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Back to Basics: The Magician’s Apprentice 50 Years On

By John Bradshaw

The prefix "neuro" these days appears before so many other existing disciplines – neuroethics, neurophilosophy, neuroeconomics and neuroforensics – but can all these disciplines be better comprehended and mastered through the lens of brain mechanisms?

In Greek mythology, Narcissus, son of the river god Cephisus and the water nymph Leirope, was a beautiful youth, beloved by the nymph Echo whom he cruelly repulsed. For this offence, Aphrodite, goddess of love, punished him by making him pathologically enamoured of his own image as reflected in a pool of water. His continuing and fruitless attemptes to approach his beautiful self image led to his despair and death. Are we not all just a little tempted by a similar fascination, an urge to understand, see even, something of the workings of our own minds, maybe to be glimpsed through a study of that latest of scientific endeavours, passions one might almost say, Cognitive Neuroscience? It can be no accident that the prefix “neuro-“ nowadays appears before so many other existing disciplines – neuroethics, neurophilosophy, neuroeconomics, neuroforensics.....Can all these disciplines be better comprehended and mastered through the lens of brain mechanisms?

The human brain, that most exquisitely complex of all known systems, manages so much of what seems to render us human – possession of a mind, however defined with respect to a substrate such as the brain, consciousness, will, intention, attention, ethics, personal and legal responsibility, thought, emotion, cognition.....the list goes on and on. And in the last couple of decades so many wonderful new procedures and technologies, “boys’ toys” one might call them, have been developed, whose operators can present to us dazzling images of brain structure (at macro and micro levels) and function, both of region and of inter-regional connectivities, in colours and tones often so aesthetically stunning that a Rennaisance painter in Italy would have given a limb for access to them.

Pictures may have launched a thousand ships, they may be worth more than a thousand words, but such pictures as come from the scanners of today must always be interpreted with caution, a caution which is not always observed in this brave new world which seems to open a window into The Last Great Mystery. Indeed, some say that ultimately it requires the brain to understand itself, a logically impossible and futile act of Narcissism. Time alone will tell, but plans are currently afoot in several parts of the world to fully characterize and even build a brain in all its barely imaginable complexity. The new discipline, Cognitive Neuroscience, is now almost come of age, but it will require, were it to make any truly meaningful progress, a thorough understanding of experimental and statistical principles, and this I fear is where basic scientific training may nowadays be falling behind the rigour which was once deemed necessary for a thorough apprenticeship in understanding how to formulate hypotheses, rigorously design studies, collect, analyse and interpret data, and draw statistically and scientifically valid conclusions.

Fifty years ago I commenced my PhD in what was then known as Experimental Psychology. I chose a completely novel topic in the area called Physiological Psychology; I set out to measure the effect upon the oculo-motor system of cognitive, thought and problem solving processes, as mediated by the autonomic or involuntary motor system. In those distant days, Psychology encompassed such broad disciplines as learning (animal and human), sensory and perceptual processes, behaviour genetics, personality, skills and ergonomics, clinical psychology, and much of what in the popular mind was thought to be the true domain of a soft or inexact science, or simply descriptive common sense.

Shortly after my doctoral completion, I was offered a lectureship at Monash, then a very new institution indeed, headed by a very far seeing foundation professor, Ross Henry Day. He insisted that as a biological discipline Psychology should be placed firmly within the Faculty of Science, and that the proper object of teaching and research should be the scientific analysis and description of behaviour – human and animal – with the understanding, of course, that we too belong to the animal kingdom. Not everyone was happy with this, and for years there would echo the occasional, residual student complaint “when are we going to do some real psychology?”

My professional career commenced in the golden years of the late 1960s, a period of near universal postwar optimism, and just before the full angst of Australia’s adventure in Vietnam had taken hold. There were abundant funds to develop new lab-based courses, and I was asked to run the new 1st year lab classes (130 students), and to lecture in Cognitive Processes and Animal Learning. I knew nothing about the latter, except that there seemed to be a tedious Skinner-driven obsession with Classical and Operant learning in rats, and schedules of reinforcement, an arid characterisation which seemed to me to miss totally the full richness of behaviour change. So in the first year I surreptitiously dropped the “Animal” qualifier in the designated course, Animal Learning, concentrating instead upon the biological bases or substrates which involve neurones, synapses, neurotransmitters, brain regions and the effects, upon the acquisition of new behaviours, of lesions, natural and artificial and localised to certain structures. In the second year, as no-one seemed to have noticed the change of emphasis, I made a further change to the title, from “Biological Bases of Learning” to “Biological Bases of Behaviour”, which enabled me to address such interesting topics as drive, motivation, sleep, language and other higher cortical functions.

Just before I had arrived in Australia, two seminal volumes had appeared, which enthralled and inspired me, and which I believe formed the substrate of the slowly emerging field of Cognitive Neuroscience. Aleksandr Romanovich Luria’s magisterial Higher Cortical Functions in Man (published in Moscow in 1962, English translation in 1966) surveyed lucidly, systematically and comprehensively an enormous Soviet corpus of findings of the effects of World War 2 wounds in discrete cerebral areas upon cognitive functions. The other book was Ulric Neisser’s Cognitive Psychology, published in 1967. He described exciting new findings from a host of ingenious experiments where visual material (letters, numbers, words, patterns), singly, in a matrix or sequentially, were flashed to normal healthy individuals under tightly controlled temporal or spatial constraints, to determine how it was all processed and what was ultimately seen or reported. Absolutely nothing like it had ever been done before, and the conclusions opened up the emergent field of Cognitive Psychology. I based my teaching and research around these two works, which, I believe, combined to form the union later to be known as Cognitive Neuroscience.

