In Appreciation: Mark Rosenzweig

When I arrived in Mark Rosenzweig’s lab in the late 1970s, I learned quickly that Mark was game. If we were short-handed when running rats in mazes, you’d find him in the lab with a stopwatch and clipboard. If the task was gathering samples for neuroanatomical or neurochemical analysis, he was at the bench with the rest of us. And when he had me coordinating our research on ground squirrels in the mountains of California, he showed up in his floppy hat and hiking boots, ready to go. He was unfailingly polite, modest, and reserved; you would never know from talking to him just how profoundly important his work was.

The early 1950s was an interesting time to begin working in the area of how the brain manages learning and memory. There was widespread frustration at the lack of progress on the problem in the preceding decades, leading Karl Lashley to conclude in 1950: “I sometimes feel, in reviewing the evidence on the localization of the memory trace, that the necessary conclusion is that learning is just not possible.’’

But still, there were individual differences in problem-solving ability. As good scientists, Mark and his colleagues knew that these differences had to have some basis in the brain. The methodologies this group used to study individual differences in brain chemistry led to the accidental discovery of use-dependent changes in brain chemistry and then to the discovery that the anatomy of the brain could also be changed by experience. To say that these results were greeted with skepticism is a colossal understatement. So fundamental was the challenge to a long-held assumption in the field that criticisms and alternate hypotheses took on a kitchen-sink quality. But, a series of careful experiments gradually answered the critics and disproved the alternate hypotheses, leaving only the explanation that experience really could change the brain.

Other research, coming along shortly after these results, pointed to the same reality, but Mark and his co-workers were the first, and it changed everything. This discovery is both simple and profound. The brain is plastic — it can rewire itself in response to experience — and this is one of the fundamental bases for our contemporary understanding of neuroscience. It is difficult for younger folk in the field to grasp just how radical a change that was.

But Mark was also a teacher, and I’d like to describe his generosity in that arena by borrowing his own description of Edward Tolman. In 2006, Mark wrote: “Although Tolman had many productive students, he did not try to establish a school but instead encouraged students to pursue their own directions.” The same could be said of Mark; his students have worked in a broad range of areas. In my own case, he was always supportive, even as my intellectual migration took me far afield from what he thought he had been training me to do, as I moved from behavioral neuroscience into studies of the connection between spontaneous curiosity and learning, and then to studying animal cognition and the adaptations of endangered species to captive environments in zoos. My most recent paper, on the management of aggression in captive polar bears, seems in hindsight to be good preparation for my current work as a provost.

No account of Mark is complete without addressing his stealthy sense of humor. He loved puns and wordplay; any time that either of these could be worked into the draft of a paper was a big plus. I also still remember my first experience as his teaching assistant; he was baffled by the students’ apparent obliviousness to his frequent humorous asides (including quoting lines from Monty Python in contexts that often made them witty and unnerving). I tried, and failed, to convince him that the students had trouble believing that a professor with such a refined presence would be funny and that his humor was sometimes so subtle it was easy to miss.

This was a life that deserves to be celebrated and I was honored to be asked to organize this collection. Mark Rosenzweig was a noteworthy scientist, a generous teacher, and a good human being. Thanks, Mark.

Michael J. Renner
Drake University

My research and friendship with Mark and his family spanned 55 years. In 1954, when David Krech was studying the “hypotheses behavior” of rats, Krech and Mark met with Melvin Calvin, who sent Mark and Krech over to me with his blessing for “help.”

I had never had the equivalent of Psych 101, and I doubt if either Mark or Krech had had Chem 101, much less Neurochemistry 101. But together we decided that acetylcholine-acetylcholinesterase, one of the few neurotransmitter systems recognized at the time, would make a good start. We postulated that the rats solving the maze using visual hypotheses would have higher acetylcholinesterase activity in the “visual” area of the cortex, whereas those solving the maze using spatial hypotheses would have higher enzyme activity in the “spatial” area. We were wrong, but we were off and running for a long series of experiments with grant requests to keep the project going and to support graduate students to do the work. We relied on Mark to take the lead in preparing grant requests and writing papers. I was always amazed at his ability to recall references with journal, volume, and date. Mark had an interest in science history; references going back to the 19th century and earlier will be found in some of his papers.

