However, the old brain is not merely concerned with taste, smell and
visceral sensations, leaving the new to turn its gaze outward: that would
be an idyllic distribution of labour. The 'Papez theory of emotions'
originated in the study of pathological conditions in which the 'old
tube' interferes with the new, and tends to usurp its functions. Papez
noted that damage to the limbic system caused a variety of symptoms,
which primarily affected the emotional behaviour of animal and man. An
extreme case is the terrible disease of rabies, whose virus appears to
have a predilection for the limbic system, and in which 'the patient
is subject to paroxysms of rage and terror'. [24] Less extreme but
equally telling are the emotional states in the 'sacred disease',
epilepsy. Hughlin Jackson, one of the pioneers of neurology, described
the epileptic aura preceding the attack as the 'dreamy state', a kind
of 'double consciousness', in which the patient is aware of the reality
around him, but as if it were a dream, or a repetition o[ something
that happened before (déjà vu). During the actual fit of
psycho-motor epilepsy, the 'animalistic' brain seems to take over the
personally. Biting, chewing and grinding the teeth, terror or furore are
well-known distressing accompaniments of the fit, of which as a rule the
sufferer retains no memory. All the clinical evidence points in these
cases to the limbic system as the focus of the epileptic discharge. [25]
Typical of the clinical material is, for instance, the case of. a
nymphomaniac woman of fifty-five 'who, for more than ten years, complained
of a persistent "passionate feeling." Later she developed convulsions. It
is notable that perfume was thought to exaggerate her symptoms' [26] --
smell is the most 'visceral' of the senses. She underwent brain surgery,
and the operation revealed a lesion affecting the limbic lobe.
The human clinical material is limited, and electro-encephalography is a
recent invention; thus most of the evidence is provided by experimentation
on animals. They are basically of two kinds: electrical or chemical
excitation of the brain, and surgical elimination of certain areas of
it. Let me quote MacLean again:
From animal experimentation on limbic epilepsy (induced by electrical
stimulation) it has become evident that seizure-discharges induced
in the limbic lobe tend in their spread to be confined to the limbic
system. Seldom do the discharges, analogous to stampeding bulls,
burst out of this corral and jump the fence into the neo-mammalian
brain. Such experiments provide the most striking evidence
available of a dichotomy of function (or what has been called a
'schizophysiology' of the limbic and neocortical systems). Patients
with smouldering limbic epilepsy may manifest all the symptoms of
schizophrenia; the schizophysiology in question is possibly relevant
to the pathogenesis of this disease. . . .
From the standpoint of the patient lying on the couch, the
schizophysiology under consideration is significant because it
indicates that the lower mammalian brain is able to some degree to
function independently, to make up its own mind. The primitive,
crude screen provided by the limbic cortex might be imagined as
portraying a confused picture o[ the inside world and the outside
world. This may partly account for the manifest confusion that has
been described in psychosomatic conditions -- the confusion, for
example, in which food or other edibles serve as representations of
something in the external world that is desired to be assimilated
into the self or mastered and destroyed like a prey or enemy.* One
finds descriptions of the patient who eats presumably because of the
need for love, because of anxiety or nervousness, or because of the
need to chew up or get rid of what arouses his anger and hate. [27]
* The relevance of this to the phenomena discussed on
pp 228 f is obvious.
More recent methods of experimentation with implanted electrodes which
permit low-voltage stimulation of precisely defined points of the monkey's
brain, produced even more striking results. Stimulation of certain loci
in the limbic system caused penile erection or ejaculation in males;
stimulation of other points caused feeding reactions -- chewing and
salivation; yet other areas elicited exploratory, aggressive-defensive or
fearful behaviour. (It should be pointed out that these experiments are
painless, and that monkeys with implanted electrodes in the so-called
'pleasure centres' quickly and willingly learn to stimulate themselves
by pressing a lever which activates the current.) However, excitement of
one kind readily spills over to adjacent points which arouse emotions of
another kind. Thus oral activity --- chewing, srtiffing, salivation --
may combine with aggression; aggressive display with sex; sex with oral
activity. Feeding often produces erection in babies and dogs; and some
other aspects of doggy behaviour also fall far below Victorian standards.
