biological mechanism Case Study
Contributions of Neuroscience to Our Understanding of Cognitive Development Adele Diamond1 and Dima Amso2
1 Department of Psychiatry, University of British Columbia, and Department of Child and Adolescent Psychiatry,
BC Children’s Hospital, Vancouver, Canada; and 2 Sackler Institute for Developmental Psychobiology,
Weill Medical College of Cornell University
ABSTRACT—One major contribution of neuroscience to
understanding cognitive development has been in demon-
starting that biology is not destiny—that is, demonstrating
the remarkable role of experience in shaping the mind,
brain, and body. Only rarely has neuroscience provided
wholly new insights into cognitive development, but often
it has provided evidence of mechanisms by which obser-
vations of developmental psychologists could be explained.
Behavioral findings have often remained controversial
until an underlying biological mechanism for them was
offered. Neuroscience has demonstrated promise for de-
tecting cognitive problems before they are behaviorally
observable—and, hence, promise for early intervention. In
this article, we discuss examples drawn from imitation and
mirror neurons, phenylketonuria (PKU) and prefrontal
dopamine, maternal touch and stress reactivity, and non-
genetic (behavioral) intergenerational transmission of bi-
ological characteristics.
KEYWORDS—plasticity; epigenesis; mothering; executive
functions; animal models; molecular genetics; memory
Neuroscience research has made its greatest contributions to the
study of cognitive development by illuminating mechanisms
(providing a ‘‘how’’) that underlie behavioral observations made
earlier by psychologists. It has also made important contribu-
tions to our understanding of cognitive development by dem-
onstrating that the brain is far more plastic at all ages than
previously thought—and thus that the speed and extent by which
experience and behavior can shape the brain is greater than al-
most anyone imagined. In other words, rather than showing that
biology is destiny, neuroscience research has been at the fore-
front of demonstrating the powerful role of experience throughout
life. Besides the surprising evidence of the remarkable extent
of experience-induced plasticity, rarely has neuroscience given
us previously unknown insights into cognitive development, but
neuroscience does offer promise of being able to detect some
problems before they are behaviorally observable.
PROVIDING MECHANISMS THAT CAN ACCOUNT FOR
BEHAVIORAL RESULTS REPORTED BY
PSYCHOLOGISTS
Here we describe two examples of behavioral findings by psy-
chologists that were largely ignored or extremely controversial
until underlying biological mechanisms capable of accounting
for them were provided by neuroscience research. One such
example concerns cognitive deficits documented in children
treated early and continuously for phenylketonuria (PKU). The
second example involves neonatal imitation observed by psy-
chologists and mirror neurons discovered by neuroscientists.
Prefrontal Dopamine System and PKU Cognitive Deficits
Since at least the mid-1980s, psychologists were reporting
cognitive deficits in children with PKU that resembled those
associated with frontal cortex dysfunction (e.g., Pennington,
VanDoornick, McCabe, & McCabe, 1985). Those reports did not
impact medical care, however. Doctors were skeptical. No one
could imagine a mechanism capable of producing what psy-
chologists claimed to be observing.