UNIT ONE (7-12)

Consciousness

State of being aware of & able to perceive one’s thoughts, feelings, sensations, & surroundings

• Involves various levels, from alert wakefulness to altered states such as sleep/meditation

Circadian Rhythm

Natural, internal process that regulates sleep-wake cycle & repeated roughly every 24 hrs. Influences patterns of alertness, hormone release, body temp, & other physiological processes

Jet Lag

Temporary disruption of body’s circadian rhythm due to rapid travel across multiple time zones.

• Can result in fatigue, sleep disturbances, & difficulty concentrating as the body adjusts to new time zone.

Shift Work

Employment schedules that require working outside typical daytime hrs, often disrupting body’s natural circadian rhythm.

• Can → sleep disturbances, fatigue, & inc risk of health problems due to mismatch b/w work hrs & body’s internal clock

Non-Rapid Eye Movement (NREM) Stage 1

Drifting in & out of sleep, lasting only few mins

• Brain waves slow down, muscles relax, & individuals may experience sudden muscle contractions known as hypnic jerks

NREM Stage 2

Light sleep, lasting abt 20 mins

• Brain waves further slow down, & sleep spindles (short bursts of brain activity) & K-complexes (sudden, sharp waveforms) appear

NREM Stage 3

Deepest stage, presence of predominately delta waves

• Restoration of Resources: Process during sleep where body & brain replenish energy, repair tissues, & remove waste products, promoting physical & mental well-being

REM (Rapid Eye Movement) Sleep

Stage of sleep characterized by rapid eye movements, vivid dreams, & muscle paralysis

• Associated w/ inc brain activity, including dreaming, & plays role in memory consolidation & emotional processing

REM Rebound

Phenomenon where body increases time spent in REM sleep after period of REM deprivation

• Occurs as compensatory response to lack of REM sleep, often resulting in more intense & frequent REM sleep episodes

Activation-Synthesis (Dreams)

Theory proposing dreams = result of random neural activity in brainstem during REM sleep, which is then interpreted & synthesized by cerebral cortex → narrative/story

Consolidation Theory (Dreams)

Theory suggesting dreams play role in memory consolidation & processing of memories

• During sleep, brain organizes & integrates info acquired throughout day, contributing → memory storage & learning

Insomia

Sleep disorder characterized by difficulty falling asleep, staying asleep, or experiencing restorative sleep, → daytime impairment such as fatigue, mood disturbances, & decreased cognitive function

Narcolepsy

Sleep disorder characterized by excessive daytime sleepiness, sudden episodes of muscle weakness (cataplexy), sleep paralysis, & hallucinations during sleep onset or awakening

Sleep Apnea

Sleep disorder characterized by pauses in breathing/shallow breathing during sleep, → disrupted sleep patterns, daytime fatigue, & other health problems

REM Sleep Behavior Disorder

Sleep disorder where individuals physically act out their dreams during REM sleep, potentially causing injury to themselves/others due to loss of muscle paralysis

Sommambulism “Sleepwalking”

Sleep disorder characterized by walking/performing other activities whiles till asleep. Typically occurs during non-REM sleep stages & can result in injuries/accidents

Psychoactive Drugs

Substances that alter brain function, → changes in perception, mood, consciousness, cognition, or behavior

• Act on CNS & can be categorized → stimulants, depressants, hallucinogens, & opioids

Agonists

Substances that bind to neurotransmitter receptors & mimic their effects, enhancing neural activity

Antagonists

Substances that bind to neurotransmitter receptors w/o activating them, blocking the effects of neurotransmitters

Reuptake Inhibitors

Medications that block reabsorption of neurotransmitters by the sending neuron, thereby inc concentration of neurotransmitters in synaptic clef & enhancing neurotransmission

Stimulants

Drugs that inc neutral activity & arousal, → heightened alertness, attention, & energy levels

Caffeine

Natural stimulant found in coffee, tea, & some sodas. Acts on CNS, inc alertness & reducing fatigue by blocking neurotransmitter adenosine

Cocaine

Powerful stimulant derived from coca plant. Inc neural activity, → euphoria, inc energy, & alertness

• Works by blocking reuptake of domaine, serotonin, & norepinphrine

Depressants

Drugs that slow down neural activity & bodily functions. Induce relaxation, sedation, & can lower inhibitions

Alcohol

Depressant drug that slows down neural activity in CNS. Can impair judgement, coordination, & cognitive functions, → relaxation, euphoria, & in higher doses, intoxication

Hallucinogens

Drugs that alter perception, mood, & cognitive processes, often causing hallucinations/profound changes in consciousness

