VCE Units 3 & 4 Psychology - Comprehensive Review

A comprehensive vocabulary review of VCE Units 3 & 4 Psychology spanning Nervous System Functioning, Stress, Mental Wellbeing, Specific Phobia, Learning Approaches, Memory Mechanisms, and Sleep.

Nervous system

A complex communication network that receives internal and external sensory stimuli, processes the information, and coordinates an appropriate biological response.

Central nervous system (CNS)

The major division comprising the brain and spinal cord; it processes incoming sensory information from internal and external environments and activates motor responses.

Brain

The master organ of the CNS that coordinates all bodily functions and mental processes, linked to the peripheral body via the spinal cord and $12\text{ pairs}$ of cranial nerves.

Spinal cord

A column of nerve tissue extending from the brainstem that conveys sensory information afferently to the brain, motor commands efferently to the body, and coordinates independent spinal reflexes.

Peripheral nervous system (PNS)

The network of nerves outside the central nervous system that transmits sensory information from receptors to the CNS and carries motor messages from the CNS to skeletal muscles, organs, and glands.

Somatic nervous system (SNS)

A PNS subdivision carrying sensory (afferent) messages from receptor sites (skin, muscles, joints) to the CNS, and motor (efferent) signals from the CNS to voluntary skeletal muscles.

Autonomic nervous system (ANS)

A self-regulating PNS subdivision that connects the CNS to internal organs and glands, regulating involuntary, vital physiological processes like heart rate, respiration, and digestion.

Sympathetic nervous system

The activating branch of the ANS that prepares the body for vigorous physical exertion or emergency survival by triggering adrenaline release, increasing heart rate, and dilating pupils.

Parasympathetic nervous system

The homeostatic branch of the ANS that maintains daily baseline functioning and restores physiological calm after sympathetic activation by lowering heart rate and stimulating digestion.

Enteric nervous system (ENS)

A specialized ANS subdivision consisting of nerve cells embedded in the lining of the gastrointestinal tract from the oesophagus to rectum, regulating digestion subconsciously and communicating via the vagus nerve.

Conscious response

A reaction to a sensory stimulus that is voluntary, intentional, and involves conscious awareness and cognitive control from the brain.

Unconscious response

An automatic, involuntary, and unintentional reaction to a stimulus that occurs without conscious awareness or effort.

Spinal reflex

An unconscious, involuntary, automatically occurring adaptive motor response initiated at the spinal cord via an interneuron without initial input from the brain, saving critical time to avoid injury.

Sensory neurons (afferent)

Nerve cells that detect sensory information via specialized receptors and transmit neural messages inward along afferent pathways toward the CNS.

Motor neurons (efferent)

Nerve cells situated in the lower brainstem and spinal cord that carry motor commands outward along efferent pathways to skeletal muscles, organs, and glands.

Interneurons

Connecting neurons located exclusively within the CNS that relay neural information between sensory neurons and motor neurons.

Dendrite

A branched extension of a neuron equipped with receptor sites designed to detect and receive chemical neurotransmitters from presynaptic axon terminals across the synaptic gap.

Axon

A single, tubelike neuronal extension that transmits electrical action potentials unidirectionally from the soma toward the axon terminals.

Myelin sheath

A segmented white, fatty substance insulating the axon that prevents electrical signal distortion, stops cross-axonal interference, and speeds up neural impulse transmission.

Axon terminal button

A small knob at the distal ending of an axon terminal that stores neurotransmitters within synaptic vesicles and secretes them into the synaptic gap.

Synapse

The functional site of communication between adjacent neurons, consisting of the presynaptic terminal button, the fluid-filled synaptic gap, and the postsynaptic dendrite.

Lock-and-key process

The principle that a neurotransmitter's unique chemical shape (the key) must precisely match and bind to a complementary postsynaptic receptor site (the lock) to produce its biological effect.

Reuptake

The process by which excess neurotransmitter molecules remaining in the synaptic cleft are reabsorbed back into the presynaptic terminal buttons.

Excitatory effect

A stimulating influence on a postsynaptic neuron that depolarises its membrane, increasing the likelihood that it will generate an action potential.

