CAT Critical Reasoning Practice question with Solution 77

Baking for winter holidays is tradition that may have a sound medical basis. In midwinter, when days are short, many people suffer from a specific type of seasonal depression caused by lack of sunlight. Carbohydrates, both sugars and starches, boost the brain’s levels of serotonin, a neurotransmitter that improve the mood. In this respect, carbohydrates act on the brain in the same way as some antidepressants. Thus, eating holiday cookies may provide an effective form of self-prescribed medication.

Which one of the following can be properly inferred from the passage?

[A]. Seasonal depression is one of the most easily treated forms of depression.
[B]. Lack of sunlight lowers the level of serotonin in the brain.
[C]. People are more likely to be depressed in midwinter than at other times of the year.
[D]. Some antidepressants act by changing the brain’s level of serotonin.
[E]. Raising the level of neurotransmitters in the brain effectively relieves depression.
Answer: E

The key to this question is the phrase “in this respect.” We’re told that carbohydrates increase the brain’s level of serotonin, and that “in this respect” carbohydrates act on the brain in the same way as antidepressants. Critical reading tells us that the “respect” in question must be the increase in serotonin—the way the sentence is structured, the author simply can’t be referring to anything else. And that leads right to the correct inference in (D): Some antidepressants must also boost the brain’s level of serotonin.

(A) introduces a false contrast. The stimulus never compares seasonal depression to any other types of depression.

(B) We know that lack of sunlight can cause seasonal depression. We also know that an increase in serotonin can cheer people up. But we cannot combine these facts to conclude that there’s any connection between lack of sunlight and serotonin—the stimulus doesn’t specify why a lack of sunlight is depressing; it may have nothing to do with serotonin.

(C), like (A), offers another comparison that the stimulus simply doesn’t address: The stimulus never compares midwinter to any other season. There may be other times of the year when other causes, more serious than a lack of sunlight, make more people depressed.

(E) attempts to slip a scope shift by us: Serotonin is the only neurotransmitter mentioned in the passage that has the stated effect on depression; (E) tries to extend the argument to include all neurotransmitters. There’s no basis for that—for all we know, some neurotransmitters may even have a depressing effect.

Previous QuestionNext Question

Bodhee Prep's YouTube channel
CAT Prep Whatsapp Group
CAT Prep Telegram Group
CAT prep Telegram Group