Chapter 23 — Quiz
Twenty-two questions. Answer before opening the key. Several questions have deliberately similar options; the distinctions they turn on are the ones the chapter is about.
1. The claim "this peptide is a nootropic," offered without further specification, receives ❌ in this chapter primarily because:
- A. Animal data contradicts it
- B. The compounds so described have failed randomized trials
- C. It names no endpoint, no instrument, and no population, so nothing could confirm or refute it
- D. Nootropics are not peptides
2. Semax is related to a fragment of which molecule?
- A. Tuftsin
- B. Adrenocorticotropic hormone (ACTH)
- C. Angiotensin IV
- D. Brain-derived neurotrophic factor
3. Selank is a synthetic analog related to:
- A. An ACTH fragment
- B. Ciliary neurotrophic factor
- C. Tuftsin, an endogenous tetrapeptide from the heavy chain of immunoglobulin G
- D. Vasopressin
4. Semax and Selank share a C-terminal Pro-Gly-Pro extension. Its principal purpose is to:
- A. Increase receptor affinity
- B. Resist rapid peptidase degradation and extend the molecule's useful life
- C. Enable crossing of the blood-brain barrier from the bloodstream
- D. Reduce immunogenicity
5. Which statement about the approval status of Semax and Selank is correct?
- A. Both are approved in the E.U. but not the U.S.
- B. Both are registered medicines in Russia and are not approved in the United States or the European Union
- C. Both are approved in the U.S. for narrow neurological indications
- D. Neither is approved anywhere; both are research chemicals
6. A compound is unapproved in the United States. In the large majority of such cases, the reason is:
- A. The FDA reviewed a submitted dossier and rejected it on safety grounds
- B. The FDA reviewed a submitted dossier and rejected it on efficacy grounds
- C. No sponsor ever filed, usually for commercial reasons
- D. An approval was granted and later withdrawn
7. "The accessibility of a finding to you is not a property of the finding." This sentence is directed against:
- A. The credulous failure
- B. The parochial failure
- C. Rule 3
- D. Publication bias
8. Which of the following is a documented problem of Western research literatures specifically named in §23.3?
- A. Publication bias
- B. Industry funding effects
- C. Selective outcome reporting
- D. All of the above
9. In the six-question grid of §23.3, an entry of "?" means:
- A. The study failed that criterion
- B. The study passed that criterion but did not report it
- C. You could not determine the answer, and you are recording that fact rather than guessing
- D. The criterion does not apply to that literature
10. Cerebrolysin is best described as:
- A. A single synthetic peptide of defined sequence
- B. A recombinant human neurotrophic protein
- C. A preparation of low-molecular-weight peptides and free amino acids derived from porcine brain tissue
- D. A mixture of amino acids only, with no peptide content
11. The chapter's rating for Cerebrolysin in stroke or dementia is ⚠️ because:
- A. No human trials have been conducted
- B. Randomized trials and meta-analyses exist and produce genuinely mixed results, with substantial heterogeneity and sustained methodological criticism
- C. The evidence is uniformly positive but the product is unapproved in the U.S.
- D. The evidence is entirely inaccessible in English
12. When a body of randomized evidence remains mixed after many trials and many years, the most common explanations include all of the following EXCEPT:
- A. The true effect is small
- B. The effect is conditional on population or timing
- C. The effect is absent and positive results reflect ordinary bias
- D. The effect is large but has been consistently overlooked
13. Dihexa is:
- A. A tuftsin analog
- B. A synthetic angiotensin IV analog reported to affect synaptogenesis in animal models
- C. A porcine brain-derived mixture
- D. A dipeptide ethyl ester
14. The ❌ assigned to Dihexa and P21 means:
- A. The compounds have been shown not to work in humans
- B. The compounds are unsafe
- C. The confident human claims being made are unsupported, because no human trials have been completed
- D. The preclinical work is unreliable
15. Noopept is discussed in this chapter mainly to make which point?
- A. That dipeptides are more potent than longer peptides
- B. That calling something a peptide borrows credibility the compound has not earned, and readers should notice when a category is doing rhetorical work
- C. That small molecules are always safer than peptides
- D. That oral administration is generally achievable for peptides
16. Which property of Noopept is inconsistent with it being a peptide drug in this book's sense?
- A. It contains a proline residue
- B. It is routinely administered orally and is roughly 320 daltons
- C. It has been studied for cognitive endpoints
- D. It is synthetic
17. An uncontrolled before-and-after cognitive study will typically show improvement even if the intervention is inert. The single largest reason is:
- A. Regression to the mean
- B. Practice effects
- C. Measurement noise
- D. Reporting bias
18. Baseline dependence implies which of the following?
- A. A positive result in sleep-deprived participants supports a claim about rested participants
- B. A null result in healthy young adults refutes a claim about impaired populations
- C. A positive result in an impaired population does not support a claim about healthy adults
- D. Effects are always larger in healthy populations
19. A results section reads: "Significant improvements were observed in verbal fluency and processing speed, with a trend toward improvement in delayed recall." The most important missing piece of information is:
- A. The participants' ages
- B. The total number of comparisons performed, and which endpoint was pre-specified as primary
- C. The manufacturer of the test battery
- D. The time of day of testing
20. A "blinding integrity check" is:
- A. Confirming that the placebo and active preparations look identical
- B. Asking participants at the end of the study which arm they believe they were in, and reporting the result
- C. Verifying that the randomization list was concealed from investigators
- D. Testing the placebo for contamination
21. Why is the placebo arm of a cognitive enhancement trial not an inert condition?
- A. Because placebos often contain active excipients
- B. Because believing you have taken something that sharpens focus genuinely increases effort, arousal, and persistence, which genuinely improve task performance
- C. Because participants in the placebo arm practice less
- D. Because placebo response does not occur for objective endpoints
22. Which of the following is NOT part of the chapter's specification for a convincing trial?
- A. Pre-registration of protocol, primary endpoint, and analysis plan
- B. A single pre-specified primary endpoint on a validated instrument
- C. Results reported regardless of outcome
- D. Approval by the United States Food and Drug Administration before publication