Chapter 24: Cognitive Development

The Brain During Adulthood

• New brain cells: Neurons form and dendrites grow in adulthood, particularly in the hippocampus.
• Cognitive Adaptability: New neurons provide cognitive adaptability to succeed in challenging and changing environments.
• Limited Growth: Brain growth is slow, limited, and not sufficient to restore itself to its younger state.

Ongoing Development

• New Cells: New neurons appear in the adult brain, particularly in the hippocampus (memory center) and the olfactory (smell) areas.
• Dendrite Growth: Dendrite growth is variable and crucial, providing evidence of lifelong plasticity.

Senescence and the Brain

• Slower Thinking: Attributed to overall slowdown in reaction time, movement, speech, and thought.
• Neurotransmitter Production: Reduced neurotransmitter production.
• Neural Changes: Neural fluid decreases, myelination thins, and cerebral blood circulates more slowly.
• Smaller Brains: Total brain volume becomes smaller.
• Gray and White Matter: Gray matter volume is reduced in every part of the brain, and white-matter lesions form.
• Transmission Disruption: Transmission of brain impulses is disrupted.

Step-by-Step Processing

• Input:
  • Sensory Loss: May be undetected as the brain fills in missed sights and sounds.
  • Interpretation of Facial Expressions: May be impaired, especially for anger and sadness.
  • Understanding of Speech: May be hampered by reduced hearing and vision acuity.
• Memory:
  • Stereotype Threat: Impedes memorial processes; suspecting memory loss can impact memory.
  • Memory Loss: Can be normal and pathological; explicit memory loss is generally greater than implicit memory loss.
  • Source Amnesia: May contribute to less analysis of information when elders cannot remember the origin of a fact.
• Prospective Memory:
  • Includes the ability to quickly shift mentally among tasks.
  • Involves remembering to perform a future task.
  • Fades notably with age.
  • May be aided through routines.
• Control Processes:
  • Involved in the underlying impairment of cognition in late adulthood, especially impaired retrieval.
  • Include executive function of the brain: selective attention, strategic judgment, and appropriate action.
  • Shift as analysis and forethought give way to reliance on prior knowledge, general principles, and rules of thumb.

Output

• Gradual Decline: Normal decline in output of primary mental abilities (e.g., verbal meaning, spatial orientation, inductive reasoning, number ability, word fluency).
• Verbal Output: In daily life, output is usually verbal.
• Modifiers: Health and training are important modifiers.
• Cognitive Tests:
  • Measured output of five primary mental abilities show decline, beginning around age 60 (Seattle Longitudinal Study).
  • Tests are normed and validated on younger adult output.
  • Awareness of ecological validity may help restructure memory research.

Neurocognitive Disorders (NCD)

• Ageism of Words: Lines between normal age-related problems, mild disorder, and major disorder are not clearly defined, and the symptoms vary depending on the specifics of brain loss and context.
• Caution Advised: Caution is advised in the use of words to describe cognitive decline in the elderly.
• Older Terms: Senile, dementia.
• DSM-5: Reference to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition.

Incidence of NCD

• Worldwide Statistics: 50 million people worldwide are affected; 60% in low-income nations; approximately 9% of the world’s population over 65.
• Decline in Prevalence: Decline in prevalence in England, Wales, and Sweden.

Types of Neurocognitive Diseases

• Alzheimer’s disease.
• Vascular disease.
• Frontotemporal NCDs.
• Other disorders.

Alzheimer’s Disease (AD)

• Global Prevalence: Diagnosed in every large nation.
• Main Symptom: Severe and worsening memory loss.
• Genetic Impact: Most cases begin much later, and many genes have some impact (e.g., SORL1 and ApoE4).
• Definitive Diagnosis: Not definitive until autopsy.
• Five Stages

Major and Minor Impairment

• Brain Comparison: A diseased brain is shrunken compared to a normal brain due to neuron degeneration. Plaques and tangles are indicated in the diseased brain.

