module 6
our brain's -------- cortex registers and processes body touch and movement sensations. the ------- cortex controls our voluntary movements
somatosensory ; motor
The seizures all but disappeared patients with these split brains were surprisingly
surprisingly normal, their personality and intellect hardly affected By sharing their experiences, these patients have greatly expanded our understanding of interactions between the intact brain's two hemispheres.
people with damaged frontal lobes may have high intelligence
test scores and great cake-baking skills, yet they would not be able to plan ahead begin baking a cake for a birthday party, and if they did being to bake, they might forget the recipe
cerebrum
the 2 cerebral hemispheres contributing 85% of the brain's weight
which area of the human brain is the most similar to that of less complex animals ?
the brainstem
which part of the human brain distinguish us most from less complex animals?
the cerebral cortex
as we move up the ladder of animal life
the cerebral cortex expands, tight genetics rely and the organism's adaptability increase
the brain devotes more
tissue to sensitive areas and areas requiring precise control
Similar right hemisphere damage has less
visibly dramatic effects.
If we flash a red light to the right hemisphere of a person with split brain, and flash a great light to the left hemisphere, will each observe its own colour?
yes
the flexible brain's ability to respond to damage is especially evident in the brain of
young children
under the surface of our awareness
your brain is constantly changing, building new pathways as it adjust to new experience, and to mishaps, small and large
missing frontal lobe brakes
With part of his left frontal lobe (in this downward-facing brain scan) lost to injury, Cecil Clayton became more impulsive and killed a deputy sheriff. Nineteen years later, his state executed him for this crime
what these wrinkly things in our brain what would happen
a flattened cerebral cortex would require triple the area
MRI scans of people with schizophrenia have revealed
active auditory areas in the temporal lobes during the false sensory experience of auditory hallucinations
plasticity may also occur
after serious damage, especially in young children
motor cortex
an area at the Rear of the frontal lobes that controls voluntary movements output right hemisphere section controls the body's left side
the "uncommitted" area that make up about 3/4s of the cerebral cortex are called
association areas
stimulate a point on the top of this band of tissue and a person may report
being touched on shoulder ; stimulate some point on the side and the person may feel something on the face
how was scientist able to predict a monkey's arm motion a tenth of a seconds before it moved
by repeatedly measuring motor cortex activity preceding specific arm movements, such finding have opened the door to research on brain-controlled computer technology
one newborn who suffered damage to temporal lobe
facial recognition area was never able to recognize faces some neural tissues can reorganize in response to damage
are people are either right brained or left brained
false
what does the newer neural networks with the cerebrum enables us
form specialized work teas that enable our perceiving, thinking's , and speaking
judging and planning are enable by the ---- lobes
frontal
which of the following body regions has the greatest representation in the somatosensory cortex?
lips
most brain-damage effects can be treated to 2 hard facts
1) Severed brain and spinal cord neurons, unlike cut skin, usually do not regenerate. (If your spinal cord were severed, you would probably be permanently paralyzed.) And (2) some brain functions seem preassigned to specific areas.
what will the person verbally report seeing /
green
damage to the brain's right hemisphere is most likely to reduce a person's ability to
make inferences
if a neurosurgeon stimulated your right motor cortex, you would most likely
move your left leg
will the person be aware that the colors differ?
no
an experimenter flashes the word HERON across the visual field of a man whose corpus callous has been severed. HER is transmitted to his right hemisphere and ON to his left hemisphere, when asked to indicate what he saw the man says he was -------- but his left hands point to ---------
on ; her
studies of people with split brains and brain scans of those with undivided brain indicate that left hemisphere excels in
processing language
how do different neural networks communicate with one another to let you respond when a friend greets you at a party
the visual cortex is a neural network of sensory neurons connected via interneurons to other neural networks, including auditory networks, this allows you to integrate visual and auditory information to respond when a friend you recognize greets you at a party
the amount of cortex devoted to body part in the motor cortex or in the somatosensory cortex is not
proportional to that body part's size
small cortical area that either
receive sensory input to direct muscular output, and together these occupy about one-fourth of the humans brain's thin wrinkled cover
using more than 10 percent of our brain
1- electrically probing an association area leads to no observable response 2- this vast association area "silence" has led to the false claim that we really use only 10% of our brain - " one of the hardiest weeds in garden of psychology" 3-is there really a 90% chance that a bullet to your brain would land in an unused area? (no)4-brain-damaged animals and humans bear witness: association area interpret, integrate, and act on sensory information and link it with stored memories, more intelligent animals have larger association
try moving your right hand in a circular motion, as if cleaning a table, then start your right food doing the same motion, synchronized with your hand. now reverse the right foot motion/s, but not the hands's finally, try moving the left foot opposite to the right 1- why is reversing the right foot's motion so hard? 2- why is it easier to move the ;eft foot opposite to the right hand?
