WHEN IS THE BRAIN Y DEVELOPED FREE AS POSSIBLE

When Is The Brain Y Developed Free As Possible

For example, a teacher may tell a parent that her child has not turned in three assignments. Measure and map brain activity, researchers can more clearly see how the brain develops.If the lower centers of the brain are not fully developed, yes people hear words, but they don’t always process the actual message that was conveyed. Mother should avoid toxins, cigarettes, heavy metals, alcohol, drugs.Friday, July 30, 2004: VOL 305 30 JULY 2004 599 CREDIT: CORBISYour childs brain is not fully mature until their mid-20s. Pregnant woman should stay as stress-free as possible, take folic acid, B6 & B12, stimulate this young developing brain with sounds and sensations. Let’s review each of the five stages of human brain growth: Stage 1: 0 to 10 months Neurons and connections growing.

The rational part of a teen’s brain isn’t fully developed and won’t be until age 25 or so. Good judgment isn’t something they can excel in, at least not yet. An immature frontal cortex explains the spectrum of teenage behaviors: it’s what makes adolescents adolescent, says Sapolsky.It doesn’t matter how smart teens are or how well they scored on the SAT or ACT. Everything is there except for the frontal cortex, which is the last thing to mature.

Adds physician David Fassler, spokesperson for the American Psychiatric Association (APA) and the American Academy of Child and Adolescent Psychiatry, the argument “does not excuse violent criminal behavior, but it’s an important factor for courts to consider” when wielding a punishment “as extreme and irreversible as death.”The Supreme Court has addressed some of these issues before. “Capacities relevant to criminal responsibility are still developing when you’re 16 or 17 years old,” says psychologist Laurence Steinberg of the American Psychological Association, which joined the brief supporting Simmons. In a joint brief filed on 19 July, eight medical and mental health organizations including the American Medical Association cite a sheaf of developmental biology and behavioral literature to support their argument that adolescent brains have not reached their full adult potential. Supreme Court will hear the case in October, and its decision could well rest on neurobiology.At issue is whether 16- and 17-year-olds who commit capital offenses can be executed or whether this would be cruel and unusual punishment, banned by the Constitution’s eighth amendment. Now 27, Simmons could again face execution: The state of Missouri has appealed to have the death penalty reinstated. In a whipsaw of legal proceedings, the Missouri Supreme Court set the sentence aside last year.

Today, 31 states and the federal government have banned the juvenile death penalty. They claim that this view reflects worldwide “changing standards of decency,” a trend that has been recognized in many U.S. Cruel and unusual?Simmons’s lawyers argue that adolescents are not as morally culpable as adults and therefore should not be subject to the death penalty. That is the standard Simmons’s lawyers now want the court to extend to everyone under 18. Thirteen years later, it decided that mentally retarded people shouldn’t be executed because they have a reduced capacity for “reasoning, judgment, and control of their impulses,” even though they generally know right from wrong (see sidebar on p.

Shades of grayStructurally, the brain is still growing and maturing during adolescence, beginning its final push around 16 or 17, many brain-imaging researchers agree. Although brain research should probably take a part in policy debate, it’s damaging to use science to support essentially moral stances, says neuroscientist Paul Thompson of the University of California, Los Angeles (UCLA). “The very part of the brain that is judged by the legal system process comes on board late.”But other researchers hesitate to apply scientists’ opinions to settle moral and legal questions.

This process is thought to shape the brain’s neural connections for adulthood, based on experience.In arguing for leniency, Simmons’s supporters cite some of the latest research that points to the immaturity of youthful brains, such as a May study of children and teens, led by NIMH’s Nitin Gogtay. This is followed by massive “pruning” in which about 1% of gray matter is pared down each year during the teen years, while the total volume of white matter ramps up. In 1999, Giedd and colleagues showed that just before puberty, children have a growth spurt of gray matter. Various types of brain scans and anatomic dissections show that as teens age, disordered-looking neuron cell bodies known as gray matter recede, and neuron projections covered in a protective fatty sheath, called white matter, take over. Others, such as Jay Giedd of the National Institute of Mental Health (NIMH) in Bethesda, Maryland, consider 25 the age at which brain maturation peaks.

“It’s quite possible that the brain maturation peaks after age 21,” he adds.The images showed a rapid conversion from gray to white matter. The brain changes continued up to age 21, the oldest person they examined. Starting from the back of the head, “we see a wave of brain change moving forward into the front of the brain like a forest fire,” says UCLA’s Thompson, a co-author. As previous research had suggested, the frontal lobes matured last.

The joint brief cites a 1999 study by Tomás Paus of McGill University in Montreal and colleagues that used structural MRI to show that neuronal tracts connecting different regions of the brain thickened as they were coated with a protective sheath of myelin during adolescence (Science, 19 March 1999, p. In addition to growing volume, brain studies document an increase in the organization of white matter during adolescence. Imaging doesn’t provide high enough resolution to distinguish among the possibilities, he notes: “Right now we can image chunks of millions of neurons, but we can’t look at individual cells.” A type of spectroscopy that picks out N-acetylaspartate, a chemical found only in neurons, shows promise in helping to settle the issue.

In 2001, Luna and colleagues showed that adolescents’ prefrontal cortices were considerably more active than adults’ in this test. They are told not to look at the light, which is difficult because “the whole brainstem is wired to look at lights,” says Luna.Adolescents can prevent themselves from peeking at the light, but in doing so they rely on brain regions different from those adults use. Subjects focus on a cross on a screen and are told that the cross will disappear and a light will show up. Using functional MRI-which lights up sites in the brain that are active-combined with simple tests, neuroscientist Beatriz Luna of the University of Pittsburgh has found that the brain switches from relying heavily on local regions in childhood to more distributive and collaborative interactions among distant regions in adulthood.One of the methods Luna uses to probe brain activity is the “antisaccade” test: a simplified model of real-life responses designed to determine how well the prefrontal cortex governs the more primitive parts of the brain. A fully developed frontal lobe curbs impulses coming from other parts of the brain, Gur explains: “If you’ve been insulted, your emotional brain says, ‘Kill,’ but your frontal lobe says you’re in the middle of a cocktail party, ‘so let’s respond with a cutting remark.’ “As it matures, the adolescent brain slowly reorganizes how it integrates information coming from the nether regions. Don’t look at the lightAdults behave differently not just because they have different brain structures, according to Gur and others, but because they use the structures in a different way.

“The adolescent is using slightly different brain mechanisms to achieve the goal,” says Luna. In work in press in Child Development, Luna found that volunteers aged 14 years and older perform just as well on the task as adults, but they rely mainly on the frontal lobe’s prefrontal cortex, whereas adults exhibit a more complex response.

When Is The Brain Fully Developed