Transcript Biological Basis of Cognitive Development

Biological
Basis of
Cognitive
Development
LECTURE: UNIT 2
DR. NEIL SCHWARTZ
PSY 353
Introduction
Biological functions of the brain are important to touch
on, because talking about cognition and cognitive
functions is relatively unexciting without knowledge of
the way the brain works. So much more is known
about the brain today that validates theories of
cognition.
Developmental Systems and the
Concept of Epigenesis

Developmental Systems Approach
suggests that development occurs as a
function of the interaction of multiple layers of
an organism and its environment.
 Epigenesis suggests that a human, at any
given developmental level, will be
qualitatively different—both in terms of
structure (what they look like/what they know)
and function (what they can do). These
changes occur at all levels of an organism
because of bi-directional relationships with all
of these levels.
Epigenesis

The emergence of new structures and
functions during the course of development.
 Development is characterized by an increase
of complexity of organization.
 Reflects a biderectional relationship between
between all levels of biological and
experiential variables, such that genetic
activity both influences and is influenced
structural maturation, which is bidirectionally
related to function and activity.
Genetic activity (DNA
RNA
proteins)
structural maturation
function, activity
Consider the levels and
what they can do...
Environment
 Behavior
 Neural Activity
 Genetic Activity

All four levels influence each
other
bi-directionally...
So, what is the support for the bidirectional affects of biology and
experience?

Genes direct biochemical production
(proteins, for example).
 Bio-chemicals determine structural
development (like various tissues—
nerves, muscles, bones).
 Use or disuse of these structures
(nerve cells or muscle cells, for
example) can turn on or off genes—
which in turn can create or allow to
atrophy nerve or muscle cells.
Epigenesis is probabilistic, then...
WHAT DOES THIS MEAN?
WHAT ARE THE RAMIFICATIONS?
The Answer?

There are no simple genetic or experiential
causes of behavior. Instead, the two interact
to increase or decrease the probability of
behavior based on the interaction of genetic
predisposition and experience.

But, remember… experience is not just
experience generically defined. Rather it is
species-typical environmental experience—
both prenatally and postnatally.
Critical Periods

Critical periods are the time in development when
infants/children are “ripe” for the influence of
environmental experiences. (when a specific skill or ability
is most easily acquired)

Humans are prepared neurologically for certain
experiences and not others. When the time is right, the
experiences exert their most effective and efficient effect
on development.
What does it mean to be
neurologically-prepared?

Neurological preparedness suggests that there
are undifferentiated neurons that become
specialized for various functions as a result of their
location in the brain and experience. When these
neurons are made available for differentiation,
the nature of experience can and will have a
clear affect on them, and hence all of
development.
Behavior Genetics

Behavior Genetics — studies genetic effects on
behavior and complex psychological
characteristics, such as intelligence and
personality.

So, is biology truly destiny?

No… remember, all genetic effects are
moderated by environmental effects.
Genotype
Theory

Environment
A person’s genetic makeup influences which
environments one encounters
and the type of experiences one has.

Genes drive experience and determine how we
organize our world and how our experiences are
perceived.
Child’s
Genotype
Environment
sought out and
established by
the Child
Child’s
Phenotype
Genotype of
the Parents
Genotype of
the Child
Phenotype of
the Child
Rearing
Environment of the
Child
Therefore, characteristics of the child, as well as the
rearing environment and genetic contributions of
the parents, influence the course of development.
Genetic and Environmental
Influences on Human
Development

Passive Genotype — The environmental
influences parents provide for their kids exert a
gradually decreasing effect on the children as the
children get older.

Environmental effects decrease with age.
Genetic and Environmental
Influences on Human
Development

Evoactive Genotype — Temporamental
characteristics of children that elicit responses
from others.

Environmental effects remain constant with age.
Genetic and Environmental
Influences on Human
Development


Active Genotype — As children get older, they
have more and more ability to select
environments that suit their own particular needs.
Environmental effects increase with age.