Self-study
In an experiment testing whether hyperactivity is due to a brain abnormality, the brain activity of 25 hyperactive adults was compared to the brain activity of 25 adults who were not hyperactive. ███ █████ ████████ ████ ███ ███████████ ██████ ███ ████ ████ █████ ████████ ██ ███ ████████ ███████ █ ██████ ██ ███ █████ ████████ ██ ███████ ███████ ████ ███ ███ ██████████████ ███████ ███ █████████████ █████████ ████ ██████████ ████████ ██ ███ ████████ ██████ ██ ███ █████ ██ ██████████████
Summarize Argument: Phenomenon-Hypothesis
The experimenters hypothesize that diminished activity in the premotor cortex is a cause of hyperactivity. Their evidence is a study that shows hyperactive adults had significantly less brain activity in the premotor cortex, while non-hyperactive adults had with normal activity levels.
Notable Assumptions
Based on a mere correlation, the experimenters assumes that less brain activity in the premotor cortex causes hyperactivity. This means they assume that the relationship isn’t the reverse (that hyperactivity causes less brain activity in the premotor cortex), and also that there isn’t some other, hidden cause that’s actually responsible for both hyperactivity and less brain activity in the premotor cortex.
4.
Which one of the following, ██ █████ ████ ██████████ ███ ██████████ █████ ██ ███ ██████████████
a
Some of the ██████████████ ██████ ██ ███ █████ ███ ████████ ███ ██████ ████ ██████████████
We don't know anything about those children's brain activity, so this doesn't affect the argument. It's just irrelevant.
b
The hyperactive adults ███ ████████████ ██ ███ ██████████ ██████ ██ ███ ████████ ██ █████ █████████
Even if the hyperactive adults varied in the severity of their symptoms, they all generally had lower levels of brain activity in the premotor cortex. This doesn't give us any reason to doubt the hypothesis.
c
The neuropsychologists who ████████ ███ ██████████ ████ ███ ███████ ████ ███ █████ ████ ██████████
This doesn’t change how much we can trust the study, so it's irrelevant. There’s no reason to believe those same neuropsychologists had to be present for the experiment to be performed correctly.
d
All of the ███████████ ██████ ██ ███ █████ ███ ████ ███████ ███ █████████████ ████ █ ██████████ ████ ██ █████ ██ ███████ ████████ ██ ████ ███████ ██ ███ ██████ █████ ████ ██ ███ ██████████████ ██████ ███ ████ ██ ████████
This gives us an alternative causal explanation for the correlation the researchers identified. Premotor cortex activity is diminished by a treatment for hyperactivity, which casts doubt on the hypothesis that diminished activity causes hyperactivity.
Alternate explanation
Alternate explanation
Weaken: Introduce or support an alternate explanation for a phenomenon.
Strengthen: Helps to eliminate an alternate explanation for a phenomenon.
e
The test was █████████ ████ ██ ██████ ███████ ████ ██████ ███ ██████ ██ █████ ███ ████ ████████ █████ ████████ ██ ████████ ██ ███████ ██ ████ ███████ ███ ███ ██ ██████████ █████ █████ ██ ███████ ██ █████████
It doesn’t matter what’s harmful to the participants, or why the researchers only tested adults. This isn't relevant to the causal relationship between hyperactivity and brain function in the premotor cortex.