This is a research report on concepts which underlie a clinical science of child development
even while a child sleeps, he grows
he develops as an individual
but he obeys laws of growth which are universal
he comes by his behavior as he comes to wake up: spontaneously
he stirs
his eyes open to receive light
his hands are mostly closed
but brain, hands, and eyes are coming into increasing coordination
behavior patterns are formed
and in the newborn infant, the eyes begin to move as though seeking experience
they rove, but they tend to look in the sidewise direction of the averted head
the month-old infant assumes a well-defined asymmetric posture:
the tonic neck reflex posture, a kind of fencing attitude
head to one side, one arm extended, the other flexed toward the shoulder
this behavior pattern, here shown in stop motion, channelizes vision toward the outstretched hand
a reflex attitude so basic, that it is already present in the fetal infant born two months prematurely
the asymmetric tonic neck posture dominates the action system, either in right or left hand versions
for handedness is in the making
at the age of two months, the infant's eyes are more mobile
they seek distant light areas and they may ignore the ring dangled in the near field of vision
the ring moves across the field, but he does not at present pursue it either with eyes or with hands
by the age of three months, he shows more visual interest in nearby objects
spontaneously, he looks at his own hands
an important forward step in the embryology of eye-hand behavior
his eyes now fix upon the dangling ring
they pursue it in the rightward quadrant to the midline
but the right tonic orientation prevents them from following through
at about four months, however, both head and hands begin to prefer the mid plane
asymmetric postures give way to symmetric postures
the eyes now converge and fasten upon the dangling ring at midpoint
at about five months, the eyes pursue the dangling ring with greater competence both rightward and leftward
the hands now close in upon the ring
primitive prehension has been achieved
the eyes are pathfinders
the infant takes hold of the world with his eyes long before he takes hold with his hands
a one-inch cube reveals his eye-hand coordination at the age of four months
he moves his eyes selectively
he looks from cube to hand
and then back again, from hand to cube
his eyes fasten upon the test object, and they maintain a firm grasp
the hands are activated even though they cannot as yet obey precisely
it is again evident that the eyes have a top priority in the scheme of development
he can reach with his eyes
but not with his hands
two months later, at 24 weeks of age he can reach with his hands
he contacts the cube with the precarious palmar grasp
he fumbles
but vision and touch are coming into correlation
at seven months of age, prehension is much less crude
the fingers close upon the cube with decision
a new and most significant pattern of behavior emerge spontaneously:
transfer from hand to hand
the infant transfers the cube from one hand to the other, and re-transfers
the nine-month old infant reaches on sight, with dispatch
his grasp is more delicate, more digital
vertical banging is replaced by horizontal rubbing
exploitably, it brings two cubes into productive combination
visual grasp, manual grasp and manipulation mature in close interaction
there is increasing refinement of eye-hand coordination
the hand of the young infant remains fisted for weeks, lacking cortical control
the eyes, however, are alert and take hold early
while manual grasp is still primitive and paw-like
here in stop motion, the middle fingers crudely grip the cube
at a later stage, the forefinger and thumb come into play with ever increasing dexterity
by the end of the first year the infant grasps with fingertips: opposing thumb to forefinger and forefinger to thumb
by 18 months he exhibits almost adult skill
he can release a cube at will with purpose and intent
maturing cortical control
he places one block upon another, evidence of his growing mastery of spatial relationships at
18 months he commands the vertical dimension - he builds a tower
by two years of age, he favors the horizontal dimension - he builds a wall
by three years - a bridge, combining the vertical and horizontal
command of the oblique must wait
there is a geometry of growth in the conquest of space
compared with the cube, the tiny pellet requires refinement of eye and hand coordination
it's a small pellet, but it stirs the whole being of this four months old infant
he picks up the pellet with his eyes and does not relax his attention
he glances at his hands but he cannot bring them under control
it will take a half year of growth before he can pick up the test pellet with fingers as neatly, as he now does with his eyes
at about seven months, he makes a direct approach, all fingers out-spread
he rakes
and he contacts, but he cannot grasp the pellet
at about 10 months, the maturing nervous system prompts him to probe with index finger
a refinement which leads towards precise prehension
thumb and index come into increasing opposition
in due course, he plucks the pellet with pincer grasp
and completes the pattern hand to mouth
These complex eye-hand behavior patterns develop in the central nervous system and are organized by a process called "reciprocal interweaving"
reciprocal interweaving, symbolized by this moving light,
is the growth process which brings into working balance, the vast and dual networks of the central and autonomic nervous systems
the human organism is built on a bilateral basis
two hemispheres of the brain
two eyes
two arms
two legs
this duality demands that each side be structurally and functionally interwoven with its paired opposite
growth therefore, does not advance in a straight line - it shuttles back and forth
now accenting the right hemisphere,
now the left
the tonic neck reflex at one age
the symmetrotonic reflex later
extension dominant at one age,
flexion dominant at another
grasp,
and then release
monocular fixation at one age,
binocular fixation at another
the central nervous system, interweaves its dualities progressively
the organizing process follows an ascending path of maturation to create an integrated organism
a total action system symbolized by this spiral
the principle of reciprocal interweaving, pervades the entire embryology of behavior
the newborn infant grown and helpless can be visualized against the background of many interwoven growth spirals
stage by stage, he brings flexors and extensors into reciprocal relationship
he crawls.
he creeps,
and in his own time he rises to the upright
he toddles,
walks,
steps forth: a biped
the newborn infant wages a contest - with gravity
in a short year he retraces in telescope time the evolutionary ascent of man
this upwards driving has one developmental goal:
the release of eyes and hands for higher uses
in about 10 months of age, the creeping infant is under an irresistible urge to pull himself to his feet
in due course he casts off his mooring and strides the earth
a potential maker and user of tools
his eyes and hands emancipated
his hands are now free to wield: a crayon
at 18 months, he scribbles
at about two years, he executes a vertical stroke
at two and a half years, a horizontal stroke
at three and four years, a cross, combining vertical and horizontal, and a circle
at five, a square
and the triangle
which leads to advanced skills of eye, hand, and brain