,PSYC 380 Quiz 4 | Physiological Psychology (2026)
Q&A | Liberty University
1. Which of the following best describes the role of the suprachiasmatic nucleus in
circadian rhythms?
A) It regulates the sleep-wake cycle by receiving light input from the retina.
B) It controls voluntary movement through connections to the motor cortex.
C) It processes auditory information from the cochlear nuclei.
D) It stores long-term memories in the temporal lobe.
Correct Answer: It regulates the sleep-wake cycle by receiving light input from
the retina.
Rationale: The suprachiasmatic nucleus is the master circadian clock located in
the hypothalamus, receiving light signals from the retina to entrain daily rhythms.
It does not control voluntary movement, process auditory information, or store
memories. Its role is essential for synchronizing internal biological rhythms with
the external environment.
2. What is the primary function of melatonin in the body?
A) It promotes wakefulness and alertness during the day.
B) It regulates circadian rhythms and promotes sleep.
C) It increases heart rate and blood pressure.
D) It enhances memory consolidation during REM sleep.
Correct Answer: It regulates circadian rhythms and promotes sleep.
,Rationale: Melatonin is secreted by the pineal gland, primarily at night, and
helps regulate the sleep-wake cycle by promoting sleepiness. It does not promote
wakefulness, increase cardiovascular activity, or directly enhance memory
consolidation. Its secretion is inhibited by light exposure.
3. According to the activation-synthesis hypothesis, dreams are the result of which
process?
A) The brain's attempt to interpret random neural activity during REM sleep.
B) The replay of memories from the previous day's experiences.
C) The expression of unconscious desires and conflicts.
D) The consolidation of procedural memories during slow-wave sleep.
Correct Answer: The brain's attempt to interpret random neural activity during
REM sleep.
Rationale: The activation-synthesis hypothesis proposes that dreams arise when
the brain tries to make sense of random signals generated by the brainstem during
REM sleep. It does not emphasize memory replay, unconscious desires, or
procedural consolidation. This theory highlights the brain's narrative construction
from chaotic neural firing.
4. Which brain region is most critical for the production of orexin, a
neurotransmitter that promotes wakefulness?
A) Lateral hypothalamus
B) Ventromedial hypothalamus
C) Suprachiasmatic nucleus
D) Pineal gland
, Correct Answer: Lateral hypothalamus
Rationale: Orexin, also called hypocretin, is produced by neurons in the lateral
hypothalamus and is essential for maintaining wakefulness. Loss of orexin-
producing neurons is associated with narcolepsy. The ventromedial hypothalamus
regulates satiety, the suprachiasmatic nucleus controls circadian rhythms, and the
pineal gland secretes melatonin.
5. What is the primary effect of caffeine on the nervous system?
A) It blocks adenosine receptors, reducing sleepiness.
B) It increases GABA activity, promoting relaxation.
C) It inhibits dopamine reuptake, enhancing reward.
D) It activates serotonin receptors, improving mood.
Correct Answer: It blocks adenosine receptors, reducing sleepiness.
Rationale: Caffeine acts as an adenosine receptor antagonist, preventing
adenosine from inducing sleepiness. It does not increase GABA activity, inhibit
dopamine reuptake, or directly activate serotonin receptors. Its stimulant effects
are primarily due to adenosine blockade.
6. Which of the following best describes long-term potentiation (LTP)?
A) A persistent strengthening of synaptic connections based on recent patterns of
activity.
B) A temporary increase in neurotransmitter release during high-frequency
stimulation.
C) A decrease in synaptic strength following low-frequency stimulation.
D) A form of synaptic plasticity that only occurs during development.
Q&A | Liberty University
1. Which of the following best describes the role of the suprachiasmatic nucleus in
circadian rhythms?
A) It regulates the sleep-wake cycle by receiving light input from the retina.
B) It controls voluntary movement through connections to the motor cortex.
C) It processes auditory information from the cochlear nuclei.
D) It stores long-term memories in the temporal lobe.
Correct Answer: It regulates the sleep-wake cycle by receiving light input from
the retina.
Rationale: The suprachiasmatic nucleus is the master circadian clock located in
the hypothalamus, receiving light signals from the retina to entrain daily rhythms.
It does not control voluntary movement, process auditory information, or store
memories. Its role is essential for synchronizing internal biological rhythms with
the external environment.
2. What is the primary function of melatonin in the body?
A) It promotes wakefulness and alertness during the day.
B) It regulates circadian rhythms and promotes sleep.
C) It increases heart rate and blood pressure.
D) It enhances memory consolidation during REM sleep.
Correct Answer: It regulates circadian rhythms and promotes sleep.
,Rationale: Melatonin is secreted by the pineal gland, primarily at night, and
helps regulate the sleep-wake cycle by promoting sleepiness. It does not promote
wakefulness, increase cardiovascular activity, or directly enhance memory
consolidation. Its secretion is inhibited by light exposure.
3. According to the activation-synthesis hypothesis, dreams are the result of which
process?
A) The brain's attempt to interpret random neural activity during REM sleep.
B) The replay of memories from the previous day's experiences.
C) The expression of unconscious desires and conflicts.
D) The consolidation of procedural memories during slow-wave sleep.
Correct Answer: The brain's attempt to interpret random neural activity during
REM sleep.
Rationale: The activation-synthesis hypothesis proposes that dreams arise when
the brain tries to make sense of random signals generated by the brainstem during
REM sleep. It does not emphasize memory replay, unconscious desires, or
procedural consolidation. This theory highlights the brain's narrative construction
from chaotic neural firing.
4. Which brain region is most critical for the production of orexin, a
neurotransmitter that promotes wakefulness?
A) Lateral hypothalamus
B) Ventromedial hypothalamus
C) Suprachiasmatic nucleus
D) Pineal gland
, Correct Answer: Lateral hypothalamus
Rationale: Orexin, also called hypocretin, is produced by neurons in the lateral
hypothalamus and is essential for maintaining wakefulness. Loss of orexin-
producing neurons is associated with narcolepsy. The ventromedial hypothalamus
regulates satiety, the suprachiasmatic nucleus controls circadian rhythms, and the
pineal gland secretes melatonin.
5. What is the primary effect of caffeine on the nervous system?
A) It blocks adenosine receptors, reducing sleepiness.
B) It increases GABA activity, promoting relaxation.
C) It inhibits dopamine reuptake, enhancing reward.
D) It activates serotonin receptors, improving mood.
Correct Answer: It blocks adenosine receptors, reducing sleepiness.
Rationale: Caffeine acts as an adenosine receptor antagonist, preventing
adenosine from inducing sleepiness. It does not increase GABA activity, inhibit
dopamine reuptake, or directly activate serotonin receptors. Its stimulant effects
are primarily due to adenosine blockade.
6. Which of the following best describes long-term potentiation (LTP)?
A) A persistent strengthening of synaptic connections based on recent patterns of
activity.
B) A temporary increase in neurotransmitter release during high-frequency
stimulation.
C) A decrease in synaptic strength following low-frequency stimulation.
D) A form of synaptic plasticity that only occurs during development.
