Neural connections carrying signals

A free, expert breakdown of this official LSAT Logical Reasoning question.

TopicsSufficient Assumption

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Stimulus

Neural connections carrying signals from the cortex (the brain region responsible for thought) down to the amygdala (a brain region crucial for emotions) are less well developed than connections carrying signals from the amygdala up to the influence on the cortex than vice versa.

What this question is testing

Sufficient Assumption

Your task

Find the assumption that, if added, guarantees the conclusion follows.

Common trap

Answers that only partly bridge the gap, leaving the conclusion unproven.

Winning move

Identify the new term in the conclusion and pick the choice that links it to the evidence.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question

20.

The argument's conclusion follows logically if which one of the following

Answer choices

Out of Scope3% picked this
The influence that the amygdala exerts on the rest of the brain is dependent on the influence that the cortex exerts on
The amount of influence the amygdala exerts on the rest of the brain is irrelevant to a comparison between the influence the amygdala and the cortex exert on each other.
3%
Too Weak6% picked this
No other brain region exerts more influence on the cortex than
This answer only ensures that the amount of influence the amygdala exerts on the cortex is greater than the influence any other part of the brain exerts on the cortex. This answer leaves unknown the amount of influence the cortex exerts on the amygdala.
6%
Too Weak18% picked this
The region of the brain that has the most influence on the cortex is the one that has the most highly developed
This answer strengthens the relationship between the development of neural connections and the influence one part of the brain has on another. However, the relationship is limited to the amount of influence each part of the brain has on the cortex, but leaves unknown the amount of influence the cortex has on the amygdala.
18%
Out of Scope3% picked this
The amygdala is not itself controlled by one or more other regions
The amygdala could be controlled by one or more other parts of the brain and yet still influence the cortex more than the cortex influences the amygdala. If the amygdala were controlled by another part of the brain it would not diminish the influence it has on the cortex.
3%
Correct69% picked this
The degree of development of a set of neural connections is directly proportional to the influence
Why this is right
If the amount of influence one part of the brain has on another is directly proportional to the development of neural connections transmitting signals in that direction and the neural connections are strong from the amygdala to the cortex than from the cortex to the amygdala, then the amygdala exerts more influence on the cortex than the cortex exerts on the amygdala.
Skill tested: Sufficient Assumption · how this choice captures the argument's function is the move to repeat next time.
69%

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