'Schizophysiology'
Here again, the contrast between old and new cortex provides an unexpected
clue, and an added dimension to the psychoanalytical approach. On
the new TV screen (the sensory cortex) the body is represented in the
well-known form of a little homunculus, shown in all textbooks, on which
the mouth and the anal-genital region are placed correctly at opposite
ends of the projection area. In the old, lower mammalian brain, however,
'nature apparently found it necessary to bend the limbic lobe upon itself
in order to afford the olfactory sense close participation in both oral
and anogenital functions'. [28]
This is a truly unexpected vindication of Freud's theory of infantile
sexuality. It is at the same time a reminder that the survival of the
lower mammalian brain in our heads is not metaphor but fact. In the
sexual, as in all other contexts, maturation seems to mean a transition
from the domination of the old brain towards the domination of the
new. But quite apart from emotional upsets and pathological conditions,
the transition even in the normal person can never be complete.
The
schizophysiology is built into our species.
In surgical ablation experiments, the effects are more drastic. After
excision of certain parts of the limbic lobe, monkeys of previously
savage temperament seem to lose the instinctive reactions necessary for
survival. They become docile, show neither fear nor anger, do not fight
back when provoked, do not learn to avoid painful situations. They also
lose their instinctive feeding habits: a monkey which normally lives on
fruit will now eat raw meat or fish, and show a compulsive tendency to
put every object into its mouth: nails, faeces, burning matches. Lastly,
the sexual and maternal instincts also go haywire: male cats will try
to copulate with chickens, and mother rats will let their litter die. [29]
However, the old brain is not merely concerned with affect; it also
perceives, remembers and 'thinks' in its own, quasi-independent ways. In
primitive animals, the limbic system is the highest integrative centre
for the drives of hunger, sex, fight and flight; and the anatomical
and physiological evidence indicates that it continues to serve these
functions in higher animals, including man. It occupies, as already
mentioned, a strategically central position for correlating internal
sensations with perceptions from the outside world, and for initiating
appropriate action according to its own lights. Though dominated by
instinct, it is clearly capable of learning simple lessons: a monkey
will taste a burning match only once, if its limbic system is intact;
if it is damaged, it will burn its mouth over and again. 'One can hardly
imagine a more useless brain than one that sat around by itself all
day generating nothing but emotions and not participating in cognitive,
memory and other functions.' [30] But it functions all the same in a
phylogenetically old-fashioned way -- in a way which psychiatrists call
infantile or primitive.
On the basis of the foregoing observations one might infer that [the
old cortex] could hardly deal with information in more than a crude
way, and was possibly too primitive a brain to analyse language.
Yet it might have the capacity to participate in a non-verbal type
of symbolism. This would have significant implications as far as
symbolism affects the emotional life of the individual. One might
imagine, for example, that though the visceral brain could never
aspire to conceive of the colour red in terms of a three-letter word
or as a specific wave-length of light, it could associate the colour
symbolically with such diverse things as blood, fainting, fighting,
flowers, etc. -- correlations leading to phobias, obsessive-compulsive
behaviour, etc. Lacking the help and control of the neocortex,
its impressions would be discharged without modification into the
hypothalamus and lower centres of affective behaviour. Considered in
the light of Freudian psychology, the old brain would have many of
the attributes of the unconscious id. One might argue, however, that
the visceral brain is not at all unconscious (possibly not even in
certain stages of sleep), but rather eludes the grasp of the intellect
because its animalistic and primitive structure makes it impossible
to communicate in verbal terms. Perhaps it were more proper to say,
therefore, it was an animalistic and illiterate brain.
(MacLean [31]; italics in the original).
