Keith Andrew Wesnes in memoriam

Abstract

It was with great sadness that I learned recently of Keith's passing. He was truly a giant of our field, always direct and utterly consistent in his views, he was a valuable colleague, a challenging adversary, and a much-cherished fellow-traveler. The assessment of cognition was, for the 20 years I knew Keith, the focus of his professional interest. Inspired by his PhD experience of investigating the effects of nicotine on cognition, Keith recognized the gaps in our cognitive testing armamentarium and sought to plug them with a suite of computerized cognitive measures. In establishing his core set of tests, Keith borrowed judiciously from experimental psychology, wisely selecting brief, reliable, and valid measures of episodic memory, attention, and working memory, in his view the key cognitive domains. In doing so he borrowed thoughtfully and effectively from cognitive psychology's rich history of experimentation and especially the work of Franciscus Donders (1818–1889) and Saul Sternberg. Characteristic of the man was his focus on precision and reliability. This is evident in the content of the cognitive testing system he created. Keith recognized that attention and visual working memory are both more efficiently and reliably assessed using digital technology rather than with traditional “paper-and-pencil” testing. His dogged pursuit of precision and reliability drove him to find innovative means of mitigating repeated assessment effects and especially the impact of practice. His solution was the inspired idea that study participants should be tested on pre-baseline study visits so that post-baseline practice effects would be minimal, maximizing the chances of detecting treatment effects. His need for precision and reliability were also characteristics of his conversational style. He would constantly demand of speakers and commentators that they be precise in their questioning and opinions. So much were these core aspects of his personality that he would often demonstrate impatience with those who in his view were being glib or inconsistent. This could often make him appear brusque and impatient. However, this was not the inherent nature of the man, who I came to understand as a slightly shy and modest individual whose robust style masked his own uncertainties. Keith's no-nonsense approach required clarity and precision to operate successfully. This aspect of him is again reflected in his professional activities, particularly the practical approach he took to data analysis. He would delight in observing robust reliability correlations, but woe betide the critic who would point out that a Pearson's r value of 0.8 was less than perfection. Similarly, the nomenclature he employed to describe factors from correlative analyses of the data from the Clinical Dementia Rating core assessment belied his desire for precision, hence the slightly challenging title of “quality of episodic secondary memory” for one factor. This imposition of order on an unruly world sat well with Keith, though he was much less patient when engaged in definitions of executive function. Some psychologists are drawn not to the certainty that a correlation of 0.8 appears to offer, but instead that performance on one measure predicts “only” 64% of the variance in another. Keith was naturally drawn to the prodigious correlation of 0.8, others to the mere 64% explanation of the variance, and sometimes discussions of the relative merits of these two positions could be rather animated, especially when conducted in a conference bar or pub. Readers will note that much of this tribute focuses on Keith's work rather than on the man himself. I think this is exactly what he would want, to be remembered for his ingenuity, enterprise, and industry, much of which will live on through the system he created and via those of us who admired his work and were inspired by his efforts. He leaves us an extraordinary legacy. If imitation is the sincerest form of flattery, then perhaps the greatest testament to Keith's professional legacy is the tendency of modern psychological test vendors to incorporate technology, tests, and methods that were pioneered by him. John Harrison April 28, 2020