The Ageing Brain

• A. Severe loss of memory affecting daily independence
• B. Gradual slowing of information processing speed ✓
• C. Widespread neuron death leading to dementia
• D. Persistent confusion about time and place

Why: Gradual slowing of processing speed is a common part of healthy ageing, whereas severe memory loss, widespread neuron death, and persistent disorientation are associated with pathological conditions such as dementia.

• A. It steadily increases throughout adult life
• B. It remains completely stable after age 25
• C. It gradually decreases, particularly in the frontal and temporal regions ✓
• D. It decreases only in people who develop disease

Why: Brain volume typically shrinks gradually with age, with the frontal and temporal lobes often showing some of the most noticeable reductions, even in healthy older adults.

• A. The brain's ability to reorganise and form new connections in response to experience ✓
• B. The permanent loss of neurons after early childhood
• C. The hardening of brain tissue due to calcium deposits
• D. The fixed number of synapses present at birth

Why: Neuroplasticity refers to the brain's capacity to adapt structurally and functionally by forming new synaptic connections and reorganising networks, which continues across the lifespan.

• A. Processing speed
• B. Working memory capacity
• C. Crystallised knowledge and vocabulary ✓
• D. Ability to learn entirely new motor skills quickly

Why: Crystallised intelligence, including accumulated knowledge and vocabulary, tends to remain stable or grow with age, while processing speed, working memory, and rapid learning of novel tasks typically decline.

• A. Cognitive reserve depletion ✓
• B. Synaptic pruning
• C. Myelin regeneration
• D. Neurogenesis overdrive

Why: Cognitive reserve refers to the brain's resilience to damage; as reserve is depleted through ageing and other factors, the brain has less capacity to compensate, which can influence when symptoms of disease appear.

• A. Cerebellum
• B. Hippocampus ✓
• C. Occipital cortex
• D. Brainstem

Why: The hippocampus is central to forming new episodic memories. It shows modest volume reduction with normal ageing, which contributes to some of the memory changes seen in healthy older adults, though the decline is far slower than in disease.

• A. Serotonin
• B. Dopamine ✓
• C. GABA
• D. Acetylcholine

Why: Dopamine signalling, particularly in the striatum and prefrontal cortex, declines with age through reduced receptor density and transporter availability. This is linked to slower processing speed and changes in executive functions such as working memory and attention.

• A. Myelination
• B. Neuroplasticity ✓
• C. Apoptosis
• D. Gliosis

Why: Neuroplasticity refers to the brain's capacity to change through synaptic remodelling, neurogenesis in some regions, and reorganisation. While plasticity is reduced in older age, it is not lost, which is why cognitive training and enriched environments can still produce benefits later in life.

• A. Increased myelin thickness across all tracts
• B. Reduced white matter integrity, particularly in frontal regions ✓
• C. Complete loss of myelin in the corpus callosum
• D. Increased number of axons in the frontal lobe

Why: Diffusion imaging studies show reduced white matter integrity with age, especially in frontal tracts. Myelin breakdown and changes in axonal structure slow signal conduction, which contributes to reduced processing speed in healthy older adults.

• A. Processing speed
• B. Working memory capacity
• C. Vocabulary and crystallised knowledge ✓
• D. Spatial reasoning speed

Why: Crystallised intelligence, including vocabulary and general knowledge, tends to be maintained or even improve into later life. In contrast, fluid abilities such as processing speed and working memory tend to decline with age.

• A. The permanent loss of neurons after early adulthood
• B. The brain's ability to reorganise its structure and function in response to experience and learning ✓
• C. The fixed set of connections a person is born with
• D. The process by which muscles develop memory

Why: Neuroplasticity refers to the brain's capacity to change its connections and activity patterns throughout life in response to experience, learning, and injury.

• A. The brain stops changing after age 25
• B. Older adults cannot form any new neural connections
• C. The brain retains the capacity to form new connections and adapt, though this may be slower than in youth ✓
• D. Only children can experience neuroplastic changes

Why: Research shows that neuroplasticity continues across the lifespan. While plasticity may decline in rate or magnitude with age, older adults can still form new synapses and adapt to learning.

