brain

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brain

by mgmt_gmat » Fri Feb 12, 2010 1:42 am
For most people, the left half of the brain controls linguistic capabilities, but some people
have their language centers in the right half. When a language center of the brain is
damaged, for example by a stroke, linguistic capabilities are impaired in some way.
Therefore, people who have suffered a serious stroke on the left side of the brain without
suffering any such impairment must have their language centers in the right half.
Which of the following is an assumption on which the reasoning in the argument above
depends?


A. No part of a person's brain that is damaged by a stroke ever recovers.
B. Impairment of linguistic capabilities does not occur in people who have not
suffered any damage to any language center of the brain.
C. Strokes tend to impair linguistic capabilities more severely than does any other
cause of damage to language centers in the brain.
D. If there are language centers on the left side of the brain, any serious stroke
affecting that side of the brain damages at least one of them.
E. It is impossible to determine which side of the brain contains a person's language
centers if the person has not suffered damage to either side of the brain.
Source: — Critical Reasoning |

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by komal » Fri Feb 12, 2010 2:15 am
A. No part of a person's brain that is damaged by a stroke ever recovers.
Incorrect : Recovery is not discussed in the stimulus above.

B. Impairment of linguistic capabilities does not occur in people who have not suffered any damage to any language center of the brain.
Incorrect : This is irrelevant to the scope of the argument.

C. Strokes tend to impair linguistic capabilities more severely than does any other cause of damage to language centers in the brain.
Incorrect : Any other cause of damage other than stroke is strictly out of scope.

D. If there are language centers on the left side of the brain, any serious stroke affecting that side of the brain damages at least one of them.
Correct : If we negate this answer choice, any damage to the left side of the brain does not damage any of the language centers. Then in that case, it cannot be said that language center is in the right half, since absence of impairment might be because none of the language center is affected rather than because it is on the right side of the brain.

E. It is impossible to determine which side of the brain contains a person's language centers if the person has not suffered damage to either side of the brain.
Incorrect : 'Impossible' is an extreme word here. Eliminated.

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by reply2spg » Fri Feb 19, 2010 9:47 am
IMO E
mgmt_gmat wrote:For most people, the left half of the brain controls linguistic capabilities, but some people
have their language centers in the right half. When a language center of the brain is
damaged, for example by a stroke, linguistic capabilities are impaired in some way.
Therefore, people who have suffered a serious stroke on the left side of the brain without
suffering any such impairment must have their language centers in the right half.
Which of the following is an assumption on which the reasoning in the argument above
depends?


A. No part of a person's brain that is damaged by a stroke ever recovers.
B. Impairment of linguistic capabilities does not occur in people who have not
suffered any damage to any language center of the brain.
C. Strokes tend to impair linguistic capabilities more severely than does any other
cause of damage to language centers in the brain.
D. If there are language centers on the left side of the brain, any serious stroke
affecting that side of the brain damages at least one of them.
E. It is impossible to determine which side of the brain contains a person's language
centers if the person has not suffered damage to either side of the brain.
Please post OA then I will explain.

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by boazkhan » Fri Feb 19, 2010 4:47 pm
IMO - E

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by amazonviper » Fri Feb 19, 2010 10:59 pm
IMO E as well. OA please
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by paddle_sweep » Thu Apr 29, 2010 5:13 am
IMO 'B'. Please post OA.

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by bichoo » Thu Apr 29, 2010 7:18 am
IMO D.

E is tempting but there is the word 'impossible,' which is extreme. Also, if you think about it, is there really no way to determine which side of the brain contains a person's language centers? You have to suffer brain damage to determine this? Does not make sense to me.

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by FightWithGMAT » Thu Apr 29, 2010 8:15 am
IMO B

This is a casual statement.

Now we need to prove that even if cause occurs, effect does not

or

Even effect is there, cause is not there.

Negate B, and you will get this.

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by ironstar37 » Thu Apr 29, 2010 8:34 am
+1 for D.. using negate strategy.

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by kaushals » Thu Apr 29, 2010 8:46 am
IMO D

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by ansh.kumar » Thu Apr 29, 2010 11:03 am
my pick is ^d^, delve into the conclusion u will find that b says about the cause , it missed sumthing while conclusion says about the location of the language centres.

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by shalzz9 » Fri Apr 30, 2010 5:38 am
IMO D


If D is negated the Conclusion is not valid.

i.e if there are language centers on the left side of the brain, any serious strike affecting that side of the brain does not damage any of them.
This means that even though there were language centers to the left they were not damaged and hence we cannot conclude that the language centers are to the right of the brain

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by FightWithGMAT » Fri Apr 30, 2010 6:34 am
What is OA????

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by beat_gmat_09 » Fri Apr 30, 2010 6:56 am
mgmt_gmat wrote:For most people, the left half of the brain controls linguistic capabilities, but some people
have their language centers in the right half. When a language center of the brain is
damaged, for example by a stroke, linguistic capabilities are impaired in some way.
Therefore, people who have suffered a serious stroke on the left side of the brain without
suffering any such impairment must have their language centers in the right half.
Which of the following is an assumption on which the reasoning in the argument above
depends?


A. No part of a person's brain that is damaged by a stroke ever recovers.
B. Impairment of linguistic capabilities does not occur in people who have not
suffered any damage to any language center of the brain.
C. Strokes tend to impair linguistic capabilities more severely than does any other
cause of damage to language centers in the brain.
D. If there are language centers on the left side of the brain, any serious stroke
affecting that side of the brain damages at least one of them.
E. It is impossible to determine which side of the brain contains a person's language
centers if the person has not suffered damage to either side of the brain.

IMO B.

Premises are -
i) mostly left half controls linguistic capa.
ii) some have ling cap in right half
iii) when language center is damaged, linguistic capa are impaired in some way

Conclusion -
i) ppl who suffered on left side without suffering such impairement must have lang center in right half.

A - recovery broadens the scope of argu,which is not answerable.
B - It is assumed that ling capab are impaired only when lang center is damaged, note the bold text. Just getting
out of scope of the argument, liguistic capabilities may also be hampered if one suffers damage to tongue etc.
C - Strokes is just an example, the assumption should be accepted to this argument as a whole.
D - "At least one of them" , narrows the scope of argu.
E - Assumption does not justify the bridge between the premises and the conclusion, which B does.