Stages of Sleep and Sensory Perception

Suprachiasmatic Nucleus (SCN)

Hypothalamic cells regulating circadian rhythms.

Hypnagogic Sensations

Bizarre experiences while transitioning to sleep.

Stage 2 Sleep

Deeper relaxation lasting about 20 minutes.

Narcolepsy

Disorder characterized by sudden REM sleep attacks.

REM Rebound

Increased REM sleep after deprivation.

Priming

Activation of perception or memory associations.

Embodied Cognition

Influence of bodily states on cognitive processes.

signal detection theory

predicts how/when you detect presence of faint stimulus amid background noise

gate-control theory

the theory that the spinal cord contains a neurological "gate" that blocks pain signals or allows them to pass on to the brain. The "gate" is opened by the activity of pain signals traveling up small nerve fibers and is closed by activity in larger fibers or by information coming from the brain.

frequency (temporal coding) theory

a hearing theory that explains the sense of pitch; the rate of nerve impulses traveling up the auditory nerve matches the frequency tone

Alpha Waves

Relatively slow brain waves during relaxed awake state.

Delta Waves

Large, slow brain waves associated with deep sleep.

Melatonin

Hormone adjusted by light affecting sleepiness.

REM Sleep

Stage with vivid dreams and muscle paralysis.

Stage 1 Sleep

Consciousness fades with possible hallucinations.

Stage 3 Sleep

Slow-wave sleep lasting approximately 30 minutes.

Sleep Apnea

Disorder with temporary breathing cessation during sleep.

REM Sleep Behavior Disorder

Acting out dreams due to lack of paralysis.

Absolute Threshold

Minimum stimulus energy needed for detection.

Difference Threshold

Minimum difference required for detection half the time.

Transduction

Conversion of physical stimuli to neural impulses.

Weber's Law

Two stimuli must differ by constant percentage.

Sensory Adaptation

Diminished sensitivity due to constant stimulation.

Top-Down Processing

Guided by higher-level mental processes.

Place Theory

Links pitch to cochlea membrane stimulation location.

Cochlear Implant

Device converting sounds into electrical signals.

Sensorineural Hearing Loss

Most common hearing loss from cochlea damage.

Middle Ear

Chamber containing bones that amplify vibrations.

Kinesthesis

Sense of movement and position of body parts.

Gustation

Sense of taste.

Olfaction

Sense of smell.

Vestibular Sense

Sense of balance and body movement.

inner ear

the innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs

cochlea

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

trichromatic theory

theory of color vision that proposes three types of cones: red, blue, and green; and with that combination every color is created

opponent process theory

the theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green

optic nerve

the nerve that carries neural impulses from the eye to the brain

cornea

The clear tissue that covers the front of the eye

lens

the transparent structure behind the pupil that changes shape to help focus images on the retina

cones

retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations.

fovea

the central focal point in the retina, around which the eye's cones cluster

retina

the light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information

rods

retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don't respond

conduction hearing loss

less common form of hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea

McGurk Effect

an error in perception that occurs when we misperceive sounds because the audio and visual parts of the speech are mismatched.