Over the years, our studies showed the susceptibility of the brain to actual physical and chemical changes in the environment. At first this idea was greeted with skepticism, but it is now accepted.

Our first studies were with rats. Later investigations, using mice and chicks, were among the first to demonstrate the essential role of proteins in memory formation. Studies with chicks using a one-trial avoidance test produced new concepts of stages in memory formation.

Mark was generous with his time with students working with him. Many hours were spent with the students planning experiments. In addition to “working” time with students, Mark and his wife, Janine, frequently invited them to their home for dinner and holidays.

Mark will be missed, but his legacy will live on.

Edward L. Bennett
University of California, Berkeley

Mark Rosenzweig’s work was well known to me when I interviewed for a faculty position at Berkeley in 1982. Mark was soft-spoken and gracious, and I really felt privileged to meet him. But I was amazed by his desk, which was covered in at least four inches of paper, without discernible stacks, just melded all together! On several occasions, I would watch Mark look under a particular pile of paper and find the very sheet he wanted, so there must have been a system to the geological strata.

That fall, I was responsible for the weekly guest speaker series. Without a travel budget, I could only invite local scientists, but I had no idea whom to ask. Mark gallantly pitched in to rescue me. I learned of his artistic abilities when Mark sketched a logo for the announcements, depicting the two of us facing each other in profiles like that on the cover of Smith Brothers’ Cough Drops, titled “Colloquium Brothers,” with “Mark” under his likeness and “Marc” under mine. He even sported a beard to match the scene. (Years later, my kindergartener daughter asked me whether our visitor with the white beard was Santa Claus.) That sketch was just one of many instances of Mark’s lively, wry sense of humor that belied his rather formal demeanor. Nor was this the only time Mark offered to help junior colleagues. A few years later, when I made a bid to buy a home (quite a trial in the Bay area even then), the University discovered it had made a mistake at the last minute — they couldn’t loan me as much money as they’d said — and the deal was imperiled. Mark approached another colleague offering to loan me the difference! We found another way around the problem, but I’ll never forget Mark’s generous, sensitive offer.

Mark and Arnold Leiman were wrapping up the first edition of their biological psychology textbook when I interviewed. Arnie excitedly showed me figure proofs and shared their enthusiasm for a comprehensive text embracing all of biology, including evolutionary and developmental perspectives, and an art program to show rather than describe how things worked. Ten years later, when Mark and Arnie asked me to help remake Biological Psychology in full color, I jumped at the chance. I loved working on the book, and our meetings were always a highlight of my day because they were both so funny. I got reminded of my Gentile status one day when I remarked about some story in the Old Testament. Arnie smiled, looked at me like my hair was on fire, and said, “Old Testament?” Then Mark leaned forward and quietly said, “We call that the Bible.” I burst out laughing, and still do whenever I recall Mark’s deadpan look. Arnie passed away, and I left Berkeley in 2001, but Mark and I continued to work together on our textbook. During revision cycles, we had daily e-mails as well as phone calls and meetings in Berkeley. I was always amazed at Mark’s encyclopedic knowledge and calm, rigorous work ethic. Collaborating with Mark was one of the most gratifying events of my career and my life. I will miss him.

Marc Breedlove
Michigan State University

I first met Mark Rosenzweig in 1962, when I arrived in Berkeley as a postdoctoral fellow. From my first days in Berkeley, Mark was wonderfully hospitable. And, every now and then, between 1962 and 1964, Mark and I would have good conversations about the latest results, from their studies of enriched environments or from Jim McGaugh’s studies of memory consolidation.

Mark was also a serious scholar, who could get interested in topics well outside his field. I had two illustrations of that. First, in the early 1970s, when he and Paul Mussen asked me to contribute a chapter on comparative psychology to an introductory text  they were preparing, and in the 1980s when Mark and I published a joint article on comparative studies of learning, in historical perspective. In the first case, Mark and Paul’s commitment to scholarship was illustrated by the mere act of including a comparative psychology chapter in their text. It was not going to sell the book to psychologists in that era.

