1st
Part: 2nd Part:
In addition to the above generalization of our considerations, from the visual
facts only to perception in general, the solution of the paradox still requires
the correction of a simplifying assumption which is not seriously tenable, but which
has been made up to now. It is impossible that the spatial relationships in phenomenal
space simply corrrespond to the geometrical relationships of their respective processes
in the brain field. G. E. MÜLLER pointed out a long time ago that this is not
conceivable because, for example, visual space acts like a fairly uniform continuum,
while the corresponding processes of the brain field are anatomically-geometrically
distributed over the two hemispheres; and therefore, from purely geometrical considerations,
something, like a gap or at least a gross disturbance of continuity would have to
be brought about by this inhomogeneity of the geometrical distribution of the processes.
The same thing follows from the irregular arrangement of blood vessels in the nervous
tissue (also emphasized by MÜLLER). Quite aside from such considerations, phenomenal
space has a large number of characteristics which would be alttogether incomprehensible
on the assumption that its structure and its articulation in each concrete case
were determined by nothing but purely geometrical relations of individual local
processes. The new psychology of perception has demonstrated beyond any doubt that
only the functional distribution of processes, as well as gradations and articulations
in such a context, can be regarded as the physiological basis of the phenomenal
spatial order. Accordingly, the physiological theory of phenomenal space must be
dynamic, not geometrical. The symmetry of a perceived circle, for example, would
not depend on the mere geometrical relationships between the loci of independent
individual processes, but on the fact that, in an extended whole process which underlies
the visual circle, a corresponding symmetry of the functional context exists. A
more detailed discussion would lead us too far from our topic. (5)
It will suffice if we show, by means of an analogy from elementary physics, how
this changed assumption permits us also to solve those difficulties arising from
the anatomical peculiarities.
Let a three-dimensional network or lattice be formed from filiform conductors,
such that the conductors may be considered the edges of many equal small cubes.
Consequently, at the corners of each such cube six filaments are in electrical contact,
while they are otherwise encased in insulating sheaths. If such a network is connected
to the poles of a battery in a certain manner, then the distribution of the stationary
current may, of course, be represented purely geometrically. But this is a rather
superfidal procedure, since purely spatial data mean very little for what takes
place here, and since the distribution of the current must essentially be related
to portions of the conductor. As far as geometry is concerned, the stationary
distribution of current would be very different - it would be distorted - if the
network were "bent," if some filaments were curved, etc. At the same time,
however, in terms of length of conductor or amount of resistance, the distribution
would be the same as before. Indeed, in these terms the distribution could still
be considered the same even if some of the filaments (between two junctions) differed
in length from the others but had the same resistance. Under these conditions there
would certainly be considerable discrepancies between a description of the current
in purely geometrical coordinates and one (the only adequate one) in functional
coordinates. For instance, in the latter terms a certain distribution of current
would have to be characterized as "homogeneous" while its density per
square centimeter would vary considerably from place to place.
Since the distinction between functional and geometrical coordinates may be applied
to other events, and thus must not be restricted to the case of stationary electrical
currents, it may well be applied to the central nervous system and especially to
that part of it whose processes underlie the spatial order of our perception. It
is clear, then, that only functional coordinates may be used and that, therefore,
the geometrical-anatomical position of the individual conducting structures and
cells relative to each other becomes meaningless (a position partly determined by
all kinds of secondary factors). With this step, the difficulties discussed by MÜLLER
disappear. As a very rough approximation we can, of course, still assume a correspondence
of geometrical-anatomical and functional coordinates of the system. For functionally
neighboring parts of the tissue are usually also geometrical-anatomical neighbors,
and functionally very distant parts are also separated anatomically from each other
by a certain distance in space. But this correspondance will not hold in detail
and will not apply strictly. lt will be irrelevant for the understanding of the
ordering of events in such a field since the functional distances are the only ones
that really matter.
Without this principle it is impossible to understand even the relation between
visual ordering of space and the corresponding brain events. It is all the
more necessary if we want to make comprehensible in physiological terms the fitting
coordination of the phenomena of the various sensory modalities in one common space.
(This needs to be considered in relation to the simplifying formulation above [2nd part].) But perhaps this point of view is most important
for the understanding of the construction of the phenomenal self from such different
sensory material. Again, it cannot seriously be maintained that in the brain region
in question the corresponding process complex represents a kind of geometrical copy
of the phenomenal body. For what matters are precisely the functional coordinates,
and these may be "distorted" in a great many ways. This correction of
the relevant coordinate system will not in the least change the relative localization
of phenomenal self and phenomenal environment. "Being outside" and the
changing distance of phenomenal objects relative to the phenomenal body are again
to be thought of as functionally determined only, as a gradation in the extended
context of processes which the purely geometrical distributions reflect only very
roughly.
