Reflections of a Neuropsychologist

Brushes with Brains

John Bradshaw

• Publisher: Routledge
• Year: 2018
• ISBN:
  9781351060738
• Edition: 1
• Topic: Psychology
• Subtopic: History & Theory in Psychology
• Index: Psychology

Reflections of a Neuropsychologist: Brushes with Brains follows the life of an influential neuropsychologist's fascinating and varied career. Unique in its autobiographical approach, it features coverage of research into human evolution, archaeology and neurology.

Beginning with his earliest memories (and implications for memory processes), John L. Bradshaw reflects on his archaeological expeditions preceding his primary career as a physiological psychologist and a behavioural neuroscientist. His influential research covers such rare neurological disorders as Huntington's disease, Friedreich ataxia and Williams syndrome, and more common maladies like Parkinson's and Alzheimer's diseases, stroke, Fragile X, Tourette's syndrome, obsessive compulsive and attention deficit hyperactivity disorders, schizophrenia, autism and depression.

His fascinating personal experiences illustrating scientific discoveries will entertain, enthuse, encourage and inspire, and provide established research scientists and practising clinicians with a unique road map.

1

THE EVOLUTION OF ALL THINGS

The past is not just another country, or even another continent; it is another island universe, wherein the laws of thought allow one to reverse at will time’s speeding arrow.

We were camped, my botanist wife and 9-year-old daughter Catriona and I, just where we always tried to be at nightfall, while travelling in the vast Australian outback – camped in the hard, red-earth centre of a lonely clay-pan, a hollow nestled in the all-surrounding country of dune, sparse scrub, and patches of gibber. These dark stones, polished by aeons of wind, glinted feebly in the rays of a red-setting sun. The best part of the day, with the omnipresent flies at last at rest, and time for a beer and to light a sweet-smelling campfire of resinous wood, rich in volatiles and rare oils, dead and dried by the relentless sun of daytime. A desert, but a friendly desert, alive with little creatures beginning to venture out for night-time activities, calling to each other with faint, pure notes of an exquisite beauty. Above us soon would shine an incomparable night sky, under the sway of the Southern Cross, with a luminosity you could practically read by, beneath the blazing arc of the Milky Way: a jet of milk projected from the full breasts of Hera, consort of the great Greek god Zeus, god of the daytime? Or, mundanely, a cartwheel galaxy, seen almost edge on, from a lonely Earth located near its outer perimeter; a galaxy of billions of stars, many with circling planets like our own, a galaxy among billions of similar astronomical structures scattered seemingly randomly through a measureless, uncaring universe, itself maybe only one of an infinite number of other, similar universes. And we were, are, privileged to gaze upon this emerging glory, from the safe haven of our own little clay-pan in our own little island continent of Australia, on our own little blue planet, our only home, endlessly circling our own little middle-aged sun. Privileged to view this celestial scene, sparked and tracked from time to time by rushing meteorites, burning up in our atmosphere at the end of their journeys from – where? And we are privileged to be able to ask how it all began – the universe (ours?), the solar system, life, humanity, consciousness … the ability to ask, if not always to answer, such questions.

Matter and the universe as we know it may have existed for around 13.6–13.8 billion years or maybe even somewhat longer, depending upon the accuracy of the measurements of the speed of recession of the distant galaxies, their actual distance, and a number of other critical assumptions. It is tempting to try asking what came before this Beginning Big Bang (or First Whimper?) when space, time, energy and matter all supposedly came into being together, almost a theological question, some might say, and nowadays some cosmologists are even returning to this apparently illegal question, although, according to ‘traditional’ Einsteinian thinking, there can be no time before its beginning, unless perhaps an infinity of universes predated our familiar four-dimensional ‘home’. But all such issues belong to the conceptual domain of cosmologists and theoretical physicists. At a more mundane (in every sense) level, our own middle-aged sun, on an outer limb of our parent spiral galaxy, one of maybe 100 billion, and alone composed of 100 billion stars which we know as the familiar Milky Way as seen from many an outback clay-pan, is upwards of 5 billion years old; our ever-orbiting Earth has maybe been around for some 4.6 billion years. Life, in the form of primitive single-celled organisms, first appeared on our little lifeboat maybe a billion years later, almost as soon as the latter had cooled, oceans had appeared, and the rain of comets and giant meteorites, abounding as the solar system settled into an uneasy equilibrium, had diminished to a ‘safe’ and steady level. Such an early advent of life could almost suggest the presence of precursors then, and now, maybe microbial, on comets in seed form, throughout the solar system and perhaps even beyond. Such providential panspermia, as envisaged by the much-maligned astronomer and sci-fi writer, Fred Hoyle, is currently enjoying a recurrent renaissance, although not perhaps to the extent that it may, as Fred suggested, even be linked to recurrent outbreaks of earthly influenza. It is, however, increasingly evident that simple chemical compounds, capable of combining to form biologically promising precursors, are abundant everywhere in the, our, universe.

