Source: Official Guide Revised GRE 1st Ed. Part 4; Set 4; #9

1

According to the passage, as the process

According to the passage, as the process of arousal in an organism continues, all of the following may occur EXCEPT The evolution of intelligence among early large mammals of the grasslands was due in great measure to the interaction between two ecologically synchronized groups of these animals, the hunting carnivores and the herbivores that they hunted. The interaction line resulting from the differences between predator and prey led to a general 5 improvement in brain functions; however, certain components of intelligence were improved far more than others. The kind of intelligence favored by the interplay of increasingly smarter catchers and increasingly keener escapers is defined by attention—that aspect of mind carrying consciousness forward from one moment to the next. It ranges from a passive, free-floating 10 awareness to a highly focused, active fixation. The range through these states is mediated by the arousal system, a network of tracts converging from sensory systems to integrating centers in the brain stem. From the more relaxed to the more vigorous levels, sensitivity to novelty is increased. The organism is more awake, more vigilant; this increased vigilance results in the apprehension of ever more subtle signals as the 15 organism becomes more sensitive to its surroundings. The processes of arousal and concentration give attention its direction. Arousal is at first general, with a flooding of impulses in the brain stem; then gradually the activation is channeled. Thus begins concentration, the holding of consistent images. One meaning of intelligence is the way in which these images and other alertly searched information are used in the context of 20 previous experience. Consciousness links past attention to the present and permits the integration of details with perceived ends and purposes. The elements of intelligence and consciousness come together marvelously to produce different styles in predator and prey. Herbivores and carnivores develop different kinds of attention related to escaping or chasing. Although in both kinds of animal, 25 arousal stimulates the production of adrenaline and norepinephrine by the adrenal glands, the effect in herbivores is primarily fear, whereas in carnivores the effect is primarily aggression. For both, arousal attunes the animal to what is ahead. Perhaps it does not experience forethought as we know it, but the animal does experience something like it. The predator is searchingly aggressive, inner-directed, tuned by the 30 nervous system and the adrenal hormones, but aware in a sense closer to human consciousness than, say, a hungry lizard’s instinctive snap at a passing beetle. Using past events as a framework, the large mammal predator is working out a relationship between movement and food, sensitive to possibilities in cold trails and distant sounds —and yesterday’s unforgotten lessons. The herbivore prey is of a different mind. Its 35 mood of wariness rather than searching and its attitude of general expectancy instead of anticipating are silk-thin veils of tranquillity over an explosive endocrine system the production of adrenaline, the production of norepinephrine, a heightening of sensitivity to stimuli, as increase in selectivity with respect to stimuli, an expansion of the range of states mediated by the brain stem

4 Explanations

1

Rajagopal Lakshman

Hello, could you please explain why choice E is incorrect? The passage states, in lines 6-10, that the kind of intelligence favored is attention and the attention ranges from a passive, free flowing awareness to a highly focused active fixation. The range through these states is mediated by systems in the brain stem.

Does this not mean an increase in the range mediated by the brain stem?

Jun 12, 2018 • Comment

Sam Kinsman, Magoosh Tutor

Hi Rajagopal,

You are right that E is a true answer: it backed up by the passage.

However, E doesn't answer the question. The question asks us for things that happen as the process of arousal in an organism continues. And E (an expansion of the range of states) does not occur as the process of arousal takes place.

The passage is saying that there is a range of types of attention ("states") in animals. But it does not say that the mediation of these states (by the brain stem) happens as the process of arousal takes place.

I hope that helps! :D

Best,
Sam

Jun 16, 2018 • Reply

1

BAlaji

I dont understand 'increase in selectivity' what in the Option E refers to 'D an increase in selectivity with respect to stimuli' - Could you please explain?

Nov 11, 2016 • Comment

Adam

"An increase in selectivity with respect to stimuli" means that the organism would become more selective about which stimuli it responds to. In other words, rather than responding to all stimuli, it would only respond to certain (select) stimuli.

Nov 15, 2016 • Reply

2

Madhu Balla

In line 16, author talks about "Arousal is at first general, with a flooding of impulses in the brain stem; then gradually the activation is channeled." So how is E incorrect.

Sep 13, 2016 • Comment

David Recine, Magoosh Tutor

In line 16, there are two keywords that (E) is actually incorrect. These keywords are "general" and "channeled." "General" refers to a wider variety of impulses. "Channeled" is the opposite of general here.

If the activation in the brain stem starts out as genera" and then becomes channeled, the brain stem goes from handling a wide variety of impulses to handling a much smaller group of impulses. So the states mediated by the brain stem-- the types of impulses-- shrink in range, rather than expanding. So line 16 actually says that the OPPOSITE of E is true.

Sep 13, 2016 • Reply

1

Gravatar Chris Lele, Magoosh Tutor

Oct 5, 2012 • Comment

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