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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.
Q.
Which of the following best represents the author’s primary goal in writing the passage?
  • a)
    to outline a theory and suggest options for further research
  • b)
    to act as an advocate for additional research to help elucidate a particular theory’s validity
  • c)
    to introduce a theoretical construct that has not yet been sufficiently proven
  • d)
    to demonstrate the complexities involved in conducting a certain type of scientific research
  • e)
    to articulate a hypothesis and lay out the case for proving it
Correct answer is option 'C'. Can you explain this answer?
Verified Answer
Scientific advances in the latter half of the twentieth century have a...
We are asked to find the purpose of the passage. The first paragraph of the passage introduces a theory that seeks to show a link between dreams and hallucinations based upon two chemicals. The second paragraph elaborates on the role of the two chemicals in dreams and the third paragraph does the same for hallucinations. The third paragraph also concludes by noting that the theory remains unproven and would benefit from further testing.
(A) While the passage does outline a theory it does not suggest options for further research; it merely notes that further research would be beneficial.
(B) The author does not act as an advocate, or try to convince the audience of the need for additional research; instead, the author merely notes that further research would be beneficial. 
(C) CORRECT. A "theoretical construct" is equivalent to a theory; the author does introduce a theory that is "inconclusive," or not sufficiently proven.
(D) While the first sentence does imply that research associated with the brain is complex, the rest of the passage does not focus on this topic or attempt to demonstrate the specific complexities involved.
(E) While the passage does articulate a hypothesis, it only presents current research; it does not "lay out the case for proving it." In fact, the last sentence says the hypothesis is "inconclusive."
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Most Upvoted Answer
Scientific advances in the latter half of the twentieth century have a...
Primary Goal of the Passage
The passage aims to introduce a theoretical construct regarding the relationship between dreams, hallucinations, and neurotransmitters, particularly serotonin and norepinephrine.
Key Points Supporting the Answer
- Introduction of the Jacobs Hypothesis:
The author explains Jacobs' theory, which postulates a shared neurochemical mechanism between dreams and hallucinations. This sets the stage for discussing a theoretical framework rather than presenting conclusive evidence.
- Chemical Mechanisms in Sleep:
The passage elaborates on how serotonin and norepinephrine function in the brain during sleep cycles, emphasizing the intricacies of these neurotransmitters. This explanation highlights the theoretical basis of the hypothesis.
- Role of LSD:
The text discusses how LSD interacts with serotonin and norepinephrine, further illustrating the theoretical constructs related to dreaming and hallucination. The effects of LSD are presented as a possible link to understanding the hypothesis.
- Promise for Future Research:
The author acknowledges that while the research is promising, it remains inconclusive. This suggests an ongoing exploration of the theory rather than asserting it as definitively proven.
Conclusion
In summary, the passage introduces a theoretical construct—the Jacobs hypothesis—regarding the neurochemical basis of dreams and hallucinations, which has not been sufficiently proven yet. This aligns with option 'C', as it emphasizes the introduction of a theory rather than advancing a conclusive argument or advocating for extensive research.
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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.Q.Which of the following, if true, would most undermine the central premise of the Jacobs hypothesis?

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.Q.According to the passage, all of the following are true EXCEPT

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.Q.According to the passage, which of the following is true of the drug lysergic acid diethlyamide?