Writing the joint article, on a topic that was remote from Mark’s field, was great fun. He dug in, learned a lot, and taught me a great deal about presentation of data. I had watched Mark work with Arnie Leiman and Marc Breedlove on illustrations for their textbook of biological psychology, and I noted his exceptional sense of design. In my case, Mark’s distillation of a complex table, originally produced by George Romanes in 1883, for modern readers was just masterful. Finally, a non-scholarly observation: I have one of the messiest offices in Tolman Hall (the home of the Berkeley Psychology Department). Mark was in the next office for 30 years and, superficially, his office looked more disorganized than mine. There were times when I considered the possibility that Mark had done this to make me feel more comfortable. But, he had the uncanny ability to search for and find, with apparent ease, a single article buried in one of the many disorderly stacks of papers, which were piled on his desk, chairs, tables and the floor. I could not do that.

Obviously, I will miss him.

Steve Glickman
University of California, Berkeley

I first met Mark Rosenzweig when I entered the graduate program in psychology at the University of California, Berkeley in 1953. At that time, he was working on electrophysiological studies of binaural sound localization. The following year, he shifted his research, in collaboration with David Krech, to studies of the effects of environmental enrichment on brain morphology. I joined that research group and, ultimately, had the opportunity to have Mark as my thesis advisor. Those of us who worked closely with him knew that he had an extraordinarily systematic mind that was matched, strangely, by the remarkable disorderliness of his office. How the mounds of files stacked in random on his desk led to highly orderly and important findings reported in many publications remains a mystery to me. Later, I worked closely with Mark on matters involving the International Congress of Psychology, a program that was one of his highest priorities. When we established the Center for the Neurobiology of Learning and Memory, we invited Mark to be a founding member and he contributed very significantly to the Center for many years. His contributions were especially significant in providing sustained and insightful historical perspective to current research inquiry. He also provided sparks of humor that were always punctuated by a modest smile and twinkle of his eyes. Mark was a quiet, thoughtful, insightful, and warm mentor and colleague who, over many decades, made significant contributions to psychology and neuroscience.

James L. McGaugh
University of California, Irvine

I arrived at U.C. Berkeley during the summer before my first year in graduate school (1979). My research background in the neural basis of learning and memory pointed me in the direction of Mark Rosenzweig’s laboratory. On the day of my first visit there, his research technician called in sick. As is the case for many behavioral experiments, a precise timetable of testing and experimental manipulation must be followed or months of preparation may be lost. Thus, in what I would come to find is his usual gentle way, Mark persuaded me to jump right in and spend the afternoon learning to make cortical lesions in animals that were part of an environmental enrichment study. Mark’s style of training graduate students was a true reflection of the kind of person that he was outside of the lab. He spent an enormous amount of time helping students to be successful both in his lab and in the local community. In my case, this meant spending many hours pouring over details of my manuscripts. As a Professor, I now see that those hours must have been quite painful for him. As a student, however, I never sensed impatience or frustration on his part. The graduate fellowship that has recently been established in his name at Berkeley is quite fitting.

Mark was an illustrious writer, scholar, and historian. The breadth and depth of his knowledge was nothing short of inspiring. He was incredibly organized and detailed, yet he had a broad and integrative perspective on current issues in his research field, as well as on changes in perspective across time. In numerous chapters, he provides this field with sometimes rare glimpses of our past. I became acutely aware of how important it was to Mark to link generations of scientists when he shook my hand after I passed my general examination, saying “Now you can say that you shook the hand that shook the hand that shook the hand of Ramon y Cajal.” Mark held Cajal in extremely high regard. I took away many (professional) life lessons from Mark: Follow lines of research that I truly believe in, even if they are not the most popular or are met with initial disbelief; conduct your research with high integrity and respect; and work hard to achieve your goals throughout your life — that is how to keep your brain plastic as you age gracefully.

Sheri J. Y. Mizumori
University of Washington

Having enjoyed close collaboration with Mark Rosenzweig over more than 30 years, I am writing these lines in deep sadness.

From the late 1970s and until the recent turn of the century, Mark Rosenzweig and I have been acting and working (as well as globally duty-travelling) together, in changing mandatory roles in the International Union of Psychological Science, up to his, and subsequently my, Presidency of the Union. Over all those years, this was cooperation in fine harmony and warm friendship, also between families, as it grew out of collegiate commonality.

