can happen in at least two ways. First, new brain cell connections are made when a child learns,
which requires exposure to the appropriate stimuli during certain critical periods of
development. 85 For example, young healthy children quickly learn the language they are exposed
to and become emotionally attached to their familiar caregiver. 86 If a child is not exposed to the
appropriate stimuli during these critical periods, that child may not acquire age-appropriate
Dr. Bruce Perry, a leading expert in the field of child trauma, offers a vivid comparison
of the brain development of two children—both of whom are three years old, but one child has
been extremely neglected while the other has had a healthy development. 88 The MRI scan shown
below demonstrates how the head of the neglected child is physically smaller and the brain is less
developed. That neglected youth is more likely to present problematic behavior at school. 89
These images illustrate the impact of neglect on the developing brain. 90
The second way in which trauma can disrupt normal brain development is through abuse.
A person’s brain possesses an alarm system that is triggered when the person senses danger. 91
The alarm system triggers certain response systems, including the release of adrenalin, which
helps people cope with the crisis. 92 This crisis alarm system is a very useful survival
mechanism. 93 If a crisis is too overwhelming, however, the brain’s crisis response systems can be
damaged. 94 Such damage can result in a youth remaining constantly in crisis mode, even when
generally available forty years ago. Id. In the past, brains were studied after head injuries and autopsies. Id. Now, changes in the brain
can be studied without opening the skull. Id.
85 See Joseph LeDoux, SYNAPTIC SELF: HOW OUR BRAINS BECOME WHO WE ARE 9-12, 86 (2002); Bruce D. Perry, Childhood
Experience and the Expression of Genetic Potential: What Childhood Neglect Tells Us About Nature and Nurture, 3 BRAIN & MIND
79, 87-88 (2002).
86 See Nelson et al., supra note 84, at 58-70 (regarding language); Putnam, supra note 72, at 5 (regarding attachment); CHILD
WELFARE INFO. GETAWAY, UNDERSTANDING THE EFFECTS OF MALTREATMENT ON BRAIN DEVELOPMENT 10 (2009),
87 Steinberg & Scott, supra note 20; see Putnam, supra note 72, at 7. “In Graham and Miller, which built on Roper, the Court similarly
looked to developmental science for guidance. This was partly because much more relevant science was available in 2010 than had
been available in 1989 (the last time the Court had considered the death penalty for a juvenile)….” Laurence Steinberg, The Influence
of Neuroscience on U.S. Supreme Court Decisions About Adolescents’ Criminal Culpability, 14 NATURE REVS. NEUROSCIENCE 513,
515 (2013); Perry, supra note 85, at 88.
88 Perry, supra note 85, at 93.
89 See HELPING TRAUMATIZED CHILDREN LEARN, supra note 60, at 4.
90 Perry, supra note 85, at 93.
91 LeDoux, supra note 85, at 86-87.
92 See id. at 120-24, 200-34.
93 Id. at 235-59.
94 See CHILD WELFARE INFO. GETAWAY, supra note 86, at 9.