Marijuana

Psychoactive drug derived from cannabis plant. Contains THC (alters mood, perception, & cognition). Effects include relaxation, altered perception of time, & heightened sensory experiences

• Can produce some hallucinogenic-like effects in certain individuals, not typically considered true hallucinogen

Opioids

Psychoactive drugs that act on opioid receptors in the brain & body, producing pain relief, euphoria, & sedation

Heroin

Highly addictive opioid drug derived from morphine. Produces intense euphoria, pain relief, & sedation by binding to opioid receptors in brain

Tolerance

Condition where inc amounts of psychoactive substance are needed to achieve same effects

• Occurs due to brain’s adaptation to the drug, → reduced sensitivity to its effects over time

Withdrawal

Onset of symptoms when a person stops using a psychoactive substance after a prolonged use. Symptoms inc physical discomfort, psychological distress, & cravings for drug

Addiction

Chronic brain disorder characterized by compulsive drug seeking & use, despite harmful consequences. Involves changes in brain structure & function, → loss of control over drug consumption

Sensation

Process by which our sensory receptors & nervous system receive & represent stimulus energies from our environment

Perception

Process of organizing & interpreting sensory info to make sense of world around us. Involves brain’s interpretation of sensory inputs, which can be influenced by past experiences, expectations, & context.

Transduction

Conversion of sensory stimuli → neural impulses that can be understood by brain

• Transformation of physical energy → electrochemical signals, enabling brain to interpret & perceive sensory info

Absolute Threshold

Min amount of stimulation required for a stimulus to be detected by a sensory system. Represents point @ which a stimulus becomes noticeable to an individual at least 50% of the time.

• Determines if stimulus can be noticed at all

Just-Noticeable Difference

Smallest change in stimulus that can be detected by an individual. Min difference needed for a person to perceive that a change has occurred.

• Measures sensitivity to differences in stimulus intensity

Weber’s Law

Perceived difference in a stimulus must be proportional to original intensity of stimulus

• Bigger smth is = more you need to change it to notice a difference

Sensory Adaptation

Process sensory receptors become less responsive to constant stimuli over time (wearing perfume)

Synesthesia

Condition in which stimulation of 1 sensory pathway → automatic, involuntary experiences in another sensory pathway

Retina

Light-sensitive inner surface of the eye containing photoreceptor cells (rods & cones) that convert light → neural signs

Rods

Photoreceptor cells in the retina responsible for vision in low light conditions & detecting motion. 

• Provide black & white vision & are highly sensitive to light, allowing us to see in dim environments.

Cones

Photoreceptor cells in the retina responsible for color vision & detail in bright light.

• Enable us to perceive colors & fine visual details, such as reading text/distinguishing b/w different hues.

Fovea

Central area of the retina responsible for sharp central vision. Contains high concentration of cone cells (no rods) enabling detailed & color vision.

Blind Spot

Area on the retina where the optic nerve exits the eye, lacking photoreceptor cells. Spot where vision is absent, as there are no light-sensitive cells to detect visual stimuli.

Ganglion Cells

Neurons in the retina that receive visual info from bipolar cells & transmit it to the brain via optic nerve.

• Play a crucial role in processing visual signs & relaying them to the brain for further interpretation.

Lens

Transparent structure in the eye that focuses light onto the retina. Adjusts its shape to help the eye properly reflect light, enabling clear vision @ different distances.

Accommodation

Process by which lens of the eye changes its shape to focus on objects @ different distances. 

• Allows for clear vision of both nearby & distant objects by adjusting the curvature of the lens.

Nearsightedness

Common vision condition where close objects appear clear, but distant objects appear blurry. Occurs when the eyeball is too long/cornea is too curved, causing light to focus in front of the retina instead of on it. 

Farsightedness

Vision condition where distance objects are seen more clearly than close ones. Happens when the eyeball is too short/cornea is too flat, causing light to focus behind the retina rather than directly on it. 

Trichromatic Theory

Theory proposing that color vision is based on 3 types of cone receptors, each sensitive to diff. wavelengths of light (red, green, & blue)

• Brain combines signals from these cones to create the perception of a wide range of colors.

Opponent-Process Theory

Theory proposing that color vision is based on pairs of opposing color processes (red-green, blue-yellow, & black-white)

• Activation of 1 color in the pair inhibits the other, leading to the perception of color afterimages & explaining certain aspects of color vision.

Afterimages

Visual sensations that persist after a stimulus is removed. Occur due to temporary overstimulation of cone cells, resulting in a brief perception of an inverted/complementary image.

Dichromatism

Type of color deficiency where an individual has only 2 types of functioning cone cells, instead of normal 3. Condition typically results in difficulty distinguishing b/w certain colors, especially reds & greens.

