Table Of ContentAssembly of the
Executive Mind
Assembly of the
Executive Mind
Evolutionary Insights and
a Paradigm for Brain Health
Michael Hoffmann
University of Central Florida
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that any content on such websites is, or will remain, accurate or appropriate.
Every effort has been made in preparing this book to provide accurate and up-to-date information
that is in accord with accepted standards and practice at the time of publication. Although case
histories are drawn from actual cases, every effort has been made to disguise the identities of the
individuals involved. Nevertheless, the authors, editors, and publishers can make no warranties
that the information contained herein is totally free from error, not least because clinical
standards are constantly changing through research and regulation. The authors, editors, and
publishers therefore disclaim all liability for direct or consequential damages resulting from the
use of material contained in this book. Readers are strongly advised to pay careful attention to
information provided by the manufacturer of any drugs or equipment that they plan to use.
For Bronwyn, Jenna Leigh, and Michael.
Contents
Acknowledgments ix
Introduction 1 8 Neurological Diseases as
Networktopathies with
1 The Evolution of Larger Brains
Disconnection Phenomena 137
since the Vertebrate–Invertebrate
Divide 15 9 The Sensitivity and Vulnerability of
the Prefrontal Cortex to Changes in
2 The Profound Increase in Primate
Daily Rhythms 144
Gray Matter Growth 27
10 Implications for Treatment and
3 Exponential White Matter Growth
Management: A Network-Based
and Major Fiber Tract Systems
Approach 154
Assembly 51
11 Sense of Self Disorders 192
4 Cellular and Molecular
Changes 70 12 Implications for You and
Society 205
5 The Core Frontal Systems 87
6 Enhanced Working Memory 107
7 Unraveling of Brain Networks in
Index 219
Neurological Conditions: Nature’s
Reductionism 124
vii
Acknowledgments
The singling out of individuals for thanks no doubt will leave out many others that were
instrumental in my training and conceptualization of brain health and fitness, and for this
I apologize in advance. The evolution of my thinking and ultimately this book is a tribute
to many friends and colleagues that helped me in my formative years. I was very fortunate
to have Professor Phillip Tobias as my anatomy professor and Dean of the medical school
at the University of Witwatersrand. He taught us human anatomy from not one, but three
large books called Man’s Anatomy, Parts 1, 2, and 3, but more importantly enkindled in
his students a fascination for human origins that he was so famous for. Professors Pierre
Bill and John Cosnett of the University of Kwa-Zulu Natal, Durban for their patient and
expert teaching in clinical neurology, guiding my early career development. Professor John
Robbs, head of surgery and vascular surgery, University of Kwa-Zulu Natal, Durban for his
enthusiastic support and promotion of my early forays into cerebrovascular medicine and
helping form the Durban Cerebrovascular Group. Professor Bill Pryse-Phillips helped land
my first neurology job at Memorial University, Canada while he researched and wrote his
book, Neurology Dictionary. Professors J.P. Mohr and Ralph Sacco enthusiastically guided
me through my stroke fellowship and instilled the fervor for computerized registry analyses
at Columbia University, New York. I am very fortunate to have continued guidance and
mentorship in cognitive neurology and cognitive neuroscience from Professor Frederick
Schmitt of the Sanders Brown Aging Institute at the University of Kentucky and Professor
Ken Heilman of University of Florida. I am grateful to Dr. Fiona Crawford and Dr. Michael
Mullen for providing me with a platform for launching neuro-archeological seminars at the
Roskamp Institute in Sarasota and promoting clinical cognitive neurology to flourish side
by side with their high-level neuroscience research. The Cambridge University Press team,
Noah Tate, Gary Smith, Anna Whiting, and Emily Jones, that so enthusiastically guided this
book to fruition, were exceptional in their efficiency and professionalism. At the center of
my life are my family, Bronwyn, Jenna Leigh, and Michael, whose support is inestimable.
Registry data used
Clinical examples and radiological images were sampled from the following IRB-approved
registries of which the author was the principal investigator. These registries pertained to
the collection of clinical investigative, radiological, and management data of consecutive
stroke and cognitive impairment patients, aged 18–90 years, accrued through prospec-
tively coded dedicated stroke and cognitive disorders registries in tertiary referral cent-
ers. These were approved by the relevant University Institutional Review Boards and the
latter two registries were also in compliance with HIPAA (Health Insurance Portability
and Accountability Act) regulations when this was enacted.
1. The NIH-NINDS Stroke Data Bank (New York)
Under the following contracts: N01-NS-2-2302, N01-NS-2-2384, N01-NS-2-2398,
N01-NS-2-2399, N01-NS-6-2305.
