Какими признаками характеризуются ошибки чтения при дислексии укажите неверный вариант ответа

С учетом нарушенных операций процесса чтения Р.И. Лалаева выделяет следующие виды дислексий: фонематическую, семантическую, аграмматическую, мнестическую, оптическую, тактильную.

Она связана с недоразвитием функций фонематической системы, т.е. системы фонем языка, в которой каждая единица характеризуется определенной совокупностью смыслоразличительных признаков. В русском языке этими признаками  являются твердость или мягкость, звонкость или глухость, способ образования, место образования, участие нёбной занавески. Каждая фонема отличается от всякой другой либо одним смыслоразличительным признаком, либо несколькими. В тех случаях, когда фонемы отличаются одна от другой несколькими смыслоразличительными признаками, говорят о звуках далеких, не сходных между собой. Например, звуки К и З  отличаются рядом признаков: способом, местом образования, участием голосовых складок. Если фонемы отличаются одним признаком, то тогда они являются близкими, оппозиционными. Например, звуки С и З отличаются одним признаком  (с – глухой, з – звонкий). В языке выделяются целые группы оппозиционных фонем (твердые и мягкие, звонкие и глухие и т.д.).

В словах условно можно выделить сочетание фонем, следующих друг за другом в определенной последовательности, которое связано  с семантикой, смыслом. Изменение одной из фонем в слове (косы – козы) или изменение последовательности (липа – пила) приводит к изменению смысла или разрушению его.

Выделяют следующие функции фонематической системы:

смыслоразличительная функция (изменение одной фонемы приводит к изменению смысла)

слухопроизносительная дифференциация фонем (фонематическое восприятие: каждая фонема отличается от всякой другой фонемы акустически и артикуляционно)

фонематический анализ (разложение слова на составляющие его фонемы)

в процессе формирования устной речи у детей опора на семантику является одним из основных условий развития речевой функции.

У детей в ряде случаев могут быть недоразвиты функции фонематического восприятия, анализа и синтеза.

С учетом несформированности основных функций фонематической системы фонематическую дислексию можно подразделить на две формы.

Первая форма – нарушение чтения, связанное с недоразвитием фонематического восприятия (дифференциации фонем), которое проявляется в трудностях усвоения букв, а также в заменах звуков, сходных акустически и артикуляторно.

Вторая форма – нарушение чтения, обусловленное недоразвитием функции фонематического анализа.

Искажения звуко-слоговой структуры слова проявляются в пропусках согласных при стечении (марка – «мара»); во вставках гласных между согласными при их стечении (пасла – «пасала»); в перестановках  звуков (утка – «тука»); в пропусках и вставках звуков при отсутствии стечения согласных в слове; в пропусках, перестановках слогов (лопата – «лата», «лотапа»).

(механическое чтение) проявляется в нарушении понимания прочитанных слов, предложений, текста при технически правильном чтении, т.е. слово, предложение, текст не искажаются в процессе чтения. Эти нарушения могут отмечаться при послоговом чтении. После прочтения слова по слогам дети не могут показать соответствующую картинку, ответить на вопрос, связанный со значением хорошо известного слова. Нарушения понимания читаемых предложений могут наблюдаться и при синтетическом чтении, т.е. целыми словами.

Нарушение понимания прочитанного обусловлено двумя факторами: трудностями звуко-слогового синтеза и нечеткостью , недифференцированностью представлений о синтетических связях внутри предложения.

Разделение слова на слоги в процессе чтения – одна из причин непонимания читаемого. В результате нарушении фонематического и слогового синтеза дети не узнают слова, если они разделены на части в процессе послогового чтения, не способны объединить в единое значимое целое последовательно произнесенные слоги. Они читают механически, без понимания прочитанного. У детей оказывается недостаточно сформированной способность синтезировать, восстанавливать в представлении искусственно разделенную на слоги устную речь.

Дети с СД затрудняются  в выполнении следующих заданий: а) слитно произнести слова, предъявленные в виде последовательно произнесенных изолированных звуков с короткой паузой между ними (л, у, ж, а); б) воспроизвести слова и предложения, предъявленные по слогам (де-воч-ка со-би-ра-ет цве-ты).

Нарушение понимания прочитанных предложений обусловлена несформированностью представлений о синтетических связях слов в предложении. При этом в процессе чтения слова воспринимаются изолированно, вне связи с другими словами предложения.

обусловлена недоразвитием грамматического строя речи, морфологических и синтаксических обобщений. При этой форме дислексии наблюдается: изменение падежных окончаний и числа существительных («из-под листьях», «у товарищах», «кошка» — «кошки»); неправильное согласование в роде, числе и падеже существительного и прилагательного («сказка интересное», «детей веселую»); изменение числа местоимения («все» — «весь»); неправильное употребление родовых окончаний местоимений («такая город», «ракета наш»); изменение окончаний глаголов 3-го лица прошедшего времени («это был страна», «ветер промчалась»), а также формы времени и вида («влетел» — «влетал», «видит» — «видел»).

Аграмматическая дислексия чаще всего наблюдается у детей с системным недоразвитием речи разного патогенеза на синтетической ступени формирования навыка чтения.

Она проявляется в трудностях усвоения букв, в их недифференцированных заменах. Она обусловлена нарушением процессов установления связей между звуком и буквой и нарушением речевой памяти. Дети не могут воспроизвести в определенной последовательности ряд из 3-5 звуков или слов, а если и воспроизводят, то нарушают порядок их следования, сокращают количество, пропускают звуки, слова. Нарушение ассоциации между зрительным образом буквы и слухопроизносительным образом звука особенно ярко проявляется на этапе овладения звуко-буквенными обозначениями.

проявляется в трудностях усвоения и в смешениях сходных графически букв и их взаимных заменах. Смешиваются и заменяются буквы, как отличающиеся дополнительными элементами (Л – Д, З – В), так и состоящие из одинаковых элементов, но различно расположенные в пространстве (Т – Г, Ь – Р, Н – П – И). данная форма дислексии связана с нерасчлененностью зрительного восприятия форм, с недифференцированностью представлений о сходных формах, с недоразвитием оптико-пространственного восприятия и оптико-пространственных представлений, а также с нарушением зрительного гнозиса, зрительного анализа и синтеза.

Наблюдается некоторое нарушение оптико-пространственного гнозиса и праксиса на неречевом уровне. Так, рисование по образцу и по памяти знакомых и простых по форме предметов выполняется правильно, а при срисовывании более сложных предметов отмечаются неточности, еще больше ошибок отмечается при срисовывании по памяти.

В процессе рисования и конструирования фигура упрощается, уменьшается количество элементов, неправильно располагаются линии по сравнению с образцом.

Выявляются трудности узнавания букв, написанных одна над другою, дети не могут отличить правильную букву от неправильной, плохо конструируют знакомые буквы, не справляются с добавлением недостающих элементов буквы и преобразованием одной в другую (например, из буквы Р сделать букву В, из буквы П сделать букву Н). выполнение этих заданий требует умения определять различие сходных оптических изображений, анализировать, представлять изображение или букву как целое, состоящее из определенных элементов, по-разному расположенных по отношению друг к другу.