Monochromatism

Rare form of color blindness where an individual has only 1 type of functioning cone cell/none at all. Results in the inability to perceive colors, seeing the world in shades of gray.

Blindsight

Phenomenon where individuals w/ damage to their visual cortex can respond to visual stimuli w/o consciously perceiving them.

• Suggests that some visual processing can occur unconsciously, bypassing traditional pathways in the brain.

Prosopagnosia

Neurological condition characterized by the inability to recognize familiar faces, including 1’s own face, despite intact vision & intellect.

• Often referred to as face blindness.

Wavelength

Distance b/w sound wave peaks

• Shorter wavelengths = higher pitched sounds; Longer wavelengths = lower pitched sounds

• Sound measurement: decibels (dB) 

Place Theory

Idea that different parts of the inner ear detect diff. sound frequencies. Higher pitches = sensed near the entrance, low pitches = near the end.

Frequency Theory

Theory of pitch perception proposing that the frequency of a sound wave directly corresponds to the rate at which auditory nerve fibers fire.

• Higher frequency sounds = faster firing rates, resulting in higher perceived pitches.

Volley Theory

Theory of pitch perception proposing that groups of auditory neurons fire in rapid succession, or “volleys”, to encode the frequency of sounds above 1000 Hz.

• Allows the brain to perceive pitches that exceed the firing rate of individual neurons.

Sound Localization

Brain’s ability to determine location of a sound source in space. Rellies on cues such as differences in arrival time & intensity b/w the ears, as well as spectral cues, to accurately locate sounds. 

Conduction Deafness

Hearing impairment caused by problems w/ outer/middle ear, such as damage to the ear canal, eardrum, or middle ear bones.

• Typically results in difficulty hearing soft sounds & can often be treated medically or surgically (temporary).

Sensorineural Deafness

Hearing loss caused by damage to the inner ear or auditory nerve. Results in difficulty hearing soft sounds & understanding speech. Often permanent.

• Common causes inc aging, exposure to loud noise, & certain medical conditions. 

Sensory Interaction

Principle that 1 sense can influence another, such as when smell affects taste. Demonstrates how our senses work together to create our overall perception of the world. 

Olfactory Systems

Responsible for smell. Special receptors in the nose detect smells & send signals to the brain via olfactory nerve. Thalamus helps process this info, allowing us to identify different odors. 

Pheromones

Chemical substances released by animals, including humans, that trigger social/ behavioral responses in others of the same species. Play a role in communication, mating, & territorial marking. 

Gustation

Sense of taste, involving receptors on the tongue that detect diff. flavors.

• Taste receptors: specialized cells located on the tongue & in the mouth that detect diff. tastes.

Supertasters

Highly sensitive to taste, experiencing flavors more intensely, especially bitterness. 

Medium Tasters

Average sensitivity to taste, experiencing flavors moderately.

Nontasters

Less sensitive to taste, experiencing flavors less intensely than others.

Warm/Cold Receptors

Specialized sensory neurons in the skin that detect changes in temperature. Warm receptors respond to increases in temp, while cold receptors respond to decrease. Help us perceive & regulate the body's temp.

Pain

More difficult concept than others. Not a sensation, but an emotional response to stimuli.

• When pain is working at a manner consistent w/ tissue damage it fits the traditional understanding the function of pain, however, there are many instances where people could experience the same stimulus & 1 person could feel pain & another could experience thrill, arousal, unable to acknowledge the stimulus/perceive pain to non noxious stimuli.

Gate Control Theory

Theory proposing that the experience of pain is modulated by a neural “gate” in the spinal cord. Gate can open to allow pain signals to be transmitted to the brain or close to block them. 

Phantom Limb

Sensation of pain/other feelings in a missing limb. Occurs due to the brain’s continued perception of the limb, even though it is no longer there. 

• Phantom limb sensations can range from tingling to intense pain & are thought to result from the process of plasticity in the somatosensory cortex following amputation.

Vestibular Sense

Sense of body orientation & movement, including balance & spatial awareness. 

• Relies on receptors in the inner ear that detect changes in head position & movement, helping to maintain stability & coordinate bodily movement.

Semicircular Canals

Fluid filled structures in the inner ear that detect rotational movements of the head. 

• Play a crucial role in the vestibular sense by helping to maintain balance & coordination by sending signals to the brain about changes in head position & movement. 

Kinesthesis

Sense of body movement & position, including the awareness of muscle & joint sensations. Allows us to perceive & control our body’s movements, providing feedback to the brain about position & orientation of body parts.