1- the right limbs' opposed activities interfere with each other because both are controlled by the same (left) side of your brain 2- opposite sides of your brain control your left and right limbs, so the reversed motion causes less interference
The brain's plasticity is good news for those blind or deaf
Blindness or deafness makes unused brain areas available for other uses (Amedi et al., 2005). If a blind person uses one finger to read Braille, the brain area dedicated to that finger expands as the sense of touch invades the visual cortex that normally helps people see (Barinaga, 1992; Sadato et al., 1996).
If this technique works, why not use it to capture the words a person can think but cannot say
Cal Tech neuroscientist Richard Andersen (2005) and colleagues (2004) have speculated that researchers could implant electrodes in speech areas, then "ask a patient to think of different words and observe how the cells fire in different ways. So you build up your database, and then when the patient thinks of the word, you compare the signals with your database, and you can predict the words they're thinking. Then you take this output and connect it to a speech synthesizer. This would be identical to what we're doing for motor control." With this goal in mind, the U.S. Army has invested millions of dollars in neuroscientists' efforts to build a helmet that might read and transmit soldiers' thoughts (Piore, 2011).
brain-computer interaction
Electrodes planted in a parietal lobe region involved with planning to reach out an arm could enable a person's thoughts to move a robotic limb, stimulate muscles that activate a paralyzed limb, navigate a wheelchair, control a TV, and use the Internet visual-motor part of the parietal lobe is attached to electrode implanted in parietal lobe which will decode cognitive neural signal that will control external assistive devices
what frontal damage can do?
Frontal lobe damage also can alter personality and remove a person's inhibitions.
motor area
control of voluntary muscles
Our mental experiences arise from
coordinated brain activity.
A few people who have had split-brain surgery have been for a time bothered by the unruly independence of their left hand
It seemed the left hand truly didn't know what the right hand was doing. The left hand might unbutton a shirt while the right hand buttoned it, or put grocery store items back on the shelf after the right hand put them in the cart. It was as if each hemisphere was thinking "I've half a mind to wear my green (blue) shirt today." Indeed, said Sperry (1964), split-brain surgery leaves people "with two separate minds." With a split brain, both hemispheres can comprehend and follow an instruction to copy—simultaneously—different figures with the left and right hands (Franz et al., 2000; see also FIGURE 6.12). (Reading these reports, can you imagine a patient enjoying a solitary game of "rock, paper, scissors"—left versus right hand?)
Do we really use only 10 percent of our brain?
The unresponsiveness of our association areas to electrical probing led to the false claim that we only use 10 percent of our brain, but these vast areas of the brain are responsible for interpreting, integrating, and acting on sensory information and linking it with stored memories. Evidence from brain damage shows that the neurons in association areas are busy with higher mental functions; a bullet would not land in an "unused" area.
would you advocate pushing one person in front of a runway trolley to save 5 other?
Most people would not, but those with damage to the prefrontal cortex are often untroubled by such ethical dilemmas The frontal lobes help steer us away from violent actions With their frontal lobes ruptured, people's moral compass seems to disconnect from their behavior.
Researchers have found baby neurons deep in the brains of adult mice, birds, monkeys, and humans
These neurons may then migrate elsewhere and form connections with neighboring neurons
If mass-produced in a lab and injected into a damaged brain, might neural stem cells turn themselves into replacements for lost brain cells?
