Foto van een onderzoeker

onderzoek

Laudatio uitgesproken door prof. dr. Eric Soetens

Laudatio voor prof. dr. Michael Posner
Uitgesproken door prof. dr. Eric Soetens

Geachte rector,
Geachte vice-rectoren,
Beste collega’s,
Vrienden en sympathisanten,

It is a great pleasure for me to honor today one of the leading researchers in cognitive psychology of the last half a century. The science of psychology has witnessed dramatic changes in these last 50 years, and without doubt Michael Posner has been at the focal point of many of these changes. Presenting all of Michael’s contributions in the short time allotted for this talk is an impossible task, but I shall try to illustrate the general importance of his contributions for cognitive science.

For the major part of his career, Michael Posner has worked at the University of Oregon, where he is now professor emeritus. At this university, together with other pioneers in the field, he played an important role in introducing information processing in psychological research. The work of Michael Posner can be described as one straight line of investigation from the early 1960’s up to the present and into the future, aiming at the ultimate goal of mapping the mind to the brain, that is, to say what is the function of which part of the brain and how do these structures interact with each other? This of course is a dream that many psychologists seek to pursue, but if we look at the work that Michael has accomplished in his career, it has certainly not remained merely a dream.
Posner started this endeavor at the beginning of his career by using simple reaction-time research, presenting a stimulus to an individual, and measuring how much time it takes for the individual to give a response. The basic idea was and still is very simple: if we wish to understand everyday mental processes, whether reading or writing, talking or listening, perception or attention, learning or memory, we must think of these tasks as an interaction of many small component processes, and it is the task of the scientist to try to identify these primary functions or processes. Interpreting the small differences in time between experimental conditions as indicators ultimately leads to the isolation of these elementary component processes that make up complex behavioral processes such as those of reading and attention. The technique of isolating these component processes, which has become one of the standard procedures in psychological research, is generally referred to as ‘mental chronometry’. Much of Michael’s early work in this field was published in his 1978 book ‘Chronometric Exploration of the Mind’.

In later stages of his career, Posner also played a pioneering role in brain imaging research: PET and fMRI, suggesting the same rigorous approach of isolating elementary component processes to map mental functions to the structure of the brain. He and his collaborators helped to shape this now very popular research line in the neurosciences. Without doubt Michael Posner and his collaborators set the gold standard for research on mapping cognitive functions to brain structure and also for understanding their neurochemical underpinnings. In the book ‘Images of Mind’ published with Mark Raichlein 1994, he describes for a wide audience, the methods for localizing cognitive functions by looking at patterns of brain activity in complex cognitive tasks.

One of the major contributions of this approach is the discovery that there are different networks of attention in the brain. This constitutes a strong support for the assumption that attention is not a unitary function and that a clear distinction should be made between orienting, alerting, and executive functions. These ideas led to an important advancement in our understanding of the diversity in attentional disturbances in clinical populations. Armed with the tools of fundamental research Michael Posner set out to use these techniques in research in many different psychological disciplines, where the understanding of these attentional networks might be beneficial. This has led to important contributions, for example, in explaining the differences in cognitive deficits suffered by people with brain injuries. He also applied his knowledge of the relation between mind and brain in the study of children, demonstrating relationships between developing component processes of attention and the development of brain structures and how this may lead to individual differences. Finally, Michael took the step of looking at the influence of genetics on the development of attentional networks and how this may explain the individual differences.

Michael Posner’s contribution to the science of psychology goes far beyond the specific discoveries he and his collaborators made in their experiments. There is no doubt that many of Posner’s experiments are very well known and have been replicated numerous times in countless variations, but his major contribution lies in the paradigms and basic ideas that have guided research throughout his career. These clearly demonstrate Michael Posner’s ability to look far ahead at the development of psychological science and how this new knowledge can be used to tackle important problems in society. The importance of his work cannot be measured by his personal scientific output alone, but also by the work of the many students whom he has mentored and who have by now developed a distinguished scientific career of their own. Moreover, many other scientists throughout the world have been inspired by his work, resulting in the launching of many programs aimed at understanding the relationship between mind and brain.

It comes as no surprise that all these accomplishments have led to international recognition by the scientific world and many national and international honors and awards have been conferred on him. To name some: Michael Posner was appointed at a young age to the National Academy of Science and later to the American Academy of Arts and Sciences. He is also recipient of the American Psychological Association’s Distinguished Scientific Contribution Award and is an honorary doctor of the Universities of Granada, Nottingham, Padua, and Paris, and he has received the International Science Prize from the Fyssen Foundation in France.

Dear Michael, it is with great pleasure and pride that I have been able to take part in conferring on you, in the name of our faculty and the University, the degree of doctor honoris causa of the Vrije Universiteit Brussel.
Congratulations!