Для некоторых детей с ОД буква является сложным оптическим образованием, анализ которого на составляющие элементы затруднен. Вследствие несформированности оптического анализа представления о сходных графических буквах являются неточными и недифференцированными.

Отмечаются затруднения в определении пространственных соотношений, в их речевом обозначении. В тяжелых случаях нарушена схема тела.

При литеральной ОД наблюдаются нарушения при изолированном узнавании и различении буквы. При вербальной ОД нарушения проявляются при чтении слова.

При органическом поражении головного мозга может наблюдаться зеркальное чтение.

наблюдается у слепых детей. В основе ее лежат трудности дифференциации тактильно воспринимаемых букв азбуки Брайля. В процессе чтения наблюдаются смешения тактильно сходных букв, состоящих из одинакового количества точек, точек, расположенных зеркально (Е – И, Ж – Х), расположенных выше или ниже или отличающихся одной точкой (А – Б, Б – Л, Л – К).

У слепых детей с ТД имеются нарушения схемы тела, временной и пространственной организации, доминантности, задержки в развитии речи.

Читая слово, слепой ребенок с ТД воспринимает каждую букву изолированно от другой. У него  наблюдается не глобальное чтение, а аналитическое восприятие букв. Чтение часто замедляется из-за поисков потерянного слова или предложения. Читаемое искажается инверсиями, пропусками букв.

Отмечается прерывистость, скачкообразность движений пальцев, возвращения назад для более точной расшифровки воспринятого знака (точек), колебания, неловкость, лишние движения. Эти особенности являются следствием трудностей в процессе чтения.

Динамика дислексии носит регрессирующий характер с постепенным уменьшением видов и количества ошибок при чтении, степени выраженности.

Нарушения чтения могут отрицательно влиять на формирование личности ребенка. Так, неудачи при овладении чтением могут вызвать и закрепить у него такие черты характера, как неуверенность в себе, робость, тревожную мнительность или, наоборот, озлобленность, агрессивность, склонность к негативным реакциям. Во избежание подобных проявлений необходимо как можно раньше начать коррекционную работу».

Дислексия-
это частичное нарушение процесса чтения,
проявляющееся в стойких и повторяющихся
ошибках чтения, обусловленных
несформированностью ВПФ, частвующих в
процессе чтения. 1.Ошибки чтения при
дислексии являются стойкими и без
специальной коррекционной работы они
могут сохранялся у ребенка в течении
многих месяцев или лет. Это позволяет
отдифференцировать дислексические
ошибки от
ошибок
чтения, j
выступают как закономерности Ps-a
овладения чтением и наблюдаются у всех
детей на начальных этапах овладения
навыком чтения.2.Ошибки чтения при
дислексии носят специфический характер-
это повторяющиеся типические ошибки.
Данный признак дислексических ошибок
позволяет отдифференцировать
дислексические от случайных вариативных
ошибок, j
м/т наблюдаться при утомлении, вследствие
невнимательности, недостаточности
процесса контроля при чтении. 3.Ошибки
чтения при дислексии обусловлены
несформированностью ВПФ, обеспечивающих
процесс чтения в норме. Этот признак
дислексических ошибок дает возможность
отграничить дислексию от ошибок чтения,
которые могут наблюдаться у детей
вследствие педагогической запущенности,
неправильной методики обучения, нарушения
элементарных функций. Ошибки чтения
могут наблюдаться у детей с плохим
зрением из-за не различения букв. Т.о.
наличие ошибок чтения само по себе еще
не свидетельствует о наличии дислексии.
О дислексии речь идет лишь в том случае,
когда ошибки чтения обусловлены
недоразвитием ВПФ. Токарева классифицирует
нарушение чтения в зависимости от того
какой из анализаторов первично нарушен:
слуховой, зрительный или двигательный.
и выделяет: акустическую, оптическую и
моторную формы дислексии. Хватцев по
нарушенным механизмам выделяет:
фонематическую, оптическую,
оптико­пространственную, семантическую
и мнестическую дислексии. С учетом
несформированности ВПФ и операций
процесса чтения Лалаева выделяет
следующие виды дислексий: Фонематическая.
Она вызывается нарушением формирования
фонематического восприятия и
фонематического анализа и синтеза.
Связи с этим выделяется 2 формы
фонематической дислексии: 1) связана с
недоразвитием фонематического восприятия
и проявляется в заменах фонематически
близких звуков при чтении (аппозиционные
звуки отличаются по 1
одному
признаку); 2) связана с недоразвитием
фонематического анализа и синтеза и
проявляется в специфических ошибках
при чтении: побуквенное чтение, искажение
звуко-слоговой структуры слова.
Аграматическая.
Этот вид наблюдается на аналитико-синтетическом
и синтетическом этапе формирования
навыков чтения. В процессе чтения
ребенок, страдающий этой формой дислексии,
не правильно, воспроизводит окончания,
префиксы, суффиксы, изменяя грамматические
формы слов. 1) изменение падежных окончаний
сущ-ых 2) изменение числа имени сущ-ого
и местоимения; 3) неправильное согласование
в роде, числе, падеже; 4) изменение
окончаний глаголов третьего лица
прошедшего времени; 5) изменение формы,
времени и вида глаголов. Семантическая
(механическое чтение). Проявляется в
нарушении понимания читаемого при
технически правильном чтении. Эта форма
характерна для УО. Оптическая.
Проявляется в заменах и смешениях
графически сходных букв при чтении.
Связана с несформированностью
зрительно-пространственных функций:
зрительного гнозиса, зрительного анализа
и синтеза, пространственных представлений.
Выделяют литеральную (нарушение узнавания
изолированных букв) и вербальную
(трудности при чтении слов) оптическую
дислексию. Мнестическая.
Проявляется в нарушении узнавания букв,
в трудностях установления ассоциаций
м/у звуком и буквой. Ребенок не запоминает,
какая буква соответствует тому или
иному звуку. Тактильная.
Наблюдается у слепых детей.

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Специфические ошибки,

которые наблюдаются при дислексии

Дислексия – частичное специфическое нарушение процесса чтения, обусловленное несформированностью (нарушением) высших психических функций и проявляющееся в повторяющихся ошибках стойкого характера.

1. Неправильное прочитывание (замены) букв, соответствующих акустически или артикуляторно близким звукам. 

В этом случае ребёнок, видя, например, написанное слово «шуба», прочитывает его как «суба», а слово «цыплёнок» – как «сыплёнок» и т.п. Обычно такие дети делают аналогичные ошибки и при письме, заменяя в записываемых словах те же самые буквы. У многих детей соответствующие звуковые замены наблюдаются и в устной речи.

В этих случаях ошибки вызваны затруднениями в слуховой дифференциации соответствующих звуков (Ш – С, Ц – С и др.) Именно по этой причине ребёнок при чтении, например, слова «шапка» будет сомневаться в том, как нужно правильно прочитать первую букву — Ш или С? Ведь звуки Ш и С при их восприятии на слух кажутся ему одинаковыми. По этой же самой причине он постоянно будет сомневаться и в выборе буквы (III или С) при записи всех слов, включающих эти буквы.

