unit 1b

Consciousness

The awareness of our environment and ourselves.

Sleep

A natural loss of consciousness, as distinct from unconsciousness resulting from a coma or general anesthesia.

Circadian Rhythm

A 24

Types of Brain Waves

Different electrical patterns including Alpha, Beta, Theta, and Delta waves that can be visualized through an EEG to understand sleep stages.

Alpha Waves

Brain waves of a relaxed, awake state.

Beta Waves

Fastest brain waves, only seen in alert or stressful situations.

Theta Waves

Brain waves with lower frequency and amplitude.

Delta Waves

Slow brain waves associated with deep NREM sleep.

Insomnia

A disorder characterized by difficulty falling or staying asleep, leading to fatigue and impaired functioning during the day.

Narcolepsy

A disorder involving sudden and uncontrollable "sleep attacks," often falling directly into REM sleep.

REM Sleep Behaviour Disorder

A condition where people physically act out their dreams due to lack of muscle paralysis during REM sleep.

Sleep Apnea

A disorder where breathing repeatedly stops and starts, disrupting sleep and causing excessive daytime sleepiness.

Somnambulism

Sleepwalking; typically occurs during deep NREM sleep, where individuals walk or perform tasks while still asleep.

REM Rebound

When deprived of REM sleep, the body catches up by increasing the amount of REM sleep in subsequent nights.

Activation Synthesis Theory

A theory suggesting dreams are the brain’s way of making sense of random neural activity by creating a story.

Consolidation Theory

A theory suggesting dreams help process and solidify memories and experiences from the day, especially during REM sleep.

Altered States of Consciousness

Any conditions that differ significantly from a normal waking state, affecting awareness and perception.

NREM Sleep Stage 1

A transition period between wakefulness and sleep lasting 5 to 10 minutes, marked by alpha waves and hypnagogic sensations.

NREM Sleep Stage 2

A deeper sleep stage lasting about 20 minutes where body temperature drops, heart rate slows, and the brain produces sleep spindles.

NREM Sleep Stage 3

The deepest sleep stage characterized by slow delta waves, where muscles relax and physical restoration occurs.

REM Sleep

Rapid Eye Movement sleep; the last stage where the brain is active but the body is most relaxed, associated with vivid dreams.

Sensation

The process of receiving information from the environment through sensory neurons.

Absolute Threshold

The minimum amount of stimulation required to be able to detect a sensation 50% of the time.

Sensory Adaptation

When constant exposure to a stimulus leads to decreased sensitivity over time.

Just

Noticeable Difference (Difference Threshold)

Weber’s Law

The principle that stimuli must differ by a constant percentage (rather than amount) for the difference to be noticed.

Colour Vision Deficiencies

Conditions involving damage or irregularities to cones or ganglion cells, leading to colour blindness.

Dichromatism vs. Monochromatism

Dichromatism involves having two types of cones, while monochromatism involves having only one or none.

Prosopagnosia

Also known as face blindness; the loss of ability to recognize faces due to damage in the occipital and temporal lobes.

Blindsight

A condition resulting from damage to the primary visual cortex where a person can respond to a visual stimulus without consciously experiencing it.

Sound

The movement of air molecules at different frequencies (pitch) and amplitudes (loudness).

Photoreceptors

Cells inside the retina (rods and cones) that react to light and change light energy into an electrical signal.

Rods vs. Cones

Rods detect light and are used in low

Accommodation

The process where the lens bends to focus visual stimuli onto the retina.

Nearsighted vs. Farsighted

Nearsighted individuals see clearly up close but struggle with distance; Farsighted individuals see clearly far away but struggle with close objects.

Trichromatic Theory

Also known as Young

Opponent

Process Theory

Sensory Interaction

The idea that one sense may influence another, such as how smell can affect taste.

Synesthesia

A rare condition where stimulation of one sensory pathway leads to automatic, involuntary experiences in a second sensory pathway.

Priming

Exposure to one stimulus can influence how we perceive a subsequent stimulus.

Transduction

The process of converting sensory information into neural signals that the brain can interpret.

Cornea

The clear, outer layer at the front of the eye that helps focus light coming into the eye.

Pupil

The black circle in the middle of the eye that controls how much light enters by getting bigger or smaller.

