Question

read these two excerpts. what do both of these excerpts show?
a the scientists found that brains had healed within three days of a concussion.
b players with concussions and players who had not ever injured their brains showed no differences.
c the scientists could not tell which part of the brain was working during a task.
d players who have had concussions use more of their brains to complete tasks than they normally would.
excerpt 1 excerpt 2
within three days of a concussion, communication between different brain regions dropped a bit, mannings team found. by three months after the injury, many more brain regions were chatting with each other. however, many were doing this even when they were supposed to be at rest
the concussed brains appeared to over - compensate, manning now says. just as hudacs team had found, these injured brains were trying to recover from the long - lasting damage by spreading out their work over a larger area

Explanation:

• For option A: Excerpt 2 says communication dropped initially and then brain regions communicated more (including at rest), not that brains "healed" in three days. So A is incorrect.
• For option B: Excerpt 2 shows concussed brains have different activity (over - compensate, more brain regions involved), so they aren't the same as non - concussed. B is incorrect.
• For option C: There's no mention in either excerpt about not being able to tell which part of the brain was working during a task. C is incorrect.
• For option D: Excerpt 2 states that concussed brains "over - compensate" and "spread out their work over a larger area", which means they use more of their brains to complete tasks (compared to normal, as implied by the need to recover from damage). This matches option D.

Answer:

D. Players who have had concussions use more of their brains to complete tasks than they normally would.