Here's the version created via the use of (D).

Recently documented examples of neurogenesis, the production of new brain cells, include the brain growth in mice when placed in a stimulating environment or the increase in canaries' neurons when they learn new songs.

This part all makes sense: Recently documented examples of neurogenesis, the production of new brain cells, include the brain growth in mice

Here's the first spot in which it goes wrong: the brain growth in mice when placed in a stimulating environment

Notice that what that basically says is this: the brain growth in mice when placed in a stimulating environment

It doesn't say what is placed in a stimulating environment. Something is placed in a stimulating environment, but that can't be brain growth, because the brain growth happens when something else is "placed in a stimulating environment."

Also, the sentence does not say that the mice are placed in a stimulating environment. So, this version leaves out a key thing, what exactly is placed in a stimulating environment.

Furthermore, "when placed in a stimulating environment" has to modify a verb. Something happens "when," such as "when placed in a stimulating environment, mice experience brain growth," or "the brain growth seen in mice when they are placed in a stimulating environment," but no verb is present for "when placed in a stimulating environment" to modify.

The next issue is here: the increases in canaries' neurons

What exactly is an increase in canaries' neurons? The sentence does not say "increases in the number of neurons" or "increases in the sizes of neurons." It does not even say what (E) says, "an an increase in neurons in canaries," which is certainly not ideal but at least makes some sense. It says simply "increases in canaries' neurons,'" as if the neurons themselves somehow experience increases.

Objects can't increase. For example, this does not make sense. "After the rain, we observed increases in the tree's apples." The were increases in the apples themselves? Doesn't make sense.

So, "increases in canaries' neurons" doesn't make sense either.

The use of "they" is not ideal but not terrible. We can tell that the neurons don't learn new songs. So, "they" must refer to "canaries." The fact that "canaries''' is in the possessive form is not a clear flaw, at least in GMAT SC terms, because there are SC questions in which the correct answer includes a pronoun that refers to a noun in the possessive form. That said, the fact that "they" somehow seems to refer to "neurons" does add to the case for finding a choice better than this one.
_________________

Hi MartyTargetTestPrep - why do you say when placed in a stimulating environment should modify a verb ?

When can very well also be a relative clause trigger. My understanding is when may be a relative clause trigger or a subordinate clause trigger

If relative clause - clause will modify a noun [In 1999 when my brother was born is when I first attended school]. Here when is clearly modifying a noun (year, 1999)
If subordinate clause - when subordinate clause should be modifying a verb

How can you be so sure that When is not intended to play the role of a relative clause (noun modifier) ?

There's no clause after "when." If there were, as in, "when they are placed," the structure would be a clause.

A "trigger" is only good as a "flag." It doesn't tell the whole story.
_________________

Hi MartyTargetTestPrep :

I am little bit lost here. Please help to clarify the doubt.

(D) the brain growth in mice when placed in a stimulating environment or the increase in canaries' neurons when they
1. If " when placed in a stimulating environment" acts as relative /adjective clause then it should not be a problem.
We just want to emphaise if it is turned into sub ordinate clause then it is more clear?
mice that are placed xx
So we can't reject D on this basis , right?

2. growth in mice when placed. How growth can be placed in xx. so I don't think it is umbigous , Definitely , its an object that can be placed in xx. here object refers to mice. So again it is better but not bais to reject D .Am i right?

3. So main reason to reject D is 2nd part : increase in canaries' neurons when they
Now here they refers to neurons , so definitely D should be rejected

So I think D can not be rejected on basis of 1 and 2 reasoning.

Please confirm.

Notice that "when placed in a stimulating environment" is not a clause. It's a phrase. So, as I discussed above, it's an adverbial phrase with nothing to modify.


The issue is that the sentence does not convey that the mice were placed in that environment. We know that the growth is not placed there, but the sentence does not say what is placed there.


As I discussed above, "they" would not logically refer to "neurons" because neurons do not "learn new songs."

So, the use of "they" is not clearly incorrect, and the issues I outlined above are the best reasons for eliminating (D).
_________________

Hi DmitryFarber - In the above in yellow highlight --> how are you so sure the yello is an adverbial modifier ?

