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Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Epilogue Response Further Reading
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 One of
Sherrington's most notable pupils was the Canadian neurosurgeon
Dr. Wilder Penfield. He is best known for his remarkable studies
of, and successful treatment of, hundreds of patients afflicted
with epilepsy. This work involved surgical exposure and electrode
stimulation of brain tissue in fully conscious patients. By observing
the patient's reaction as the electrode was moved gently from
point to point over the temporal lobe, it proved possible in
many cases to locate the area of damaged tissue causing the epilepsy.  pg.1
of 12  and for a short period
under Dr. Santiago Ramon-y-Cajal in Spain, Penfield absorbed
and wholly accepted the principle that all such experimental
work must be conducted with the assumption that mind is in
the brain, that mind will in due course be entirely explained
in terms of physics and chemistry and electrical circuitry.
This shift in
point of view was not made easily. In 1950 Penfield outlined
briefly but eloquently an entirely mechanistic interpretation
of the brain's functioning. But subsequent evidence gradually
convinced him that this mechanistic and monistic view did not
adequately account for the facts. He wrote subsequently, "Something
else finds its dwelling place between the sensory complex and
the motor mechanism. . . . There is a switchboard operator
as well as a switchboard." (50) 49. Penfield, Wilder, The Mystery of the
Mind, Princeton University Press, 1975, p.xiii. pg.2
of 12 was found to be successful in hundreds of cases without further ill effect, provided that only one hemisphere had been damaged. The contralateral tissue in the other hemisphere (when the triggering site lay in the temporal lobe) was able to take over the function of the excised tissue. (See Figure 2 for area identity.)  Figure 2. Showing the relation of the temporal lobe to the rest of the brain. Penfield said
further that, for safety's sake and a fair likelihood of cure,
the surface of one hemisphere of the brain needs to be bared
extensively in order to study and possibly excise a damaged part.
This operation was considered less dangerous and more helpful
if the patient was conscious and alert during the entire procedure,
so only a local painkiller was injected into the patient's scalp.
Penfield emphasized that a great amount of doctor-patient trust
and communication were necessary to make such an operation both
successful and humane. (52) This procedure sometimes revealed the site that caused
epileptic seizures by triggering one. 52. Ibid., p.12. pg.3
of 12 movements. Since the stimulation of the temporal lobe does not produce such movements, only the conscious patient can tell the surgeon of the effects of exploration. (See Figure 3 for map of motor-control areas).  Double Consciousness This has produced
the surprising and remarkable experience in the subject of a
form of double consciousness, as Penfield termed it. The
patient is not only fully aware of his immediate surroundings,
operating room, the surgeon and his assistants — whole local
scene in fact — but also of the suddenly re-enacted
scene from the past, a scene so vivid that it includes sounds,
and in one case even included the odour of coffee being brewed! pg.4
of 12 with his cousins on a
farm in South Africa, while he was also fully conscious of being
in the operating room in Montreal." Penfield observed: "The
mind of the patient was as independent of the reflex action as
was the mind of the surgeon who listened and strove to understand.
Thus, my argument favours independence of mind-action."
(53) 53. Ibid., p.55. pg.5
of 12 Supervisory Control by the Mind Epileptic
subjects may sometimes experience total "blackout"
as to consciousness, the mind apparently ceasing entirely to
control the brain. Provided that the brain has already been programmed,
the subject becomes an automaton and completes it in a state
of total mindlessness. Patients may even complete a journey from
work by car. Provided the journey is a habitual one and
that no unexpected interference occurs, navigating the traffic
and road turns is done by means of purely conditioned reflexes;
afterwards nothing whatever of the journey will be recalled.
The efficiency of the brain as a computer is truly remarkable.
Penfield observed that the continual functions of the normally
active mind were apparent in such journeys. (56) But he emphasized that it is the mind that must first
program the computer brain, sin computer is only a thing and,
on its own, has no ability to make totally new decisions for
which it is programmed. (57) 56. Ibid., p.45. pg.6
of 12 Penfield
made many surprising discoveries about the potential of temporal
lobe exploration in this way. A particular site when contacted
by the electrode produces a specific recollection. It is so specific
that the re-lived experience begins always at precisely the same
point in the sequence of events. There is not a continuation
where the last scene finished off, but a repeat performance.