Vascular Disease

• Former Term: Formerly called vascular or multi-infarct dementia.
• Characterization: Sporadic and progressive loss of intellectual functioning caused by repeated infarcts, or temporary obstructions of blood vessels, which prevent sufficient blood from reaching the brain.
• Correlation: Correlates with the ApoE4 allele and, for some of the elderly, is caused by surgery that requires general anesthesia.
• Transient Ischemic Attacks (TIAs): May cause TIAs.

Frontotemporal NCD

• Definition: Deterioration of the frontal lobes and the amygdala.
• Incidence: May be a cause of 15% of all major NCDs; tends to occur before age 70.
• Characteristics: Emotional and personality changes in which compassion, self-awareness, and judgment fade.

Progression of Alzheimer’s Disease and Vascular Disease

• Different Patterns of Decline: Victims of AD show steady, gradual decline, while those who suffer from vascular disease get suddenly worse, improve somewhat, and then experience another serious loss.

Other Disorders

• Parkinson’s Disease:
  • Does not always lead to NCD.
  • Starts with rigidity or tremor of the muscles as neurons that produce dopamine degenerate.
  • Younger adults with Parkinson’s disease may avoid cognitive problems for years.
• Lewy Body Disease:
  • Named after round deposits of protein (Lewy bodies) in the neuron.
  • Numerous and dispersed throughout the brain.
  • Motor movements and cognition are impacted.
  • Main symptom is loss of inhibition.

Causes of NCDs

• Huntington’s disease.
• Multiple sclerosis.
• Severe head injury.
• Last stages of syphilis.
• AIDS.
• Chronic traumatic encephalopathy (CTE).
• Bovine spongiform encephalopathy (BSE, mad cow disease).

Preventing Impairment

• Irreversible Damage: Severe brain damage cannot be reversed, but the rate of decline and some symptoms can be treated.
• Declining Risk: Declining risk for NCD incidence or prevalence is found in high-income countries.
• Amelioration: Education, exercise, medication, and good health may ameliorate mild losses and prevent worse ones.
• Avoidance: Avoidance of specific pathogens and toxins is critical.
• Early Diagnosis: Early, accurate diagnosis leads to more effective treatment.

Reversible Impairment

• Accurate Diagnosis: Crucial when a person is wrongly thought to have NCD.
• Common Cause: The most common reversible cause of NCD symptoms is depression.
• Other Causes: Malnutrition, dehydration, alcohol, brain tumors, physical illness, and overmedication can cause NCD-like symptoms.
• Inefficient Digestion: With age, bodies become less efficient at digesting food and using its nutrients.
• Polypharmacy:
  • When the elderly are prescribed several drugs, the side effects can cause NCD symptoms.
  • Some drug combinations can produce confusion and psychotic behavior.
  • Underuse of medication may also have adverse effects.

New Cognitive Development

• Erikson and Maslow:
  • Integrity versus Despair: The final stage in Erikson’s model in which older people gain interest in the arts, in children, and in human experience as a whole.
  • Self-Actualization: The final stage in Maslow’s hierarchy of needs, characterized by aesthetic, creative, philosophical, and spiritual understanding.

Aesthetic Sense and Creativity

• Elderly Artists: Elderly artists with extraordinary talents did not feel their abilities had been impaired by age.
  • Michelangelo and Sistine Chapel—age 75.
  • Verdi and Falstaff—age 80.
  • Frank Lloyd Wright and Guggenheim Museum design—age 91.
• Artistic Expression: May aid social skills, resilience, and even brain health.

Looking Back

• Life Review: An examination of one’s own role in the history of human life, engaged in by many elderly people; results are almost always positive.
• Wisdom: Expert knowledge system dealing with the conduct and understanding of life; life review, self-actualization, and integrity are considered parts of wisdom; some elderly people are unusually wise.