Official Explanation
The first word is defined in the sentence as a device useful for “inciting and guiding discovery.” That’s one of the meanings of “heuristic,” which is the correct answer. A “literary device” is a common expression and so sounds good, but the meaning is wrong because a “literary device” is a technique used in writing to produce a specific effect. An “allegorical” (symbolic or metaphorical) device is a specific type of “literary device” and so doesn’t work either. If you are not meant to take the “model of the psyche” as a guide to the physical structure of the brain, then you want a word that means something like show or depict for the second blank. “Represent” is the closest choice. The word “dictate” is incorrect because a model of the brain doesn’t determine the physical form of the brain. “Ameliorate” (make a bad thing better) also does not fit the desired meaning.
Answer: A,F