Researchers at universities and biotech companies continue to break new ground on how to produce stem cells that resemble functioning human neurons. Such stem cell research not only helps treat the diseased or damaged brain, but also aids understanding of brain development, memory, and other basic psychological processes.
oes this mean that the right hemisphere is just along for the ride?
Researchers found that the "minor" right hemisphere was not so limited after all.
What do split brains reveal about the functions of our two brain hemispheres?
Split-brain research (experiments on people with a severed corpus callosum) has confirmed that in most people, the left hemisphere is the more verbal. The right hemisphere excels in visual perception, perceiving emotion, and making inferences, and helps us modulate our speech and orchestrate our self-awareness. Studies of healthy people with intact brains confirm that each hemisphere makes unique contributions to the integrated functioning of the brain
each hemisphere's cortex is
Subdivided into 4 lobes, separated by prominent issues or folds frontal lobes, parietal lobes. temporal lobes, occipital lobe
During a complex task
a brain scan shows many islands of brain activity working together—some running automatically in the background, and others under conscious control
What four lobes make up the cerebral cortex, and what are the functions of the motor cortex, somatosensory cortex, and association areas?
The cerebral cortex has two hemispheres, and each hemisphere has four lobes: the frontal, parietal, occipital, and temporal. Each lobe performs many functions and interacts with other areas of the cortex. The motor cortex, at the rear of the frontal lobes, controls voluntary movements. The somatosensory cortex, at the front of the parietal lobes, registers and processes body touch and movement sensations. Body parts requiring precise control (in the motor cortex) or those that are especially sensitive (in the somatosensory cortex) occupy the greatest amount of space. Most of the brain's cortex—the major portion of each of the four lobes—is devoted to uncommitted association areas, which integrate information involved in higher mental functions such as learning, remembering, thinking, and speaking. Our mental experiences arise from coordinated brain activity.
cerebral cortex
The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information-processing center. a thin surface layer of interconnected neural cells
split brains
a condition resulting from surgery that isolates the brain's two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them.
Association areas are found in all four lobes
The prefrontal cortex in the forward part of the frontal lobes enables judgment, planning, and processing of new memories
In an early experiment, Gazzaniga (1967) asked split-brain patients to stare at a dot as he flashed HE·ART on a screen
Thus, HE appeared in their left visual field (which transmits to the right hemisphere) and ART in the right field (which transmits to the left hemisphere). When he then asked them to say what they had seen, the patients reported that they had seen ART. But when asked to point to the word they had seen, they were startled when their left hand (controlled by the right hemisphere) pointed to HE. Given an opportunity to express itself, each hemisphere indicated what it had seen. The right hemisphere (controlling the left hand) intuitively knew what it could not verbally report. When an experimenter flashes the word HEART across the visual field, a woman with a split brain verbally reports seeing the portion of the word transmitted to her left hemisphere. However, if asked to indicate with her left hand what she saw, she points to the portion of the word transmitted to her right hemisphere.
to what extent can a damaged brain reorganize itself, and what is neurogenesis?
While brain and spinal cord neurons usually do not regenerate, some neural tissue can reorganize in response to damage. The damaged brain may demonstrate plasticity, especially in young children, as new pathways are built and functions migrate to other brain regions. Reassignment of functions to different areas of the brain may also occur in blindness and deafness, or as a result of damage and disease. The brain sometimes mends itself by forming new neurons, a process known as neurogenesis.
Constraint-induced therapy aims to
rewire brains and improve the dexterity of a brain-damaged child or even an adult stroke victim
the visual cortex and auditory cortex
the visual cortex in the occipital lobes at the rear of your brain receives input from your eyes. The auditory cortex in your temporal lobes—above your ears—receives information from your ears.
Somatosensory cortex
an area at the front of the parietal lobes that registers and processes body touch and movement sensation
Master stem cells that can develop into
any type of brain cell have also been discovered in the human embryo.
