Q3 - Researcher: Newly formed neurons

[smiller]

Question Type:
Inference

Stimulus Breakdown:
1. newly formed neurons help heal injured brain → they develop into type most common in injured area

2. striatum is injured → newly formed neurons never become midsized spiny (the most common type in striatum)

Answer Anticipation:
The contrapositive of the first statement is:

newly formed neurons do not develop into type most common in injured area → they do not help heal injured brain

Combining this with the second statement tells us that if the striatum is injured, newly formed neurons will not help heal it. Let's see if any of the answers match this!

Correct answer:
(D)

Answer choice analysis:
(A) The stimulus doesn't allow us to conclude that newly formed neurons ever develop into midsized spiny neurons anywhere. We only know that this does not happen in the striatum.

(B) Nothing allows us to conclude how commonly newly formed neurons are found, or how soon they are found after an injury occurs.

(C) We don't know how common midsized spiny neurons are in any part of the brain other than the striatum. We only know that they're common in the striatum.

(D) This matches our prediction nicely.

(E) The stimulus only allows us to conclude that newly formed neurons don't help the striatum heal. We don't know if most cases of brain injury involve the striatum, or how helpful newly formed neurons are when other areas of the brain are injured. We don't have enough evidence to make an inference about "most" cases of brain injury.

Takeaway/Pattern:
Learn to recognize conditional statements and notice when they appear in the stimulus of an Inference question. The correct answer will often be the result of combining two conditional statements from the stimulus. Beware of answers that basically state, "because it happens in this case, it happens in other cases," or "because it happens in this case, it doesn't happen in other cases." We can't make those kinds of inferences without direct support for them in the stimulus.

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