) detect physical stimuli from the environment and send this information to the brain.

perception

is the process by which the brain organizes, interprets, and gives meaning to the sensory information it receives

vision

occurs when light rays strike the retina at the back of the eye, causing cells to send messages to the brain. we do not send sight rays out of the eyes.

stimulus

energy from the world around us that affects us in some way

receptors

specialized cells that convert environmental energies into signals for the nervous system

electromagnetic spectrum

the continuum of all frequencies of radiated energy

Young-Helmholtz theory (or trichromatic theory)

theory that color vision depends on the relative rate of response of three types of cones

Opponent-process theory

theory that we perceive color in terms of paired opposites: red versus green, yellow versus blue, and white versus black

Negative afterimages

experiences of one color after the removal of another

Brightness contrast

the increase or decrease in an object’s apparent brightness by comparison to objects around it

Color constancy

tendency of an object to appear nearly the same color under a variety of lighting conditions

Retinex theory

concept that the cerebral cortex compares the patterns of light coming from different parts of the retina and synthesizes a color perception for each area

sound waves

vibrations of the air, water, or other medium

Hertz (Hz)

cycles (vibrations) per second

pitch

perception closely related to frequency

loudness

perception of the intensity of sound waves

timbre

tone complexity, based on the relative amount of harmonics of the basic tone

cochlea

fluid-filled canals of the snail-shaped organ, which contains the receptors for hearing

frequency principle

concept that a sound wave through the fluid of the cochlea vibrates all the hair cells, which produce action potentials in synchrony with the sound waves

volley principle

idea that “volleys” (groups) of hair cells respond to each vibration with an action potential

place principle

idea that the highest frequency sounds vibrate hair cells near the stirrup end, and lower frequency sounds (down to about 100 to 200 Hz) vibrate hair cells at points farther along the membrane

vestibular sense

system that detects the tilt and acceleration of the head and the orientation of the head with respect to gravity

cutaneous senses

skin senses that allow us to detect touch, temperature, pain, and other sensations through specialized receptors in the skin

warmth

detects heat or higher temperature on the skin

pain

signals harm or injury to the body

itch

sensation that triggers the urge to scratch

vibration

sense of rapid movement or trembling on the skin

tickle

light touch that causes an involuntary laugh or reflex Cutaneous senses depend on several kinds of receptors

pain

The experience of _____ is a mixture of body sensation and emotional reaction, which depend on different brain areas.

gate theory

the idea that pain messages must pass through a gate, presumably in the spinal cord, that can block the messages

endorphins

neurotransmitters that weaken pain sensations

capsaicin

chemical that stimulates receptors that respond to painful heat

phantom limbs

continuing sensations, including pain, in a limb long after it has been amputated. Caused by the brain’s map of the body still including the missing limb

taste

sensory system that detects chemicals on the tongue

taste bud

fold on the surface on the tongue that holds taste receptors

sweet

energy-rich foods (sugars)

sour

acids, may signal spoiled food

salty

essential minerals (sodium)

bitter

often poisonous compounds, natural warning

umami

savory taste, proteins (glutamate)

synesthesia

a condition in which a stimulus of one type, such as sound, also elicits another experience, such as color

perception

is the process of interpreting and organizing the incoming information in order that we can understand it and react accordingly.

selective attention

Focusing on one thing while ignoring others.

form perception

Recognizing objects and patterns (figure vs. background)

depth perception

Seeing in 3D and judging distance.

perceptual constancy

Seeing objects as the same despite changes (size, shape, color).

perceptual illusion

When your brain is tricked and misinterprets what it senses

law of similarity

Objects that look similar (in shape, color, size, or texture) are perceived as belonging together.

Law of Proximity

Objects that are close to each other are perceived as a group, even if they are not similar.

Law of Continuity

We perceive lines or patterns as continuous and smooth, rather than abruptly changing direction.

Law of Closure

The brain fills in missing parts to see a complete object

Law of Connectedness

Connection implies relationship or grouping, which the brain prioritizes over proximity or similarity

size constancy

Object stays same size despite distance.

shape constancy

Object stays same shape despite angle.

color constancy

Object stays same color despite lighting

Müller-Lyer illusion

lines look different lengths but are equal

Ponzo illusion

converging lines make objects look bigger/smaller

gestalt psychology

a field that emphasizes perception of overall patterns

bottom-up process

perceptual activity in which tiny elements combine to produce larger items; Perception starts with raw sensory input and builds up to a full picture.

top-down process

applying experience and expectations to interpret each item in context; Perception starts with our expectations, experiences, and prior knowledge, which guide how we interpret what we sense

ESP (Extra Sensory Perception)

Perception that occurs independently of the known sensory. processes. Usually included in this category of phenomena are telepathy, or thought transference between persons; clairvoyance, or supernormal awareness of objects or events not necessarily known to others; and precognition, or knowledge of the future

precognition

knowing or predicting the future

psychokinesis

affecting or moving objects using only the mind.

telepathy

reading or communicating thoughts without words.

clairvoyance

perceiving events, objects, or information that are distant or hidden