This lateralization is
apparent after brain damage. Research spanning more than a century has shown that left hemisphere accidents, strokes, and tumors can impair reading, writing, speaking, arithmetic reasoning, and understanding.
association areas
areas of the cerebral cortex that are not involved in primary motor or sensory functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking.
unlike the somatosensory and motor area,
association are functions cannot be neatly mapped
why are association area important?
association area are involved in higher mental functions- interpreting, ingraining, and action on information processed in other areas
these findings suggest that our perception of moving flows not from the movement itself
but rather from out intention and the results we expected
Stimulation of one parietal lobe area in brain-surgery
patients produced a feeling of wanting to move an upper limb, the lips, or the tongue without any actual movement. With increased stimulation, patients falsely believed they had moved. Curiously, when surgeons stimulated a different association area near the motor cortex in the frontal lobes, the patients did move but had no awareness of doing so
Plasticity also helps explain why some studies have found that
deaf people who learned sign language before another language have enhanced peripheral and motion-detection vision people whose native language is sign, the temporal lobe area normally dedicated to hearing waits in vain for stimulation. Finally, it looks for other signals to process, such as those from the visual system.
Similar reassignment may occur when
disease or damage frees up other brain areas normally dedicated to specific functions. If a slow-growing left hemisphere tumor disrupts language (which resides mostly in the left hemisphere), the right hemisphere may compensate
temporal lobes
he portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, each receiving information primarily from the opposite ear.
wilder penfiels
identified cortical area- at the front of the portal lobes , parallels to and just behind to the motor cortex that specializes in receiving information form the skin sense, such as touch and temperature, and from the movement of body parts , and the area is called somatosensory cortex
visual information travels form the occipital lobes to other areas that specialize in task such as
identifying words, detecting emotions and recognize faces
spanish neuroscientist Jose delgado
in one his many demonstrations of motor behavior mechanics, he stimulated a spot on a patient's left motor cortex, triggering the right hand and make a fist, he asked the patient to keep his fingers open but the patient was unable to keep them open
where is the sounds we hear register
in the auditory cortex in your temporal lobes most of this auditory information travels a circuitous route form one ear to the auditory receiving area above your opposite ear. If stimulated in your auditory cortex, you might hear a sound.
what , then, goes on in the remaining vast regions of the cortex?
in these association areas, neurons are busy with higher mental functions - many if the task that makes us human
the larger cortex of mammals offer
increased capacities for learning and thinking enabling them to adaptable
somatosensory cortex
input left hemisphere section receives input from the bod's right side
what does the cerebral cortex contain?
it contains 20-23 billion of brain's nerve cells and 3000 trillion synaptic connection
Although the brain often attempts self-repair by reorganizing existing tissue
it sometimes attempts to mend itself through neurogenesis—producing new neurons.
parietal lobes
located at the top and to the rear, the portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position.
this neural change is called
plasticity, and although this ability is strongest in childhood it continues throughout life
Philip Vogel and Joseph Bogen speculated that
major epileptic seizures were caused by an amplification of abnormal brain activity bouncing back and forth between the two cerebral hemispheres, which work together as a whole system. if so, they wondered, could they end this biological tennis match by severing the corpus callosum, the wide band of axon fibers connecting the two hemispheres and carrying messages between them
because the brain has no sensory receptors, Otfrid forester and wilder penfiels were Abel to
map the motor correct in 100s of wide-awake patients by stimulating different cortical areas and observing responses, which they discovered that body area requiring precise control, such as the finger and mouth , occupy the greatest amount of cortical space
if everything is psychological is also biological if for example every thought is also a neural event
micro electrodes is also biological detect complex thought well enough to enable people to control their enviroment with ever grater precision
what important discovery did Gustav Fritsch and Eduard Hitzig find
mild electrical stimulation to parts of animals cortex made parts of its body move the effect were selective: stimulation cause movement only when applied to an arch-shaped region at the back of the frontal lobe, tuning roughly ear-to-eat across the top of the brain, moreover, stimulating parts of this region in the left or right hemisphere caused movements of specific body parts on the opposite side of the body they have discovered what we now call motor cortex
from have the researchers recorded messages ?
not only from the arm-controlling motor neurons, but from a brain area involved in planning and intention example: in one study , a money seeking juice reward awaited a cue telling it to reach toward a spot flashed on a screen in one of up to eight locations. A computer program captured the monkey's thinking by recording the associated activity.
