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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?
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?
- a)LSD does not completely inhibit normal transmission of serotonin.
- b)Serotonin is only one of many chemicals that play a role in regulating sleep.
- c)Researchers prove conclusively that the level of norepinephrine in the brain is a significant factor in enabling the brain to sleep
- d)Some semi-synthetic hallucinogenic drugs other than LSD do not inhibit serotonin.
- e)The first four stages of sleep are as crucial to the process of dreaming as the fifth stage.
Correct answer is option 'D'. Can you explain this answer?
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Verified Answer
Scientific advances in the latter half of the twentieth century have a...
We are asked to "undermine the central premise" of the presented hypothesis, which is summarized in the second sentence of the first paragraph. Jacobs proposed that dreams and hallucinations function via a similar brain mechanism involving the levels of two chemicals, serotonin and norepinephrine. Jacobs tried to prove this by demonstrating that the levels of these two chemicals fluctuate in a similar fashion while both dreaming (natural state) and hallucinating (via ingestion of a hallucinatory drug).
(A) In sentence 2, paragraph 3, we are told that LSD binds "at most of the neurotransmitter's receptor sites" (italics added), indicating that we (and Jacobs) already know that LSD does not completely inhibit serotonin transmission. This has already been taken into account, therefore, and does not undermine Jacobs' theory.
(B) The theory in question does not require serotonin to be the only chemical, or one of only a few chemicals, involved in regulating sleep. It merely proposes that two of of the chemicals involved with sleep also function similarly when the brain is hallucinating. This choice is out of scope.
(C) This could undermine Jacobs' theory under certain circumstances, but it could also bolster the theory. Jacobs believed that the drop in norepinephrine levels enabled the brain to sleep. This choice merely says the "levels" are significant; it does not quantify these levels, so we do not know whether this choice supports or contradicts Jacobs' hypothesis.
(D) CORRECT. If other hallucinogens (i.e., drugs that cause hallucinations) are able to produce hallucinations without inhibiting serotonin, then the central premise of Jacobs' hypothesis--that dreams and hallucinations function via a similar brain mechanism involving the levels of serotonin and norepinephrine--would not hold.
(E) This choice says these stages are "crucial" to the overall process of dreaming (which we can already infer from the passage - we have to fall asleep before we dream), but it does not say anything else. Perhaps if we were told that dreaming occurs during the first four stages, when levels of the two chemicals are higher, we might conclude that this weakens the hypothesis; the information is too vague as presented, however, to conclude anything.
(A) In sentence 2, paragraph 3, we are told that LSD binds "at most of the neurotransmitter's receptor sites" (italics added), indicating that we (and Jacobs) already know that LSD does not completely inhibit serotonin transmission. This has already been taken into account, therefore, and does not undermine Jacobs' theory.
(B) The theory in question does not require serotonin to be the only chemical, or one of only a few chemicals, involved in regulating sleep. It merely proposes that two of of the chemicals involved with sleep also function similarly when the brain is hallucinating. This choice is out of scope.
(C) This could undermine Jacobs' theory under certain circumstances, but it could also bolster the theory. Jacobs believed that the drop in norepinephrine levels enabled the brain to sleep. This choice merely says the "levels" are significant; it does not quantify these levels, so we do not know whether this choice supports or contradicts Jacobs' hypothesis.
(D) CORRECT. If other hallucinogens (i.e., drugs that cause hallucinations) are able to produce hallucinations without inhibiting serotonin, then the central premise of Jacobs' hypothesis--that dreams and hallucinations function via a similar brain mechanism involving the levels of serotonin and norepinephrine--would not hold.
(E) This choice says these stages are "crucial" to the overall process of dreaming (which we can already infer from the passage - we have to fall asleep before we dream), but it does not say anything else. Perhaps if we were told that dreaming occurs during the first four stages, when levels of the two chemicals are higher, we might conclude that this weakens the hypothesis; the information is too vague as presented, however, to conclude anything.
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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?a)LSD does not completely inhibit normal transmission of serotonin.b)Serotonin is only one of many chemicals that play a role in regulating sleep.c)Researchers prove conclusively that the level of norepinephrine in the brain is a significant factor in enabling the brain to sleepd)Some semi-synthetic hallucinogenic drugs other than LSD do not inhibit serotonin.e)The first four stages of sleep are as crucial to the process of dreaming as the fifth stage.Correct answer is option 'D'. 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, if true, would most undermine the central premise of the Jacobs hypothesis?a)LSD does not completely inhibit normal transmission of serotonin.b)Serotonin is only one of many chemicals that play a role in regulating sleep.c)Researchers prove conclusively that the level of norepinephrine in the brain is a significant factor in enabling the brain to sleepd)Some semi-synthetic hallucinogenic drugs other than LSD do not inhibit serotonin.e)The first four stages of sleep are as crucial to the process of dreaming as the fifth stage.Correct answer is option 'D'. 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, if true, would most undermine the central premise of the Jacobs hypothesis?a)LSD does not completely inhibit normal transmission of serotonin.b)Serotonin is only one of many chemicals that play a role in regulating sleep.c)Researchers prove conclusively that the level of norepinephrine in the brain is a significant factor in enabling the brain to sleepd)Some semi-synthetic hallucinogenic drugs other than LSD do not inhibit serotonin.e)The first four stages of sleep are as crucial to the process of dreaming as the fifth stage.Correct answer is option 'D'. 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, if true, would most undermine the central premise of the Jacobs hypothesis?a)LSD does not completely inhibit normal transmission of serotonin.b)Serotonin is only one of many chemicals that play a role in regulating sleep.c)Researchers prove conclusively that the level of norepinephrine in the brain is a significant factor in enabling the brain to sleepd)Some semi-synthetic hallucinogenic drugs other than LSD do not inhibit serotonin.e)The first four stages of sleep are as crucial to the process of dreaming as the fifth stage.Correct answer is option 'D'. Can you explain this answer?.
