to monitor and control one’s emotional state—is also
associated with frontal lobe functioning. Substantial
frontal lobe development occurs in adolescence.
Thetemporal lobesmediate linguistic expression,
reception, and analysis. They are also involved in
auditory processing of tones, sounds, rhythms, and
meanings that are nonlanguage in nature. The
parietal lobesare related to tactile and kinesthetic per-
ception, understanding, spatial perception, and some
language understanding and processing. They are
also involved in body awareness. Theoccipital lobes
are mainly oriented toward visual processing and
some aspects of visually mediated memory. Motor
coordination, as well as the control of equilibrium
and muscle tone, is associated with thecerebellum.
Antecedents or Causes
of Brain DamageWhat causes brain damage? There are a number of
possibilities.
Trauma. It is estimated that brain injury occurs in
more than 500,000 Americans every year (Zillmer
et al., 2008). Incidents producing these injuries
range from automobile accidents, to sports injuries,
to falls off a stepladder. The outcomes are wide-
ranging, and the nature of the head injury (e.g.,
closed vs. open/penetrating) may have implications
as well. Although most head injuries are considered
mild, a substantial percentage of cases require hospi-
talization. Head trauma is a leading cause of death and
disability in young Americans (Zillmer et al., 2008).
The major effects of head trauma can be cate-
gorized as concussions, contusions, and lacerations.
Concussions(jarring of the brain) usually result in
momentary disruptions of brain function, although
permanent damage is uncommon (unless there are
repeated concussions, as might be the case in foot-
ball, soccer, or boxing, for example).Contusionsrefer
to cases in which the brain has been shifted from its
normal position and pressed against the skull. As a
result, brain tissue is bruised. Outcomes can often be
severe and may be followed by comas and deliriums.
Lacerationsinvolve actual ruptures and destruction of
brain tissue. They can be caused by bullets or flying
objects, for example. These lacerations are, of course,
exceedingly serious forms of damage.Cerebrovascular Accidents. The blockage or
rupture of cerebral blood vessels is often termed a
“stroke.”This is a very common cause of brain dam-
age in adults, and stroke is one of the leading causes
of death in the United States (and other countries).
Although primarily occurring in the elderly, stroke is
also one of the most common causes of death in
middle-aged adults. Inocclusions,abloodclotblocks
the vessel that feeds a particular area of the brain.
This can result in aphasia(language impairment),
apraxia(inability to perform certain voluntary move-
ments), oragnosia(disturbed sensory perception). In
the case of acerebral hemorrhage, the blood vessel rup-
tures and the blood escapes onto brain tissue and
either damages or destroys it. The exact symptoms
that ensue depend on the site of the accident and its
severity. In very severe cases, death is the outcome.
Those who survive often show paralysis, speech prob-
lems, memory and judgment difficulties, and so on.
It is very important to get stroke patients to the
hospital immediately. Medications that essentially dis-
solve occlusions (“clot-busting” medications) can
limit the permanent damage from occlusive strokes.
In addition, new medications are being developed
that prevent the cascade of chemical reactions respon-
sible for neuronal damage or even death (e.g., tissue
plasminogen activator, tPA). Therefore, in many
cases, prompt action can be of major benefit.Tumors. Brain tumors may grow outside the
brain, within the brain, or result from metastatic
cells spread by body fluids from some other organ
of the body, such as the lung or the breast. Initial
signs of brain tumors are often quite subtle and can
include headaches, vision problems, gradually
developing problems in judgment, and so on. As
the tumor grows, so does the variety of other symp-
toms (e.g., poor memory, affect problems, or motor
coordination). Tumors can be removed surgically,
but the surgery itself can result in more brain dam-
age. Some tumors are inoperable or located in areas
too dangerous to operate on. In such cases, radia-
tion treatments are often used.NEUROPSYCHOLOGY 519