Panspermia or not, the currently preferred scenario for life’s earthly origin is around hot volcanic ‘smokers’, plumes of superheated water replete with minerals and metals emerging from the mantle, and located deep in the early ocean. Charles Darwin instead envisioned a warm thermal pool, on land, and it is noteworthy that recent findings of fossils of very early life forms in Australia’s Pilbara, dating from 3.5 to 3.8 billion years ago in hot spring deposits, support Darwin’s usual, inspired, hypothesis. Modern methanogens, relatives of the oldest microorganisms on Earth, are often found near such hydrothermal vents. In the absence of oxygen, they convert carbon dioxide and hydrogen into methane. They may thus have produced, 3.5 billion years ago, some of the greenhouse gases, needed to stabilise the Earth’s early climate, opening the way for other more complex life forms to evolve. Oxygen, of biogenic (photosynthetic) origin from primitive algae, introduced to Earth’s atmosphere the element essential for more advanced life, some 2 billion years ago.

Whether life on Earth was of endogenous or exogenous origin, it is composed of chiral molecules. These appear in two forms, mirror images of each other, like a pair of gloves. However, life seems to have preferred molecules of a single chiral, chemical, handedness; all DNA twists clockwise, like threads on a right-handed screw, and consequently nearly all amino acids are left-handed. It is noteworthy that chiral molecules are and have been present in interstellar space, from long before the existence of our solar system. Such observations, and uniformities in the DNA of all living things, support the proposal that life evolved – somewhere – only once, or alternatively that the way it did evolve is perhaps the best solution to the constraints operating.

In my paternal grandmother’s house, hundreds of years old, and contiguous with that of my parents’, was a very early, and possibly priceless, copy of Darwin’s magisterial and iconic Origin of Species, one of many books on geology, such as Lyell’s Principles of Geology, roughly contemporaneous with Darwin’s in the mid-nineteenth century. Darwin of course proposed that organisms continually change or mutate, usually with maladaptive consequences leading nowhere. However, the fittest, and only the fittest, will survive and breed, to pass on to their offspring these adaptive changes. Thus, evolution is by ‘natural selection’, with the inheritance of adaptive characteristics, an essentially gradual change, although from time to time maybe hastened as a result of catastrophic events drastically changing the environmental pressures.

There was even a tattered copy of Alfred Russell Wallace’s The Malay Archipelago, with its stirring descriptions of travel, danger, butterflies and beetles, in the remains of my deceased grandfather’s science library. Wallace, who independently of Darwin developed his own version of evolutionary theory, was a great read notwithstanding. I wish I had known my bibliophile grandfather, but he apparently ‘dropped dead’ while out cycling with my father, then a teenager.

Lyell’s Principles of Geology was not a light read, but this book, which almost out of an existing vacuum, set the whole stage of modern palaeontology and maybe even archaeology, came into its own for me when I stumbled upon my very first fossil. Aunty Betty, Grandfather Bradshaw’s daughter and my father’s sister, in 1950 had a caravan on Britain’s south coast, near the tiny Somerset harbour of Watchet; we spent a typical British summer holiday with them when I was 11. The cliffs there expose the famous fossil beds of the Jurassic Blue Lyas (layers, in dialect; the strata are so distinctive), the same as in the iconic exposures at nearby Lyme Regis. Waiting on the beach were wonderful fossil treasures: pearly ammonites, resembling the modern Nautilus, crinoids (stalked relatives of sea urchins and starfish), and, oh delight, the occasional small vertebrae (‘wortieberries’ in the local dialect) possibly from a dinosaur! All small boys develop obsessive tendencies; until then for me it was stamps, but I soon rearranged my life so as to fill my corner of one of our many decaying greenhouses at home with shelves of fossils gleaned from cliffs, beaches, quarries, stream beds, road cuttings and stone walls all over the country. In Lyell’s book I read of what he had believed, well over 100 years earlier, to be the oldest fossil of all, Eozoon canadense. What a wonderfully evocative name! The first element, translating (as my expanding education in Classical Greek at the time taught me), means Creature of the Dawn. Lyell we now know was wrong, both on dates and on its status as a fossil, but that is by the way.

