EPPP Test Biological Bases of Behavior Questions and Answers — Questions and Answers
Question 1: A client who recently suffered a stroke is referred for a neuropsychological evaluation. The client's speech is fluent and grammatically correct, but the content is nonsensical and they have significant difficulty understanding both spoken and written language. The client seems unaware of their communication deficits. This clinical presentation is most consistent with damage to which of the following brain regions?
- Broca's area in the frontal lobe
- Wernicke's area in the temporal lobe (Correct answer)
- The primary motor cortex
- The occipital lobe
Correct answer: Wernicke's area in the temporal lobe
This scenario describes Wernicke's aphasia, also known as receptive or fluent aphasia. It is characterized by impaired language comprehension and the production of fluent but meaningless speech ('word salad'). It is caused by damage to Wernicke's area, which is located in the posterior part of the superior temporal gyrus in the dominant cerebral hemisphere (usually the left).
Question 2: Benzodiazepines are commonly prescribed for anxiety disorders. Their primary mechanism of action involves enhancing the effects of which neurotransmitter?
- Dopamine
- Serotonin
- Norepinephrine
- Gamma-aminobutyric acid (GABA) (Correct answer)
Correct answer: Gamma-aminobutyric acid (GABA)
Benzodiazepines are positive allosteric modulators of the GABA-A receptor. They bind to a site on the receptor that is distinct from the GABA binding site, causing a conformational change that increases the affinity of GABA for its receptor. This action potentiates the inhibitory effects of GABA, leading to a calming or sedative effect by increasing the frequency of chloride ion channel opening and hyperpolarizing the neuron.
Question 3: A psychologist is working with a patient who exhibits severe memory deficits, particularly an inability to form new memories (anterograde amnesia). The patient also has a tendency to invent stories to fill in gaps in their memory (confabulation). This patient has a long history of chronic alcohol abuse. Which of the following conditions is the most likely diagnosis?
- Alzheimer's disease
- Korsakoff's syndrome (Correct answer)
- Huntington's disease
- Somatic symptom disorder
Correct answer: Korsakoff's syndrome
Korsakoff's syndrome is a chronic memory disorder caused by a severe thiamine (vitamin B1) deficiency, which is most commonly seen in individuals with long-term alcohol misuse. Its hallmark symptoms include severe anterograde amnesia (inability to form new memories) and confabulation.
Question 4: Which of the following physiological responses is mediated by the activation of the sympathetic nervous system during the 'fight-or-flight' response?
- Increased digestion
- Constriction of pupils
- Increased heart rate and respiration (Correct answer)
- Stimulation of salivation
Correct answer: Increased heart rate and respiration
The 'fight-or-flight' response is an acute stress response initiated by the sympathetic nervous system. This system prepares the body for action by increasing heart rate and respiration to deliver more oxygenated blood to the muscles, dilating pupils to enhance vision, and diverting blood flow away from non-essential functions like digestion.
Question 5: Damage to the parietal lobe of the cerebral cortex is most likely to result in deficits in which of the following areas?
- Auditory processing
- Regulating basic drives like hunger and thirst
- Integrating sensory information and spatial awareness (Correct answer)
- Executive functions like planning and decision-making
Correct answer: Integrating sensory information and spatial awareness
The parietal lobe is a critical association cortex that integrates sensory information from various modalities to form a coherent perception of the world. It is essential for spatial processing, navigation, proprioception (sense of body position), and integrating sensory input (e.g., visual and somatosensory) to guide movement.
Question 6: The dopamine hypothesis of schizophrenia suggests that positive symptoms (e.g., hallucinations, delusions) are primarily related to an overactivity of dopaminergic pathways in the __________, while negative symptoms (e.g., anhedonia, avolition) are associated with underactivity in the __________ pathway.
- nigrostriatal; tuberoinfundibular
- mesocortical; mesolimbic
- tuberoinfundibular; nigrostriatal
- mesolimbic; mesocortical (Correct answer)
Correct answer: mesolimbic; mesocortical
The revised dopamine hypothesis of schizophrenia posits a dysregulation of dopamine pathways. Specifically, it suggests that hyperactivity of dopamine in the mesolimbic pathway contributes to the positive symptoms of psychosis. In contrast, hypoactivity (underactivity) of dopamine in the mesocortical pathway, which projects to the prefrontal cortex, is thought to be responsible for the negative and cognitive symptoms of the disorder.
