AP Psychology Unit 1- Sensation and the Senses

Sensation

processing environmental stimuli

Transduction

energy converted to neural signals

Absolute Threshold

the weakest amount of a stimulus that a person can detect half the time

just noticeable difference

the minimal change in a stimulus that can just barely be detected

Weber's Law

The change needed is proportional to the intensity of the stimulus.

Optic Nerve

sends info to the occipital lobe

Photoreceptors

rods and cones

Rods

black and white, low light

Cones

color, bright light

Fovea

Area of sharpest vision, highest concentration of cones

Blind Spot

Area where the optic nerve exits the eye

Vision

Eyes receive light energy and transduce into a neural message

Nearsighted

image focuses in front of retina

Farsighted

images focus on a point behind the retina

Dichromatism (colorblindness)

One cone is deficient, person can't see certain colors. Ex: Red-green colorblindness

Monochromatism (colorblindness)

See the world in only one color or black and white. Only one cone works or all are deficient

Conduction Deafness

Damage to middle ear, or born w/o ossicle bones

Sensorineural Deafness

deafness that results from damage to the auditory nerve

Outer Ear

anatomy canal

Middle Ear

Tympanic membrane, middle ear bones

Inner Ear

semicircular canals, cochlea, and auditory nerve

Pitch

How high or low a sound is

Amplitude

loudness

Place Theory

We hear different pitches because different sound waves trigger activity in different places on the cochlear membrane

Frequency Theory

The rate of nerve impulses traveling up the auditory nerve matches the frequency of the tone

Olfaction

Smell. Molecules reach receptor cells in the nasal cavity then go straight to the olfactory bulb.

Gustation

Taste. Chemical molecules in the mouth.

Six Tastes

Sweet, sour, salty, bitter, umami, and oleogustus (fatty)

Super tasters

More taste buds on their tongues, able to detect flavors that most people can't. Cilantro-soap gene.

Touch

receptors on skin sensitive to warmth, pressure, cold, light touch, and pain.

Nociceptors

detect painful stimuli

gate control theory of pain

a theory of pain perception based on the idea that signals arriving from pain receptors in the body can be stopped, or gated, by the spinal cord

Small Nerve Fibers (gate theory)

Open the gate

Large Nerve Fibers (gate theory)

Close the gate. (Also medicine and endorphins can close the gate).

Vestibular Sense

the sense of body movement and position, including the sense of balance

Kinesthetic Sense

sense of the location of body parts in relation to the ground and each other

phantom limb sensation

the perception of sensations or pain in an amputated limb.

cochlea

a coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses

ossicles of middle ear

hammer, anvil, stirrup, bones that vibrate

ear drum

The part of the ear that vibrates to allow us to hear sound.

auditory nerve fibers

These carry impulses from the inner ear to the brain (cerebral cortex).