#15 - Baking for winter holidays is a tradition that may

[JeoVela]

Dave,

I would first like to state that I have purchased all of your LSAT bibles as well as your workbooks for the Logic Games and Logic Reasoning and they are fantastic study materials.

Most importantly I have a question concerning a MBT question in your question type training book. Question number 23 (on page 27) makes it difficult to discern the correct answer because of the presence of conditional reasoning indicators and casual reasoning indicators in the stimulus. Im confused on searching for an answer choice that address the conditional reasoning (with either a contrapositive or repeat form) or an answer choice that disproves the casual reasoning described in the stimulus.

[Steve Stein]

Hi JeoVela,

First, thank you for your kind words about our books--It's great to hear that you've found them so helpful.

With regard to the Must Be True question that you asked about, we must consider just the facts presented and whatever inferences may be properly drawn. The author tells us that carbs boost the level of serotonin in the brain, and then goes on to say that in this way carbs act the same as some antidepressants. From this we can see that some antidepressants work by boosting serotonin, and this is what correct answer choice D provides.

Let me know if this clears this one up--otherwise, let me know which other answer choice(s) you found appealing--thanks!

~Steve

[abifafun]

Hi,

I need help with identifying why my answer, choice C, for this question is wrong and why choice D is a better answer.

Thank you.

[David Boyle]

Hi,

I need help with identifying why my answer, choice C, for this question is wrong and why choice D is a better answer.

Thank you.

Hello,

Answer C, "People are more likely to be depressed in midwinter than at other times of the year", is not really provable. Yes, there are winter factors promoting depression--but for all we know, maybe "excess sunshine depression" gets people depressed in the summer! (heh) So answer C isn't reliable, even if it sounds good.
Answer D is better because the stimulus says, "Carbohydrates, both sugars and starches, boost the brain's levels of serotonin, a neurotransmitter that improves the mood. In this respect, carbohydrates act on the brain in the same way as some antidepressants." Answer D, "Some antidepressants act by changing the brain's level of serotonin", just links up the various ideas in that chunk of the stimulus.

David

[lggabra]

Hello,

Why is B not the correct answer for this question? Could you not infer that since carbohydrates boost the brain's levels of serotonin to medicate depression, and that this seasonal depression is caused by lack of sunlight, that lack of sunlight is what is causing the original lowered level of serotonin that caused the depression in the first place?

Also, I had a general question about "Infer" type questions. When the question stem says to infer, does that mean that you can assume the answer choices could all be evaluated based on solely whether the claims they make are true? Or could there be a case where the answer choice is true because it reworded a claim made in the stimulus, but invalid because in that case it's not technically an inference.

Thank you in advance,
Lauren

[Kristina Moen]

Hi lggabra,

Answer Choice (B) is incorrect because we don't know why lack of sunlight causes depression. Maybe the serotonin levels stay the same. However, having higher levels of serotonin makes up for whatever else a lack of sunlight does to your brain or body. For example, maybe lack of sunlight means people stay inside and get lonely. So they lose human interaction. But by eating cookies, they boost their serotonin levels, and now they aren't as sad anymore, even though they still don't have human interaction. Answer Choice (B) could be true, but this is a Must Be True question.

However, the stimulus does say "carbohydrates act on the brain in the same way as some antidepressants" and "carbohydrates... boost the brain's levels of serotonin." Thus, it must be true that some antidepressants also boost the brain's level of serotonin, so Answer Choice (D) is correct

To respond to your second question - This is a Must Be True question. Be careful not to call it an "infer" question because the word "infer" can also appear in a Justify question (e.g. "The conclusion is properly inferred if which one of the following is assumed?"). In a Must Be True, the correct answer choice is something that absolutely, unequivocally must be true based on the information in the stimulus. The word "infer" does not change that. The correct answer choice is not something that could be true (because that means it could also not be true!) or is most likely true. If it's a rewording of something in the stimulus, then it could be the correct answer. In fact, often what seems like a "rewording" to a test taker is really in inference, but the test taker made the inference in their head. If the answer choice must be true, it is the correct answer choice!

[whardy21]

I was choosing between E and D and chose E. I did come to figure out why E was wrong to me. Answer choice E says Raising the level of neurotransmitters in the brain effectively relieves depression. However, the stimulus does not state it effectively relieves depression. It states nuerotransmitters just improves the mood. Which gives credence to why Answer D is correct. Improving the mood is changing the brains level. Whether or not nuerotransmitters are effective is not relevant. The last sentence states cookies may provide effective form of self prescribed medicine. So in essence, it's not that antidepressants like cookies are definitley effective. It's that they can be and thats why Answer choice E is wrong. Does that sound about right?

[Adam Tyson]

That's certainly part of why D is better than E, whardy21, but there's more to it. We know something about one neurotransmitter - serotonin - but we don't know anything about neurotransmitters in general. What impact would an increase in, say, acetylcholine have on depression? We have no idea! Probably none, since that particular neurotransmitter deals with things like muscle contractions and digestion, but we aren't expected to know that. We are, however, expected to not overgeneralize - if the evidence is about serotonin, which is a neurotransmitter, then we can say that we know something about ONE neurotransmitter, or SOME neurotransmitters (because 1 is some), but we cannot leap to general claims about all neurotransmitters. That's the big problem with answer E, in my view.

[wisnain]

Hi, I'm curious about the second sentence in the stimulus. Is it a conditional or a causal sentence? It contains a conditional indicator "when," but it also states 'depression is caused by lack of sunlight.'

Additionally, is there a way I could predict what the stimulus infers before going through the answer choices with the process of elimination(maybe like, look for comparisons like this stimulus or something)? Infer questions can be frustrating for me because I'm not sure where to focus on the stimulus while reading it.

Thanks.

[Rachael Wilkenfeld]

Hi wisnain,

The "when" here is not acting conditionally---it's not introducing an if---then relationship. You could look at it as "when days are short, it's midwinter" but that's not particularly helpful or useful for the overall argument. The causal argument is the central one here.

Seasonal depression is caused by a lack of sunlight.
Carbohydrates cause an increase in serotonin.
Carbohydrates cause something similar to antidepressants.

When I prephrase here, I look for similarities or links across the facts. That's a common tactic for me when there is a set of facts in the stimulus. I want to think about how those facts fit together to find an area of possible prephrase.

Here, I can use the fact that carbs cause an increase in serotonin and that work similarly to some antidepressants to say that some antidepressants work by causing an increase in serotonin, which is pretty close to answer choice (D).

Hope that helps!