Status: Stroke Research Fellow (1990–1991)
ix
x Acknowledgments
2. The Durban Stroke Data Bank
IRB approval: University of Natal, Durban, South Africa (approved by the Ethics
Board of the University of Kwa-Zulu Natal).
Status: Principal Investigator (1992–1998)
3. The USF-TGH Stroke Registry
IRB #102354 (University of South Florida).
Status: Principal Investigator (2002–2006)
4. The USF-Cognitive Stroke Registry
IRB #106113 (University of South Florida)
Status: Principal Investigator (2007–2010)
Consent
All patients signed informed consent for the evaluation and the collection of the their
neurological, medical, and neurocognitive data.
Cover Image
Cover image designed and drawn by Michael S. Hoffmann, MS ISOM, Washington DC,
USA, adapted from artwork © Can Stock Photo Inc. / woodoo.
Introduction
Deciphering the natural environment, including human form and function, is best
achieved by interdisciplinary study. The differing sciences inform each other and there is
often two- way or bidirectional information exchange between disciplines. For example,
evolution informs neuroscience and neuroscience has the power to inform evolution.
This was well described by David Lewis- Williams in his interpretation of cave rock paint-
ings in which certain artistic depictions reflected different stages of hallucination in the
human mind. In his elegant overview of how ancient art helps understand the neuro-
science of our minds, presented in his book The Mind in the Cave, he describes how the
intensified trajectory of altered consciousness level of visual hallucinations (fully fledged
hallucinations) in ancestral humans was recognized as being identical to migrainous for-
tification spectra (jagged lines), familiar to contemporary neurology [1].
The Nobel prize- winning physiologist Eric Kandel eloquently portrayed how neuro-
science and art inform each other, detailed in his two exceptional books, The Age of Insight
[2] and Nature’s Reductionism: Bridging the Two Cultures [3]. The parent field of medicine,
biology, is often instrumental in the understanding of human brain mechanisms, such as
theories of how we developed superb color vision. Isbell’s snake-d etection theory helped
inform current- day neurology and psychiatry about snakes having acted as a primary
selective pressure operating on primates and expanding their visual systems. In brief,
evolutionary exposure to venomous snakes, which are usually patterned and colored,
induced trichromacy in the African primates, as opposed to the mere dichromacy of
the South American primates, the latter having had minimal venomous snake exposure.
The third component of the theory, the Madagascar lemur, which has the worst color
vision of the primates, had no exposure to venous snakes at all [4]. Many arts and sci-
ences are therefore valuable in helping to understand the evolution of the human execu-
tive mind. From my perspective, the discipline of clinical neurology, which is concerned
with brain lesions and their consequences, or fractured brain circuits, can inform the
discipline of archeology that deals with the analysis of fractured skulls. Hence, fractured
minds and brain circuits can similarly be regarded as a two- way process in the study of
neuro- archeology. As can be seen from Figure 0.1, many disciplines helped inform the
assembly of our frontal lobes and our minds. There are, of course, numerous disciplines
in the arts and sciences. Perhaps increased interaction among them will lead to ever-
greater insights. Clinical medicine just happens to be a discipline that is among the least
interdisciplinary at the present time, as we shall see in Chapter 12. The great visionary
and biologist Edward Wilson coined the term consilience in his book of the same name,
emphasizing the unity of all knowledge and disciplines, and conceived of all the arts
1
2 Introduction
Clinical Sciences:
Neurology, Neurosurgery,
Psychiatry, Psychology,
Psychopharmacology,
Speech/Language
Earth Sciences: Geology,
Philosophy, Art, Music,
Paleoclimatology,
Literary Arts, Sociology
Volcanology
Neuroimaging: Archeology,
functional, anatomical, Anthropology,
resting state Paleobiology
Neuroscience:
Genetics, Epigenetics,
computational, cognitive,
Molecular Clocks
and laboratory
Figure 0.1 Science, art and clinical disciplines inform our brain functions.
Piecing together the components from Piecing together the components from
fractured skulls fractured minds
Figure 0.2 The unravelling of the human mind: a method of studying human cognitive evolution.
Reprinted by permission from Springer Nature from Wood B. Hominid revelations from Chad. Nature
2002;418:133–135.
and sciences as being innately bound by a small number of natural laws in physics and
chemistry [5].
One can either gather fractured skulls and bones or study fractured brain circuits in
deciphering brain function and how it evolved (Figure 0.2). Similar to the approach of
Vilayanur Ramachandran and Oliver Sacks, individual case reports and sometime case
series can be very illuminating, as have the recent spate of n-of-1 trials that are gaining