Another important local influence was, unexpectedly, the very excellent local fish-and-chips shop, which caused a local commotion when a family portion rose with inflation from 3-pence to 4-pence, and which, curiously, and from some unknown source, for a long time would wrap the precious cargo in old copies of that august medical journal, The Lancet, which certainly was excellent at resisting grease. Therein I avidly read intriguing accounts of obscure and euphoniously named creations such as gamma globulin, and determined one day to become a medical doctor, and invent and name some more myself, and was indeed later to tailor my subjects at school so as to include appropriate subjects to qualify for entry into medical school.

It was Richard Dawkins, in the mid-twentieth century, who was the first to radically modify classical Darwinism, with his selfish gene metaphor. (Darwin, of course, writing long before the discovery of genes, could not have known then the exact mechanisms of inheritance.) Dawkins proposed that it is the directing genes, and not the organism as a whole, merely the vehicle for the contained genes, which drives evolution. Very recently a third modification has been proposed (and creationists love modifications, which they claim discredit Darwinian thinking, not realising that modifications are the life-blood of the fundamental principle of self-correction in science). Genes, coding for proteins, the constituents of all things living, are not the whole story. Genes may be turned on or off by epigenetic processes, switches, so that every cell, containing the entire genetic blueprint for the entire organism, throughout its own changes in developmental morphology, and with its many different bodily organs and systems, only ever behaves in a fashion appropriate for its context in place and time – heart cell for heart, liver cell for liver. Think of a butterfly, with its many external and internal parts, radically changing in morphology (larva, pupa, imago) as it passes through life’s stages. Moreover, such switches, principally involving methylation, may also be turned on or off as a consequence of adventitious environmental pressures (temperature changes, food shortage or over-abundance, over-crowding). And some switch changes may outlast the organism experiencing them, and be passed on to succeeding generations down the germ line – an additional, fast-acting, adaptive mode of individual inheritance, over and above the much slower classical-Darwinian process of natural selection via variation. I am reminded of memory mechanisms – short-term electrical patterns of storage in neural circuits, followed by a long-term series of structural changes in the neurons and neuronal junctions themselves. A nice recent demonstration of epigenetic changes conserved and transmitted across generations, comes from male mice aversively trained to avoid an otherwise innocuous odour of cherry blossom; their offspring also avoided such odours, and in their sperm exhibited relevant epigenetic changes.

In the geological record, older rocks must have successfully survived the continual recycling of fossil material; consequently there are fewer such survivors, the further one goes back in time. That observation, and the fact that very early life forms almost had to be simple, single cell structures, mean that they are hard to find, hard to see, and are often ambiguous markings in rare silica rocks like chert.

The oldest fossils are often of structures resembling modern stromatolites, layered structures forming through microbiologically modified sediment accretions, such as I have found, and photographed, in the hard red rocks of the Pilbara of Western Australia. Other examples, at 3.5 billion years old, occur in the same general region, surprisingly close to the otherwise fairly uncommon living examples in the hypersaline waters of adjacent Shark Bay. On the edge of the Greenland icecap, there are slightly older specimens very shortly postdating the period at 3.7 billion years ago when the Earth was battered by asteroids. At the time of writing, there are contested claims of filamentous structures, originating around hydrothermal vents deep in an ancient ocean, said to date from between 3.8 and 4.3 billion years ago. As mentioned above, such vents have long been proposed as possible sources for an anaerobic origin of life.