Mark Rosenzweig’s contributions to international psychology have been numerous, and his wise advice was ever so welcome. I enjoyed this when working with him, for example, on the restructuring of the Union to its present form allowing for different forms of national membership, from traditional scientific societies to the new national committees of psychology under the aegis of  national academies of sciences. And I enjoyed it ever the more when working with him on joint scientific publications and editions, such as the International Handbook of Psychology in the late 1990s. This in particular was a fine opportunity also to experience first-hand two of Mark’s great aptitudes: His going about a problem, be it scientific or practical, serious or small, in a never-tiring rational-systematic step-by-step fashion, and his great mastery and command (in the good double sense of the word!) in precise usage of the English language.

An outstanding scientist, Mark was a key figure not only in his own field of the neuropsychology of learning and memory and in biopsychology at large, but also inspiring to exchange with on a wide range of topics and issues, way beyond psychology proper. There one could sense the breadth of his inquiring scholarly interests, transgressing natural and behavioral sciences into history, humanities, the arts, and human rights and their preservation, a topic close to his mind and his heart. I hold fine memories of these complementary sides of Mark: working with him on widely diverse issues of psychological science, professional practice and their development in different continents; joint study travels to such diverse places as the Galapagos, the Peruvian Andes, Eastern Europe prior to the 1990 opening, Australia or Central China; and the stimulating exchanges as his sometime guest in the intellectual gemstone Friday Luncheons at the Berkeley Faculty Club.

Mark Rosenzweig’s research contributions to psychological science and his service to international psychology have earned him high distinction and lasting impact. In psychology’s record and in our personal memory, he will stay alive and unforgettable as an eminent scholar, a great colleague, and a dear friend.

Kurt Pawlik
University of Hamburg

My relationship with Mark Rosenzweig was somewhat special in that I was at Berkeley when he arrived and was his colleague for nearly 60 years. Others will comment on Mark’s professional life, his career, and his many achievements. I will restrict my comments to some thoughts about Mark and especially about some of his defining but often unnoticed characteristics. One was that he was consistently self-effacing. If he did something truly special, unless you were directly involved, you would not know about it.

Mark’s early work was in acoustics, and when he arrived in 1951, an auditory chamber was designated as his lab. Lew Petrinovich and I had been considering doing some work on auditory learning, but really didn’t have a proper place to conduct the research. Mark got word of this, and without any discussion, turned over part of his lab to us to use as we saw fit. Was this a hardship for him? I truly don’t know. I only know that it was an act of kindness and generosity to a stranger that asked nothing in return. As another instance of this feature of Mark’s style, I think that during all the years when Mark was a principal developer and promoter of the Berkeley Campus program for enhancing the education of disadvantaged and minority students, very few of his colleagues were even aware of this side of his activities. Mark just had a way of effectively doing things that reflected his social values without drawing attention to himself.

So what do we have so far? Good, self-effacing, and effective. What else do I directly know? I know that he had a sense of humor that at least tickled my funny bone. We once collaborated on some research that showed that rats can correctly negotiate a maze on the basis of self-generated very high frequency sounds that are reflected off of barriers on the path to a goal.  This discovery prompted Mark to announce that the title of this paper would be “Rats is Bats.” I, for one, thought it very funny. Whenever he pulled one of his bon mots out of the air, there would be a hint of a smile and alighting up of the eyes — nothing more. As with his kindness and generosity, Mark also underplayed his humor.

And it would be a mistake not to mention his incredible organizational skills. I was not alone in observing Mark’s filing system, which consisted of vast piles of papers and notes in seeming disarray in his office. Of course, the disarray was only in the eye of the beholder. Mark knew exactly where every item was carefully stored. What to others might have looked like disarray, was in fact a model of high efficiency.

Our friend Mark was dedicated to his family, his craft, his University, and to making the world a better place. Those of us who knew him well will miss a good friend. But all of us will be poorer because of the passing of an exceptionally talented man who thought globally, and acted both locally and globally.

Donald A. Riley
University of California, Berkeley

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