Transcript Brain Compatible Learning

Brain Factoids
Dr. Diane Cepela
[email protected]
815.258.5251
Abused Children Have Smaller
Brains
Parts of the brain of a severely
abused and neglected child can be
substantially smaller than that of a
healthy child.
Babies Lose Half their Neurons at
Birth
It is estimated that a baby loses
about half their neurons before
they are born. This process is
sometimes referred to as pruning
and may eliminate neurons that
do not receive sufficient input
from other neurons.
Baby Talk Increases Vocabulary
A study showed that when mothers
frequently spoke to their infants,
their children learned about 300
more words by age two than did
children whose mothers rarely
spoke to them.
Birdsong and human speech have
similar characteristics. Birds, like
humans, learn their complex
vocalizations early in life and imitate
their adult counterparts to acquire
these skills. These two species have
evolved a complex hierarchy of
specialized forebrain areas where
motor and auditory areas interact
continuously in order to produce
detailed vocalizations.
The optic nerve exits the retina as a
single bundle. The exit point within the
retina has no receptor cells. This location
forms a blind spot in each eye. We rarely
notice these spots because they do not
overlap within the image formed by the
two eyes. Your ophthalmologist can only
detect your blind spots by having you
close the eye not being tested.
The effects of a stroke depend on the
affected blood vessel and the area of brain
that it supplies with nutrients. For instance,
if the middle cerebral artery is occluded,
motor areas in the frontal cortex can be
damaged resulting in the loss of voluntary
muscle movements on the contralateral, or
opposite, side of the body from the
damaged side of the brain. This condition is
known as hemiplegia.
Strokes or "brain attacks" are the 3rd
leading cause of death in the United
States. A stroke occurs when the blood
flow to the brain is disrupted.
Disruption takes place either when a
brain artery is blocked or when an
artery explodes. Recently, exciting
medical breakthroughs have been
announced with respect to treating
stroke.
Electroencephalogram, or EEG, is a noninvasive technique used to record small
changes of electrical activity in the brain with
surface electrodes on the scalp. Scientists
who study sleep find EEG especially useful.
The tiny fluctuations detected with EEG are
clear indicators of whether a person is
asleep, aroused, or somewhere in between.
Approximately 20% of the blood flowing
from the heart is pumped to the brain.
The brain needs constant blood flow in
order to keep up with the heavy
metabolic demands of the neurons. Brain
imaging techniques such as functional
magnetic resonance imaging (fMRI) rely
on this relationship between neural
activity and blood flow to produce
images of deduced brain activity.
Although the brain
accounts for only 2% of
the whole body's mass, it
uses 20% of all the oxygen
we breathe. A continuous
supply of oxygen is
necessary for survival. A
loss of oxygen for 10
minutes can result in
significant neural damage.
Measures of brain activity show that
during the second half of a child's first
year, the prefrontal cortex, the seat of
forethought and logic, forms synapses
at such a rate that it consumes twice
as much energy as an adult brain. That
furious pace continues for the child's
first decade of life.
Commisurotomy, the transection of the
corpus callosum, is one possible
treatment for patients with severe
epilepsy. This procedure causes a
complete split between the two
hemispheres of the brain. As a result of
this split, words presented to the patient's
far left visual field cannot be read (alexia),
and hidden objects placed into the left
hand cannot be named (anomia). This is
significant evidence for hemispheric
specialization.
During the first month of life, the
number of connections or synapses,
dramatically increases from 50 trillion to
1 quadrillion. If an infant's body grew at
a comparable rate, his weight would
increase from 8.5 pounds at birth to 170
pounds at one month old.
Did you know that healthy ears actually
emit sounds? These sounds are usually
very soft, but can occasionally be heard
by others. Surprisingly, the sounds are
rarely heard by the person whose ear is
emitting the sounds! The cause of these
sounds is still under debate, but is
thought by some to be due to input from
the central nervous system.
Nearsightedness (myopia)
is the most common
visual problem we
experience. It is the result
of an overly elongated
eye, which has become
specialized for seeing near
objects extremely well.
Yawning is an age-old activity
that occurs in reptiles, birds
and, of course, mammals. This
behavior is controlled by
chemicals in the brain called
neurotransmitters.
