LSAT 155 | Section 4 | Logical Reasoning: Q3

LR Question 3 Explanation

QUESTION TEXT: Researcher: Newly formed neurons can help to heal an injured…

QUESTION TYPE: Must be True

FACTS:

1. Newly formed neurons can heal injuries, but only if they develop into the neural type that’s most common in the injured area.
2. When the striatum is injured, new neurons in the striatum never become midsized spiny neurons.
3. Midsized spiny neurons are the most common type of neuron in the striatum.

ANALYSIS: We’ve learned a bit about healing brain injuries. Healing can only happen through newly formed neurons if those neurons become the most common type for the area. The most common type of neuron in the striatum is the midsized spiny neuron, so a striatum injury would need new neurons to become midsized spiny neurons.

However, they cannot become midsized spiny neurons in the striatum, so newly formed neurons cannot heal striatum injuries at all.

___________

1. We can’t infer this. It could be true that midsized spiny neurons only form in the striatum.
2. We don’t know this either. It would certainly help healing if it were true, but we’re never told anything that lets us conclude this.
3. We don’t know that midsized spiny neurons are exclusive to the striatum. They could be the most common type of neuron in every area of the brain, for all we know.
4. CORRECT. See above – injuries require newly formed neurons to become the most common neuron type, but that’s not possible if the striatum is injured.
5. We can’t conclude that newly formed neurons are unhelpful in most areas. We really only know about the striatum.

Recap: The question begins with “Researcher: Newly formed neurons can help to heal an injured”. It is a Must be True question. Learn how to master LSAT MBT questions on the LSAT Logical Reasoning question types page.