In aphasia, a person may be unable to comprehend or unable to formulate language because of damage to specific brain regions. The major causes are stroke and head trauma; prevalence is hard to determine but aphasia due to stroke is estimated to be 0.1–0.4% in the Global North. Aphasia can also be the result of brain tumors, epilepsy, autoimmune neurological diseases, brain infections, or neurodegenerative diseases.
Dyslexia, previously known as word blindness, is a learning disability that affects either reading or writing. Different people are affected to different degrees. Problems may include difficulties in spelling words, reading quickly, writing words, "sounding out" words in the head, pronouncing words when reading aloud and understanding what one reads. Often these difficulties are first noticed at school. The difficulties are involuntary, and people with this disorder have a normal desire to learn. People with dyslexia have higher rates of attention deficit hyperactivity disorder (ADHD), developmental language disorders, and difficulties with numbers.
Phonics is a method for teaching reading and writing to beginners. To use phonics is to teach the relationship between the sounds of the spoken language (phonemes), and the letters (graphemes) or groups of letters or syllables of the written language. Phonics is also known as the alphabetic principle or the alphabetic code. It can be used with any writing system that is alphabetic, such as that of English, Russian, and most other languages. Phonics is also sometimes used as part of the process of teaching Chinese people to read and write Chinese characters, which are not alphabetic, using pinyin, which is.
Hyperlexia is a syndrome characterized by a child's precocious ability to read. It was initially identified by Norman E. Silberberg and Margaret C. Silberberg (1967), who defined it as the precocious ability to read words without prior training in learning to read, typically before the age of five. They indicated that children with hyperlexia have a significantly higher word-decoding ability than their reading comprehension levels. Children with hyperlexia also present with an intense fascination for written material at a very early age.
Agnosia is the inability to process sensory information. Often there is a loss of ability to recognize objects, persons, sounds, shapes, or smells while the specific sense is not defective nor is there any significant memory loss. It is usually associated with brain injury or neurological illness, particularly after damage to the occipitotemporal border, which is part of the ventral stream. Agnosia only affects a single modality, such as vision or hearing. More recently, a top-down interruption is considered to cause the disturbance of handling perceptual information.
The origin of language, its relationship with human evolution, and its consequences have been subjects of study for centuries. Scholars wishing to study the origins of language must draw inferences from evidence such as the fossil record, archaeological evidence, contemporary language diversity, studies of language acquisition, and comparisons between human language and systems of communication existing among animals. Many argue that the origins of language probably relate closely to the origins of modern human behavior, but there is little agreement about the facts and implications of this connection.
Conduction aphasia, also called associative aphasia, is an uncommon form of difficulty in speaking (aphasia). It is caused by damage to the parietal lobe of the brain. An acquired language disorder, it is characterised by intact auditory comprehension, coherent speech production, but poor speech repetition. Affected people are fully capable of understanding what they are hearing, but fail to encode phonological information for production. This deficit is load-sensitive as the person shows significant difficulty repeating phrases, particularly as the phrases increase in length and complexity and as they stumble over words they are attempting to pronounce. People have frequent errors during spontaneous speech, such as substituting or transposing sounds. They are also aware of their errors and will show significant difficulty correcting them.
Language change is variation over time in a language's features. It is studied in several subfields of linguistics: historical linguistics, sociolinguistics, and evolutionary linguistics. Traditional theories of historical linguistics identify three main types of change: systematic change in the pronunciation of phonemes, or sound change; borrowing, in which features of a language or dialect are altered as a result of influence from another language or dialect; and analogical change, in which the shape or grammatical behavior of a word is altered to more closely resemble that of another word.
Phonemic awareness is a part of phonological awareness in which listeners are able to hear, identify and manipulate phonemes, the smallest mental units of sound that help to differentiate units of meaning (morphemes). Separating the spoken word "cat" into three distinct phonemes,, , and, requires phonemic awareness. The National Reading Panel has found that phonemic awareness improves children's word reading and reading comprehension and helps children learn to spell. Phonemic awareness is the basis for learning phonics.
