• Economist Test Prep
    Free Trial & Practice Exam
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    Economist Test Prep
  • Kaplan Test Prep
    Free Practice Test & Review
    How would you score if you took the GMAT

    Available with Beat the GMAT members only code

    MORE DETAILS
    Kaplan Test Prep
  • e-gmat Exclusive Offer
    Get 300+ Practice Questions
    25 Video lessons and 6 Webinars for FREE

    Available with Beat the GMAT members only code

    MORE DETAILS
    e-gmat Exclusive Offer
  • Varsity Tutors
    Award-winning private GMAT tutoring
    Register now and save up to $200

    Available with Beat the GMAT members only code

    MORE DETAILS
    Varsity Tutors
  • Magoosh
    Magoosh
    Study with Magoosh GMAT prep

    Available with Beat the GMAT members only code

    MORE DETAILS
    Magoosh
  • Target Test Prep
    5-Day Free Trial
    5-day free, full-access trial TTP Quant

    Available with Beat the GMAT members only code

    MORE DETAILS
    Target Test Prep
  • EMPOWERgmat Slider
    1 Hour Free
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    EMPOWERgmat Slider
  • PrepScholar GMAT
    5 Day FREE Trial
    Study Smarter, Not Harder

    Available with Beat the GMAT members only code

    MORE DETAILS
    PrepScholar GMAT
  • Veritas Prep
    Free Veritas GMAT Class
    Experience Lesson 1 Live Free

    Available with Beat the GMAT members only code

    MORE DETAILS
    Veritas Prep

Normally , the pineal gland governs CR

This topic has 2 member replies
georgepaul0071987 Senior | Next Rank: 100 Posts Default Avatar
Joined
14 Sep 2011
Posted:
81 messages
Thanked:
2 times

Normally , the pineal gland governs CR

Post Tue Sep 11, 2012 5:56 pm
Elapsed Time: 00:00
  • Lap #[LAPCOUNT] ([LAPTIME])
    Normally, the pineal gland governs a person's sleep-wake cycle by secreting melatonin in response to the daily cycle of light and darkness as detected by the eye. Nonetheless, many people who are totally blind due to lesions in the visual cortex of the brain easily maintain a 24-hour sleep-wake cycle. So the neural pathway by which the pineal gland receives information from the eye probably does not pass through the visual cortex.

    For purposes of evaluating the argument it would be most useful to establish which of the following?


    (A) Whether melatonin supplements help people who have difficulty maintaining a 24-hour sleep cycle to establish such a pattern

    (B) Whether the melatonin levels of most totally blind people who successfully maintain a 24-hour sleep-wake cycle change in response to changes in exposure to light and darkness

    (C) Whether melatonin is the only substance secreted by the pineal gland

    (D) Whether most people who do not have a 24-hour sleep-wake cycle nevertheless have a cycle of consistent duration

    (E) Whether there are any people with normal vision whose melatonin levels respond abnormally to periods of light and darkness

    Source : OG 13

    OA :B

    What's the best way to solve this question ?

    Need free GMAT or MBA advice from an expert? Register for Beat The GMAT now and post your question in these forums!
    akashkumar1987 Senior | Next Rank: 100 Posts Default Avatar
    Joined
    27 Aug 2012
    Posted:
    58 messages
    Thanked:
    2 times
    Post Tue Sep 11, 2012 8:22 pm
    If we go through the argument,Information we got from "totally blind" is used for making the argument.

    So to evaluate the argument the best thing is to ask question from "totally blind" people only,

    Answer Correct s B

    If anybody is having any other best strategy then please share.

    vikram4689 Legendary Member
    Joined
    01 Nov 2009
    Posted:
    1325 messages
    Followed by:
    14 members
    Thanked:
    105 times
    Post Wed Sep 12, 2012 9:07 am
    arg. says that pineal secretes melatonin as a response to light and governs sleep cycle. but since blind people having damaged cortex have same sleep cycle, therefore light does not enter form cortex. therefore link to be evaluated: coz people with damaged cortex have same sleep cycle, pineal does not get light from cortex.

    to evaluate, we need to see is melatonin is produced in blind people. if yes then light does not pass through cortex. if no then light does pass through cortex

    A - difficulty maintaining sleep cycle is not discussed
    C - even if pineal secretes more substances, it does not affect us
    D - duration is not our concern
    E - we are concerned about blind people

    _________________
    Premise: If you like my post
    Conclusion : Press the Thanks Button Wink

    Best Conversation Starters

    1 Vincen 180 topics
    2 lheiannie07 61 topics
    3 Roland2rule 61 topics
    4 ardz24 40 topics
    5 VJesus12 14 topics
    See More Top Beat The GMAT Members...

    Most Active Experts

    1 image description Brent@GMATPrepNow

    GMAT Prep Now Teacher

    160 posts
    2 image description Rich.C@EMPOWERgma...

    EMPOWERgmat

    102 posts
    3 image description GMATGuruNY

    The Princeton Review Teacher

    99 posts
    4 image description Jay@ManhattanReview

    Manhattan Review

    86 posts
    5 image description Matt@VeritasPrep

    Veritas Prep

    80 posts
    See More Top Beat The GMAT Experts