Inhibitory effect

A suppressing influence on a postsynaptic neuron that hyperpolarises its membrane, decreasing the likelihood that it will generate an action potential.

Glutamate

The primary excitatory neurotransmitter in the CNS; stimulates postsynaptic firing and plays an indispensable role in synaptic plasticity, learning, and memory formation.

Gamma-aminobutyric acid (GABA)

The primary inhibitory neurotransmitter in the CNS; counterbalances excitatory signals to fine-tune neurotransmission, prevent uncontrolled overstimulation/seizures, and regulate anxiety.

Neuromodulator

A chemical messenger released into extracellular neural tissue that diffuses across broad brain regions to alter the sensitivity, cellular properties, and transmission efficacy of groups of neurons.

Dopamine

A neuromodulator active in the reward pathway that modulates motivation, pleasure, appetite, attention, and voluntary movement, reinforcing rewarding behaviours.

Serotonin

An inhibitory neuromodulator synthesized primarily in the gastrointestinal tract ($90\%$) and projecting across the neocortex to regulate mood stability, sleep onset, impulsivity, and aggression.

Synaptic plasticity

The biological capacity of a synapse to undergo functional and structural modifications—strengthening or weakening—in response to experience and learning.

Long-term potentiation (LTP)

The long-lasting strengthening of synaptic connections resulting from repeated, high-intensity activation of a neural pathway, mediated by increased glutamate release and receptor growth.

Long-term depression (LTD)

The long-lasting weakening of synaptic connections resulting from repeated, low-intensity activation of a neural pathway, allowing unneeded or inefficient connections to be eliminated.

Sprouting

A structural plastic modification involving the growth of new dendritic spines or axon terminal branches, creating additional synapses to strengthen a neural pathway.

Rerouting

A structural plastic adaptation wherein active neurons establish alternative neural circuits that bypass damaged, unneeded, or disused pathways.

Pruning

The activity-dependent elimination of unused, weak, or excess synaptic connections and neurons, increasing overall neural efficiency and fine-tuning brain networks.

Stressor

Any internal or external stimulus, event, or challenge that disrupts equilibrium and taxes an individual's coping resources.

Stress

A psychobiological state of mental, emotional, and physiological tension produced when internal or external stressors are appraised as challenging or exceeding personal coping resources.

Acute stress

A brief, sudden form of physiological and psychological arousal triggered by an immediate threat that resolves rapidly once the stressor is removed.

Chronic stress

A prolonged, continuous state of physiological and psychological arousal resulting from persistent, unresolved stressors that can lead to immune system suppression.

Flight-or-fight-or-freeze response

An automatic, acute biological survival response to immediate threat, preparing the body to confront (fight) or escape (flight) via sympathetic activation, or immobilise (freeze) via parasympathetic dominance.

Freeze response

An acute stress response characterised by physical immobility, vocal inhibition, and parasympathetic brake activation alongside sustained physiological alertness to avoid detection.

Cortisol

The primary glucocorticoid stress hormone secreted by the adrenal cortex during chronic stress to mobilize glucose and accelerate tissue repair, which suppresses immune function if prolonged.

Adrenal medulla

The inner core of the adrenal glands that secretes adrenaline and noradrenaline into the bloodstream during acute stress following sympathetic stimulation.

Adrenal cortex

The outer layer of the adrenal glands that synthesises and secretes the glucocorticoid cortisol during prolonged or chronic stress.

Gut-brain axis (GBA)

The bidirectional communication network linking the central nervous system to the enteric nervous system via neural (vagus nerve), endocrine, and immunological pathways.

Vagus nerve

The tenth cranial nerve serving as the principal structural pathway of the GBA, carrying $90\%$ of its neural signals afferently from the gastrointestinal tract up to the brain.

Gut microbiota

The population of trillions of microorganisms residing in the gastrointestinal tract that assist digestion and synthesize key neurotransmitters like GABA, serotonin, and dopamine.

Dysbiosis

An imbalance or disruption in the normal composition of the gut microbiota, which impairs gut-brain communication and increases susceptibility to stress and poor wellbeing.

