Motor Development

Motor Development Study Notes

Chapter 6 - Part 1 Overview

This chapter covers key concepts related to motor development, focusing on reflexes, gross and fine motor skills, and Dynamic Systems Theory.

Reflexes

Reflexes are unlearned and automatic responses to stimuli. They can be temporary or permanent.

Types of Reflexes

  • Permanent Reflexes:

    • Breathing Reflex: Essential for survival, remains throughout life.

    • Blinking Reflex: Protects eyes, also remains permanent.

    • Pupillary Reflex: Adjusts pupil size in response to light, remains in effect.

Survival Reflexes

  • Rooting Reflex: Helping infants locate food; typically disappears around 3-4 months.

  • Sucking Reflex: Assists in feeding; also disappears around 3-4 months.

Primitive Reflexes

These are responses that develop in utero and typically fade as the child matures.

  1. Moro Reflex:

    • Description: A startle reflex; infants spread arms then pull them back in.

    • Disappears after 3-4 months.

  2. Grasping Reflex:

    • Description: Infants will grasp objects placed in their palms.

    • Disappears after 3-4 months.

  3. Babinski Reflex:

    • Description: Toes fan out when the sole is stroked.

    • Disappears after 9-12 months.

  4. Swimming Reflex:

    • Description: Infants will move their limbs and hold their breath when placed in water.

    • Disappears after 6-7 months.

  5. Stepping Reflex:

    • Description: Infant appears to take steps when held upright.

    • Disappears after 3-4 months.

  6. Spinal Galant Reflex:

    • Description: Infant will turn towards a side when the lower back is stroked.

    • Disappears after 3-6 months.

  7. Tonic Neck Reflex:

    • Description: When the head is turned to one side, the arm on that side extends while the opposite arm bends.

    • Disappears after 2 months.

Why Do Reflexes Disappear?
Traditional View

The traditional view indicates that reflexes disappear due to the switch from subcortical control to cortical, voluntary control, signifying a developmental progression.

Alternate View: Stepping Reflex Study

  • Study Groups:

    • Group 1: 2-6-week-old babies who lost the stepping reflex when immersed in water.

    • Group 2: 2-6-week-old babies who retained the stepping reflex with little weights tied to their legs.

  • Findings: The study indicates that reflexes might not solely vanish but can be influenced by situational factors, showcasing the dynamic interplay between biology and environment (Thelen, Fisher, & Ridley-Johnson, 1984).

Gross Motor Skills

Motor Milestones

  • 1 Month: Ability to hold head up.

  • 2-4 Months: Ability to roll over.

  • 5-7 Months: Ability to sit without support.

  • 8-12 Months: Ability to walk with support.

  • 11-14 Months: Ability to walk unassisted.

Note on Importance

Any development that is less than these milestones is considered subpar, emphasizing the importance of achieving motor milestones within these ages.

Fine Motor Skills

Examples of Fine Motor Skills

  1. Reaching:

    • Pre-Reaching: Occurs around 1 month.

    • Directed Reaching: Occurs around 3-4 months, guided by proprioception (body position feedback) and vision.

  2. Grasping:

    • Ulnar Grasp: Develops around 4-5 months where infants use their fingers without a thumb grip.

    • Pincer Grasp: Develops by about 9 months where infants use thumb and index finger to grasp objects.

U-Shaped Motor Development Pattern

  • The strength of motor behavior typically follows a U-shaped curve in development across age, indicating a progression, decline, then re-establishment of skills as a child matures.

Dynamic Systems Theory

Key Concepts

  • Both biological and experiential factors play crucial roles in motor development.

  • The infant acts as an active participant in its own development, striving to be efficient, effective, and have fun in its learning process.

Interaction of Factors in Motor Development

Motor development is characterized as an interaction between biology and learning, which involves:

  • Motivation of the infant

  • Attention, perception, and cognitive factors that contribute to the acquisition of motor skills.

Continuity in Motor Development through Childhood

  • Development of both gross and fine motor skills continues to improve.

  • Motor development can be categorized into initial and mature phases to observe growth over time.

  • Additionally, the study notes sex differences that can influence motor development through childhood, highlighting unique trajectories based on gender.