On July 20, international psychology lost a great friend and scholar. Mark R. Rosenzweig, emeritus professor of psychology at the University of California, Berkeley, influenced the direction of research in learning and memory in the 1950s by demonstrating the role of neurochemical and neuroanatomical changes in the brain in response to experience. His contributions to the advancement of neuroscience then and in subsequent years are described in an autobiography filed with the Society for Neuroscience. Mark was elected a member of the US National Academy of Sciences (1979) and received many awards in the United States and abroad for his scientific work, including Distinguished Scientific Contribution Award from the American Psychological Association (1982).

Mark also was a leading figure in the organization of international science. Psychology, which long had established itself as an international force, formally joined the International Council of Scientific Unions in 1951 as the International Union of Psychological Science (IUPsyS) and the American Psychological Association (APA) was the US "adhering member" on behalf of US psychologists. Mark was a member of the US representation to this international organization, and joined its Executive Committee in 1972, continuing in its service as vice president (1980-84) and president (1988-1992).
 
In the middle of the 1980s, the US representation to IUPsyS moved from the APA to become a committee at the US National Academy of Sciences (NAS). This move strengthened psychology's position within the National Academy and US science context, and fostered a broad coalition across several psychology organizations in the US in international matters. I had the distinct honor of working closely with Mark during this time when the NAS agreed to establish the US National Committee for Psychology — which among other responsibilities advises the President of the National Academy of Sciences on matters pertaining to US participation in the Union. As a senior staff officer with the National Academy of Science/National Research Council, I was invited in 1985 to support the newly formed committee and it was clear from the beginning that Mark – the founding Chair of the USNC/ IUPsyS and at that time an Executive Committee member of IUPsyS — had a vision for the committee which involved an active agenda and close working relations with the Union itself. During the 3 years that Mark served as Chair, the USNC/ IUPsyS regularly convened to formulate strategies to strengthen ties with colleagues within the United States and abroad. Under his leadership, the committee also developed an ambitious agenda of formal workshops, which continued under the leadership of the next USNC/IUPsyS chair, James L. McGaugh. One workshop, for example that Mark and his dear friend and colleague, physiological psychologist Roger W. Russell, helped organize was an international workshop in Canberra in conjunction with the XXIV International Congress of Psychology (Sydney, 1988). A report from the Canberra conference was issued by the National Research Council as Behavioral Measures of Neurotoxicity (1990).

There are many memorable interactions I had, of course, as a result of working closely with Mark during the early years of the committee, including our co-authorship of an article describing the origins of the USNC (Rosenzweig and Flattau, International Journal of Psychology, 23: 367–376, 1988). However, one thing that firmly established Mark in my personal pantheon of great psychologists was the unexpected discovery of our shared appreciation of the work of Donald O. Hebb — a Canadian psychologist whose scientific contributions figured into the experimental psychology curriculum at the University of Leeds where I earned my undergraduate degree in 1969!

Mark was also a very wise and gentle advisor for those of us learning to work at the interface of US and international science, counseling us to work cooperatively with colleagues abroad in areas where a US perspective was sought. I had the opportunity, for example, to organize an international meeting in conjunction with the European Commission in 1993 (Careers in Science & Technology: An International Perspective, 1995) through the National Research Council/National Academies of Science. Some of you will remember that US researchers dominated studies in career formation 20 years ago. Thus, staff organizing the meeting that took place in Brussels took to heart Mark's dictum and we made certain that the meeting featured the most innovative analysts from the most diverse set of countries possible, which ultimately benefited all attendees!

These are just some of the memories I hold from the time I had the opportunity to work with a truly great scientist and international diplomat.