Left Hemisphere Vs Right Hemisphere Stroke
Along with different lobes and structures, the brain is alsodivided into two halves, called hemispheres.
Aside from the different areas of the brain that can beaffected by stroke, its also helpful to look at difference between the twohemispheres.
Generally speaking, the left hemisphere controls languageand logical reasoning while the right hemisphere is believed to control creativityand object recognition. This is why language difficulties after stroke areoften associated with left hemispherestrokes.
Furthermore, each hemisphere controls movement on the opposite side of the body. Usually, a left hemisphere stroke will cause motor impairments on the right side of the body while a right hemisphere stroke will likely impair the left side of the body.
When stroke impacts both hemispheres, its possible tosustain motor impairments on both sides of the body.
Speech Recognition From Brain Activity
Speech is produced in the human cerebral cortex. Brain waves associated with speech processes can be directly recorded with electrodes located on the surface of the cortex. It has now been shown for the first time that it is possible to reconstruct basic units, words, and complete sentences of continuous speech from these brain waves and to generate the corresponding text. Researchers at KIT and Wadsworth Center, USA present their Brain-to-Text system in the scientific journal Frontiers in Neuroscience .
It has long been speculated whether humans may communicate with machines via part of the brain activity alone, says Tanja Schultz, who conducted the present study with her team at the Cognitive Systems Lab of KIT. As a major step in this direction, our recent results indicate that both single units in terms of speech sounds, as well as continuously spoken sentences, can be recognized from brain activity.
These results were obtained by an interdisciplinary collaboration of researchers of informatics, neuroscience, and medicine. In Karlsruhe, the methods for signal processing and automatic speech recognition have been developed and applied. In addition to the decoding of speech from brain activity, our models allow for a detailed analysis of the areas of the brain involved in speech processes and their interaction, outline Christian Herff und Dominic Heger, who developed the Brain-to-Text system within their doctoral studies.
How The Brain Controls Our Speech
Speaking requires both sides of the brain. Each hemisphere takes over a part of the complex task of forming sounds, modulating the voice and monitoring what has been said. However, the distribution of tasks is different than has been thought up to now, as an interdisciplinary team of neuroscientists and phoneticians at Goethe University Frankfurt and the Leibniz-Centre General Linguistics Berlin has discovered: it is not just the right hemisphere that analyzes how we speakthe left hemisphere also plays a role.
Until now, it has been assumed that the spoken word arises in the left side of the brain and is analyzed by the right side. According to accepted doctrine, this means that when we learn to speak English and for example practice the sound equivalent to ‘th,’ the left side of the brain controls the motor function of the articulators like the tongue, while the right side analyzes whether the produced sound actually sounds as we intended.
His team, together with the phonetician Dr. Susanne Fuchs, was able to demonstrate this division of labor in temporal and spectral control of speech for the first time in studies in which speakers were required to talk while their brain activities were recorded using functional magnetic resonance imaging.
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Where Do Emotions Come From
The limbic system is a group of interconnected structures located deep within the brain. Its the part of the brain thats responsible for behavioral and emotional responses.
Scientists havent reached an agreement about the full list of structures that make up the limbic system, but the following structures are generally accepted as part of the group:
- Hypothalamus. In addition to controlling emotional responses, the hypothalamus is also involved in sexual responses, hormone release, and regulating body temperature.
- Hippocampus. The hippocampus helps preserve and retrieve memories. It also plays a role in how you understand the spatial dimensions of your environment.
- Amygdala. The amygdala helps coordinate responses to things in your environment, especially those that trigger an emotional response. This structure plays an important role in fear and anger.
- Limbic cortex. This part contains two structures, the cingulate gyrus and the parahippocampal gyrus. Together, they impact mood, motivation, and judgement.
Ventricles And Cerebrospinal Fluid
Deep in the brain are four open areas with passageways between them. They also open into the central spinal canal and the area beneath arachnoid layer of the meninges.
The ventricles manufacture cerebrospinal fluid, or CSF, a watery fluid that circulates in and around the ventricles and the spinal cord, and between the meninges. CSF surrounds and cushions the spinal cord and brain, washes out waste and impurities, and delivers nutrients.
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How Is Aphasia Treated
Following a brain injury, tremendous changes occur in the brain, which help it to recover. As a result, people with aphasia often see dramatic improvements in their language and communication abilities in the first few months, even without treatment. But in many cases, some aphasia remains following this initial recovery period. In these instances, speech-language therapy is used to help patients regain their ability to communicate.
Research has shown that language and communication abilities can continue to improve for many years and are sometimes accompanied by new activity in brain tissue near the damaged area. Some of the factors that may influence the amount of improvement include the cause of the brain injury, the area of the brain that was damaged and its extent, and the age and health of the individual.
Aphasia therapy aims to improve a person’s ability to communicate by helping him or her to use remaining language abilities, restore language abilities as much as possible, and learn other ways of communicating, such as gestures, pictures, or use of electronic devices. Individual therapy focuses on the specific needs of the person, while group therapy offers the opportunity to use new communication skills in a small-group setting.
