Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 36 to 42.

Hi-tech maps of the mind show that computer games are damaging brain development and could lead to children’s being unable to control violent behaviour. Computer games are creating a dumbed-down generation of children far more disposed to violence than their parents, according to a controversial new study. The tendency to lose control is not due to children’s absorbing the aggression involved in the computer game itself, as previous researchers have suggested, but rather to the damage done by stunting the developing mind.

Some experts used the most sophisticated technological devices available to measure the level of brain activity of hundreds of teenagers playing a Nintendo game and compared to the brain scans of other students doing a simple, repetitive arithmetical exercise. To the surprise of brain-mapping expert Professor Ryuta Kawashima and his team at Tohoku University in Japan, it was found that the computer game only stimulated activity in the parts of the brain associated with vision and movement. In contrast, arithmetic stimulated brain activity in both the left and right hemispheres of the frontal lobe, which is the area of the brain most associated with learning, memory and emotion. The most worrying of all was that the frontal lobe, which continues to develop in humans until the age of about 20, also has an important role to play in keeping an individual’s behaviour in check. Whenever you use self-control to refrain from lashing out or doing something you should not, the frontal lobe is hard at work.

The students who played computer games were halting the process of brain development and affecting their ability to control potential anti-social elements of their behaviour. “The importance of this discovery cannot be underestimated”, Kawashima said, “there is a problem we will have with a new generation of children, who play computer games that we have never seen before.” The implication are very serious for an increasingly violent society and these students will be doing more and more bad things if they are playing games and not doing other things like reading aloud or learning arithmetic.

The word "aggression" in the first paragraph is closest in meaning to______.