If you look at the list of relative pronouns list (noun modifiers ) - who / whom / which / where / in which / when / that /

When falls as a noun modifier list.

Hi MartyTargetTestPrep - I have not gone through the TTP verbal book. Perhaps thats why I am not sure why the stuff in yellow is important to determine if the phrase in question is adjectival or adverbial.

Are you saying -- ALL noun modifiers are ALWAYS clauses ? If so, that is news to me.

Otherwise, I still don't understand why the bit in yellow is a determiner to realize whether when placed in a stimulating environment is adjectival or adverbial ?

For example :
Roger federer, who was placed 4th in the tournament, is 40 years old.

==Above "who was placed 4th in the tournament" is a clause and is adjectival

Roger federer, who was placed 4th in the tournament, is 40 years old.

== Here who was placed 4th in the tournament is NOT a clause as PLACED is a past participle BUT "who placed 4th in the tournament is still adjectiival in nature per my understanding.

Not all noun modifiers are clauses, although both of the modifiers you mentioned above are clauses.

The only reason I said, "Notice that "when placed in a stimulating environment" is not a clause," is that mSKR had made a point based on the idea that that modifier is a clause. So, I was making clear that that point was not valid, partly because that modifier is not a clause.
_________________

Thanks so much. MartyTargetTestPrep

So - "when placed in a stimulating environment" - you figured this was adverbial in nature - how ? I think I am struggling to figure out how one can determine if the phrase "when placed in a stimulating environment" is adverbial and adjectival in this context ?

Is it by process of elimination perhaps ? "When ....."

If a When phrase is to used for noun modifiers, it should be used for Time periods or years or dates only. Given you only saw "Brain growth" or "Mice" -- you figured .."Oh well, neither "Brain growth" nor "Mice" are Time periods or years or dates.

Hence "when placed in a stimulating environment" could only be adverbial in nature given the nouns for nouns modiifers are just not there.

Was that your thinking when figuring out if "when placed in a stimulating environment" was adverbial or adjectival ?

jabhatta2

"When" normally works as an adverbial modifier. As you stated in your follow-up, we can use "when" to modify time periods-- "The year when I visited Singapore"--but this is the exception, not the rule. There is simply no way for a phrase such as "when placed in a stimulating environment" to work as a noun modifier. What would it mean? That phrase can only describe what a noun (e.g. animal) does in a certain situation. That's an adverbial modifier.
_________________

Hi DmitryFarber - i thought the following could be an example of a "when" worked as a noun modifier

I like chicken when it is roasted

when it is roasted i thought referred to the object-noun "chicken" only.
when it is roasted cannot be adverbial (Referring to the subject-verb)

Reason i thought when it is roasted was a noun modifer and NOT adverbial :

- Subordinate clauses can be adjectival
- In this case, the sentence makes logical sense if the subordinate clause (I like chicken when it is roasted) modifies the noun only

Thoughts ?

Regarding Option D

WHEN can be a noun modifier or an adverb BOTH.

- See if when can be a noun modifier (is there a time stamp) – if there is none (Growth nor Mice are NOT time tamps) hence when CANNOT be a noun modifier in option D

Can When be an adverb ?
- See if when can an adverb making sense with the subject – verb.
- The subject is brain growth. The verb is missing completelely

Thus, when cannot be used as adverb as the subject (Brain growth) then would be modified and there is no verb

Thus eliminate D because of incorrect usage of WHEN (incorrect usage as a noun modifier or incorrect usage of adverb)

In E -- THAT makes sense as a noun modifier for RATs

jabhatta2


I somehow missed your "chicken" post before. In that case, "when it is roasted" is still adverbial. When do I like chicken? When it is roasted. In this case, it works a lot like "if": if the chicken is roasted, I like it. "Chicken when it is roasted" isn't a thing I can like. We have the simple "roasted chicken" for that. The only reason to go with "when it is roasted" would be to place a limit on when you like chicken, not on the chicken itself. In general, we're safest if we default to treating "when" as adverbial. The noun modifier usage is not going to show up much, and we certainly need more than a time stamp/period to tell us we have a noun modifier.
_________________