Family involvement is often a crucial component of aphasia treatment because it enables family members to learn the best way to communicate with their loved one.
Family members are encouraged to:
Risks Of Damage To The Frontal Lobe
Seizures. Some seizure disorders are caused by damage to â or a malformation in â the brain’s frontal lobe. Seizures impact your motor abilities and speech. Your doctor will assess your seizures and determine which region of your frontal lobe may be impacted.
Personality and social skills. Because the frontal lobe is large and in the front of your skull, it is susceptible to damage. Any damage may contribute to changes in your social behavior. Damage may impact your spatial orientation and coordination of your facial muscles.
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Communication Problemsafter Brain Injury
Communication problems after brain injury are very common. Although most of us take it for granted, the ability to communicate requires extremely complex skills and many different parts of the brain are involved.
There are four main categories of the effects of brain injury. Any of these can cause communication problems:
- Physical – affecting how the body works
- Cognitive – affecting how the person thinks, learns and remembers
- Emotional – affecting how the person feels
- Behavioural – affecting how a person acts
Many people will experience more than one form of communication problem after brain injury, depending on the areas of the brain affected and the severity of the injury. It is also important to recognise that such problems may occur alongside other changes in physical, cognitive, emotional and behavioural functions.
The diagram below shows the cerebral cortex. The cortex is the outer part of the brain, which is responsible for our more sophisticated thinking skills. Many of the functions listed are important for communication and injury to any of these areas can impair communication skills.
This section explains some of the ways brain injury can affect communication.
What Part Of The Brain Controls Fear
From a biological standpoint, fear is a very important emotion. It helps you respond appropriately to threatening situations that could harm you.
This response is generated by stimulation of the amygdala, followed by the hypothalamus. This is why some people with brain damage affecting their amygdala dont always respond appropriately to dangerous scenarios.
When the amygdala stimulates the hypothalamus, it initiates the fight-or-flight response. The hypothalamus sends signals to the adrenal glands to produce hormones, such as adrenaline and cortisol.
As these hormones enter the bloodstream, you might notice some physical changes, such as an increase in:
- heart rate
- blood sugar
In addition to initiating the fight-or-flight response, the amygdala also plays a role in fear learning. This refers to the process by which you develop an association between certain situations and feelings of fear.
Exercises Used To Improve Speech After Stroke
There is no one-exercise-fits-all regimen for speech therapy. The speech therapy exercises that help one person may not help another.
For instance, some stroke patients might speak with clarity but struggle with comprehension. Others might comprehend speech correctly but struggle with word formation.
This is where SLPs really help. Through a thorough evaluation, they can make a clear diagnosis in order to focus your therapy on exercises targeting difficulties specific to you.
For example, exercises for aphasia may involve reading comprehension and naming therapy. Whereas exercises for apraxia of speech, which focus on motor control, may involve tongue and lip exercises. These are just a few examples out of hundreds of possibilities.
Therefore, one set of speech therapy exercises will not benefit all stroke patients with affected speech. Rather, every patient needs a highly individualized plan.
Usually, it works best to work with an SLP one-on-one initially, and then to continue with your therapy through the use of speech therapy apps at home. We recommend the CT Speech & Cognitive Therapy App, created by SLPs, because it assigns specific exercises based on your needs.
How Wernickes Area Was Discovered
Early neuroscientists were interested in discovering where certain abilities were localized in the brain. This localization of brain function suggests that certain abilities, such as producing and understanding language, are controlled by certain parts of the brain.
One of the pioneers of this research was a French neurologist named Paul Broca. During the early 1870s, Paul Broca discovered a region of the brain associated with the production of spoken language. He found that damage to this area resulted in problems producing language.
Broca described how one patient known as Leborgne could understand language although he could not speak aside from isolated words and a few other utterances. When Leborgne died, Broca conducted a postmortem exam on the man’s brain and found a lesion in an area of the frontal lobe. This area of the brain is now referred to as Broca’s area and is associated with the production of speech.
About 10 years later, a neurologist named Carl Wernicke identified a similar type of problem in which patients were able to speak but were not able to actually comprehend language. Examining the brains of patients suffering from this language problem revealed lesions at a junction of the parietal, temporal, and occipital lobes.
This region of the brain is now known as Wernicke’s area and is associated with the understanding of spoken and written language.
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References Areas Of The Brain Involved In Reading And Writing
Blanke, M. L., & VanDongen, A. M. . Activation Mechanisms of the NMDA Receptor. In A. M. VanDongen , Biology of the NMDA Receptor . Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK5274/
Britannica.com. . Wernicke area. Retrieved February 4, 2017, from https://www.britannica.com/science/Wernicke-area
Britannica.com. . Broca area. Retrieved February 4, 2017, from https://www.britannica.com/science/Broca-area
Carlson, N. R., & Birkett, M. A. . Physiology of Behavior . Boston, MA: Pearson Education.
