Chapter 6

infantile reflexes

An involuntary, stereotypical movement response to a specific stimulus; the term refers to such responses seen only during infancy. There are there types of : the primitive and locomotor reflexes and the postural reactions.

supine kicking

If a child is on his back (the supine position), he will likely spontaneously thrust his legs.

Spontaneous Arm Movements

Infants also move their arms, and newborns spontaneous arm movements show well-coordinated extension of the elbow, wrist, and finger joints.Different environmental constraints influenced the spontaneous arm movements.

cocontraction

Infants tend to activate both the muscles for flexing the limb (flexors) and for extending the limb (extensors).

Primitive Reflexes

When a newborn infant grasps an object placed in her hand, she does so automatically and without conscious thought. This is an example of a primitive reflex, an involuntary response to specific stimulation which is often mediated by lower brain centers

Motor Milestones

a fundamental motor skill whose attainment is associated with the acquisition of later voluntary movements. The order in which an infant attains these milestones is relatively consistent, although the timing differs among individuals.

Individual constraints

act as rate limiters, or controllers. That is, for an infant to exhibit a certain skill, she needs to develop a certain system to a particular level.

Locomotor Reflexes

appear much earlier than the corresponding voluntary behaviors and typically disappear months before the infant attempts the voluntary locomotor skill. There are three locomotor reflexes: stepping, swimming, and crawling.

Norm-referenced Scales

compare an individual or group with previously established norms. Such a comparison indicates where a person falls within a group of like individuals matched on relevant factors, such as age, gender, and race.

Criterion-referenced Scales

designed to indicate where a child falls on a continuum of skills that we know are acquired in sequence. The developmentalist administers the criterion-referenced scale periodically, comparing individuals with their own previous performances rather than with a population norm.

Spontaneous movements

infants movements that occur without any apparent stimulation.

Postural Reactions

reflexes, help the infant automatically maintain posture in a changing environment. Some of these responses keep the head upright, thereby keeping the breathing passage open. Others help the infant roll over and eventually attain a vertical position.

Functional

suggests that reflexes exist to help the infant survive- to eat, breath, and grasp.

Structural

views reflexes as a byproduct of the human neurological system. That is, some theorists believe that reflexes merely reflect the structure of the nervous system-in other words, the human is "wired."