Table of Contents
The Mysterious Matter of Mind
Laying the Experimental Foundations
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.
Excising these damaged tissues
reduced and sometimes halted the recurrence of fits. An unexpected
discovery was the finding that in many cases there was involuntary
recall of extremely vivid and often dramatic scenes from the
patient's past life, which scenes he or she was able to describe
in great detail, being fully conscious of the surgeon's activity.
This work was carried out in the Montreal Neurological Institute
over a period of thirty years.
In his training at Oxford under
Sir Charles Sherrington
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.
At the close of active surgical
practice he observed: (49)
Throughout my own scientific
career, I, like the other scientists, have struggled to prove
that the brain accounts for the mind. But now, perhaps, the time
has come when we may profitably consider the evidence as it stands,
and ask the question: "Do brain mechanisms account for
the mind?" Can the mind be explained by what is now
known about the brain? If not, which is the more reasonable of
the two possible hypotheses: that man's being is based on one
element, or on two?
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)
In his Mystery of the Mind,
there is a frank discussion of the thoughts which went continually
through his mind as he probed the brain tissues of epileptic
patients in the search for root causes. He wrote that, while
agreeing with Lord Adrian that we must always guard against introducing
ideas into our science which are not part of science, yet we
must subject our research to our own speculation at times and
that, where we do, critical evaluation is still possible. (51)
He then describes very briefly
the procedure which he came to adopt in the operating room and
the rationale behind it. The object was to locate, in epileptic
subjects, the cause and location of the point of irritation of
the neuron bombardment which is the trigger of the epileptic
fit, and, having precisely located it, to excise the tissue in
that area. The procedure
49. Penfield, Wilder, The Mystery of the
Mind, Princeton University Press, 1975, p.xiii.
50. Penfield, Wilder, The Physical Basis of Mind, edited
by P. Laslett, Oxford, Basil Blackwell, 1950, p.64.
51. Penfield, Wilder, The Mystery of the Mind, Princeton
University Press, 1975, pp.45.
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.
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.
To the layman, it seems an awesome
undertaking. But the secret of success depends on the patient's
being able to tell the surgeon what his conscious experience
is as the operator explores the exposed cerebral tissue with
the electrode. [A single contact point is used, carrying a 60-cycle
2-volt current.] Without this, the only guide to the surgeon
would be spasmodic and involuntary muscular
52. Ibid., p.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).
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!
He records one such occasion in
which "a young South African patient lying on the operating
table exclaimed, when he realized what was happening, that it
was astonishing to him to realize that he was laughing
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."
Penfield was thus driven to conclude
that the stimulus of the electrode was responsible in effect
for a kind of TV program which the subject was watching objectively,
while the subject's own mind was directing the production
of an equally complete record of the events occurring in the
room around him. Just as we can objectively watch a TV program
in the company of others whose presence we are fully conscious
of, so here were two different kinds of consciousness. The mind
was observing by its own will a program presented to it mechanistically
by electrode stimulation much as the TV operated independently
of the viewer. As Penfield put it, if we liken the brain to a
computer, man has a computer, not is a computer.
This discovery was totally unexpected.
But it was in no way singular. It was repeated again and again
for hundreds of patients, each of whom could identify the scene
recalled with ease and virtually instantaneously. Patients could
elaborate on what they saw and explain the circumstances, much
as a TV viewer seeing a serial program might explain the circumstances
to a watching companion who was ignorant of the previous events.
In such a situation there are clearly two elements. The viewer
is not part of the TV program but an observer. Yet he
is more than an observer insofar as the viewer can adjust the
set, clarify the image, change the program, and (in a recall
situation) shut it off at will under normal circumstances by
a shifting of attention (i.e., turning to another program). Here,
then, we have a dualism of object and subject, of brain and mind.
It is no longer safe to view the
mind as a computer, though the brain is indeed a computer
of extraordinary refinement. But this computer has a programmer
and an operator who is using it as a tool of recall and of motor
53. Ibid., p.55.
54. Ibid., p.108.
55. Ibid., p.40.
by the Mind
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)
Wonderful though the brain is as
a computer, we see its limitations and its dependence upon the
conscious directives of the mind for purposeful levels of activity
normal to human life. It is indeed something the individual possesses
but not something that possesses the individual.
Penfield was led to believe that
only what the mind has "attended to" is apparently
programmed into the brain. (58) If the subject has walked through traffic, consciously
observing avoidance patterns for maintaining his own safety,
this motor activity will be programmed in the computer automatically
and in the event of epileptic automatism the subject, though
wholly unconscious, will still navigate safely through traffic
unless some previously unexperienced complication arises. Penfield
described the normally healthy person as an individual who goes
about his world constantly depending on his own personal computer
which he programs to fit into his own continually changing objectives
and concerns. (59) *
56. Ibid., p.45.
57. Ibid., p.47.
58. Ibid., pp.39-40, 58-59.
59. Ibid., p.61.
*It should, however, be noted that under hypnosis some
recall of details that are only with difficulty attributed to
attentive observation in the past is possible. For example, under
hypnosis a man drew accurately every lump and grain on the top
surface of a brick he had laid in a wall twenty years before.
Since his trade was bricklaying, it is difficult to believe he
consciously attended to the surfaces of each brick he laid day
by day. Ralph Gerard. who reported this instance, in which the
accuracy of reporting was verified because the building was being
demolished, observed, "Men remember and recall innumerable
details never consciously perceived" ("What is Memory?"
