Maturation theory

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Brain development is the result of genetic mechanisms. Babies are born with "innate modules" and "core knowledge" relevant to the physical and social world. In a sense, the newborn is "preprogrammed" for brain development and maturation occurs over time.  Interaction with the environment may promote or hinder this maturation process.

Maturation theory was already rather dominant in the 1930s. Arnold Gesell argued that babies are born with a “developmental clock” that will determine when developmental milestones will occur – for example, when they will sit, walk, talk, and engage in abstract thinking. He argued that these milestones occur in a fixed sequence and at a specific time.  This theory would have a major effect on other theorists' "stage theories" - for example, Piaget's theory of cognitive development.

Based on the comprehensive overview of brain development psychology, here are the keynotes:

Maturation Theory in Brain Development

Overview

• Maturation Theory: Suggests that brain development is primarily driven by genetic mechanisms. Babies are born with innate modules and core knowledge, and development unfolds according to a "developmental clock."

Influential Theorists

• Arnold Gesell: Proposed that developmental milestones occur in a fixed sequence and at specific times.
• Konrad Lorenz: Introduced the concept of critical periods in development, influencing theories like Bowlby's attachment theory.

Classic Studies

• Lorenz's Imprinting: Demonstrated that birds form attachments to the first moving object they see, suggesting innate behaviors in development.

Modern Research Support

• Visual Development: Studies indicate that vision development is linked to brain maturation, with specific phases corresponding to the maturation of different brain regions.

Critical Periods

• Le Grand et al. (2001): Found that children with bilateral cataracts did not develop full visual skills, indicating critical periods for visual processing development.

Hubel and Wiesel (1964)

• Study on Vision: Investigated the development of the visual cortex in children with congenital cataracts.
• Methodology: Used kittens with one eye sewn shut to study the impact on visual cortex development.
• Ethical Considerations: Raises questions about the use of animals in research for human benefit.

Chugani (1999)

• PET Scan Research: Showed that newborns have high activity in the brain stem and limbic system, indicating innate capacities for basic reflexes and emotional processing.
• Limbic System Lesions in Monkeys: Bachevalier et al. (1999) found that lesioning areas of the limbic system in newborn monkeys impaired social behavior.

Neuroplasticity and Learning

• Interaction with Environment: While infants may be pre-wired for certain learning, experiences play a crucial role in development.
• Combination of Maturation and Neuroplasticity: Development involves both genetic maturation and learning from the environment.

Adolescent Brain Development

• Giedd (2004): Found that the prefrontal cortex undergoes a growth spurt just before puberty, continuing to mature until around age 20.
• Implications: Highlights the ongoing development of brain regions responsible for higher cognitive functions and impulse control in adolescents.

These notes encapsulate the key aspects of maturation theory in brain development, emphasizing the interplay between genetic factors and environmental influences in shaping the developing brain.