After this, nothing at all remains of the paradox of the localization of our
phenomenal environment around us. Whatever relative phenomenal localization may
take place is determined by functional proximities and distances in the underlying
nervous process distributions. The fact that in their totality these are contained
within the meninges and the skull in no way enters into these functional connections.
Therefore they could not possibly appear in our perception, whose spatial character,
indeed, depends only on those functional connections. Only if, during the analysisis,
we shift from one kind of coordinate sytem to an entirely different kind, can we
possibly still find difficulties here. If the phenomenal self depends on one
process complex, the phenomenal environment on other such complexes, and
if the relative phenomenal localization of the two corresponds to functional externality
(just as two different phenomenal objects in the environment are outside of each
other), then there is no problem left.
I do not wish to give the impression that this discussion leads to nothing more
than to the disappearance of the old paradox. So far the emphasis has been on the
fact that, in general, separate localization of phenomenal environment and self
is natural and necessary for consistent thinking. From a slightly different point
of view, however, these same considerations lead, rather, to a functional equivalence
and kinship of the phenomenal self and phenomenal objects, which again cannot be
understood as long as this self is not recognized as a separate part of the phenomenal
world. Physiologically, the self and the objects of the environment represent complexes
of processes in one and the same brain field. It is by no means necessary, and not
even likely that these proccess complexes are functionally entirely indifferent
to each other. The psychology of perception is full of instances of mutual influences
between the objects nd occurrences of the phenomenal environment. For example, forms,
sizes, and directions of seen objects may be strongly influenced by a suitably chosen
surrounding visual environment. Because objectively and physically these are nothing
but independent and mutually practically indifferent objects, forms, or contours,
because there is thus no corresponding influence outside the organism, these distortions
are usually called "illusions." But psychology is coming more and more
to realize that, physiologically in any case, this is a matter of true influences
on visual process complexes by their neighbors in the field. After what has been
said, it is not astonishing that among the processes which underlie the phenomenal
organization of space, more intimate functional connections exist than between the
individual objects in physical space, whose forms, sizes, etc., are independent
of each other under ordinary circumstances. Particularly striking influences are
often observed in phenomenal space when there are movements in the field. Everybody
has noticed, for example, that the moon clearly moves in the opposite direction
when clouds pass in front of it. This is called "induced" movement of
a phenomenal object, and recently DUNCKER has been able to offer a satisfactory
explanation of its remarkable properties. (6) If,
now, the phenomenal self belongs to the same interconnected field in which objects
of the phenomenal environment can exert such an influence on one another, we may
then expect that the same influence which is exerted, for instance, on the moon
by the passing clouds may, under suitable conditions, also be exerted on the phenomenal
self by vigorous movements of the phenomenal surroundings. Now, it is well known,
and has even become a favorite amusement at country fairs, that obvious rotation
of the visual environment leads regularly to rotation of the phenomenal self in
the opposite direction, while the physical organism remains at rest. This phenomenon
becomes, in principle, fully comprehensible if we consider the organization of the
process complex which underlies the phenomenal self as part of the whole field of
connected processes corresponding to everything phenomenal.
This simple example shows particularly impressively that phenomenal space and
the underlying physiological field structure have qualities which do not exist in
the same way in physical space. In particular, there are dynamic relations between
the process complex of the self and the environment processes in the brain field
which have no correlate in any analogous causal connections between the physical
organism and its physical environment. But if we have gone this far, to be consistent,
we must go very much farther. For, considerations of continuity demand that every
kind of behavior in which we are directed toward a part of the environment will
have to be understood as the expression of a vectorial state or event between the
momentary process of the self and the environmental process in question. Depending
on the actual characteristics of the two which, of course, always determine such
a vectorial state, very different directions may occur. Such psychological facts
as "attending to," "feeling attracted or repelled by," "hesitating
before something," etc., occur in experienced space as directed from a phenomenal
object to the self or vice versa. If one wants to be consistent, these will have
to be incorporated in the schema outlined here of a correspondence between phenomenal
order and functional connections in the brain field. But a more concrete development
of this idea is hardly possible without also treating the phenomena of memory; it
would therefore lead us too far from our problem.
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