 2. Грубое искажение при чтении звуко-слоговой структуры слов, иногда до полной их неузнаваемости. 

Ребёнок в процессе чтения пропускает буквы или даже целые слоги, меняет их местами, добавляет лишние буквы и слоги, что резко затрудняет понимание прочитанного. Например, если вместо слова «карандаш» ребёнок прочитал «кардадаш», то не удивительно, что он не может узнать этого «слова». При этой форме нарушений чтения нередко отмечаются и затруднения в синтезе (т.е. слиянии) звуков в слоги. Слово тогда читается не по слогам («го-ло-ва»), а по отдельным буквам («г-о-л-о-в-а»), между которыми к тому же вставляются и какие-то неопределённые призвуки. Это так же затрудняет узнавание ребёнком «прочитанного» слова, и, как следствие, приводит к непониманию читаемого. 

Конкретно эти ошибки могут проявляться в следующем:

1. пропуски букв в словах («лто» вместо «лето», «катрюля» вместо «каст рюля»);
2. вставка лишних букв («тарава» вместо «трава», «коромила» вместо «кормила»);
3. перестановка букв («прота» вместо «тропа», «онко» вместо  «окно»);
4. пропуск слогов в словах («весипед» вместо «велосипед», «мисанер» вместо «милиционер»);

1. вставка лишних слогов («гололова» вместо «голова»);
2. перестановка слогов («мотолок» вместо «молоток»);
3. слияние нескольких слов в одно слово («детиигралиналугу»);
4. разделение одного слова на части («на ступила»).

Причина всех этих затруднений кроется в том, что ребёнок не овладел приёмами анализа и синтеза речевого потока. Если такого ребёнка спросить, сколько слов, например, в предложении «Девочка собирает цветы» или «Цветы стоят на столе», то он или вообще не поймёт вопроса, и будет называть вместо слов слоги (или звуки), или даст ошибочный ответ, но, во всяком случае «на столе» он обязательно сочтёт за одно слово. Примерно то же самое произойдёт и при попытке проанализировать звуко-слоговой состав отдельного слова. Ребёнок затруднится в определении количества слогов в слове и скажет, что, допустим в слове «стол» два или даже три слога («с-тол» или «с-то-л»).

3. Аграмматизмы при чтении.

Выражаются в неправильном согласовании слов между собой, в искажении или полном отсутствии окончаний в словах и пр. На первый взгляд причину этих нарушений даже трудно объяснить. Ведь, казалось бы, ребенок читает только то, что написано, и здесь просто не должно оставаться места для его собственного «творчества». Так почему же тогда вместо ясно написанного словосочетания «много зеркал» он прочитывает «много зеркалов»?

Дело в том, что по мере овладения навыком чтения ребенок все чаще и чаще начинает узнавать слова «в лицо», уже не вчитываясь при этом в каждую составляющую их букву. По этой причине он уже не дочитывает, а как бы «домысливает» окончания слов. И если у ребенка имеются аграмматизмы в устной речи (то есть если он привык говорить «много зеркалов» вместо «много зеркал»), то это неизбежно проявится и при чтении, и при самостоятельном письме (изложения, сочинения и пр.).

4. Неправильное прочитывание (замены) букв по принципу их оптического сходства.

       Этот вид нарушений чтения чаще всего встречается у тех детей, у которых к началу обучения грамоте недостаточно сформированы зрительно — пространственные представления. По этой причине дети затрудняются в различении сходных по начертанию букв, как бы не замечая «мелких» различий между ними. Например, читая слово «щавель», ребёнок будет сомневаться в том, как нужно назвать первую букву этого слова: то ли Ш, то ли Ц, то ли, наконец, Щ? Естественно, что ошибочное прочтение этой буквы не позволит понять и значения всего слова (что такое «шавель» или «цавель»?) Аналогичные трудности в различении оптически сходных букв дети испытывают и при письме.

Учитель-логопед КО РА «Школа-интренат

 для детей-сирот и детей, оставшихся

без попечения родителей, им. Г.К.Жукова»

Герасимцева И.В.

Дислексия

Дислексия — лечение в Москве

Dyslexia
Other names	Reading disorder, alexia
Dyslexia handwriting
Specialty	Neurology, pediatrics
Symptoms	Trouble reading[1]
Usual onset	School age[2]
Types	Surface dyslexia
Causes	Genetic and environmental factors[2]
Risk factors	Family history, attention deficit hyperactivity disorder[3]
Diagnostic method	Series memory, spelling, vision, and reading test[4]
Differential diagnosis	Hearing or vision problems, insufficient teaching[2]
Treatment	Adjusting teaching methods[1]
Frequency	3–7%[2][5]

Dyslexia, also known until the 1960s as word blindness, is a disorder characterized by reading below the expected level for one’s age.^[1][6] Different people are affected to different degrees.^[3] 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.^[3][7] Often these difficulties are first noticed at school.^[2] The difficulties are involuntary, and people with this disorder have a normal desire to learn.^[3] People with dyslexia have higher rates of attention deficit hyperactivity disorder (ADHD), developmental language disorders, and difficulties with numbers.^[2][8]

Dyslexia is believed to be caused by the interaction of genetic and environmental factors.^[2] Some cases run in families.^[3] Dyslexia that develops due to a traumatic brain injury, stroke, or dementia is sometimes called «acquired dyslexia»^[1] or alexia.^[3] The underlying mechanisms of dyslexia result from differences within the brain’s language processing.^[3] Dyslexia is diagnosed through a series of tests of memory, vision, spelling, and reading skills.^[4] Dyslexia is separate from reading difficulties caused by hearing or vision problems or by insufficient teaching or opportunity to learn.^[2]

Treatment involves adjusting teaching methods to meet the person’s needs.^[1] While not curing the underlying problem, it may decrease the degree or impact of symptoms.^[9] Treatments targeting vision are not effective.^[10] Dyslexia is the most common learning disability and occurs in all areas of the world.^[11] It affects 3–7% of the population;^[2][5] however, up to 20% of the general population may have some degree of symptoms.^[12] While dyslexia is more often diagnosed in boys, this is partly explained by a self-fulfilling referral bias among teachers and professionals.^[2][13] It has even been suggested that the condition affects men and women equally.^[11] Some believe that dyslexia is best considered as a different way of learning, with both benefits and downsides.^[14][15]

Classification

Dyslexia is divided into developmental and acquired forms.^[16] Acquired dyslexia occurs subsequent to neurological insult, such as traumatic brain injury or stroke. People with acquired dyslexia exhibit some of the signs or symptoms of the developmental disorder, but require different assessment strategies and treatment approaches.^[17] Pure alexia, also known as agnosic alexia or pure word blindness, is one form of alexia which makes up «the peripheral dyslexia» group.^[18]

