RC FROM MANHATTAN .. PLEASE RESOLVE DOUBT

[GUEST]

Scientific advances in the latter half of the twentieth century have allowed researchers to study the chemical activities taking place in the human brain during the sleep cycle in more detail. In the 1970s, Jacobs employed these advances to postulate that dreams and hallucinations share a common neurochemical mechanism with respect to the neurotransmitters serotonin and norepinephrine that accounts for the observable similarities between the two states of mind. To test the theory, researchers attempted to elucidate the role of these transmitters in the normal sleep cycle and the effect of hallucinogenic drugs on them.

Although scientists still have much to discover about the chemical complexities of the brain, serotonin appears important for managing sleep, mood, and appetite, among other important functions, while neurons release norepinephrine to facilitate alertness and mental focus. Both are discharged in high quantities only during waking states. At the onset of sleep, the activity levels of neurons that release both the neurotransmitters drop, allowing the brain first to enter the four non-rapid eye movement (Non-REM) stages of sleep. When the brain is ready to enter the fifth stage, REM, which is associated with dreaming, the levels of these two chemicals drop virtually to zero. The Jacobs hypothesis held that the absence of norepinephrine was required to enable the brain to remain asleep, while the absence of serotonin was necessary to allow dreaming to occur.

Lysergic acid diethylamide, or LSD, is a semi-synthetic psychedelic drug which causes significant alteration of the senses, memories and awareness; at doses higher than 20 micrograms, it can have a hallucinogenic effect. LSD mimics serotonin well enough to be able to bind at most of the neurotransmitter’s receptor sites, largely inhibiting normal transmission. In addition, the drug causes the locus ceruleus, a cluster of neurons containing norepinephrine, to greatly accelerate activity. If the drug stimulates norepinephrine, thereby precluding sleep, and inhibits serotonin, which Jacobs had postulated was a necessary condition for dreaming, then the resulting hallucinations could merely be "dreaming while awake." The research thus far is promising but inconclusive; future scientific advances should allow this theory to be tested more rigorously.



According to the passage, all of the following are true EXCEPT
A) Norepinephrine and serotonin are discharged only during waking states.
B) Ingesting more than 20 micrograms of LSD will cause some people to hallucinate.
C) Rapid eye movement is the stage of sleep during which people dream.
D) LSD causes neurons to increase the rate at which they discharge norepinephrine.
E) The absence of serotonin seems to be necessary in order to enable the brain to dream


MANHATTAN ANSWER A)

==============EXPLAINATION BY MANHAATTN ==============
(A) CORRECT. False. The second sentence of the second paragraph says of the chemicals that "Both are discharged in high quantities only during waking states." Later sentences tell us that the chemical levels drop during non-REM sleep, not that they disappear completely.
=================================================

MY DOUBT :


second para second statement says Both are discharged in high quantities only during waking states

So
According to the passage, all of the following are true EXCEPT
A) Norepinephrine and serotonin are discharged only during waking states. <== because its except we cannot say A is answer ?


please clarify your answer ?

[GUEST]

just to be clear .. this is from MANHATTAN online test as stated in subject line too .. just thought to make it clear

[esledge]

Yes, because this is a "according to the passage, all are true EXCEPT" question, it should be possible to find proof in the passage of all 4 wrong answer choices. The words "according to the passage" often signal that you will find a verbatim proof sentence, matching very closely between passage and answer choice.