Logical ReasoningDifficulty: Easy

PT105 S1 Q4 Explanation

In an experiment testing whether

A free, expert breakdown of this official LSAT Logical Reasoning question.

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Stimulus

In an experiment testing whether hyperactivity is due to a brain abnormality, the brain activity of 25 hyperactive adults was compared to the brain activity of 25 adults who were not hyperactive. The tests revealed that the hyperactive adults had much less brain activity in the premotor cortex, a region of the that diminished activity in the premotor cortex is one cause of hyperactivity.

What this question is testing

Weaken

Your task

Find the choice that makes the argument's conclusion less likely to be true.

Common trap

Answers that look negative but attack a claim the argument never relied on.

Winning move

Find the assumption the argument depends on, then pick the choice that undermines it.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question
4.

Which one of the following, if true, most undermines the conclusion drawn

Answer choices

  1. Trap0% picked this

    Some of the nonhyperactive adults in the study had children who

  2. Trap3% picked this

    The hyperactive adults who participated in the experiment varied in the severity

  3. Trap1% picked this

    The neuropsychologists who designed the experiment were not present when the

  4. Correct95% picked this

    All of the hyperactive adults in the study had been treated for hyperactivity with a medication that is known to depress activity in some

    Why this is right

    Answer D is correct.

    Skill tested: Weaken · how this choice captures the argument's function is the move to repeat next time.

  5. Trap1% picked this

    The test was performed only on adults because even though the method by which the test measured brain activity is harmless to adults, it

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