Signs and symptoms

In early childhood, symptoms that correlate with a later diagnosis of dyslexia include delayed onset of speech and a lack of phonological awareness.^[10] A common myth closely associates dyslexia with mirror writing and reading letters or words backwards.^[19] These behaviors are seen in many children as they learn to read and write, and are not considered to be defining characteristics of dyslexia.^[10]

School-age children with dyslexia may exhibit signs of difficulty in identifying or generating rhyming words, or counting the number of syllables in words—both of which depend on phonological awareness.^[20] They may also show difficulty in segmenting words into individual sounds (such as sounding out the three sounds of k, a, and t in cat) or may struggle to blend sounds, indicating reduced phonemic awareness.^[21]

Difficulties with word retrieval or naming things is also associated with dyslexia.^[22]: 647 People with dyslexia are commonly poor spellers, a feature sometimes called dysorthographia or dysgraphia, which depends on the skill of orthographic coding.^[10]

Problems persist into adolescence and adulthood and may include difficulties with summarizing stories, memorization, reading aloud, or learning foreign languages. Adults with dyslexia can often read with good comprehension, though they tend to read more slowly than others without a learning difficulty and perform worse in spelling tests or when reading nonsense words—a measure of phonological awareness.^[23]

Associated conditions

Dyslexia often co-occurs with other learning disorders, but the reasons for this comorbidity have not been clearly identified.^[24] These associated disabilities include:

Dysgraphia

A disorder involving difficulties with writing or typing, sometimes due to problems with eye–hand coordination; it also can impede direction- or sequence-oriented processes, such as tying knots or carrying out repetitive tasks.^[25] In dyslexia, dysgraphia is often multifactorial, due to impaired letter-writing automaticity, organizational and elaborative difficulties, and impaired visual word forming, which makes it more difficult to retrieve the visual picture of words required for spelling.^[25]

Attention deficit hyperactivity disorder (ADHD)

A disorder characterized by problems sustaining attention, hyperactivity, or acting impulsively.^[26] Dyslexia and ADHD commonly occur together.^[5][27][28] Approximately 15%^[10] or 12–24% of people with dyslexia have ADHD;^[29] and up to 35% of people with ADHD have dyslexia.^[10]

Auditory processing disorder

A listening disorder that affects the ability to process auditory information.^[30][31] This can lead to problems with auditory memory and auditory sequencing. Many people with dyslexia have auditory processing problems, and may develop their own logographic cues to compensate for this type of deficit. Some research suggests that auditory processing skills could be the primary shortfall in dyslexia.^[32][33]

Developmental coordination disorder

A neurological condition characterized by difficulty in carrying out routine tasks involving balance, fine-motor control and kinesthetic coordination; difficulty in the use of speech sounds; and problems with short-term memory and organization.^[34]

Causes

Researchers have been trying to find the neurobiological basis of dyslexia since the condition was first identified in 1881.^[35][36] For example, some have tried to associate the common problem among people with dyslexia of not being able to see letters clearly to abnormal development of their visual nerve cells.^[37]

Neuroanatomy

Neuroimaging techniques, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), have shown a correlation between both functional and structural differences in the brains of children with reading difficulties.^[38] Some people with dyslexia show less electrical activation in parts of the left hemisphere of the brain involved with reading, such as the inferior frontal gyrus, inferior parietal lobule, and the middle and ventral temporal cortex.^[32] Over the past decade, brain activation studies using PET to study language have produced a breakthrough in the understanding of the neural basis of language. Neural bases for the visual lexicon and for auditory verbal short-term memory components have been proposed,^[39] with some implication that the observed neural manifestation of developmental dyslexia is task-specific (i.e., functional rather than structural). fMRIs of people with dyslexia indicate an interactive role of the cerebellum and cerebral cortex as well as other brain structures in reading.^[40][41]

The cerebellar theory of dyslexia proposes that impairment of cerebellum-controlled muscle movement affects the formation of words by the tongue and facial muscles, resulting in the fluency problems that some people with dyslexia experience. The cerebellum is also involved in the automatization of some tasks, such as reading.^[42] The fact that some children with dyslexia have motor task and balance impairments could be consistent with a cerebellar role in their reading difficulties. However, the cerebellar theory has not been supported by controlled research studies.^[43]

Genetics

Research into potential genetic causes of dyslexia has its roots in post-autopsy examination of the brains of people with dyslexia.^[37] Observed anatomical differences in the language centers of such brains include microscopic cortical malformations known as ectopias, and more rarely, vascular micro-malformations, and microgyrus—a smaller than usual size for the gyrus.^[44] The previously cited studies and others^[45] suggest that abnormal cortical development, presumed to occur before or during the sixth month of fetal brain development, may have caused the abnormalities. Abnormal cell formations in people with dyslexia have also been reported in non-language cerebral and subcortical brain structures.^[46] Several genes have been associated with dyslexia, including DCDC2^[47] and KIAA0319^[48] on chromosome 6, and DYX1C1 on chromosome 15.^[49]

Gene–environment interaction

The contribution of gene–environment interaction to reading disability has been intensely studied using twin studies, which estimate the proportion of variance associated with a person’s environment and the proportion associated with their genes. Both environmental and genetic factors appear to contribute to reading development. Studies examining the influence of environmental factors such as parental education^[50] and teaching quality^[51] have determined that genetics have greater influence in supportive, rather than less optimal, environments.^[52] However, more optimal conditions may just allow those genetic risk factors to account for more of the variance in outcome because the environmental risk factors have been minimized.^[52]

As environment plays a large role in learning and memory, it is likely that epigenetic modifications play an important role in reading ability. Measures of gene expression, histone modifications, and methylation in the human periphery are used to study epigenetic processes; however, all of these have limitations in the extrapolation of results for application to the human brain.^[53][54]

Language

The orthographic complexity of a language directly affects how difficult it is to learn to read it.^[55]: 266 English and French have comparatively «deep» phonemic orthographies within the Latin alphabet writing system, with complex structures employing spelling patterns on several levels: letter-sound correspondence, syllables, and morphemes.^[56]: 421 Languages such as Spanish, Italian and Finnish primarily employ letter-sound correspondence—so-called «shallow» orthographies—which makes them easier to learn for people with dyslexia.^[55]: 266 Logographic writing systems, such as Chinese characters, have extensive symbol use; and these also pose problems for dyslexic learners.^[57]

Pathophysiology

For most people who are right-hand dominant, the left hemisphere of their brain is more specialized for language processing. With regard to the mechanism of dyslexia, fMRI studies suggest that this specialization is less pronounced or absent in people with dyslexia. In other studies, dyslexia is correlated with anatomical differences in the corpus callosum, the bundle of nerve fibers that connects the left and right hemispheres.^[58]

Data via diffusion tensor MRI indicate changes in connectivity or in gray matter density in areas related to reading and language. Finally, the left inferior frontal gyrus has shown differences in phonological processing in people with dyslexia.^[58] Neurophysiological and imaging procedures are being used to ascertain phenotypic characteristics in people with dyslexia, thus identifying the effects of dyslexia-related genes.^[59]