A Taste of the Sun
Our emotions are indeed notoriously inarticulate, incommunicable in
verbal terms. The novelist's main difficulty is to describe what his
characters
feel
-- as distinct from what they think or do. We can
describe intellectual processes in the most intricate detail, but have
only the crudest vocabulary even for the vital sensations of bodily
pain -- as both physician and patient know to their sorrow. Suffering is
'dumb'. Love, anger, guilt, mourning, joy, anxiety command a vast rainbow
spectrum of emotions of varied colour and intensity which we are unable
to convey verbally, except for trite clichés -- 'broken hearts'
and 'pangs of despair'; or else by the indirect method of invoking
visual imagery and the hypnotic effect of rhythm and euphony, which
'lull the mind into a waking trace'.
Poetry could thus be said to achieve a synthesis between the sophisticated
reasoning of the neocortex and the more primitive emotional ways of the
old brain. This
reculer pour mieux sauter
, draw-back-to-leap process,
which seems to underlie all creative achievement, may reflect a temporary
regression from over-concrete, neocortical thinking to more fluid and
'instinctive' modes of limbic thinking -- a 'regression to the id in
the service of the ego'. We also remember that sometimes 'we have to get
away from speech to think clearly' -- and speech is a monopoly of the new
cortex. In a similar way, other phenomena discussed in the chapters on
creativity and on memory can be interpreted in terms of hierarchic levels
in the evolution of the brain. Thus, for instance, the distinction we have
made between abstractive memory, on the one hand, and the emotionally
significant 'picture-strip' on the other (
Chapter VI
),
seems to reflect the characteristic distinction between the new and
ancient brain.*
* Cf. also Kluever's three levels of visual memory [31a]
(p. 90).
The consequences of the innate 'schizophysiology' of man thus range from
the creative to the pathological. If the former is a
reculer pour mieux
sauter
, the latter is a
reculer sans sauter
. Its forms vary from what
we regard as more or less normal behaviour, where unconscious emotional
bias distorts reasoning only to a moderate extent, in socially approved
or tolerated ways, through the open or smouldering conflicts of neurosis,
to psychosis and psychosomatic disease. In extreme cases, the distinction
between the outer and inner world can become blurred -- not only by
hallucinations, but also in other ways; the patient seems to regress to
the magic universe of the primitive: 'The impression is gained clinically
that [these] patients . . . show an exaggerated tendency to regard the
external world as though it were part of themselves. In other words,
internal feelings are blended with what is seen, heard or otherwise
sensed in such a way that the outside world is experienced as though
it were inside. In this respect there is a resemblance to children and
primitive peoples.' [32] An example of such confusion is the remark of
a girl suffering from epilepsy about her first seizure -- which occurred
when, as a child, she walked into the bright sunlight: 'I had a funny
taste in my mouth of the sun.' A poet might have written that line;
but unlike the poor child, he would have been aware of his own confusion.
'Knowing with one's Viscera'
We all can sometimes feel the taste of the sun in the mouth; but our
major confusions arise, not from such visceral interference with our
perceptions
, but with our convictions and
beliefs
.
Irrational beliefs are anchored in emotion; they are
felt
to be true. Believing has been described as 'knowing with one's
viscera'. More correctly we should say that it is a type of knowing which
is
dominated
by the influence of the inarticulate old brain, even
if it is
formulated
in articulate verbal terms. At this point,
these neurophysiological considerations merge with the psychological
phenomena discussed in the previous chapter. The schizophysiology of
the brain provides a clue to the delusional streak in the history of man.
A closed system, as defined in the previous chapter, is a cognitive matrix
with a distorted logic, the distortion being caused by some central axiom,
postulate, or dogma, to which the subject is emotionally committed,
and from which the rules of processing the data are derived. Cognitive
systems are, of course, not exclusive products of the reptilian or
paleo-mammalian or neo-mammalian brain, but of their combined efforts. The
amount of distortion varies according to which level dominates, and to
what extent. Without some contribution from the ancient levels concerned
with internal, bodily sensations, the experience of our own reality would
probably be absent -- we should be like 'disembodied spirits' (MacLean
[33]). Without the neocortex, we should be at the mercy of affect,
and our thinking would be like the monkey's or infant's. But detached,
rational thought is a new and fragile acquisition; it is affected by
the slightest irritation of the old brain which, once aroused, tends to
dominate the scene.