In my 1st year lab classes, as a bow to the original “Animal Learning” title of one of my lecture courses, I decided to go beyond the old, tired, tried and tedious lab rat; with my wife Judy, a biologist, I collected hermit crabs from the local shore line. These little marine crustaceans inhabit the cast-off, conical spiral shells of sea snails. With a blob of plasticine, the tip of the inhabited shell could be stuck to a substrate so that the crab itself could protrude from the open end of the shell in a jar of sea water. I placed a small light bulb above the creature, and two wires, insulated except for the tips, one on each side of the shell opening, such that a 6 volt current could briefly be passed across the animal, causing it rapidly to withdraw. The students were then free to determine how many exposures of a brief, low-intensity light flash alone, which normally had no effect upon the animal, or a pairing of light flash and current (in either order, and with various intervals) could “condition” the animal to withdraw just to a light flash, and how many such light-flash alone trials would suffice for the animal to “extinguish” its learnt, withdrawal response.
It was, however, in the cognitive realm that I, and I believe the students, had the best time.

Before computers, with monitors upon which all manner of material can be presented for controlled durations and intensities, and perhaps in particular sequences, cognitive scientists were reliant upon the tachistoscope, literally “very brief or fast viewing”. This device became an essential tool analogous to the biologist’s microscope; indeed, we had an enormous multichannel device occupying its very own room, with its lenses, mirrors, filters, prisms and electronic controls of exposure durations and sequences, via plug board and multiple timers.

However to do what I had in mind for teaching the students, I needed 12, for groups of three – participant or subject, experimenter and data recorder – to devise experiments and presentation procedures and collect and analyse data. I devised a beam tachistoscope, consisting of a pivoted arm, weighted at one end with a weight that could be changed or slid along the arm so that the other end, bearing a set of mirrors, would pass a viewing hole at chosen speeds. The mirrors, set at different angles, passed removable cards mounted so that their images would be reflected to the eye piece.. Crude but effective, with later modifications based upon an adjustable pneumatic door closer, we were able to simulate and extend, maybe less elegantly but quite effectively, the “classical” findings described by Neisser in his book.

Other devices I pioneered included sets of adjustable and filtered audio-oscillators to act as audiometers in studies on Signal Detection Theory and Auditory Psychophysics, where we could apply appropriate mathematical treatments. We also devised and constructed sets of visual simple and choice reaction-time gear, to study the mathematical application of Information Theory in the context of various schedules of a priori and a posteriori probability series.

I also found a way to modify and set up tape recorders to provide auditory feedback, delayed by various intervals between 100 and 400msec, of the ongoing speech of participants reading from a prepared text; at a critical value of 200msec, a fundamental interval within which we now know the brain continuously monitors and corrects ongoing speech and other complex sequential movements, speech typically breaks down into stuttering incoherence or is blocked. The procedure is known as delayed auditory feedback, and we were able to study the effect of different volumes, intervals and materials. Indeed with such and other techniques and instruments, enthusiastically manufactured by our talented departmental workshops (mechanical, electronic and later IT), I was able to teach eager 18 year olds sophisticated theoretical concepts and experimental procedures. While then considered as lying under the aegis of Experimental Psychology, they have now become part of a rebadged Cognitive Neuroscience, and I believe gave students a very valuable hands-on lesson in technique and how to improvise in what Neisser called an ecologically valid framework, unlike the often artificial and rather sterile procedures available nowadays to students from computer monitors.

Indeed, apart from running rather artificial studies, pedagogically speaking, by computer, the other great “laboratory” cop-out, based upon financial savings and economies of scale, is the substitution of a video for real hands-on experience. Apprentice researchers should get their hands dirty as soon as possible, maybe to build, and certainly to operate apparatus which may be comparatively simple in realization but sophisticated conceptually. They should collect, analyse, apply appropriate statistical tests and interpret their findings, and present them clearly, concisely and coherently, in the context of prior findings and of any initial hypotheses driving the study, in a paper which in principle is publishable, and in practice is intelligible to unsophisticated readers or those from other disciplines.

Similarly, web-based and online learning can never replace the stimulation of being before a real, live lecturer, excitedly telling the class about his latest findings or those of a colleague, and who extemporizes and answers interesting questions from the audience. And that new phenomenon, the Massive Online Course (MOOC), to which often hundreds of thousands sign up but apparently much less than 10% ever finish, may turn out to be a proverbial flash in the pan.

We are celebrating our departments 50th anniversary this year, 2014, and I do regret and deplore how, maybe universally, lab teaching in many disciplines has dwindled nowadays, supposedly for reasons of cost and efficiency, with the demise of those wonderful workshops with which I once worked, where we could devise simple, robust and ever interesting analogues of the cutting edge techniques and concepts of yester year. Indeed I have recently, and very profitably, resurrected a number of them, in updated form, to study patient groups suffering from inherited and acquired disorders of the motor system involving motor cortex, cerebellum or basal ganglia.

In summary, upcoming neuroscientists have some wonderful new toys – big, expensive and flashy generators of Big Data, to use the latest buzz word, but without a good practical grounding in experimental technique, it could all be an expensive waste of time. How else can we play Narcissus at his own game, without coming to a similar sad end of error, frustration and disappointment?

John L Bradshaw is Emeritus Professor (Neuropsychology) in the School of Psychological Sciences at the Monash Institute of Cognitive & Clinical Neurosciences. Reproduced from Ockham's Razor, Radio National, with permission.