Dual route theory

The dual-route theory of reading aloud was first described in the early 1970s.^[60] This theory suggests that two separate mental mechanisms, or cognitive routes, are involved in reading aloud.^[61] One mechanism is the lexical route, which is the process whereby skilled readers can recognize known words by sight alone, through a «dictionary» lookup procedure.^[62] The other mechanism is the nonlexical or sublexical route, which is the process whereby the reader can «sound out» a written word.^[62][63] This is done by identifying the word’s constituent parts (letters, phonemes, graphemes) and applying knowledge of how these parts are associated with each other, for example, how a string of neighboring letters sound together.^[60] The dual-route system could explain the different rates of dyslexia occurrence between different languages (e.g., the consistency of phonological rules in the Spanish language could account for the fact that Spanish-speaking children show a higher level of performance in non-word reading, when compared to English-speakers).^[55][64]

Diagnosis

Dyslexia is a heterogeneous, dimensional learning disorder that impairs accurate and fluent word reading and spelling.^[65][66] Typical—but not universal—features include difficulties with phonological awareness; inefficient and often inaccurate processing of sounds in oral language (phonological processing); and verbal working memory deficits.^[67][68]

Dyslexia is a neurodevelopmental disorder, subcategorized in diagnostic guides as a learning disorder with impairment in reading (ICD-11 prefixes «developmental» to «learning disorder»; DSM-5 uses «specific»).^[69][70][71] Dyslexia is not a problem with intelligence. Emotional problems often arise secondary to learning difficulties.^[72] The National Institute of Neurological Disorders and Stroke describes dyslexia as «difficulty with phonological processing (the manipulation of sounds), spelling, and/or rapid visual-verbal responding».^[1]

The British Dyslexia Association defines dyslexia as «a learning difficulty that primarily affects the skills involved in accurate and fluent word reading and spelling» and is characterized by «difficulties in phonological awareness, verbal memory and verbal processing speed».^[73] Phonological awareness enables one to identify, discriminate, remember (working memory), and mentally manipulate the sound structures of language—phonemes, onsite-rime segments, syllables, and words.^[74][75]

Assessment

The following can be done to assess for dyslexia:

Apply a multidisciplinary team approach involving the child’s parent(s) and teacher(s), school psychologist, pediatrician, and, as appropriate, speech and language pathologist (speech therapist), and occupational therapist.^[76]

Gain familiarity with typical ages children reach various general developmental milestones, and domain-specific milestones, such as phonological awareness (recognizing rhyming words; identifying the initial sounds in words).^[77]

Do not rely on tests exclusively. Careful observation of the child in the school and home environments, and sensitive, comprehensive parental interviews are just as important as tests.^[78][79]

Look at the empirically supported response to intervention (RTI) approach,^[80] which «… involves monitoring the progress of a group of children through a programme of intervention rather than undertaking a static assessment of their current skills. Children with the most need are those who fail to respond to effective teaching, and they are readily identified using this approach.»^[81]

Assessment tests

There is a wide range of tests that are used in clinical and educational settings to evaluate the possibility of dyslexia.^[82] If initial testing suggests that a person might have dyslexia, such tests are often followed up with a full diagnostic assessment to determine the extent and nature of the disorder.^[83] Some tests can be administered by a teacher or computer; others require specialized training and are given by psychologists.^[84] Some test results indicate how to carry out teaching strategies.^[84][85] Because a variety of different cognitive, behavioral, emotional, and environmental factors all could contribute to difficultly learning to read, a comprehensive evaluation should consider these different possibilities. These tests and observations can include:^[86]

• General measures of cognitive ability, such as the Wechsler Intelligence Scale for Children, Woodcock-Johnson Tests of Cognitive Abilities, or Stanford-Binet Intelligence Scales. Low general cognitive ability would make reading more difficult. Cognitive ability measures also often try to measure different cognitive processes, such as verbal ability, nonverbal and spatial reasoning, working memory, and processing speed. There are different versions of these tests for different age groups. Almost all of these require additional training to give and score correctly, and are done by psychologists. According to Mather and Schneider (2015), a confirmatory profile and/or pattern of scores on cognitive tests confirming or ruling-out reading disorder has not yet been identified.^[87]
• Screening or evaluation for mental health conditions: Parents and teachers can complete rating scales or behavior checklists to gather information about emotional and behavioral functioning for younger people. Many checklists have similar versions for parents, teachers, and younger people old enough to read reasonably well (often 11 years and older) to complete. Examples include the Behavioral Assessment System for Children, and the Strengths and Difficulties Questionnaire. All of these have nationally representative norms, making it possible to compare the level of symptoms to what would be typical for the younger person’s age and biological sex. Other checklists link more specifically to psychiatric diagnoses, such as the Vanderbilt ADHD Rating Scales or the Screen for Child Anxiety Related Emotional Disorders (SCARED). Screening uses brief tools that are designed to catch cases with a disorder, but they often get false positive scores for people who do not have the disorder. Screeners should be followed up by a more accurate test or diagnostic interview as a result. Depressive disorders and anxiety disorders are two-three times higher in people with dyslexia, and attention-deficit/hyperactivity disorder is more common, as well.^{[88][89][90][91]}
• Review of academic achievement and skills: Average spelling/reading ability for a dyslexic is a percentage ranking <16, well below normal. In addition to reviewing grades and teacher notes, standardized test results are helpful in evaluating progress. These include group administered tests, such as the Iowa Tests of Educational Development, that a teacher may give to a group or whole classroom of younger people at the same time. They also could include individually administered tests of achievement, such as the Wide Range Achievement Test, or the Woodcock-Johnson (which also includes a set of achievement tests). The individually administered tests again require more specialized training.^[92][93][94]

Screening

Screening procedures seek to identify children who show signs of possible dyslexia. In the preschool years, a family history of dyslexia, particularly in biological parents and siblings, predicts an eventual dyslexia diagnosis better than any test.^[95] In primary school (ages 5–7), the ideal screening procedure consists of training primary school teachers to carefully observe and record their pupils’ progress through the phonics curriculum, and thereby identify children progressing slowly.^[96][97] When teachers identify such students they can supplement their observations with screening tests such as the Phonics screening check^[98] used by United Kingdom schools during Year one.

