AP Psychology Unit 1: Sensation

Audition

The biological process by which our ears process sound waves.

Frequency (Sound)

The number of vibration wavelengths per second, measured in Hertz (Hz).

Pitch

The perceptual property of how high or low a sound seems, determined by frequency.

Amplitude

The physical property of sound waves interpreted by the brain as loudness or volume.

Pinna

The visible, external part of the ear that concentrates and funnels sound waves.

Auditory Ossicles

The three smallest bones in the body (malleus, incus, stapes) that concentrate vibrations onto the cochlea.

Cochlea

A snail-shaped, fluid-filled structure of the inner ear where sound vibrations are converted.

Organ of Corti

Contains hair cells that transduce sound vibrations into nerve impulses sent to the auditory nerve.

Place Theory

Theory that different places on the basilar membrane respond to different frequencies, best for high-pitched sounds.

Frequency Theory

Theory that the entire basilar membrane vibrates and auditory nerve fibers fire at the same rate as the sound wave.

Volley Theory

Theory that groups of neurons take turns firing ("tag teaming") to match middle-frequency sounds.

Conduction Deafness

Hearing loss caused by damage or disorders in the outer or middle ear structures that transmit sound.

Sensorineural Deafness

Hearing loss caused by damage to the inner ear, hair cells, or auditory nerve.

Gustation

The biological sense of taste.

Papillae

Bumps on the surface of the tongue that house taste buds.

Olfaction

The biological sense of smell, which is unique in bypassing the thalamus.

Olfactory Bulbs

Brain projections above the sinus cavity that receive smell signals and project to the amygdala and hippocampus.

Somesthetic Senses

The body senses consisting of skin senses, kinesthetic sense, and vestibular senses.

Gate Control Theory

Theory that pain signals must pass through a neural "gate" in the spinal cord that can be modulated by non-pain signals.

Substance P

A neurotransmitter that transmits pain signals from the peripheral nervous system to the spinal cord and brain.

Phantom Limb Pain

The feeling of pain or presence in an amputated limb, often caused by maladaptive neuroplasticity in the cortex.

Kinesthesis

The awareness of body movements and positions without visual input, using receptors in muscles, tendons, and joints.

Vestibular Sense

The awareness of balance, head position, and spatial orientation in relation to gravity.

Semicircular Canals

Fluid-filled tubes in the inner ear that detect head rotation, acceleration, and balance.