Iris

The coloured part of the eye surrounding the pupil that changes the pupil's size to regulate light entry.

Lens

A clear, flexible structure behind the pupil that bends (accommodates) to focus light onto the retina.

Retina

The back of the eye containing rods and cones where light is turned into neural signals.

Fovea

A small area in the centre of the retina where vision is the sharpest, used for detailed tasks.

Optic Nerve

The nerve that sends visual information from the eye to the brain for processing.

Pheromones

Chemical signals released by an individual that affect the behaviour of other individuals.

Gustation

The sense of taste, which detects chemicals in food through receptors on the tongue.

Taste Buds

Specialized structures located on the tongue that contain taste receptors.

Sweet Taste

Signals energy

Sour Taste

Signals acidic foods, which may indicate spoilage.

Salty Taste

Signals sodium, which is essential for body functions.

Bitter Taste

Can signal toxins, leading to aversion.

Umami Taste

A savory taste often linked to proteins or meats.

Oleogustus

The taste of fat, which plays a role in food preferences.

Place Theory

Suggests pitch is determined by the specific location on the basilar membrane that is stimulated (best for high frequencies).

Frequency Theory

Suggests pitch is determined by the rate at which neural impulses travel through the auditory nerve (best for low frequencies).

Volley Theory

Suggests groups of neurons fire in a combined sequence to match the frequency of higher pitch sounds.

Sensorineural Deafness

A decline in the clarity and range of sounds due to damage in the inner ear or auditory nerve.

Conduction Deafness

Loss of hearing caused by damage or blockage preventing sound from travelling efficiently from the outer ear to the inner ear.

Olfactory System

The system responsible for the sense of smell, working by detecting chemical molecules in the air.

Pinna

The visible outer part of the ear that collects sound waves and funnels them into the ear canal.

Ear Canal (Auditory Canal)

A tube that channels sound waves from the pinna to the eardrum and amplifies them.

Eardrum (Tympanic Membrane)

A thin membrane that vibrates when sound waves hit it, transferring energy to the middle ear.

Ossicles

Three tiny bones (malleus, incus, stapes) in the middle ear that amplify vibrations and transfer them to the inner ear.

Eustachian Tube

A canal connecting the middle ear to the throat to equalize air pressure.

Cochlea

A fluid

Auditory Nerve

Carries electrical signals from the cochlea to the brain to be interpreted as sound.

Wavelength (Pitch)

The distance between two identical parts of a wave; determines the highness or lowness of a sound.

Amplitude (Loudness)

The height or strength of a sound wave; determines the loudness of the sound.

Sound Localization

The process by which the brain determines the origin, direction, and distance of sounds.

Vestibular Sense

The sense that helps maintain balance, posture, and spatial orientation by detecting head and body position relative to gravity.

Semicircular Canals

Three fluid

Vertigo

A spinning sensation often caused when fluid in the semicircular canals keeps moving after the body stops.

Kinesthetic Sense

Provides awareness of the movement and position of body parts relative to each other without looking.

Thermoreceptors

Skin receptors that detect changes in temperature.

Nociceptors

Skin receptors that detect pain or tissue damage.

Structures that Process Touch

Includes skin receptors, the thalamus (relay station), and the somatosensory cortex (processing area).

Processes and Complexities of Pain

Pain is processed through both physical signals from nociceptors and emotional pathways in the limbic system [cite: 132

[cite_start]Gate Control Theory

Suggests the spinal cord has a "gate" that can block or allow pain signals to pass to the brain.

Phantom Limb Sensation

When amputees feel sensation or pain in a missing limb because the brain's sensory map still includes it.

Taste Receptors

Located within taste buds, these detect chemicals dissolved in saliva.

Supertasters

People with more taste buds than average, making them highly sensitive to flavors like bitterness.

Medium Tasters

People with a moderate/average number of taste buds.

Nontasters

People with fewer taste buds and reduced sensitivity to tastes.

Interaction and Coordination of Chemical Senses

The concept that taste and smell work together; much of "taste" is actually smell.

Skin Receptors

Specialized cells in the skin that detect pressure, temperature, and pain.

Mechanoreceptors

Skin receptors that detect pressure and texture.