studies of other with damaged frontal lobes have revealed similar impairments
not only they may be become less inhibited (without the frontal lobe brakes on their impulse). bu their moral judgments may seem unrestrained example: With part of his left frontal lobe (in this downward-facing brain scan) lost to injury, Cecil Clayton became more impulsive and killed a deputy sheriff. Nineteen years later, his state executed him for this crime
On the underside of the right temporal lobe
nother association area enables us to recognize faces. If a stroke or head injury destroyed this area of your brain, you would still be able to describe facial features and to recognize someone's gender and approximate age, yet be strangely unable to identify the person as, say, Taylor Swift, or even your grandmother.
association areas also prefer,
other mental functions
Sperry and Gazzaniga could
send information to a patient's left or right hemisphere. As the person stared at a spot, they flashed a stimulus to its right or left. They could do this with you, too, but in your intact brain, the hemisphere receiving the information would instantly pass the news to the other side. Because the split-brain surgery had cut the communication lines between the hemispheres, the researchers could, with these patients, quiz each hemisphere separately.
Our brain's look-alike left and right hemispheres
serve differing functions.
plasticity
the brain's ability to change, especially during childhood, by reorganizing after damage or by building new pathways based on experience.
scientists have identified additional areas where
the cortex receives inout form senses other than touch, any visual information you receiving now is going to the visual cortex in you occipital lobes at the back of the brain , if you have normal vision, you might see flashed of light or dashes of the colour if stimulated in you occipital lobes
each eye revives sensory information from
the entire visual field but in each eye, information form the left half of your fiesta of vision goes to your right hemisphere, and information from the right half of your visual field goes to your left hemisphere, which usually controls speech. Information received by either hemisphere is quickly transmitted to the other across the corpus callosum. In a person with a severed corpus callosum, this information-sharing does not take place.
neurogenesis
the formation of new neurons
corpus
the large band of neural fibers connecting the two brain hemispheres and carrying messages between them
the more sensitive the body region
the larger the somatosensory cortex area devoted to it
When a monkey merely thought about a move
the mind-reading computer moved the cursor with nearly the same proficiency as had the reward-seeking monkey. both monkeys and humans have learned to control a robot arm or wheelchair that could help them receive food
by matching this neural activity to the monkey's subsequent pointing
the mind0reading researchers could program a cursor to move in response to the monkey's thought money think, computer do
When a picture of a spoon was flashed to their right hemisphere,
the patients could not say what they had viewed. But when asked to identify what they had viewed by feeling an assortment of hidden objects with their left hand, they readily selected the spoon. If the experimenter said, "Correct!" the patient might reply, "What? Correct? How could I possibly pick out the correct object when I don't know what I saw?" It is, of course, the left hemisphere doing the talking here, bewildered by what the nonverbal right hemisphere knows.
occipital lobes
the portion of the cerebral cortex lying at the back of the head; includes areas that receive information from the visual fields
frontal lobes
the portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgments.
as monkeys gained reward by using the joystick to follow the red target
the researchers matched the brain signals with the arm movements. then they programmed a computer to motor the signals and operate the joystick
If a finger is amputated,
the somatosensory cortex that received its input will begin to receive input from the adjacent fingers, which then become more sensitive
Your memory, language, and attention result from
the synchronized activity among distinct brain areas and neural networks
This large band of neural fibers connects
the two brain hemispheres.
By restraining a fully functioning limb
therapists force patients to use the "bad" hand or leg, gradually reprogramming the brain. one stroke victim, a surgeon in his fifties, was put to work cleaning tables, with his good arm and hand restrained. Slowly, the bad arm recovered its skills. As damaged-brain functions migrated to other brain regions, he gradually learned to write again and even to play tennis
what is the brain's left and right hemispheres are filled with
they are mainly filled with axons connecting the cortex to the brain's other regions
electrically probing as association area won't
trigger any observable response
clinical trials of such cognitive neural prosthetics are now
under way with people who have severe paralysis or have lost a limb