Christian, N. . Amnesia: Causes, Symptoms, and Treatments. Retrieved February 3, 2017, from http://www.medicalnewstoday.com/articles/9673.php
Logopenic Primary Progressive Aphasia
Degeneration of the angular gyrus in the temporal lobe and inferior parietal lobe can lead to lvPPA. Typical symptoms include slowed speech with normal articulation, impaired comprehension of sentence syntax as well as impaired naming of things. lvPPA is probably associated with Alzheimers disease pathology.
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Functions Of The Frontal Lobe
The frontal lobe plays a key role in future planning, including self-management and decision-making.
People with frontal lobe damage often struggle with gathering information, remembering previous experiences, and making decisions based on this input.
Some of the many other functions the frontal lobe plays in daily functions include:
One of the most infamous frontal lobe injuries happened to railroad worker Phineas Gage.
Gage survived after a railroad spike impaled a portion of his frontal lobe. Though Gage survived, he lost his eye and much of his personality.
Gages personality dramatically changed, and the once mild-mannered worker struggled to stick to even simple plans. He became aggressive in speech and demeanor and had little impulse control.
Much of what we know about the frontal lobe comes from case reports on Gage. Those have been called into question since, however. Little is known for sure about Gages personality before his accident, and many stories about him may be exaggerated or false.
The case demonstrates a larger point about the brain, which is that our understanding of it is constantly evolving. Hence, it is not possible to accurately predict the outcome of any given frontal lobe injury, and similar injuries may develop quite differently in each person.
In general, however, damage to the frontal lobe due to a blow to the head, a stroke, growths, and diseases, can cause the following symptoms:
- speech problems
How Does It Affect Speech
Two proteins, beta-amyloid and tau, become toxic to the brain. What results are tangles of neurons and built-up plaques that affect normal functioning.
In a normal brain, millions of neurons work together to communicate thought and action. The beta-amyloid and tau spread to other parts of the brain. The neurons die and the brain shrinks.
Usually, one of the first affected areas is the hippocampus, which is responsible for forming memories. This formation is linked to semantic understanding, allowing individuals to finish sentences and connect words to items.
When the brain deteriorates, language processing abilities deteriorate with it.
Speech challenges related to Alzheimers are serious, and if an specialized therapy plan is not followed, they can become worse and impact overall quality of life. Schedule a free introductory call with us here at Great Speech today, and well make sure you or your loved one makes consistent progress and regains any lost skills.
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How Does The Brain Work
The brain sends and receives chemical and electrical signals throughout the body. Different signals control different processes, and your brain interprets each. Some make you feel tired, for example, while others make you feel pain.
Some messages are kept within the brain, while others are relayed through the spine and across the bodys vast network of nerves to distant extremities. To do this, the central nervous system relies on billions of neurons .
What Part Of The Brain Controls Speech
Your brain is responsible for nearly all functions of your body and for interpreting sensory information from the world around you.
Your brain has many parts but speech is primarily controlled by the largest part of the brain, the cerebrum.
The cerebrum can be divided into two parts, called hemispheres, which are joined by a band of nerve fibers called the corpus callosum.
Your speech is typically governed by the left side of your cerebrum. In about a third of people who are left-handed, however, speech may actually be controlled by the right side.
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What Are The Treatments For Aphasia
Some people fully recover from aphasia without treatment. But most people should begin speech-language therapy to treat aphasia as soon as possible.
Treatment may be one-on-one with a speech therapist or in a group. Therapy using a computer may also be helpful.
The specific therapy depends on the type of language loss that a person has. It may include exercises in reading, writing, following directions, and repeating what the therapist says. Therapy may also include learning how to communicate with gestures, pictures, smartphones, or other electronic devices.
Family participation may be an important part of speech therapy. Family members can learn to help with recovery in many ways, such as:
- Using simpler language
How Does The Brain Process Speech We Now Know The Answer And Its Fascinating
Neuroscientists have known that speech is processed in the auditory cortex for some time, along with some curious activity within the motor cortex. How this last cortex is involved though, has been something of a mystery, until now. A new study by two NYU scientists reveals one of the last holdouts to a process of discovery which started over a century and a half ago. In 1861, French neurologist Pierre Paul Broca identified what would come to be known as Brocas area. This is a region in the posterior inferior frontal gyrus.
This area is responsible for processing and comprehending speech, as well as producing it. Interestingly, a fellow scientist, whom Broca had to operate on, was post-op missing Brocas area entirely. Yet, he was still able to speak. He couldnt initially make complex sentences, however, but in time regained all speaking abilities. This meant another region had pitched in, and a certain amount of neuroplasticity was involved.
In 1871, German neurologist Carl Wernicke discovered another area responsible for processing speech through hearing, this time in the superior posterior temporal lobe. Its now called Wernickes area. The model was updated in 1965 by the eminent behavioral neurologist, Norman Geschwind. The updated map of the brain is known as the Wernicke-Geschwind model.
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