Neurotransmitters, such as
nitric oxide and dopamine, act
in the hypothalamus to induce
and control yawning.
The light-detecting receptor cells within
the retina, called rods and cones, are
actually at the back of the retina under
several layers of cells. The neurons and
support cells within the retina are fairly
translucent, so light is able to pass
through them and reach the receptors.
Because receptors (rods and cones) are
at the back of the retina, an image
actually passes through the retina three
times: as light to the receptor cells
(back); as neural signals through the
initial visual processing of the retina
(forward); as neural signals via the optic
nerve to the brain (back again).
The human cerebellum, or "little
brain", weighs about 150 grams.
Located at the lower back of the
brain, the cerebellum is key to
maintaining posture, walking, and
performing coordinated
movements. It is also thought to
play a role in olfaction or smell.
Nearsighted people can
often read the lettering on
distant signs by looking
through a small hole with
one eye. The hole focuses
the light entering the eye
and replaces the function
of the eye's own lens
There are one hundred
billion neurons in the
brain. A stack of one
hundred billion pieces of
paper would be about
5000 miles high, the
distance from San
Francisco to London.
Olfactory receptor cells, the neurons in
our nose that allow us to smell, are
neurons that can regenerate throughout
life. Although these cells are continually
being born and dying, they maintain the
same connections as their ancestors. The
result is that once we learn a smell, it
always smells the same to us -- despite
the fact that there are always new
neurons smelling it!
Children as young as four
days old can distinguish
the vowel sounds of the
language in their natural
environment from those
of a foreign language.
The octopus has a single layer of cells in
the back of its eye. These receptor cells
project directly back to the brain via the
optic nerve. Because the optic nerve
forms behind the receptors rather than
passing through them, the octopus has
no blind spot.
There is no sense of pain within the
brain itself. This fact allows
neurosurgeons to probe areas of the
brain while the patient is awake.
Feedback from the patient during
these probes is useful for identifying
important regions, such as those for
speech, that are spared if possible.
At night, our peripheral vision is
better than our foveal (straight on)
vision. Hikers at night do better when
they look slightly above the trail, and
airplane pilots are taught to look for
traffic out of the sides of their eyes.
This is because our rod cells,
photoreceptors that respond best to
dim light, are located mostly in the
periphery of the retina.
The pupillary light reflex results when
light is shined into either eye causing
both pupils to constrict. Doctors use this
reflex to determine if the reflex pathway
through the midbrain has in any way
been disrupted. If the reflex fails to
produce a response in one or both eyes,
the doctor can deduce the location of
the malfunction based on which of the
eyes failed to respond and which eye
was stimulated.
Reading aloud to children
helps stimulate brain
development, yet only
50% of infants and
toddlers are routinely
read to by their parents.
Research shows brain
growth contains its own
rhythm. Certain skills
come into preeminence
for a period of intensive
networking. At three
months, the visual cortex
dominates synapse
formation.
A child's ability to learn
can increase or decrease
by 25 percent or more,
depending on whether he
or she grows up in a
stimulating environment.
The expression "crying crocodile
tears" means expressing insincere
grief and it arose because crocodiles
appear to weep while they are
happily munching on prey. A
neurological disorder called crocodile
tears results from damage to the fifth
cranial nerve, which controls the
mucous membranes of the face.
When the patient is eating, signals
that should stimulate salivation
instead stimulate lacrimation -- crying
crocodile tears.
Receptor cells in the eye are thought to
be capable of detecting single photons,
the smallest units of light. Nocturnal
animals take advantage of this sensitivity
by having large eyes with large apertures
to let in as many photons as possible
allowing them to see remarkably well at
night.
Scratching an itch is a puzzling biological
response, because it seems to hinder rather
than help a wound's healing. One theory of
why we itch suggests that scratching
stimulates the release of endorphins,
naturally occurring opiates which block pain
sensation. Because scratching injures our
skin a little more, we release a flood of
endorphins to block the pain of the initial
injury more effectively.
It's no accident that telephone numbers in
the United States are seven digits long.
Our working memory, a very short-term
form of memory which stores ideas just
long enough for us to understand them,
can hold on average a maximum of seven
digits. This allows you to look up a phone
number and remember it just long enough
to dial.