Hebb Award Winners -
Dr. Ray Klein’s research career has been internationally recognized, sustained, and driven by the aim of unraveling the complex interaction between cognition, human performance and brain processes. It is with great enthusiasm that Ray states his career goal as being “in the tradition launched by Donald Hebb, tak[ing] aim at the fundamental questions: how does the mind work, and how is it implemented in the brain?” In this tradition, Ray’s research has focused on the fundamental mechanisms of how the mind works, particularly the concept of attention, a set of functions that control not only the directions of our thoughts, but also which objects and events are perceived, remembered and form the basis of our actions.
Ray joined the Psychology Department at Dalhousie University in 1974 immediately after earning his PhD. There he launched an internationally recognized research program on selective attention that focuses on two fundamental distinctions. One distinction concerns whether selection is accomplished by overt re-orientation of the sensory apparatus (e.g., by eye movements) or by a covert shift of an internal, mental apparatus (in the absence of eye movements). The second distinction concerns the mechanisms underlying endogenous (voluntary) or exogenous (reflexive) locus of control for these attention shifts.
In his first widely cited paper in this field, Ray proposed and tested the hypothesis that voluntary shifts of attention are accomplished by voluntary preparation of an eye movement to the to-be-attended location. This proposal was called the “Occulomotor Readiness Hypothesis”. This theory has such appeal that it continues to be espoused and subjected to empirical tests, despite early studies by Ray that supported the idea that overt and covert orienting actually are isolable subsystems when endogenously controlled.
In the mid-1980s Ray began his foray into studies about the second distinction in control mechanisms underlying attention shifts. Together with students Briand and Hansen, Ray exposed a double dissociation: exogenously controlled attention interacted with processes involved in Treisman’s feature integration, while endogenously controlled attention interacted with non-spatial expectancies similar to Broadbent’s pigeon-holing mechanisms. This and other differences strongly suggest to Ray that voluntary and reflexive control of “attention” entails the allocation of fundamentally different processing mechanisms.
Immediately after attention is exogenously drawn to a peripheral cue, targets are detected more rapidly at the cued location. However, after a sufficient delay (and usually when target probability does not call for attention to remain in the periphery) target detection at the originally cued location is slowed. Posner and colleagues named this "inhibition of return" (IOR) to convey their conclusion that attention is inhibited from returning to a location that it had recently "visited". In a paper published in Nature, Ray described, tested and confirmed a functional explanation for this inhibitory phenomenon: To be efficient when performing a difficult visual search task we require a mechanism to prevent attention from returning to previously inspected locations in which a target had not been found and IOR is that mechanism. Ray and his collaborators have since conducted some of the most illuminating studies of IOR and he has become a central figure in what has become one of the most investigated topics in the field of attention. Reflecting this stature, Ray was invited to write reviews of IOR for Trends in Cognitive Sciences and the Handbook of Cognitive Neuroscience. Since the 18th century and from subsequent modern day research using temporal order judgements, it has been claimed that stimuli presented to an attended modality are perceived earlier (relatively speaking) than unattended stimuli, a phenomenon captured by Titchener’s doctrine of “prior entry.” Indeed, it has been argued that research on this multisensory phenomenon inaugurated the discipline of psychology. Ray’s collaboration with Charles Spence and David Shore that won the British Psychological Society's best Cognition Paper Award in 2002, exposed methodological problems with the earlier demonstrations of prior entry, described procedures to minimize them and presented a series of new experiments implementing these improvements demonstrating that the 200 year-old doctrine was correct.
Though best known for his basic research on human attention, Ray has made exciting contributions in several other areas of cognitive research. In 1979, with Roseanne Armitage, he published a paper in Science describing his discovery of ultradian rhythms in cognitive style (roughly 90 minute alternations) that might be the daytime continuation of the well-known 90-minute alternation between REM (rapid eye movement) sleep and non-REM sleep. Ray also has become one of Canada’s leading scholars of reading research, co-editing a on dyslexia and reading with Patricia McMullen that has received uniformly positive reviews, and co-authoring with Mary Farmer a widely cited review of the controversial hypothesis that a temporal processing deficit may underlie a substantial number of cases of developmental dyslexia.
With respect to his mentoring of research students, Ray upholds excellence in his own work and demands excellence in the work of others. He encourages excellence through reinforcement, intellectual challenge, and example. The Klein laboratory is internationally recognized as an outstanding setting for trainees at every level – from honours undergraduates to post-doctoral fellows. This international reputation is well deserved.
We can think of no other person who is more deserving of the Hebb Award and no one who would appreciate it as much—to Ray, D.O. Hebb is a hero, a mentor and a role model. Given Ray’s leadership in the field of cognitive science and teaching and his service to the Canadian science community in the spirit of Hebb’s memory and tradition, Ray Klein is a truly worthy recipient of the Donald O. Hebb Distinguished Contribution Award.