Directions: Read the Passage carefully and answer the question as follow.Caffeine, the stimulant in coffee, has been called“the most widely used psychoactive substance on Earth .”Synder, Daly and Bruns have recently proposed thatcaffeine affects behavior by countering the activity in(5) the human brain of a naturally occurring chemical calledadenosine. Adenosine normally depresses neuron firingin many areas of the brain. It apparently does this byinhibiting the release of neurotransmitters, chemicalsthat carry nerve impulses from one neuron to the next.(10) Like many other agents that affect neuron firing,adenosine must first bind to specific receptors onneuronal membranes. There are at least two classesof these receptors, which have been designated A1 andA2. Snyder et al propose that caffeine, which is struc-(15) turally similar to adenosine, is able to bind to both typesof receptors, which prevents adenosine from attachingthere and allows the neurons to fire more readily thanthey otherwise would.For many years, caffeine’s effects have been attri-(20) buted to its inhibition of the production of phosphodi-esterase, an enzyme that breaks down the chemicalcalled cyclic AMP.A number of neurotransmitters exerttheir effects by first increasing cyclic AMP concentra-tions in target neurons. Therefore, prolonged periods at(25) the elevated concentrations, as might be brought aboutby a phosphodiesterase inhibitor, could lead to a greateramount of neuron firing and, consequently, to behav-ioral stimulation. But Snyder et al point out that thecaffeine concentrations needed to inhibit the production(30) of phosphodiesterase in the brain are much higher thanthose that produce stimulation. Moreover, other com-pounds that block phosphodiesterase’s activity are notstimulants.To buttress their case that caffeine acts instead by pre-(35) venting adenosine binding, Snyder et al compared thestimulatory effects of a series of caffeine derivatives withtheir ability to dislodge adenosine from its receptors inthe brains of mice. “In general,” they reported, “theability of the compounds to compete at the receptors(40) correlates with their ability to stimulate locomotion inthe mouse; i.e., the higher their capacity to bind at thereceptors, the higher their ability to stimulate locomo-tion.” Theophylline, a close structural relative of caffeineand the major stimulant in tea, was one of the most(45) effective compounds in both regards.There were some apparent exceptions to the generalcorrelation observed between adenosine-receptor bindingand stimulation. One of these was a compound called3-isobuty1-1-methylxanthine(IBMX), which bound very(50) well but actually depressed mouse locomotion. Snyderet al suggest that this is not a major stumbling block totheir hypothesis. The problem is that the compound hasmixed effects in the brain, a not unusual occurrence withpsychoactive drugs. Even caffeine, which is generally(55) known only for its stimulatory effects, displays thisproperty, depressing mouse locomotion at very low concentrations and stimulating it at higher ones.Q.The primary purpose of the passage is to

Directions: Read the Passage carefully and answer the question as follow.Caffeine, the stimulant in coffee, has been called“the most widely used psychoactive substance on Earth .”Synder, Daly and Bruns have recently proposed thatcaffeine affects behavior by countering the activity in(5) the human brain of a naturally occurring chemical calledadenosine. Adenosine normally depresses neuron firingin many areas of the brain. It apparently does this byinhibiting the release of neurotransmitters, chemicalsthat carry nerve impulses from one neuron to the next.(10) Like many other agents that affect neuron firing,adenosine must first bind to specific receptors onneuronal membranes. There are at least two classesof these receptors, which have been designated A1 andA2. Snyder et al propose that caffeine, which is struc-(15) turally similar to adenosine, is able to bind to both typesof receptors, which prevents adenosine from attachingthere and allows the neurons to fire more readily thanthey otherwise would.For many years, caffeine’s effects have been attri-(20) buted to its inhibition of the production of phosphodi-esterase, an enzyme that breaks down the chemicalcalled cyclic AMP.A number of neurotransmitters exerttheir effects by first increasing cyclic AMP concentra-tions in target neurons. Therefore, prolonged periods at(25) the elevated concentrations, as might be brought aboutby a phosphodiesterase inhibitor, could lead to a greateramount of neuron firing and, consequently, to behav-ioral stimulation. But Snyder et al point out that thecaffeine concentrations needed to inhibit the production(30) of phosphodiesterase in the brain are much higher thanthose that produce stimulation. Moreover, other com-pounds that block phosphodiesterase’s activity are notstimulants.To buttress their case that caffeine acts instead by pre-(35) venting adenosine binding, Snyder et al compared thestimulatory effects of a series of caffeine derivatives withtheir ability to dislodge adenosine from its receptors inthe brains of mice. “In general,” they reported, “theability of the compounds to compete at the receptors(40) correlates with their ability to stimulate locomotion inthe mouse; i.e., the higher their capacity to bind at thereceptors, the higher their ability to stimulate locomo-tion.” Theophylline, a close structural relative of caffeineand the major stimulant in tea, was one of the most(45) effective compounds in both regards.There were some apparent exceptions to the generalcorrelation observed between adenosine-receptor bindingand stimulation. One of these was a compound called3-isobuty1-1-methylxanthine(IBMX), which bound very(50) well but actually depressed mouse locomotion. Snyderet al suggest that this is not a major stumbling block totheir hypothesis. The problem is that the compound hasmixed effects in the brain, a not unusual occurrence withpsychoactive drugs. Even caffeine, which is generally(55) known only for its stimulatory effects, displays thisproperty, depressing mouse locomotion at very low concentrations and stimulating it at higher ones.Q.According so Snyder et al, caffeine differs from adenosine in that caffeine