General Adaptation Syndrome (GAS)

Hans Selye's three-stage biological model proposing that the body mounts a predictable, non-specific physiological response to sustained stress comprising alarm, resistance, and exhaustion.

Alarm reaction stage

The first stage of GAS when a stressor is first encountered, divided into an initial shock substage followed by a countershock substage.

Shock phase (GAS)

The initial substage of alarm reaction where the body's resistance drops below baseline, resulting in hypothermia, reduced blood pressure, and loss of muscle tone.

Countershock phase (GAS)

The second substage of alarm reaction where sympathetic arousal and the release of adrenaline and cortisol elevate resistance to the stressor above normal baseline.

Resistance stage (GAS)

The second stage of GAS where cortisol levels peak to maximize physiological coping resources against a persistent stressor, while immune functioning begins to deteriorate.

Exhaustion stage (GAS)

The final stage of GAS occurring when physiological energy reserves are depleted, resulting in profound immune collapse and extreme vulnerability to severe physical illness and mental disorders.

Transactional Model of Stress and Coping

Lazarus and Folkman's cognitive framework asserting that stress is a subjective transaction between an individual and environment, determined by primary and secondary cognitive appraisals.

Primary appraisal

The initial cognitive evaluation where an individual judges the personal significance of an encounter, classifying it as irrelevant, benign-positive, or stressful (harm/loss, threat, or challenge).

Harm/loss appraisal

A primary appraisal evaluating a stressful event based on physical, emotional, or social damage that has already occurred.

Threat appraisal

A primary appraisal evaluating a stressful event based on potential harm or negative consequences that may occur in the future.

Challenge appraisal

A primary appraisal evaluating a stressful event with an optimistic focus on the potential for personal gain, growth, or mastery.

Secondary appraisal

The cognitive evaluation following a stressful appraisal where an individual assesses whether their available internal and external coping resources are adequate to overcome the stressor.

Coping flexibility

The ability to recognize when a coping strategy is ineffective, discontinue it, and select and execute an alternative coping strategy that fits situational demands.

Context-specific effectiveness

The degree of match or 'good fit' between the deployed coping strategy, the unique situational demands of the stressor, and the individual's personal characteristics.

Approach coping strategies

Coping mechanisms that involve directly confronting a stressor and taking active cognitive or behavioural actions to resolve its underlying root cause.

Avoidance coping strategies

Coping mechanisms that involve evading a stressor and dealing with its effects indirectly through behavioural, psychological, or emotional disengagement.

Mental wellbeing continuum

A dynamic conceptual scale representing mental health as a fluctuating spectrum ranging from high wellbeing (mentally healthy) to low wellbeing (mental disorder).

Mental health problem

A mild, temporary, and reversible psychological disruption to daily functioning typically triggered by identifiable life stressors and resolving once the stressor passes.

Mental disorder

A clinically diagnosable psychological condition involving prolonged, severe distress, deviance, and functional impairment in cognition, emotional regulation, or behaviour.

Resilience

The psychological and biological ability to adapt to, manage, and bounce back from change, uncertainty, or adversity to restore baseline functioning.

Social and Emotional Wellbeing (SEWB) Framework

A holistic, multidimensional framework for Aboriginal and Torres Strait Islander peoples that views wellbeing as an interconnected network across seven core life domains.

Cultural continuity

The preservation and intergenerational transmission of Indigenous cultural traditions, languages, and values, serving as a protective buffer against historical trauma.

Self-determination

The sovereign right of Aboriginal and Torres Strait Islander peoples to make their own decisions and govern affairs affecting their communities, cultures, and lands.

Specific phobia

An anxiety disorder characterized by persistent, intense, and irrational fear of a specific object or situation that lasts at least $6\text{ months}$ and leads to avoidance behaviour.

GABA dysfunction (phobia)

A biological predisposing factor characterized by deficient synthesis or reception of GABA, resulting in uninhibited neural excitation and phobic anxiety.

Long-term potentiation in specific phobia

A biological contributing factor where the neural pathways connecting a phobic stimulus to conditioned fear responses are progressively strengthened via repeated activation.

