More Free Verbal Reasoning Practice
- Dec 30, 2013
- MCAT Blog, MCAT Long Form, MCAT Prep, MCAT Retake
Let’s ring in the new year with some more free VR practice!
The Navy has long had a particular focus on developing non-lethal antipersonnel weapons and a recent one, the electromagnetic personnel interdiction control (EPIC) system, has found a surprising use in medicine in the treatment of benign paroxysmal positional vertigo (BPPV). The report on the ability of EPIC to help treat the most severe cases of BPPV was classified as “restricted” because it was deemed to include too much information about US military capabilities (or rather, by inference, the limits of our abilities revealed by our need for such a system); only military doctors with security clearance were permitted to read the report. The unclassified version of the report released today is based solely on previously understood medical principles and contains no real groundbreaking ideas. Rather, the key importance of the unclassified report rests in its demonstration of the civilian medical benefits that accrue from military technology. As one military researcher put it, “in our effort to find ways to cause non-lethal harm to combatants, we often also uncover a way to cure that harm.”
As revealed by the report, the EPIC system uses a focused beam of radio frequency (RF) electromagnetic energy to disrupt the normal mechanical transduction process by which sound, position, and other sensory input are converted to messages by nerve cells and processed by the brain in order to produce complete disorientation, confusion and temporary incapacitation sufficient to temporarily and remotely render the target powerless to resist arrest. According to its developers, when the EPIC system is switched off, the removal of the RF energy will leave nerve cells and surrounding tissues with no damage and the second order effects of severe motion sickness and feeling of helplessness remain for a short time afterwards as the ear’s systems slowly return to normal. In the course of developing the weapon, insiders reveal that military scientists made several important breakthroughs in their understanding of the mechanism by which the mechanical and positional information from the inner ear is converted into changing membrane potentials and thus electrical signals the brain can interpret. The unclassified report does not reveal what those breakthroughs were, but merely states what EPIC’s effects are.
BPPV is the most common cause of the symptom of vertigo. Often misinterpreted as mere dizziness, vertigo can be a disabling symptom in which the patient feels a sense of rotation accompanied by dizziness, nausea, and commonly, vomiting. BPPV is caused when otoconia, collections of calcium crystals, become dislodged from their usual position in the utricle and migrate into one of the semicircular canals, the ear’s system for sensing position. As the head changes orientation with respect to gravity, the otoconia become dislodged and move, creating abnormal endolymph displacement which results in the sensation of vertigo. Currently, there are several simple treatments that can cure most common cases of BPPV. The patient can undergo a series of carefully controlled repositionings of the head which can cause the otoconia to be moved out of the semicircular canals and back into the utricle. These manipulations are non-invasive and can be performed in under an hour in a doctor’s office, using no high-tech equipment. Such treatment is effective in over 90% of cases.
In particularly severe cases, however, the usual treatment is often ineffective. At the moment, those patients who are disabled by their BPPV are faced with two equally unpleasant options: surgery or medication. The former carries all the risks that normally attend invasive neurosurgical procedures, and the latter entails powerful and unpleasant side-effects. It is in these cases that the EPIC system may offer a breakthrough. By pairing the RF signal emitter with a positional sensor worn on the patient’s head, the EPIC system has been successfully adapted into a mechanism for disrupting the signals that cause vertigo before they ever reach the patient’s brain. As yet, the system is not clinically viable. The positioning system requires a large, heavy computer to generate the processing power and speed necessary to let the system respond instantly to every minor movement of the patient’s head.
In the first paragraph, the author mentions “civilian” benefits in order to:
A) suggest that military research generates more positive outcomes than negative ones.
B) demonstrate that research often has benefits to unintended recipients.
C) emphasize the particular importance of military research in our nation’s research funding scheme.
D) contrast the original purposes of military research with its subsequent uses.
In another article discussing the EPIC system, a different author wrote, “if a civilian variant of the EPIC system gains FDA approval and passes human testing, BPPV sufferers may find relief in as little as 18 months.” Which of the following is the most likely reason that the passage does NOT include a statement like this sentence?
A) It is uncertain how long it will take to develop a portable version of the EPIC system.
B) Clinical decisions are not influenced by the timeline for FDA approval.
C) The author does not approve of the clinical use of therapies developed with military technology.
D) Since the treatment is non-invasive, its approval by the FDA is certain, making such a statement unnecessary.
The EPIC system’s medical use would likely be of particular interest to:
A) most BPPV sufferers.
B) Navy scientists interested in non-lethal weapons.
C) civilian surgeons who specialize in neurological disorders.
D) civilian doctors treating the most severe cases of BPPV.
From the passage, it can be inferred that the movement of otoconia within the inner ear is primarily controlled by:
A) endolymph displacement.
C) a doctor performing manipulations.
D) random chance.
An assumption underlying the discussion of the report on EPIC is that:
A) the system by which the inner ear communicates with the brain is better understood with military science than the science available to civilians.
B) any radio frequency waves can interrupt nerve conduction signals.
C) the Navy is reluctant to engage in medical investigations that don’t have an immediate connection to an operational weapon system.
D) the research involved with the development of the EPIC system will lead to an improvement in the treatment of BPPV.
Based on the assertions made in the passages, which of the following could reasonably be concluded?
A) Scientists have successfully used targeted beams of electromagnetic energy to help alleviate disease symptoms that were otherwise difficult to treat.
B) Tissues, especially the sensitive tissues of the brain and surrounding the inner ear, may be damaged when exposed to excessively high levels of electromagnetic energy.
C) When computing technology becomes powerful enough and small enough to be worn on the head, those with hard-to-treat BPPV will have their symptoms alleviated.
D) Prolonged exposure to the beams generated by the EPIC system may generate lasting damage.
And here’s the answer key:
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