MCAT (Psychological, Social, and Biological) 5 — Questions and Answers
Question 1: During REM sleep, the brain exhibits which of the following EEG patterns?
- High-amplitude, low-frequency delta waves
- Sleep spindles and K-complexes
- Low-amplitude, high-frequency waves similar to waking (Correct answer)
- Theta waves only
Correct answer: Low-amplitude, high-frequency waves similar to waking
REM sleep shows desynchronized, low-amplitude, high-frequency EEG activity resembling an awake brain, along with rapid eye movements and muscle atonia.
Question 2: A physician notices that patients from collectivist cultures tend to describe illness in terms of family and community impact rather than personal symptoms. This reflects which concept?
- Ethnocentrism
- Cultural competence
- Individualism versus collectivism (Correct answer)
- Acculturation
Correct answer: Individualism versus collectivism
Individualism-collectivism is a cultural dimension describing the extent to which people define themselves through personal versus group identity, influencing health perceptions and communication.
Question 3: Which defense mechanism involves attributing one's own unacceptable thoughts or feelings to another person?
- Reaction formation
- Projection (Correct answer)
- Displacement
- Sublimation
Correct answer: Projection
Projection is a Freudian defense mechanism in which a person unconsciously attributes their own unwanted impulses or feelings to someone else.
Question 4: Sensory adaptation is best illustrated by which of the following examples?
- A rat learning to press a lever for food pellets
- No longer noticing the smell of a bakery after being inside for 20 minutes (Correct answer)
- Flinching at an unexpected loud sound
- Becoming more sensitive to pain after an injury
Correct answer: No longer noticing the smell of a bakery after being inside for 20 minutes
Sensory adaptation refers to the diminished sensitivity to a constant stimulus over time, as receptor firing decreases with prolonged exposure.
Question 5: Which of the following best describes the concept of 'stigma' as it relates to mental illness, according to sociological perspectives?
- The neurobiological cause of psychiatric symptoms
- A mark of disgrace that sets a person apart and leads to social discrimination (Correct answer)
- The legal status of individuals with psychiatric diagnoses
- The patient's subjective experience of mental illness
Correct answer: A mark of disgrace that sets a person apart and leads to social discrimination
Goffman defined stigma as a deeply discrediting attribute that reduces a person from a 'whole' person to a 'tainted' or 'discounted' one, resulting in social exclusion and discrimination.
Question 6: The blood-brain barrier is primarily formed by:
- Oligodendrocytes wrapping around blood vessels
- Tight junctions between cerebral endothelial cells, supported by astrocytes (Correct answer)
- Microglia patrolling capillary walls
- Myelin sheaths surrounding capillaries
Correct answer: Tight junctions between cerebral endothelial cells, supported by astrocytes
The blood-brain barrier consists of tight junctions between endothelial cells lining brain capillaries, with astrocytic endfeet providing additional support and regulation.
Question 7: A researcher finds that as ice cream sales increase, drowning rates also increase. The most likely explanation is:
- Ice cream consumption causes dehydration, increasing drowning risk
- Drowning victims often had ice cream beforehand
- Both variables increase in summer, making temperature a confounding variable (Correct answer)
- The correlation proves a causal relationship between ice cream and drowning
Correct answer: Both variables increase in summer, making temperature a confounding variable
This is a classic example of a spurious correlation driven by a confounding variable (season/temperature) that independently increases both ice cream consumption and swimming-related drowning.
MCAT (Psychological, Social, and Biological) 5
During REM sleep, the brain exhibits which of the following EEG patterns?