In the medical setting, child and adolescent psychiatrist M. S. Thambirajah emphasizes that «[g]iven the high prevalence of developmental disorders in school-aged children, all children seen in clinics should be systematically screened for developmental disorders irrespective of the presenting problem/s.» Thambirajah recommends screening for developmental disorders, including dyslexia, by conducting a brief developmental history, a preliminary psychosocial developmental examination, and obtaining a school report regarding academic and social functioning.^[99]

Management

Through the use of compensation strategies, therapy and educational support, individuals with dyslexia can learn to read and write.^[100] There are techniques and technical aids that help to manage or conceal symptoms of the disorder.^[101] Reducing stress and anxiety can sometimes improve written comprehension.^[102] For dyslexia intervention with alphabet-writing systems, the fundamental aim is to increase a child’s awareness of correspondences between graphemes (letters) and phonemes (sounds), and to relate these to reading and spelling by teaching how sounds blend into words. Reinforced collateral training focused on reading and spelling may yield longer-lasting gains than oral phonological training alone.^[103] Early intervention can be successful in reducing reading failure.^[104]

Research does not suggest that specially-tailored fonts (such as Dyslexie and OpenDyslexic) help with reading.^[105] Children with dyslexia read text set in a regular font such as Times New Roman and Arial just as quickly, and they show a preference for regular fonts over specially-tailored fonts.^[105] Some research has pointed to increased letter-spacing being beneficial.^[105]

There is currently no evidence showing that music education significantly improves the reading skills of adolescents with dyslexia.^[106]

Prognosis

Dyslexic children require special instruction for word analysis and spelling from an early age.^[107] The prognosis, generally speaking, is positive for individuals who are identified in childhood and receive support from friends and family.^[1] The New York educational system (NYED) indicates «a daily uninterrupted 90-minute block of instruction in reading» and «instruction in phonemic awareness, phonics, vocabulary development, reading fluency» so as to improve the individual’s reading ability.^[108]

Epidemiology

The prevalence of dyslexia is unknown, but it has been estimated to be as low as 5% and as high as 17% of the population.^[109] Dyslexia is diagnosed more often in males.^[2]

There are different definitions of dyslexia used throughout the world. Further, differences in writing systems may affect development of written language ability due to the interplay between auditory and written representations of phonemes.^[110] Dyslexia is not limited to difficulty in converting letters to sounds, and Chinese people with dyslexia may have difficulty converting Chinese characters into their meanings.^[111][112] The Chinese vocabulary uses logographic, monographic, non-alphabet writing where one character can represent an individual phoneme.^[113]

The phonological-processing hypothesis attempts to explain why dyslexia occurs in a wide variety of languages. Furthermore, the relationship between phonological capacity and reading appears to be influenced by orthography.^[114]

History

Dyslexia was clinically described by Oswald Berkhan in 1881,^[35] but the term dyslexia was coined in 1883 by Rudolf Berlin, an ophthalmologist in Stuttgart.^{[115][116][117]} He used the term to refer to the case of a young boy who had severe difficulty learning to read and write, despite showing typical intelligence and physical abilities in all other respects.^[118] In 1896, W. Pringle Morgan, a British physician from Seaford, East Sussex, published a description of a reading-specific learning disorder in a report to the British Medical Journal titled «Congenital Word Blindness».^[119] The distinction between phonological versus surface types of dyslexia is only descriptive, and without any etiological assumption as to the underlying brain mechanisms. However, studies have alluded to potential differences due to variation in performance.^[120] Over time, we have changed from the intelligence-based model to the age-based model, in terms of those with Dyslexia.^[121][85]

Society and culture

As is the case with any disorder, society often makes an assessment based on incomplete information. Before the 1980s, dyslexia was thought to be a consequence of education, rather than a neurological disability. As a result, society often misjudges those with the disorder.^[102] There is also sometimes a workplace stigma and negative attitude towards those with dyslexia.^[122] If the instructors of a person with dyslexia lack the necessary training to support a child with the condition, there is often a negative effect on the student’s learning participation.^[123]

Since at least the 1960s in the UK, the children diagnosed with developmental dyslexia have consistently been from privileged families.^[124] Although half of prisoners in the UK have significant reading difficulties, very few have ever been evaluated for dyslexia.^[124] Access to some special educational resources and funding is contingent upon having a diagnosis of dyslexia.^[124] As a result, when Staffordshire and Warwickshire proposed in 2018 to teach reading to all children with reading difficulties, using techniques proven to be successful for most children with a diagnosis of dyslexia, without first requiring the families to obtain an official diagnosis, dyslexia advocates and parents of children with dyslexia were fearful that they were losing a privileged status.^[124]

Stigma and success

The stigma surrounding dyslexia is just beginning to be understood.^[125] As awareness increases, it is informative to observe the long list of notable people with dyslexia who have struggled and ended up with successful careers, among them Whoopi Goldberg, who said:

When I was a kid they didn’t call it dyslexia. They called it you know, you were slow, or you were retarded, or whatever. What you can never change is the effect that the words ‘dumb’ and ‘stupid’ have on young people. I knew I wasn’t stupid, and I knew I wasn’t dumb.^[126]

Their success was not without struggle. Henry Winkler said:

You want so badly to be able to do it and you can’t. And no matter how hard you try, it’s not working … I would study my words. I would know them cold. I would know them backwards and forwards. I would go to class. I would pray that I had retained them. Then I would get the test and spend a lot of time thinking about where the hell those words went. I knew them. They must have fallen out of my head … I didn’t have the slightest idea of how to spell the words that I knew a block and a half away in my apartment the night before.^[127]

Research

Most dyslexia research relates to alphabetic writing systems, and especially to European languages.^[128] However, substantial research is also available regarding people with dyslexia who speak Arabic, Chinese, Hebrew, or other languages.^[129] The outward expression of individuals with reading disability, and regular poor readers, is the same in some respects.^[130]

See also

• Dyscalculia, difficulty comprehending numbers and math
• Learning to read
• Orton-Gillingham

References

This article was submitted to WikiJournal of Medicine for external academic peer review in 2018 (reviewer reports). The updated content was reintegrated into the Wikipedia page under a CC-BY-SA-3.0 license (2019). The version of record as reviewed is:
Osmin Anis; et al. (15 October 2019). «Dyslexia». WikiJournal of Medicine. 6 (1): 5. doi:10.15347/WJM/2019.005. ISSN 2002-4436. Wikidata Q73053061.

Further reading

External links

Dyslexia
Other names	Reading disorder, alexia
Dyslexia handwriting
Specialty	Neurology, pediatrics
Symptoms	Trouble reading[1]
Usual onset	School age[2]
Types	Surface dyslexia
Causes	Genetic and environmental factors[2]
Risk factors	Family history, attention deficit hyperactivity disorder[3]
Diagnostic method	Series memory, spelling, vision, and reading test[4]
Differential diagnosis	Hearing or vision problems, insufficient teaching[2]
Treatment	Adjusting teaching methods[1]
Frequency	3–7%[2][5]

Dyslexia, also known until the 1960s as word blindness, is a disorder characterized by reading below the expected level for one’s age.^[1][6] Different people are affected to different degrees.^[3] 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.^[3][7] Often these difficulties are first noticed at school.^[2] The difficulties are involuntary, and people with this disorder have a normal desire to learn.^[3] People with dyslexia have higher rates of attention deficit hyperactivity disorder (ADHD), developmental language disorders, and difficulties with numbers.^[2][8]

Dyslexia is believed to be caused by the interaction of genetic and environmental factors.^[2] Some cases run in families.^[3] Dyslexia that develops due to a traumatic brain injury, stroke, or dementia is sometimes called «acquired dyslexia»^[1] or alexia.^[3] The underlying mechanisms of dyslexia result from differences within the brain’s language processing.^[3] Dyslexia is diagnosed through a series of tests of memory, vision, spelling, and reading skills.^[4] Dyslexia is separate from reading difficulties caused by hearing or vision problems or by insufficient teaching or opportunity to learn.^[2]

