Question

the probability of an action potential being propagated from neuron to neuron increases when the neuron receives a(n) signal.
options:
postsynaptic; inhibitory
postsynaptic; excitatory
presynaptic; inhibitory
presynaptic; modulatory
question 18 (2.5 points)
sammy is conducting research that involves placing objects in the visual fields of visually impaired elderly men. he wants to discover the specific neurons that fire in response to the features of the various objects. to effectively conduct this study, sammy should place electrodes over the mens lobes.
options:
parietal
temporal
occipital
frontal

Explanation:

First Question (about action potential propagation)

To determine the correct answer, we analyze neuron signaling:

• Postsynaptic neuron: The neuron that receives the signal from the presynaptic neuron (via a synapse).
• Excitatory signal: Increases the likelihood of an action potential (depolarizes the postsynaptic neuron, moving it toward the threshold for firing).
• Inhibitory signal: Decreases the likelihood of an action potential (hyperpolarizes the postsynaptic neuron).
• Presynaptic neurons send signals, so options with "presynaptic" are incorrect (the presynaptic neuron sends, not receives, to propagate to the next neuron). Inhibitory signals reduce propagation probability, so "postsynaptic; inhibitory" is wrong. "Postsynaptic; excitatory" fits: the postsynaptic neuron receiving an excitatory signal increases the chance of action potential propagation.

To find the correct lobe, we recall brain anatomy:

• Occipital lobe: Primary area for visual processing (interprets visual information, including object features).
• Parietal lobe: Processes sensory - motor integration, spatial awareness, not primary visual processing.
• Temporal lobe: Involved in auditory processing, memory, and some visual object recognition (but not the primary area for detecting neuron firing related to visual object features as directly as the occipital lobe).
• Frontal lobe: Associated with higher - order functions like decision - making, planning, not visual processing.

So Sammy, who wants to study neurons firing in response to object features in visually impaired men, should place electrodes over the occipital lobes.

Answer:

B. postsynaptic; excitatory

Second Question (about brain lobes and visual processing)