A reading disability is a condition in which a person displays difficulty reading. Examples of reading disabilities include: developmental dyslexia, And alexia,
A pseudoword is a unit of speech or text that appears to be an actual word in a certain language, while in fact it has no meaning. It is a specific type of nonce word, or even more narrowly a nonsense word, composed of a combination of phonemes which nevertheless conform to the language's phonotactic rules. It is thus a kind of vocable: utterable but meaningless.
Samuel Torrey Orton was an American physician who pioneered the study of learning disabilities. He examined the causes and treatment of dyslexia.
A speech sound disorder (SSD) is a speech disorder affecting the ability to pronounce speech sounds, which includes speech articulation disorders and phonemic disorders, the latter referring to some sounds (phonemes) not being produced or used correctly. The term "protracted phonological development" is sometimes preferred when describing children's speech, to emphasize the continuing development while acknowledging the delay.
Management of dyslexia depends on a multiple of variables; there is no one specific strategy or set of strategies that will work for all who have dyslexia.
Reading is the process of taking in the sense or meaning of letters, symbols, etc., especially by sight or touch.
Dyslexia is a complex, lifelong disorder involving difficulty in learning to read or interpret words, letters and other symbols. Dyslexia does not affect general intelligence, but is often co-diagnosed with ADHD. There are at least three sub-types of dyslexia that have been recognized by researchers: orthographic, or surface dyslexia, phonological dyslexia and mixed dyslexia where individuals exhibit symptoms of both orthographic and phonological dyslexia. Studies have shown that dyslexia is genetic and can be passed down through families, but it is important to note that, although a genetic disorder, there is no specific locus in the brain for reading and writing. The human brain does have language centers, but written language is a cultural artifact, and a very complex one requiring brain regions designed to recognize and interpret written symbols as representations of language in rapid synchronization. The complexity of the system and the lack of genetic predisposition for it is one possible explanation for the difficulty in acquiring and understanding written language.
The Boston Naming Test (BNT), introduced in 1983 by Edith Kaplan, Harold Goodglass and Sandra Weintraub, is a widely used neuropsychological assessment tool to measure confrontational word retrieval in individuals with aphasia or other language disturbance caused by stroke, Alzheimer's disease, or other dementing disorder. A common and debilitating feature is anomic aphasia, an impairment in the ability to name objects. The BNT contains 60 line drawings graded in difficulty. Patients with anomia often have greater difficulties with the naming of not only difficult and low frequency objects but also easy and high frequency objects. Naming difficulties may be rank ordered along a continuum. Items are rank ordered in terms of their ability to be named, which is correlated with their frequency. This type of picture-naming test is also useful in the examination of children with learning disabilities and the evaluation of brain-injured adults.
Surface dyslexia is a type of dyslexia, or reading disorder. According to Marshall & Newcombe's (1973) and McCarthy & Warrington's study (1990), patients with this kind of disorder cannot recognize a word as a whole due to the damage of the left parietal or temporal lobe. Individuals with surface dyslexia are unable to recognize a word as a whole word and retrieve its pronunciation from memory. Rather, individuals with surface dyslexia rely on pronunciation rules. Thus, patients with this particular type of reading disorder read non-words fluently, like "yatchet", but struggle with words that defy pronunciation rules. For example, a patient with surface dyslexia can correctly read regular words like "mint", but will fail when presented with a word that disobeys typical pronunciation rules, like "pint". Often, semantic knowledge is preserved in individuals with surface dyslexia.
Phonological dyslexia is a reading disability that is a form of alexia, resulting from brain injury, stroke, or progressive illness and that affects previously acquired reading abilities. The major distinguishing symptom of acquired phonological dyslexia is that a selective impairment of the ability to read pronounceable non-words occurs although the ability to read familiar words is not affected. It has also been found that the ability to read non-words can be improved if the non-words belong to a family of pseudohomophones.
In the framework of the Cultural-Historical Activity Theory (CHAT) the leading activity is the activity, or cooperative human action, which plays the most essential role in child development during a given developmental period. Although many activities may play a role in a child's development at any given time, the leading activity is theorized to be the type of social interaction that is most beneficial in terms of producing major developmental accomplishments, and preparing the child for the next period of development. Through engaging in leading activities, a child develops a wide range of capabilities, including emotional connection with others, motivation to engage in more complex social activities, the creation of new cognitive abilities, and the restructuring of old ones.