• A. The addition of new neurons in the adult hippocampus
• B. The elimination of unused or weak synaptic connections, which refines neural circuits ✓
• C. The thickening of the myelin sheath around axons
• D. The growth of blood vessels within the brain

Why: Synaptic pruning removes redundant or infrequently used synapses, making neural networks more efficient. It is especially prominent during adolescence but occurs throughout life.

• A. Prolonged periods of physical inactivity
• B. Learning new skills, such as a musical instrument or a language ✓
• C. Avoiding all mental challenges to prevent fatigue
• D. Reducing social contact to limit stimulation

Why: Engaging in novel, challenging cognitive activities such as learning a language or instrument stimulates the formation of new connections and is associated with preserved cognitive function.

• A. Apoptosis
• B. Neurogenesis
• C. Myelination
• D. Functional reorganisation ✓

Why: Functional reorganisation describes how the brain can shift tasks to undamaged areas after injury or age-related change, a key expression of neuroplasticity.

• A. Eye colour
• B. High blood pressure (hypertension) ✓
• C. Height
• D. Blood type

Why: Chronic high blood pressure damages the small and large blood vessels that supply the brain, increasing the risk of stroke, small vessel disease and cognitive decline. Because it can be controlled through lifestyle and medication, it is a modifiable risk factor.

• A. Cerebral small vessel disease ✓
• B. Multiple sclerosis
• C. Parkinsonian tremor
• D. Huntington's chorea

Why: Cerebral small vessel disease affects the arterioles, capillaries and venules deep in the brain. It commonly appears as white matter hyperintensities on MRI and is an important contributor to vascular cognitive impairment in older adults.

• A. It stores large reserves of glucose and oxygen
• B. It has a high energy demand and little capacity to store energy ✓
• C. It produces its own blood supply
• D. It does not require oxygen to function

Why: The brain uses roughly 20 percent of the body's resting energy despite being about 2 percent of body weight. It relies almost continuously on glucose and oxygen delivered by blood and stores very little energy, so interruptions in blood flow quickly impair function.

• A. Regular physical exercise ✓
• B. Prolonged periods of sitting without breaks
• C. Heavy smoking
• D. Chronic sleep deprivation

Why: Regular aerobic exercise improves blood vessel function, helps control blood pressure and blood sugar, and promotes cerebral blood flow. These effects are linked to better cognitive performance and a reduced risk of vascular dementia in older adults.

• A. Dementia caused by a loss of hearing
• B. Cognitive decline resulting from reduced blood supply to the brain, often due to stroke or small vessel disease ✓
• C. Dementia that only affects memory of past events
• D. Dementia caused by a viral infection of the blood

Why: Vascular dementia results from impaired blood flow to brain tissue, commonly after one or more strokes or from progressive small vessel disease. It is one of the most common forms of dementia and is often grouped with Alzheimer's disease as a major cause of cognitive decline in later life.

• A. Procedural memory
• B. Episodic memory ✓
• C. Semantic memory
• D. Working memory

Why: Episodic memory stores autobiographical events tied to a specific time and place. Procedural memory covers skills, semantic memory covers general facts and knowledge, and working memory holds information briefly while you use it.

• A. Vocabulary knowledge
• B. Processing speed ✓
• C. General factual knowledge
• D. Familiar skill performance

Why: Processing speed, the rate at which the brain takes in and responds to information, tends to slow steadily from early adulthood onward. Vocabulary and accumulated knowledge often remain stable or even improve with age.

• A. Permanently storing long-term facts
• B. Holding and manipulating information over a short period while performing a task ✓
• C. Controlling involuntary body functions
• D. Recognising familiar faces automatically

Why: Working memory temporarily holds and manipulates information, such as remembering a phone number while dialling it. It has limited capacity and duration, unlike long-term memory.

• A. Dividing attention equally across all stimuli
• B. Focusing on one stimulus while filtering out others ✓
• C. Remembering information for many years
• D. Responding as quickly as possible to any signal

Why: Selective attention is the ability to concentrate on relevant information while ignoring distractions, such as following one conversation at a noisy party. Dividing attention is a separate concept called divided attention.

