UNIT #1 (1.5 & 1.6)

Cognitive neuroscience

The scientific study of the biological basis of mental processing such as perception, consciousness, action, memory, decision making, language, and selective attention.

Circadian rhythm

Internal biological clock synchronizing with a 24-hour cycle.

Stage one of sleep

Brief, hypnagogic sensations.

Stage two of sleep

Sleep spindles and k-complexes.

Stage three of sleep

Slow delta waves, deep sleep.

Cycle of a typical night’s sleep

Starts in stage one and works its way down to stage 3, with stages getting longer throughout the night.

REM sleep

Vivid dreams, rapid eye movement; known as paradoxical sleep.

Hypothalamus

Regulates sleep and wakefulness, containing nerve cells that help control sleep.

Melatonin

Hormone that contributes to our circadian rhythm and creates tiredness.

Benefits of sleep

Maintains healthy weight, improves mood, lowers chronic disease risk, aids growth and development, enhances brain function, and boosts the immune system.

Sleep deprivation

Not getting the required amount of sleep.

Insomnia

Persistent problems falling or staying asleep.

Narcolepsy

Sudden attacks of overwhelming sleepiness.

Sleep apnea

Intermittent stopping of breathing during sleep.

Sleep and aging

As people age, sleep becomes more fragile, with frequent awakenings common among older adults.

Physiological dream theory

Reorganizing memory and learning during dreams.

Activation-synthesis theory

Brain trying to interpret meaningless, random neural firing during REM.

Sensation

The process by which we receive information from the environment.

Top-down processing

Guided by experience and higher-level processes; we see what we expect to see.

Bottom-up processing

Starts with sensory input; the brain builds from small details to a larger concept.

Transduction

The process of converting energy of a stimulus into neural activity.

Absolute threshold

The smallest level of stimulus that can be detected.

Difference threshold

The minimum difference between two stimuli required for detection 50% of the time.

Signal detection theory

Predicts how and when we detect a faint stimulus amid background stimulation.

Sensory adaptation

Decreased sensitivity to a constant stimulus over time.

Amplitude of light

Height of light waves, determining brightness; small amplitude results in dull color.

Cornea

The eye’s clear, protective outer layer covering the pupil and iris.

Iris

Band of muscle tissue that forms the colored portion of the eye and controls pupil size.

Pupil

The adjustable opening in the center of the eye through which light enters.

Lens

Transparent structure behind the pupil that changes shape to focus images on the retina.

Retina

Light-sensitive inner surface of the eye containing rods and cones for processing visual information.

Fovea

Central focal point in the retina responsible for greatest visual acuity.

Optic nerve

Carries neural impulses from the retina to the brain.

Accommodation

The process by which the lens changes curvature to focus on objects at various distances.

Rods

Retinal photoreceptors detecting black, white, and gray; sensitive to movement.

Cones

Retinal photoreceptors functioning in daylight, detecting fine details, and creating color sensations.

Blind spot

Point on the retina where the optic nerve leaves the eye; no photoreceptors present.

Young-Helmholtz Theory

Theory stating the retina contains three types of color receptors (red, green, blue) for color perception.

Opponent-Process Theory

Theory that opposing retinal processing enables color vision.

Parallel processing

The brain’s ability to process multiple aspects of a visual scene simultaneously.

Conduction hearing loss

Hearing loss due to damage to the mechanical system transmitting sound waves to the cochlea.

Sensorineural hearing loss

Hearing loss resulting from damage to the cochlea’s hair cells or the auditory nerve.

Outer ear

The physical ear.

Middle ear

Chamber between the eardrum and cochlea containing three tiny bones.

Inner ear

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

Tympanic membrane

Vibrates in response to sound waves.

Cochlea

Coiled, bony, fluid-filled tube in the inner ear where sound waves trigger nerve impulses.

Auditory canal

Channel in the outer ear that funnels sound waves to the eardrum.

Oval window

Membrane-covered opening of the cochlea that vibrates in response to sound waves.

Place Theory

Theory explaining pitch perception based on activity at different places along the basilar membrane.

Frequency Theory

Theory suggesting the brain reads pitch by monitoring frequency of neural impulses.

Gate-Control Theory

Theory that the spinal cord contains a 'gate' that blocks or allows pain signals to the brain.

Phantom-Limb Theory

Pain felt in an amputated limb due to the brain’s misinterpretation of sensory signals.

Gustation

Sense of taste, stimulated by chemicals in food.

Olfaction

Sense of smell, involving the detection of airborne chemicals.

Biopsychosocial approach to pain

Approach integrating biological, psychological, and social factors to understand phenomena like pain.

Chemical senses

Senses involving the detection of chemicals, including taste (gustation) and smell (olfaction).

Kinesthesis

Sense that monitors body position and movement.

Vestibular sense

Monitors position and movement of the head and body, primarily located in the inner ear.