| 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..
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