Treatment involves adjusting teaching methods to meet the person’s needs.^[1] While not curing the underlying problem, it may decrease the degree or impact of symptoms.^[9] Treatments targeting vision are not effective.^[10] Dyslexia is the most common learning disability and occurs in all areas of the world.^[11] It affects 3–7% of the population;^[2][5] however, up to 20% of the general population may have some degree of symptoms.^[12] While dyslexia is more often diagnosed in boys, this is partly explained by a self-fulfilling referral bias among teachers and professionals.^[2][13] It has even been suggested that the condition affects men and women equally.^[11] Some believe that dyslexia is best considered as a different way of learning, with both benefits and downsides.^[14][15]

Classification

Dyslexia is divided into developmental and acquired forms.^[16] Acquired dyslexia occurs subsequent to neurological insult, such as traumatic brain injury or stroke. People with acquired dyslexia exhibit some of the signs or symptoms of the developmental disorder, but require different assessment strategies and treatment approaches.^[17] Pure alexia, also known as agnosic alexia or pure word blindness, is one form of alexia which makes up «the peripheral dyslexia» group.^[18]

Signs and symptoms

In early childhood, symptoms that correlate with a later diagnosis of dyslexia include delayed onset of speech and a lack of phonological awareness.^[10] A common myth closely associates dyslexia with mirror writing and reading letters or words backwards.^[19] These behaviors are seen in many children as they learn to read and write, and are not considered to be defining characteristics of dyslexia.^[10]

School-age children with dyslexia may exhibit signs of difficulty in identifying or generating rhyming words, or counting the number of syllables in words—both of which depend on phonological awareness.^[20] They may also show difficulty in segmenting words into individual sounds (such as sounding out the three sounds of k, a, and t in cat) or may struggle to blend sounds, indicating reduced phonemic awareness.^[21]

Difficulties with word retrieval or naming things is also associated with dyslexia.^[22]: 647 People with dyslexia are commonly poor spellers, a feature sometimes called dysorthographia or dysgraphia, which depends on the skill of orthographic coding.^[10]

Problems persist into adolescence and adulthood and may include difficulties with summarizing stories, memorization, reading aloud, or learning foreign languages. Adults with dyslexia can often read with good comprehension, though they tend to read more slowly than others without a learning difficulty and perform worse in spelling tests or when reading nonsense words—a measure of phonological awareness.^[23]

Associated conditions

Dyslexia often co-occurs with other learning disorders, but the reasons for this comorbidity have not been clearly identified.^[24] These associated disabilities include:

Dysgraphia

A disorder involving difficulties with writing or typing, sometimes due to problems with eye–hand coordination; it also can impede direction- or sequence-oriented processes, such as tying knots or carrying out repetitive tasks.^[25] In dyslexia, dysgraphia is often multifactorial, due to impaired letter-writing automaticity, organizational and elaborative difficulties, and impaired visual word forming, which makes it more difficult to retrieve the visual picture of words required for spelling.^[25]

Attention deficit hyperactivity disorder (ADHD)

A disorder characterized by problems sustaining attention, hyperactivity, or acting impulsively.^[26] Dyslexia and ADHD commonly occur together.^[5][27][28] Approximately 15%^[10] or 12–24% of people with dyslexia have ADHD;^[29] and up to 35% of people with ADHD have dyslexia.^[10]

Auditory processing disorder

A listening disorder that affects the ability to process auditory information.^[30][31] This can lead to problems with auditory memory and auditory sequencing. Many people with dyslexia have auditory processing problems, and may develop their own logographic cues to compensate for this type of deficit. Some research suggests that auditory processing skills could be the primary shortfall in dyslexia.^[32][33]

Developmental coordination disorder

A neurological condition characterized by difficulty in carrying out routine tasks involving balance, fine-motor control and kinesthetic coordination; difficulty in the use of speech sounds; and problems with short-term memory and organization.^[34]

Causes

Researchers have been trying to find the neurobiological basis of dyslexia since the condition was first identified in 1881.^[35][36] For example, some have tried to associate the common problem among people with dyslexia of not being able to see letters clearly to abnormal development of their visual nerve cells.^[37]

Neuroanatomy

Neuroimaging techniques, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), have shown a correlation between both functional and structural differences in the brains of children with reading difficulties.^[38] Some people with dyslexia show less electrical activation in parts of the left hemisphere of the brain involved with reading, such as the inferior frontal gyrus, inferior parietal lobule, and the middle and ventral temporal cortex.^[32] Over the past decade, brain activation studies using PET to study language have produced a breakthrough in the understanding of the neural basis of language. Neural bases for the visual lexicon and for auditory verbal short-term memory components have been proposed,^[39] with some implication that the observed neural manifestation of developmental dyslexia is task-specific (i.e., functional rather than structural). fMRIs of people with dyslexia indicate an interactive role of the cerebellum and cerebral cortex as well as other brain structures in reading.^[40][41]

The cerebellar theory of dyslexia proposes that impairment of cerebellum-controlled muscle movement affects the formation of words by the tongue and facial muscles, resulting in the fluency problems that some people with dyslexia experience. The cerebellum is also involved in the automatization of some tasks, such as reading.^[42] The fact that some children with dyslexia have motor task and balance impairments could be consistent with a cerebellar role in their reading difficulties. However, the cerebellar theory has not been supported by controlled research studies.^[43]

Genetics

Research into potential genetic causes of dyslexia has its roots in post-autopsy examination of the brains of people with dyslexia.^[37] Observed anatomical differences in the language centers of such brains include microscopic cortical malformations known as ectopias, and more rarely, vascular micro-malformations, and microgyrus—a smaller than usual size for the gyrus.^[44] The previously cited studies and others^[45] suggest that abnormal cortical development, presumed to occur before or during the sixth month of fetal brain development, may have caused the abnormalities. Abnormal cell formations in people with dyslexia have also been reported in non-language cerebral and subcortical brain structures.^[46] Several genes have been associated with dyslexia, including DCDC2^[47] and KIAA0319^[48] on chromosome 6, and DYX1C1 on chromosome 15.^[49]

Gene–environment interaction

The contribution of gene–environment interaction to reading disability has been intensely studied using twin studies, which estimate the proportion of variance associated with a person’s environment and the proportion associated with their genes. Both environmental and genetic factors appear to contribute to reading development. Studies examining the influence of environmental factors such as parental education^[50] and teaching quality^[51] have determined that genetics have greater influence in supportive, rather than less optimal, environments.^[52] However, more optimal conditions may just allow those genetic risk factors to account for more of the variance in outcome because the environmental risk factors have been minimized.^[52]

As environment plays a large role in learning and memory, it is likely that epigenetic modifications play an important role in reading ability. Measures of gene expression, histone modifications, and methylation in the human periphery are used to study epigenetic processes; however, all of these have limitations in the extrapolation of results for application to the human brain.^[53][54]