Scientific American, September 1953, p.118). It seems
unlikely that we consciously perceive all that
idly strikes our senses. But there is no way of knowing this.
Possibly the past is not recoverable in its entirety if only
because we would need a second lifetime to recover it, and much
of it is worthless.
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
However, it was not always so.
One subject, stimulated in the same area, had four apparently
unrelated experiential responses. First he heard "footsteps";
secondly, "a company of people in the room"; thirdly,
"like being in a gymnasium"; and finally, "a lady
talking to a child at the seashore." (61) In the case of repetitious recall, nothing has been
lost, nor has anything been added. As Penfield says, "Events
are not a bit fancifully elaborated as dreams are apt to be when
And again, elsewhere, Penfield wrote:
The vividness or wealth of detail
and the sense of immediacy that goes with its evoked responses
serves to set them apart from the ordinary process of recollection
which rarely displays such qualities. Thus with stimulation at
Point No. II in subject J. V. (Case No. 15) the patient said,
"There they go yelling at me. Stop them!"
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,
61. Ibid., p.682.
62. Penfield, Wilder, "Epilepsy; Neurophysiology and Some
Brain Mechanisms Related to Consciousness," in Basic
Mechanisms in Epilepsies, edited by. Jasper, Ward, and Pope,
Toronto, Little, Brown, 1969, p.796.
63. 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.679.
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
Sometimes the re-lived experience
is so complex that the patient has to explain the background
of it later. One 23-year-old woman re-lived what she called a
"fabulous" event when she smashed a plate at dinner
with her elbow and tremendously enjoyed the experience! (65) She wanted to explain
why she so enjoyed it. Another patient suddenly found herself
sitting in the right-hand rear seat of a car, with the window
slightly down, waiting at a level crossing for a train to pass.
She could even count the train cars as they went and all the
characteristic sounds and noises were there. After the train
had passed and they crossed the tracks into town, even an old
familiar smell was experienced the odour of brewing coffee.
Penfield says this was the only case of a re-experienced smell
he came across in over a thousand patients whose brain surface
was exposed in this way in an effort to locate the cause of epileptic
Figure 5. Summary maps to indicate where,
in the two cerebral hemispheres,
experiential responses of all types
were produced by electrical stimulation.
64. Ibid., pp.64546.
65. Ibid., p.643.
66. Ibid., pp.64849.
Figure 4. Diagram of the brain of one of Penfield
's epileptic patients. (Top: right hemisphere, side view; bottom:
right hemisphere, bottom view.) The letters A-F identify points
on the brain stimulated by means of an electrode. The verbal
responses of the patient to such stimulation are given below.
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.
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."
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.
Penfield was forced to conclude
that, while he had spent years trying to explain the mind totally
on the basis of brain-action, his years of study made it far
simpler and more logical to explain mind and brain as two basic
elements instead of one. This proposition seemed to offer the
best path to lead scientists to a final understanding of the
brain/mind issue. He believed it would never be possible to explain
the mind from neuronal action within the brain, since the mind
seems to develop independently throughout a person's life as
if it were a continuing thing and since a computer, which the
brain is, must have a controlling agency capable of independent
Penfield has never suggested that
mind can get along without the brain, though clearly brain can
continue for some time without mind, as it does in epileptic
automatism. But the mind is the agent that programs the brain,
that decides what engrams [an engram is a memory trace]
shall be encoded in the computer for future retrieval.
Brain Does Not Account for Mind
As Penfield pointed out, and as
the monist would expect, if man's being consists of only one
fundamental element, then brain neuronal action must account
for everything that the mind does. (68) But in that case is there not some evidence of specific
neuronal activity corresponding to the thinking that the
individual is doing? To this Penfield answers no. Such evidence
67.Penfield, Wilder, The Mystery of the
Mind, Princeton University Press, 1975, p.80.
68. Ibid., p.78.
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.
He summed up his conclusions by
emphasizing that his own surgical experience never revealed any
area of matter in which local epileptic discharge resulted that
might be described as mind-action.* (69)
there is no evidence for such action, Penfield concluded that
the only explanation must be that there is indeed another basic
element and another form of energy, that as a programmer acts
independently of his computer, even if he depends on the computer's
action for certain things, so the mind seemingly can act independently
of the brain. (70)
If the dualistic view is never
explored, we shall never design experimental tools to uncover
the mechanism of interaction between the two elements. It before
seems logical to allow dualism as a working hypothesis and to
see whether new avenues of approach to the problem may not be
invented in the more open climate that such an allowance would
generate. Penfield was convinced we must broaden our hypothetical
In this spirit he then turns to
a consideration of some more subtle and perhaps more fundamentally
important questions that the evidence invites us to ask. He
*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.599601; G. Ungar and L. N. Irwin, "Transfer
of Acquired Information by Brain Extracts," Nature, vol.214,
1967, p.43555; 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,
69. Ibid., pp.7778.
70. Ibid., pp.7980.
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)
He makes a final observation that
he had worked as a scientist trying to prove that the mind was
accounted for by the brain and, demonstrating as many brain mechanisms
as possible, he hoped to show how it was thus explained.
He ends his reflections by saying: (73)
In the end I conclude that there
is no good evidence, in spite of new methods, such as the employment
of stimulating electrodes, the study of conscious patients, and
the analysis of epileptic attacks, that the brain alone can carry
out the work that the mind does. I conclude that it is easier
to rationalize man's being on the basis of two elements than
on the basis of one.
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.
72. Ibid., p.87.
73. Ibid., p.113.
Copyright © 1988 Evelyn White. All rights reserved
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