General Introduction to Vasopressin and Oxytocin: Structure/Metabolism, Evolutionary Aspects, Neural Pathway/Receptor Distribution, and Functional Aspects Relevant to Memory Processing -- De Wied and Colleagues I: Evidence for a VP and an OT Influence on MP: Launching the "VP/OT Central Memory Theory" -- De Wied and Colleagues II: Further Clarification of the Roles of Vasopressin and Oxytocin in Memory Processing -- De Wied and Colleagues III: Brain Sites and Transmitter Systems Involved in the Vasopressin and Oxytocin Influence on Memory Processing -- De Wied and Colleagues IV: Research into Mechanisms of Action by Which Vasopressin and Oxytocin Influence Memory Processing -- Research Studies of Koob and Colleagues: The "Vasopressin Dual Action Theory" -- Contributions of Sahgal and Colleagues: The "Vasopression Central Arousal Theory" -- Role of Attentional Processing in Mediating the Influence of Vasopressin on Memory Processing -- Expansion of Vasopressin/Oxytocin Memory Research I: Peripheral Administration -- Expansion of Vasopressin/Oxytocin Memory Research II: Brain Structures and Transmitter Systems Involved in the Influence of Vasopressin and Oxytocin on Memory Processing -- Expansion of Vasopressin/Oxytocin Memory Research III: Research Summary and Commentary on Theoretical and Methodological Issues -- Research Contributions of Dantzer, Bluthe, and Colleagues to the Study of the Role of Vasopressin in Olfactory-Based Social Recognition Memory -- Expansion of Olfactory-Based Social Recognition Memory Research: The Roles of Vasopressin and Oxytocin in Social Recognition Memory -- Brain-Fluid Barriers: Relevance for Theoretical Controversies Regarding Vasopressin and Oxytocin Memory Research -- Closing Remarks: Review and Commentary on Selected Aspects of the Roles of Vasopressin and Oxytocin in Memory Processing.