BAPSY Biological Bases of Behavior 3 — Questions and Answers
Question 1: What technique uses magnetic fields and radio waves to produce detailed images of brain structure without radiation?
- PET scan
- EEG
- MRI (Correct answer)
- TMS
Correct answer: MRI
Magnetic Resonance Imaging (MRI) uses magnetic fields and radio waves to generate high-resolution structural brain images.
Question 2: Heritability estimates from twin studies indicate the proportion of variance in a trait that is due to:
- Environmental factors exclusively
- Genetic factors in a given population (Correct answer)
- Random mutation rates
- Epigenetic modifications only
Correct answer: Genetic factors in a given population
Heritability is a population-level statistic estimating how much of trait variance within that population is attributable to genetic differences.
Question 3: Which neurotransmitter is the primary inhibitory transmitter in the adult brain?
- Glutamate
- Dopamine
- Acetylcholine
- GABA (Correct answer)
Correct answer: GABA
Gamma-aminobutyric acid (GABA) hyperpolarizes neurons by opening Cl- channels, making it the main inhibitory neurotransmitter.
Question 4: The corpus callosum primarily connects which brain regions?
- Cerebellum to brainstem
- Left and right cerebral hemispheres (Correct answer)
- Thalamus to cortex
- Hippocampus to amygdala
Correct answer: Left and right cerebral hemispheres
The corpus callosum is a massive white matter tract allowing communication between the left and right hemispheres.
Question 5: Which stress hormone, released by the adrenal cortex, is elevated during chronic stress?
- Epinephrine
- Oxytocin
- Cortisol (Correct answer)
- Melatonin
Correct answer: Cortisol
Cortisol is a glucocorticoid released by the adrenal cortex in response to ACTH, and chronically elevated levels impair immune function and memory.
Question 6: Lesions to the hippocampus most severely impair which type of memory?
- Procedural (implicit) memory
- Emotional conditioning
- New declarative memory formation (Correct answer)
- Working memory capacity
Correct answer: New declarative memory formation
The hippocampus is essential for encoding new explicit (declarative) memories; patient H.M. demonstrated this after bilateral hippocampal removal.
Question 7: What is the term for the minimum level of stimulation required to trigger a neural action potential?
- Absolute refractory period
- Resting membrane potential
- Action potential threshold (Correct answer)
- Summation potential
Correct answer: Action potential threshold
The action potential threshold is approximately -55 mV; if depolarization reaches this level, an all-or-none action potential fires.
BAPSY Biological Bases of Behavior 3
What technique uses magnetic fields and radio waves to produce detailed images of brain structure without radiation?