AP Psych Unit 6.2: Sensation

Sensation

Your body picking up info through your senses.

Psychophysics

The study of how we experience things like light, sound, and touch.

Absolute Threshold

The smallest amount of stimulation a person can notice.

Signal Detection Theory

Whether or not we detect something depends on focus, experience, and expectations.

Difference Threshold

The smallest change in a stimulus that you can tell is different.

Weber’s Law

To notice a change, it must be a big enough percentage of the original.

Sensory Adaptation

Getting used to a stimulus so you stop noticing it.

Transduction

Turning sensory signals (like light or sound) into brain signals.

Wavelength

The distance between waves that determines color (for light) or pitch (for sound).

Hue

The color we see.

Intensity

How strong or bright something is.

Pupil

The black circle in the center of your eye that controls how much light is let into your eye, in the dark it will expand to let more light in while in bright light it gets smaller to protect your eyes.

Iris

The colored part of your eyes made of muscle, it controls the size of the pupil, it tightens or relaxes to open or close the pupil.

Lens

A clear, flexible structure behind the pupil, it focuses light on your retina so you can see clearly- kind of like a camera lens adjusting for distance.

Accomodation

The process of lens changing shape to help your eyes focus on things that are either close up or far away.

Retina

A layer at the back of the eye that contains photoreceptor cells to capture light and images coming in to then send to the brain via optic nerve.

Fovea

A small central spot on the retina that has the greatest density of photoreceptors so its where your vision is the sharpest.

Optic Nerve

The nerve that connects your eye to your brain and sends visual information to the brain.

Cornea

The clear, curved outer layer of your eye that protects your eye and helps bend (focus) light onto the lens and retina, kind of like a windshield and a magnifying glass combined.

Acuity

How sharp or clear your vision is.

Nearsightedness

A vision problem where you can only see close objects clearly but far ones are blurry.

Farsightedness

A vision problem where you can see far objects clearly but close ones are blurry.

Rods

Light sensitive cells in the retina that detect black, white, and gray. They help you see in dim light or darkness but they don’t detect color.

Cones

Cells in the retina that detect color.

Blind Spot

The area on the retina where the optic nerve leaves the eye.

Ganglion Cells

Nerve cells in the retina that help send signals to the brain.

Young-Helmholtz Trichromatic Theory

A theory that says we see color because of three types of cones-red, green, and blue.

Opponent-Process Theory

A theory that says color is processed in pairs: red-green, blue-yellow, and black-white.

Color Constancy

Seeing the color of an object as the same even if the lighting changes.

Frequency

How often a sound wave repeats.

Pitch

How high or low a sound is.

Decibels

Units used to measure how loud sound is.

Place Theory

The idea that different pitches activate different places on the cochlea.

Frequency Theory

The idea that the rate of nerve impulses matches the frequency of a sound.

Volley Principle

When nerve cells take turns firing to keep up with fast sound frequencies.

Sense of Touch

Your skin can detect pressure, warmth, cold, and pain.

Gate Control Theory

The idea that a “gate” in the spinal cord controls whether pain signals reach the brain. (why sometimes when you get hurt and rub the place it doesn’t hurt as much).

Taste Buds

Tiny bumps on your tongue that detect the chemicals in your food and send it to your brain.

Taste Receptor Cells

The cells inside taste buds that actually sense taste molecules.

Olfacation

Your sense of smell.

A short wavelength is equal to a _________ frequency. It means _______ colors and _____-pitched sounds. (HBH)

high, bluish, high

A long wavelength is equal to a _________ frequency. It means _______ colors and _____-pitched sounds. (LRL)

low, reddish, low