• A. Complete loss of all past memories
• B. Occasional difficulty recalling names or words on the tip of the tongue ✓
• C. Inability to learn any new information
• D. Permanent loss of the ability to speak

Why: Occasional word-finding difficulties and slower retrieval of names are typical age-related changes. Severe, widespread memory loss or inability to learn is not a normal part of healthy ageing and warrants medical assessment.

• A. Stroke-related vascular damage
• B. Alzheimer's disease ✓
• C. Frontotemporal degeneration
• D. Lewy body disease

Why: Alzheimer's disease accounts for the majority of dementia cases in older adults. It is characterised by the accumulation of amyloid-beta plaques and tau tangles, which progressively disrupt neuronal communication and cause memory loss and cognitive decline.

• A. Difficulty remembering recent conversations or events ✓
• B. Sudden loss of balance while walking
• C. Persistent involuntary tremor at rest
• D. Loss of the sense of smell only

Why: Short-term memory impairment, such as forgetting recently learned information or repeatedly asking the same questions, is typically one of the earliest signs of Alzheimer's disease. Tremor and balance problems are more associated with Parkinson's-related conditions.

• A. Age over 65
• B. Having a family history of dementia
• C. Untreated high blood pressure in midlife ✓
• D. Being female

Why: Midlife hypertension is a modifiable risk factor because it can damage cerebral blood vessels over time. Age, family history, and sex are non-modifiable risk factors, meaning they cannot be changed by lifestyle or treatment.

• A. Normal changes never affect daily activities
• B. Normal changes involve occasional forgetfulness that does not impair independent functioning ✓
• C. Normal changes always involve complete loss of names
• D. Normal changes begin only after age 90

Why: Occasional forgetfulness, such as misplacing keys or briefly struggling to recall a name, is common with ageing and does not stop a person managing daily life. Dementia is marked by progressive decline that interferes with work, relationships, and independent living.

• A. Prolonged physical inactivity
• B. Regular aerobic exercise ✓
• C. Chronic sleep of fewer than four hours nightly
• D. Frequent heavy alcohol consumption

Why: Regular aerobic exercise supports cerebrovascular health, improves blood flow to the brain, and has been associated with better cognitive outcomes and a reduced risk of dementia. The other options are established risk factors for cognitive decline rather than protective factors.

• A. Regular physical activity ✓
• B. Consuming large amounts of refined sugar
• C. Long periods of uninterrupted sitting
• D. Irregular sleep patterns

Why: Regular physical activity increases blood flow to the brain, supports the growth of new neurons and connections, and is linked to lower rates of cognitive decline and dementia in large observational studies and trials.

• A. 30 minutes per week
• B. About 75 minutes per week
• C. About 150 minutes per week ✓
• D. At least 300 minutes per day

Why: Major public health guidelines, such as those from the WHO, recommend at least 150 minutes of moderate-intensity aerobic activity per week, which benefits both cardiovascular and brain health.

• A. Sleep stops the brain from producing any new memories
• B. During sleep, the brain clears metabolic waste products such as amyloid-beta ✓
• C. Sleep increases the number of neurons in the cortex
• D. Sleep is only important for physical muscle recovery

Why: The glymphatic system becomes more active during deep sleep, helping clear waste products including amyloid-beta, a protein linked to Alzheimer's disease. Poor or insufficient sleep may impair this clearance.

• A. A very low-carbohydrate diet with high processed meat intake
• B. The Mediterranean diet, rich in vegetables, fruit, whole grains, nuts, olive oil and fish ✓
• C. A diet consisting mainly of fried and fast foods
• D. A diet with daily alcohol consumption well above recommended limits

Why: The Mediterranean diet has been extensively studied, and several trials and cohort studies associate it with slower cognitive decline and reduced dementia risk, likely due to its anti-inflammatory and cardiovascular benefits.

• A. The amount of money a person saves for healthcare costs in old age
• B. The brain's ability to maintain function despite age-related changes or damage, built up through education, learning and mentally stimulating activities ✓
• C. The number of brain cells a person is born with that cannot be replaced
• D. The level of blood sugar stored in the brain at rest

Why: Cognitive reserve is the brain's resilience, developed through lifelong learning, education and engaging activities. People with higher reserve can tolerate more neural changes before showing noticeable symptoms.