In one subject this occurred sixty-two successive times! (60) This seems to indicate
a very specific localization within the cortex, like setting
the needle down in the same spot on a record. (See Figures 4
and 5)
The individual is able consciously to identify the meaning of the re-lived experience not as a kind of hallucination but as something as real as life from which he nevertheless stands apart. A woman listening 60. Penfield, Wilder and Phanor Perot, "The
Brain's Record of Auditory and Visual Experience: A Final Summary
and Discussion," Brain, vol.86, part 4, December,
1963, p.685. pg.7
of 12 to an orchestra
under Penfield's stimulating electrode hummed the tune she heard,
verse and chorus, thus accompanying by an act of conscious effort
the very music which was being recalled so vividly. Such recallings
were entirely involuntary. They are not memories voluntarily
brought to the surface. They are detailed and more vivid than
such memories ever are. Penfield reports the experience of one
patient who experienced an occasion on which she was sitting
in a room and listening to the children playing outside. The
sounds of motor traffic and all the other noises of urban living
provided the "natural" background. She discussed all
this with Dr. Penfield while it was happening, and so real was
the experience that it took some time to convince her afterwards
that he had not actually arranged the whole thing, including
the noises outside at the time. Needless to say, he had not done
so. (64)  Figure 5. Summary maps to indicate where, 64. Ibid., pp.645—46. pg.8
of 12 Reaction of patient upon contact at individual points as shown in Figure 4. A: "I heard something, I do not know what it was." A: (repeated without warning) "Yes. Sir, I think I hear a mother calling her little boy somewhere. It seemed to be something that happened years ago." When asked to explain she said, "It was somebody in the neighbourhood where I live." Then she added that she herself "was somewhere close enough to hear." B: "Yes. I heard voices down along the river somewhere — a man's voice and a woman's voice calling. . . I think I saw I river." C: "Just a tiny flash of a feeling of familiarity and a feeling that I knew everything that was going to happen in the near future." D: (a needle insulated except at the tip was inserted into the superior surface of the temporal lobe, deep in the fissure Sylvius, and the current was switched on) "Oh! I had the same very, very familiar memory, in an office somewhere. I could see the desks. I was there and someone was calling to me, a man leaning on a desk with a pencil in his hand." I warned her I was going to stimulate, but I did not do so. "Nothing." E: (stimulation without warning) "I had a little memory someone in a play — they were talking and I could see it — I was just seeing it in my memory." pg.9
of 12 Penfield found that if the cortical area which had
been the site of stimulation for the re-living of some experience
was subsequently removed surgically (when it was believed to
be for the benefit of the epileptic patient), the patient could
still voluntarily recall the experience afterwards. Evidently
the memory itself was not at this point but was stored in some
area to which the site was connected. Cutting the connection
made it impossible to obtain recall by electrical stimulation,
but it did not eradicate the memory itself which could still
be recalled voluntarily. Brain Does Not Account for Mind 67.Penfield, Wilder, The Mystery of the
Mind, Princeton University Press, 1975, p.80. pg.10
of 12 not been found in any
of his patients. Yet he is careful to admit that there may be
such neuronal activity not yet demonstrated. Moreover, he has
observed that substantial areas of the cerebral cortex can be
removed without any loss of consciousness by the subject even
during the operation, a fact which suggests that consciousness
is not specifically localized. *The question of whether there is an actual
memory trace in the form of RNA specifically relating to each
memory is still an open one. The experimental evidence that planaria
which have learned some avoidance action have a particular RNA
which, when fed to untaught planaria, gives them a head start
in the learning is still a matter of debate. See for further
reading: Arlene L. Harty, Patricia Keith-Lee, and W. D. Morton,
"Planaria: Memory Transfer Through Cannibalism Reexamined,"
Science, vol.146, 1964, p.75; Allan L. Jacobson et
al., "Planarians and Memory," Nature,
vol.209, 1966, p.599—601; G. Ungar and L. N. Irwin, "Transfer
of Acquired Information by Brain Extracts," Nature, vol.214,
1967, p.435—55; Ejnar J. Fjerdingstad, Chemical Transfer
of Learned Information, New York, Elsevier, 1971; R. M. Yaremiko
and W. A. Hillix, "Reexamination of the Biochemical Transfer
of Relational Learning," Science, vol.179, 1973,
p.305. pg.11
of 12 points out that the
history of the mind's development during life as opposed to the
brain's course of development is rather different. (71) For example, if one plots
a curve showing the excellence of human performance, one sees
that the body's performance (and the brain's) improves
with time as maturing takes place, until after a certain stage
in life when a decline begins to set in and ultimately senility.
By contrast, the mind reveals no characteristic or inevitable
decline. In fact, in old age it reaches toward its fullest potential
of understanding and judgment, while the body and the brain are
slowing and sometimes failing to perform. (72)
Such, then, is the much examined and carefully stated opinion of a man who has had perhaps more first hand experimental knowledge of the data than any other person at the present time. 71. Ibid., p.86. pg.12
of 12 Copyright © 1988 Evelyn White. All rights reserved
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