601142 Discloses the use of a peptide consisting of the amino acid sequence A1-Val-Val-Val-Pro-Pro-Phe-Leu-Gln-Pro-Glu-A2 wherein: A1 is absent or represents any of: Thr-Gln-Thr-Pro Pro-Leu-Thr-Gln-Thr-Pro Leu-Thr-Gln-Thr-Pro Pro Pro-Pro-Leu-Thr-Gln-Thr-Pro Ile-Pro-Pro-Leu-Thr-Gln-Thr-Pro or Asn-Ile-Pro-Pro-Leu-Thr-Gln-Thr-Pro And A2 is absent or represents Val-Met, in the manufacture of a medicament for improving brain function (such as amnesia), a method of improving brain function in non-humans and the peptide.