We must await, it was long said, the so-called Cambrian biological explosion, around 540 million years ago, for evidence of complex life forms, such as the enigmatic Archaeocyathus (something seemingly intermediate between a coral and a sponge, and which I once found in a narrow lens of limestone in Big Moro Gorge creek-bed, in the Flinders Ranges of South Australia). Or so it was thought, although the question remained as to why complex life forms seemed to have sprung fully formed out of nowhere, like the ancient Greek goddess Pallas Athene from the forehead of Zeus.

(Parenthetically, mass extinctions, followed by a whole new suite of life forms, have occurred quite regularly during Lifeboat Earth’s relatively brief, in the overall scheme of things, history, due variously to adventitious asteroid impacts or violent volcanic eruptions. Nor may we be immune to further such calamities resulting in extra-terrestrial oblivion; there are always bodies passing close to Earth, along with a continual rain of smaller fragments. Indeed, alone with my daughter at mid-day on the dry bed of a small salt lake, again in the lonely yet lovely Australian outback, we both heard a ‘whooshing’ sound pass us by, but without any sound or trace of impact or of wild (or human) life. Again, micrometeorites containing iron, the commonest type, tiny and very common, may be harvested from one’s house gutters with the aid of a small magnet.)

The unlikely rethink, about there being no complex Precambrian life forms, came about as a result of the fabulous finds of a lone geologist, Reginald Sprigg, a specially significant star in my own personal pantheon of luminaries. They were strange, bizarre even, fossils of complex, beautifully preserved organisms often many centimetres long, quite unlike anything seen before or extant later. Like mine, Reg’s childhood was spent combing cliffs and scavenging shore lines, roaming road cuttings, quarries and stream beds – for fossils!!. Born in 1919 in South Australia, he was to become a student of Sir Douglas Mawson, a professor of geology and an Olympian figure in polar exploration and survival. Towards the end of the Second World War, he was sent to prospect for uranium, for the nascent nuclear weapons industry, in the vicinity of the Ediacaran Hills in the Flinders Ranges, one of my own favourite destinations for dreaming and discovery. He found masses of uranium, but even more significantly, as it was to turn out, some of the strangest macrofossils ever seen. Moreover, despite vociferous cries of ‘Impossible’, they appeared to be securely pre-Cambrian. It was all very reminiscent of Alfred Wegener and the theory of Continental Drift. Just as I had done, as a sick child playing with a toy globe of the world, he had noticed how well the continents of Africa and the Americas fit together, jigsaw fashion, just as if they had been pulled apart. Wegener in 1912 proposed that that was effectively what had happened, decades later to be shown as due to sea-floor spreading, due in turn to its modern realisation in plate tectonics. Just so, it was to be at least a decade before Reg Sprigg’s extraordinary fossil finds, and similar ones elsewhere on Earth, were to be accepted as pre-Cambrian and dating to an interval between 635 and 541 million years ago. It should, however, perhaps be noted that genetic evidence from modern life forms, extrapolating backwards in time, suggests that basic animal groups may have in fact originated as far back as 750 million years ago. An enormous increase in oceanic algae around 650 million years ago would certainly have both increased oceanic oxygen, and provided an essential food source for animal life.

The fossils that Reg Sprigg found in the Ediacaran Hills are dated to between 560 and 550 million years ago, with finds later made elsewhere commencing around 565 million years ago. However, for the first time in nearly a century, we now have a newly named, authenticated and accepted geological period, the Ediacaran. Again, as a young man in my very early twenties, I read Glaessner’s iconic article in the Scientific American, and was inspired with a determination one day to visit the area. However, it was to be 30 years before I eventually had my wish, and camped in the arid Ediacaran landscape with my wife Judy, and fossicked among the remains of old mines, within sight of the huge salt lake, Lake Torrens. Another very famous Ediacaran site is in Namibia, at Farm Aar, explored by my friend and colleague, Professor Pat Rich, at Monash University, where we have both laboured in our very different disciplines for decades. When I visited Namibia with mutual friends and colleagues in 2013, I found the countryside surprisingly similar, in features and aridity, to my beloved Flinders, and the fossils at Farm Aar, dating to around 542 million years ago, even more dramatic, although as both regions are designated as of world significance, one cannot and should not remove anything except for scientific purposes, and should take, as I did, only photographs.