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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.Q.Which of the following best represents the author’s primary goal in writing the passage?a)to outline a theory and suggest options for further researchb)to act as an advocate for additional research to help elucidate a particular theory’s validityc)to introduce a theoretical construct that has not yet been sufficiently provend)to demonstrate the complexities involved in conducting a certain type of scientific researche)to articulate a hypothesis and lay out the case for proving itCorrect answer is option 'C'. Can you explain this answer?
Question Description
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.Q.Which of the following best represents the author’s primary goal in writing the passage?a)to outline a theory and suggest options for further researchb)to act as an advocate for additional research to help elucidate a particular theory’s validityc)to introduce a theoretical construct that has not yet been sufficiently provend)to demonstrate the complexities involved in conducting a certain type of scientific researche)to articulate a hypothesis and lay out the case for proving itCorrect answer is option 'C'. Can you explain this answer? for GMAT 2024 is part of GMAT preparation. The Question and answers have been prepared according to the GMAT exam syllabus. Information about 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.Q.Which of the following best represents the author’s primary goal in writing the passage?a)to outline a theory and suggest options for further researchb)to act as an advocate for additional research to help elucidate a particular theory’s validityc)to introduce a theoretical construct that has not yet been sufficiently provend)to demonstrate the complexities involved in conducting a certain type of scientific researche)to articulate a hypothesis and lay out the case for proving itCorrect answer is option 'C'. Can you explain this answer? covers all topics & solutions for GMAT 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for 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.Q.Which of the following best represents the author’s primary goal in writing the passage?a)to outline a theory and suggest options for further researchb)to act as an advocate for additional research to help elucidate a particular theory’s validityc)to introduce a theoretical construct that has not yet been sufficiently provend)to demonstrate the complexities involved in conducting a certain type of scientific researche)to articulate a hypothesis and lay out the case for proving itCorrect answer is option 'C'. Can you explain this answer?.
Solutions for 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.Q.Which of the following best represents the author’s primary goal in writing the passage?a)to outline a theory and suggest options for further researchb)to act as an advocate for additional research to help elucidate a particular theory’s validityc)to introduce a theoretical construct that has not yet been sufficiently provend)to demonstrate the complexities involved in conducting a certain type of scientific researche)to articulate a hypothesis and lay out the case for proving itCorrect answer is option 'C'. Can you explain this answer? in English & in Hindi are available as part of our courses for GMAT. Download more important topics, notes, lectures and mock test series for GMAT Exam by signing up for free.
Here you can find the meaning of 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.Q.Which of the following best represents the author’s primary goal in writing the passage?a)to outline a theory and suggest options for further researchb)to act as an advocate for additional research to help elucidate a particular theory’s validityc)to introduce a theoretical construct that has not yet been sufficiently provend)to demonstrate the complexities involved in conducting a certain type of scientific researche)to articulate a hypothesis and lay out the case for proving itCorrect answer is option 'C'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of 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.Q.Which of the following best represents the author’s primary goal in writing the passage?a)to outline a theory and suggest options for further researchb)to act as an advocate for additional research to help elucidate a particular theory’s validityc)to introduce a theoretical construct that has not yet been sufficiently provend)to demonstrate the complexities involved in conducting a certain type of scientific researche)to articulate a hypothesis and lay out the case for proving itCorrect answer is option 'C'. Can you explain this answer?, a detailed solution for 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.Q.Which of the following best represents the author’s primary goal in writing the passage?a)to outline a theory and suggest options for further researchb)to act as an advocate for additional research to help elucidate a particular theory’s validityc)to introduce a theoretical construct that has not yet been sufficiently provend)to demonstrate the complexities involved in conducting a certain type of scientific researche)to articulate a hypothesis and lay out the case for proving itCorrect answer is option 'C'. Can you explain this answer? has been provided alongside types of 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.Q.Which of the following best represents the author’s primary goal in writing the passage?a)to outline a theory and suggest options for further researchb)to act as an advocate for additional research to help elucidate a particular theory’s validityc)to introduce a theoretical construct that has not yet been sufficiently provend)to demonstrate the complexities involved in conducting a certain type of scientific researche)to articulate a hypothesis and lay out the case for proving itCorrect answer is option 'C'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice 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.Q.Which of the following best represents the author’s primary goal in writing the passage?a)to outline a theory and suggest options for further researchb)to act as an advocate for additional research to help elucidate a particular theory’s validityc)to introduce a theoretical construct that has not yet been sufficiently provend)to demonstrate the complexities involved in conducting a certain type of scientific researche)to articulate a hypothesis and lay out the case for proving itCorrect answer is option 'C'. Can you explain this answer? tests, examples and also practice GMAT tests.
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