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?a)LSD does not completely inhibit normal transmission of serotonin.b)Serotonin is only one of many chemicals that play a role in regulating sleep.c)Researchers prove conclusively that the level of norepinephrine in the brain is a significant factor in enabling the brain to sleepd)Some semi-synthetic hallucinogenic drugs other than LSD do not inhibit serotonin.e)The first four stages of sleep are as crucial to the process of dreaming as the fifth stage.Correct answer is option 'D'. 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, if true, would most undermine the central premise of the Jacobs hypothesis?a)LSD does not completely inhibit normal transmission of serotonin.b)Serotonin is only one of many chemicals that play a role in regulating sleep.c)Researchers prove conclusively that the level of norepinephrine in the brain is a significant factor in enabling the brain to sleepd)Some semi-synthetic hallucinogenic drugs other than LSD do not inhibit serotonin.e)The first four stages of sleep are as crucial to the process of dreaming as the fifth stage.Correct answer is option 'D'. 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, if true, would most undermine the central premise of the Jacobs hypothesis?a)LSD does not completely inhibit normal transmission of serotonin.b)Serotonin is only one of many chemicals that play a role in regulating sleep.c)Researchers prove conclusively that the level of norepinephrine in the brain is a significant factor in enabling the brain to sleepd)Some semi-synthetic hallucinogenic drugs other than LSD do not inhibit serotonin.e)The first four stages of sleep are as crucial to the process of dreaming as the fifth stage.Correct answer is option 'D'. 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, if true, would most undermine the central premise of the Jacobs hypothesis?a)LSD does not completely inhibit normal transmission of serotonin.b)Serotonin is only one of many chemicals that play a role in regulating sleep.c)Researchers prove conclusively that the level of norepinephrine in the brain is a significant factor in enabling the brain to sleepd)Some semi-synthetic hallucinogenic drugs other than LSD do not inhibit serotonin.e)The first four stages of sleep are as crucial to the process of dreaming as the fifth stage.Correct answer is option 'D'. Can you explain this answer? in English & in Hindi are available as part of our courses for GMAT.
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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, if true, would most undermine the central premise of the Jacobs hypothesis?a)LSD does not completely inhibit normal transmission of serotonin.b)Serotonin is only one of many chemicals that play a role in regulating sleep.c)Researchers prove conclusively that the level of norepinephrine in the brain is a significant factor in enabling the brain to sleepd)Some semi-synthetic hallucinogenic drugs other than LSD do not inhibit serotonin.e)The first four stages of sleep are as crucial to the process of dreaming as the fifth stage.Correct answer is option 'D'. 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, if true, would most undermine the central premise of the Jacobs hypothesis?a)LSD does not completely inhibit normal transmission of serotonin.b)Serotonin is only one of many chemicals that play a role in regulating sleep.c)Researchers prove conclusively that the level of norepinephrine in the brain is a significant factor in enabling the brain to sleepd)Some semi-synthetic hallucinogenic drugs other than LSD do not inhibit serotonin.e)The first four stages of sleep are as crucial to the process of dreaming as the fifth stage.Correct answer is option 'D'. 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, if true, would most undermine the central premise of the Jacobs hypothesis?a)LSD does not completely inhibit normal transmission of serotonin.b)Serotonin is only one of many chemicals that play a role in regulating sleep.c)Researchers prove conclusively that the level of norepinephrine in the brain is a significant factor in enabling the brain to sleepd)Some semi-synthetic hallucinogenic drugs other than LSD do not inhibit serotonin.e)The first four stages of sleep are as crucial to the process of dreaming as the fifth stage.Correct answer is option 'D'. 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, if true, would most undermine the central premise of the Jacobs hypothesis?a)LSD does not completely inhibit normal transmission of serotonin.b)Serotonin is only one of many chemicals that play a role in regulating sleep.c)Researchers prove conclusively that the level of norepinephrine in the brain is a significant factor in enabling the brain to sleepd)Some semi-synthetic hallucinogenic drugs other than LSD do not inhibit serotonin.e)The first four stages of sleep are as crucial to the process of dreaming as the fifth stage.Correct answer is option 'D'. 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, if true, would most undermine the central premise of the Jacobs hypothesis?a)LSD does not completely inhibit normal transmission of serotonin.b)Serotonin is only one of many chemicals that play a role in regulating sleep.c)Researchers prove conclusively that the level of norepinephrine in the brain is a significant factor in enabling the brain to sleepd)Some semi-synthetic hallucinogenic drugs other than LSD do not inhibit serotonin.e)The first four stages of sleep are as crucial to the process of dreaming as the fifth stage.Correct answer is option 'D'. Can you explain this answer? tests, examples and also practice GMAT tests.
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