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images intervene
action, this memory merely awaits the occurrence of a rift between the actual impression and its
corresponding movement to slip in its images. As a rule, when we desire to go back along the course of the
past and discover the known, localized, personal memory-image which is related to the present, an effort is
necessary, whereby we draw back from the act to which perception inclines us : the latter would urge us
towards the future; we have to go backwards into the past. In this sense,
(114) movement rather tends to drive away the image. Yet, in one way, it contributes to its approach. For,
though the whole series of our past images remains present within us, still the representation which is
analogous to the present perception has to be chosen from among all possible representations. Movements,
accomplished or merely nascent, prepare this choice, or at the very least mark out the field in which we
shall seek the image we need. By the very constitution of our nervous system, we are beings in whom
present impressions find their way to appropriate movements : if it so happens that former images can just
as well be prolonged in these movements, they take advantage of the opportunity to slip into the actual
perception and get themselves adopted by it. They then appear, in fact, to our consciousness, though it
seems as if they ought, by right, to remain concealed by the present state. So we may say that the
movements which bring about mechanical recognition hinder in one way, and encourage in another,
recognition by images. In principle, the present supplants the past. But, on the other hand, lust because the
disappearance of former images is due to their inhibition by our present attitude, those whose shape might
fit into this attitude encounter less resistance than the others ; and if, then, any one of them is indeed able to
overcome the obstacle, it is the image most similar to the present perception that will actually do so.
(115)
Therefore one kind of
If our analysis is correct, the diseases which affect recognition will be of two widely differing forms, and
psychic blindness may
facts will show us two kinds of psychic blindness. For we may presume that, in some cases, it is the
be due to a disturbance
memory-image which can no longer reappear, and that, in other cases, it is merely the bond between
of motor habits, not to
perception and the accompanying habitual movements which is broken,-perception provoking diffused
the loss of memory-
movements, as though it were wholly new. Do the facts confirm this hypothesis ?
images
There can be no dispute as to the first point. The apparent abolition of visual memory in psychic blindness
is so common a fact that it served, for a time, as a definition of that disorder. We shall have to consider how
far, and in what sense, memories can really disappear. What interests us for the moment is that cases occur
in which there is no recognition and yet visual memory is not altogether lost. Have we here then, as we
maintain, merely a disturbance of motor habits, or at most an interruption of the chain which unite them to
sense perceptions ? As no observer has considered a question of this nature, we should be hard put to it for
an answer if we had not noticed here and there in their descriptions certain facts which appear to us
significant.
The first of these facts is the loss of the sense of direction. All those who have treated the Subject of
psychic blindness have been struck by this pecu-
(116) -liarity. Lissauer's patient had completely lost the faculty of finding his way about his own house.[24]
Fr. Miller insists on the fact that, while blind men soon learn to find their way, the victim of psychic
blindness fails, even after months of practice, to find his way about his own room.[25] But is not this
faculty of orientation the same thing as the faculty of coordinating the movements of the body with the
visual impression, and of mechanically prolonging perceptions in useful reactions ?
There is a second, and even more characteristic fact, and that is the manner in which these patients draw.
We can conceive two fashions of drawing. In the first we manage, by tentative efforts, to set down here and
there on the paper a certain number of points, and we then connect them together, verifying continually the
resemblance between the drawing and the object. This is what is known as `point to point' drawing. But our
habitual method is quite different. We draw with a continuous line, after having looked at, or thought of,
our model. How shall we explain such a faculty, except by our habit of discovering at once the
organization of the outlines of common objects, that is to say, by a motor tendency to draft their diagram in
one continuous line? But if it is
(117) just such habits or correspondences which are lost in certain forms of psychic blindness, the patient
may still perhaps be able to draw bits of a line which he will connect together more or less well ; but he
will no longer be able to draw at a stroke, because the tendency to adopt and reproduce the general
movement of the outline is no longer present in his hand. Now this is just what experiment verifies.
Lissauer's observations are instructive on this head.[26] His patient had the greatest difficulty in drawing
simple objects; and if he tried to draw them from memory, he traced detached portions of them chosen at
random, and was unable to unite these into a whole. Cases of complete psychic blindness are, however,
rare. Those of word-blindness are much more numerous cases of a loss, that is, of visual recognition
limited to the characters of the alphabet. Now it is a fact of common observation that the patient, in such
cases, is unable to seize what may be called the movement of the letters when he tries to copy them. He
begins to draw them at any point, passing back and forth between the copy and the original to make sure
that they agree. And this is the more remarkable in that he often retains unimpaired the faculty of writing
from dictation or spontaneously. What is lost is clearly the habit of distinguishing the articulations of the
object perceived, that is to say, of completing the visual
(118) perception by a motor tendency to sketch its diagram. Whence we may conclude that such is indeed
the primordial condition of recognition.
But we must pass now from automatic recognition, which is mainly achieved through movements, to that
which requires the regular intervention of memory-images. The first is recognition by inattention ; the
second, as we shall see, is attentive recognition.
This form also begins by movements. But, whereas, in automatic recognition, our movements prolong our
perception in order to draw from it useful effects and thus take us away from the object perceived, here, on
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