The Cambrian period, following the apparently catastrophic extinctions of the prior Ediacaran biota, is noteworthy for an almost unprecedented explosion of complex, multicellular organisms, many of which continued evolving until now. It dates from around 540 million years ago, when, indeed, there appeared the earliest ancestor common to chordates, vertebrates and indeed those species such as the starfish and sea urchins which are, maybe surprisingly, invertebrates related to the chordates. Such ebullient abundance may result from the increasing availability of atmospheric oxygen, from algal or similar photosynthetic processes taking off in earlier millennia. The first chordates promptly appeared, with their stiffening notochord or longitudinal rod in a bilaterally symmetrical body, with mouth and sensors at one end, and propulsive organs down the sides and at the ‘trailing’ end, wherein there is also located the excretory apparatus. The modern lamprey closely resembles these precursors of the vertebrates (craniates), with backbones/vertebral columns, and crossed (contra-laterally represented) sensory and motor systems. Thus, the left side of the brain or head ganglion manages sensorimotor matters on the right side of the creature’s body, and vice versa. Why this crossover? One suggestion is that very early chordates may have evolved from some such creatures as acorn worms, which again for some unknown reason underwent a 180-degree rotation of the body with respect to the head. So many questions yet to be answered.

Fish may first have appeared as early as 480 million years ago, although for a long time they were exclusively cartilaginous, like the sharks, with bony fish (osteichthyes) appearing later. From the latter, a whole series of life forms emerged, apparently intermediate between fish, with fins and relying on gills for respiration, and creatures that could use modified fins as limbs whereby to climb onto the land, like modern mudskippers, and where they could respire like the modern-day lungfish. Such emerging tetrapods were the original amphibians, around 350–375 million years ago, although there seem to have been, contemporaneously and maybe earlier, many ‘failed’ taxa, resembling each other but not quite making the big jump to a firm and final (except maybe for reproductive purposes) life on the land. Indeed, there are fossil trackways made by apparent tetrapods maybe dating back to 390 million years ago. Descendants of the early amphibians include modern salamanders and the lovely Crested Newt, which occasionally would wander into the ground-level aquaria which as a chi...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright page
• Table of Contents
• Preface
• Acknowledgements
• 1 The evolution of all things
• 2 Tools: tacit and tactual symbols of civilisation
• 3 Art, graffiti, juvenilia or Kilroy?
• 4 Language: what tales the tongue may tell
• 5 The child is father to the man
• 6 The Old Forge and my first school
• 7 Secondary school early awakenings, or where the whore moans, there moan I
• 8 Dreaming spires, Oxford days, et in arcadia ego
• 9 Sticking up like a sore thumb: hitch-hiking
• 10 An industrious interlude and industrial interval: ICI
• 11 An ugly picture in a beautiful frame
• 12 The Golden Road, or a shot in the dark
• 13 Eyes, a window to your thoughts
• 14 Aotearoa: a year in the land of the long white cloud
• 15 Terra Australis (nobis adhuc) incognita
• 16 Commissural connectivity
• 17 Harry McGurk, read my lips: ventriloquism
• 18 Mirror, mirror on the wall: symmetrical stimuli and bimanual responses
• 19 Consciousness, will and time
• 20 When ignorance is bliss
• 21 I didn’t think I had noticed it: unconscious processing
• 22 When recognition fails: agnosia
• 23 Phantom legs and neglected arms
• 24 Is your Tuesday green? Synaesthesia
• 25 Bodily integrity and identity: is it really me?
• 26 Empathy for pain and mirror neurons
• 27 Stop it, it tickles: why you can’t tickle yourself
• 28 Huntington’s disease, the Lady of the Lake and the hunt for the gene
• 29 Parkinson’s disease: when go turns to slow
• 30 Musicians’ dystonia: a brain out of tune
• 31 Clothes-pegs, sex, hobbies, addiction and gambling
• 32 Fun, fraud and fabrication: what a tangled web we weave
• 33 A god of the gaps and dental distress
• 34 The little brain
• 35 The magician’s apprentice: back to basics
• 36 STROKE: the hour that struck
• 37 I’m as old as I feel
• 38 Where to now? Some forward-looking afterthoughts
• Further reading
• Index