Precipitation by classical conditioning

The behavioural acquisition of a phobia wherein an initially neutral stimulus is paired with a frightening unconditioned stimulus to elicit a learned, conditioned fear response.

Perpetuation by operant conditioning

The behavioural maintenance of a phobia where avoiding the phobic stimulus eliminates fear (negative reinforcement), strengthening the avoidance behaviour and sustaining the phobia.

Memory bias

A cognitive distortion where an individual selectively recalls frightening or negative encounters with a phobic stimulus while ignoring neutral or safe experiences.

Catastrophic thinking

A cognitive distortion where an individual habitually anticipates, exaggerates, and ruminates on the worst possible consequences of encountering a phobic stimulus.

Benzodiazepines

A class of short-acting CNS depressants that act as GABA agonists, binding to GABA receptors to amplify inhibitory effects and rapidly alleviate phobic anxiety.

Breathing retraining

A physiological intervention that trains individuals in conscious, slow, diaphragmatic breathing to regulate respiration and reverse hyperventilation during phobic panic.

Cognitive Behavioural Therapy (CBT for phobia)

A psychotherapeutic intervention that identifies, challenges, and restructures irrational phobic thoughts while replacing maladaptive avoidance behaviours with functional actions.

Systematic desensitisation

A classical conditioning behaviour therapy that replaces phobic fear with a relaxation response by pairing learned relaxation techniques with items on a graded fear hierarchy.

Fear hierarchy

A graded list of $10-15$ phobic scenarios created collaboratively with a therapist, ranked systematically from least to most anxiety-provoking.

Psychoeducation

A social intervention providing factual information about a disorder to the individual and their support network, empowering supporters to challenge unrealistic thoughts and discourage avoidance.

Classical conditioning

A passive, three-phase behaviourist learning process (before, during, after) whereby an involuntary reflex is associated with a neutral stimulus through repeated pairings with an unconditioned stimulus.

Operant conditioning

An active, voluntary learning process where the likelihood of a behaviour being repeated is determined by its environmental consequences (antecedent, behaviour, consequence).

Positive reinforcement

The delivery of a pleasant, desirable stimulus immediately following a voluntary behaviour, which increases the likelihood of that behaviour recurring.

Negative reinforcement

The removal, termination, or avoidance of an unpleasant, aversive stimulus immediately following a voluntary behaviour, which increases the likelihood of that behaviour recurring.

Positive punishment

The delivery of an unpleasant, aversive stimulus following a voluntary behaviour, which decreases the likelihood of that behaviour recurring.

Negative punishment

The removal or confiscation of a pleasant, desirable stimulus following a voluntary behaviour, which decreases the likelihood of that behaviour recurring.

Observational learning

A social-cognitive learning process where a learner acquires behaviours by watching a model's actions and consequences through five stages: attention, retention, reproduction, motivation, reinforcement.

8 Ways framework

An Indigenous learning framework articulating eight interconnected methods: story sharing, learning maps, non-verbal, symbols/images, land links, non-linear, deconstruct/reconstruct, and community links.

Atkinson-Shiffrin multi-store model of memory

A structural model asserting memory consists of three interacting stages—sensory memory, short-term memory, and long-term memory—each differing in role, capacity, and duration.

Iconic memory

The visual sub-store of sensory memory that stores an exact visual impression for approximately $0.3\text{ seconds}$ with unlimited capacity.

Echoic memory

The auditory sub-store of sensory memory that stores an exact acoustic sound trace for approximately $3-4\text{ seconds}$ with unlimited capacity.

Short-term memory (STM)

The conscious memory store with limited capacity ($7 \pm 2$ items) and limited duration ($12-30\text{ seconds}$) that actively manipulates currently attended information.

Maintenance rehearsal

The cognitive process of repeating information over and over to retain it in short-term memory beyond its typical $30\text{-second}$ duration.

Elaborative rehearsal

The process of linking new incoming information meaningfully to pre-existing knowledge in long-term memory to ensure effective encoding and long-term retention.

Long-term memory (LTM)

The permanent memory store with virtually unlimited capacity and relatively permanent duration that stores semantically encoded information for future retrieval.