Language

The orthographic complexity of a language directly affects how difficult it is to learn to read it.^[55]: 266 English and French have comparatively «deep» phonemic orthographies within the Latin alphabet writing system, with complex structures employing spelling patterns on several levels: letter-sound correspondence, syllables, and morphemes.^[56]: 421 Languages such as Spanish, Italian and Finnish primarily employ letter-sound correspondence—so-called «shallow» orthographies—which makes them easier to learn for people with dyslexia.^[55]: 266 Logographic writing systems, such as Chinese characters, have extensive symbol use; and these also pose problems for dyslexic learners.^[57]

Pathophysiology

For most people who are right-hand dominant, the left hemisphere of their brain is more specialized for language processing. With regard to the mechanism of dyslexia, fMRI studies suggest that this specialization is less pronounced or absent in people with dyslexia. In other studies, dyslexia is correlated with anatomical differences in the corpus callosum, the bundle of nerve fibers that connects the left and right hemispheres.^[58]

Data via diffusion tensor MRI indicate changes in connectivity or in gray matter density in areas related to reading and language. Finally, the left inferior frontal gyrus has shown differences in phonological processing in people with dyslexia.^[58] Neurophysiological and imaging procedures are being used to ascertain phenotypic characteristics in people with dyslexia, thus identifying the effects of dyslexia-related genes.^[59]

Dual route theory

The dual-route theory of reading aloud was first described in the early 1970s.^[60] This theory suggests that two separate mental mechanisms, or cognitive routes, are involved in reading aloud.^[61] One mechanism is the lexical route, which is the process whereby skilled readers can recognize known words by sight alone, through a «dictionary» lookup procedure.^[62] The other mechanism is the nonlexical or sublexical route, which is the process whereby the reader can «sound out» a written word.^[62][63] This is done by identifying the word’s constituent parts (letters, phonemes, graphemes) and applying knowledge of how these parts are associated with each other, for example, how a string of neighboring letters sound together.^[60] The dual-route system could explain the different rates of dyslexia occurrence between different languages (e.g., the consistency of phonological rules in the Spanish language could account for the fact that Spanish-speaking children show a higher level of performance in non-word reading, when compared to English-speakers).^[55][64]

Diagnosis

Dyslexia is a heterogeneous, dimensional learning disorder that impairs accurate and fluent word reading and spelling.^[65][66] Typical—but not universal—features include difficulties with phonological awareness; inefficient and often inaccurate processing of sounds in oral language (phonological processing); and verbal working memory deficits.^[67][68]

Dyslexia is a neurodevelopmental disorder, subcategorized in diagnostic guides as a learning disorder with impairment in reading (ICD-11 prefixes «developmental» to «learning disorder»; DSM-5 uses «specific»).^[69][70][71] Dyslexia is not a problem with intelligence. Emotional problems often arise secondary to learning difficulties.^[72] The National Institute of Neurological Disorders and Stroke describes dyslexia as «difficulty with phonological processing (the manipulation of sounds), spelling, and/or rapid visual-verbal responding».^[1]

The British Dyslexia Association defines dyslexia as «a learning difficulty that primarily affects the skills involved in accurate and fluent word reading and spelling» and is characterized by «difficulties in phonological awareness, verbal memory and verbal processing speed».^[73] Phonological awareness enables one to identify, discriminate, remember (working memory), and mentally manipulate the sound structures of language—phonemes, onsite-rime segments, syllables, and words.^[74][75]

Assessment

The following can be done to assess for dyslexia:

Apply a multidisciplinary team approach involving the child’s parent(s) and teacher(s), school psychologist, pediatrician, and, as appropriate, speech and language pathologist (speech therapist), and occupational therapist.^[76]

Gain familiarity with typical ages children reach various general developmental milestones, and domain-specific milestones, such as phonological awareness (recognizing rhyming words; identifying the initial sounds in words).^[77]

Do not rely on tests exclusively. Careful observation of the child in the school and home environments, and sensitive, comprehensive parental interviews are just as important as tests.^[78][79]

Look at the empirically supported response to intervention (RTI) approach,^[80] which «… involves monitoring the progress of a group of children through a programme of intervention rather than undertaking a static assessment of their current skills. Children with the most need are those who fail to respond to effective teaching, and they are readily identified using this approach.»^[81]

Assessment tests

There is a wide range of tests that are used in clinical and educational settings to evaluate the possibility of dyslexia.^[82] If initial testing suggests that a person might have dyslexia, such tests are often followed up with a full diagnostic assessment to determine the extent and nature of the disorder.^[83] Some tests can be administered by a teacher or computer; others require specialized training and are given by psychologists.^[84] Some test results indicate how to carry out teaching strategies.^[84][85] Because a variety of different cognitive, behavioral, emotional, and environmental factors all could contribute to difficultly learning to read, a comprehensive evaluation should consider these different possibilities. These tests and observations can include:^[86]

• General measures of cognitive ability, such as the Wechsler Intelligence Scale for Children, Woodcock-Johnson Tests of Cognitive Abilities, or Stanford-Binet Intelligence Scales. Low general cognitive ability would make reading more difficult. Cognitive ability measures also often try to measure different cognitive processes, such as verbal ability, nonverbal and spatial reasoning, working memory, and processing speed. There are different versions of these tests for different age groups. Almost all of these require additional training to give and score correctly, and are done by psychologists. According to Mather and Schneider (2015), a confirmatory profile and/or pattern of scores on cognitive tests confirming or ruling-out reading disorder has not yet been identified.^[87]
• Screening or evaluation for mental health conditions: Parents and teachers can complete rating scales or behavior checklists to gather information about emotional and behavioral functioning for younger people. Many checklists have similar versions for parents, teachers, and younger people old enough to read reasonably well (often 11 years and older) to complete. Examples include the Behavioral Assessment System for Children, and the Strengths and Difficulties Questionnaire. All of these have nationally representative norms, making it possible to compare the level of symptoms to what would be typical for the younger person’s age and biological sex. Other checklists link more specifically to psychiatric diagnoses, such as the Vanderbilt ADHD Rating Scales or the Screen for Child Anxiety Related Emotional Disorders (SCARED). Screening uses brief tools that are designed to catch cases with a disorder, but they often get false positive scores for people who do not have the disorder. Screeners should be followed up by a more accurate test or diagnostic interview as a result. Depressive disorders and anxiety disorders are two-three times higher in people with dyslexia, and attention-deficit/hyperactivity disorder is more common, as well.^{[88][89][90][91]}
• Review of academic achievement and skills: Average spelling/reading ability for a dyslexic is a percentage ranking <16, well below normal. In addition to reviewing grades and teacher notes, standardized test results are helpful in evaluating progress. These include group administered tests, such as the Iowa Tests of Educational Development, that a teacher may give to a group or whole classroom of younger people at the same time. They also could include individually administered tests of achievement, such as the Wide Range Achievement Test, or the Woodcock-Johnson (which also includes a set of achievement tests). The individually administered tests again require more specialized training.^[92][93][94]

Screening

Screening procedures seek to identify children who show signs of possible dyslexia. In the preschool years, a family history of dyslexia, particularly in biological parents and siblings, predicts an eventual dyslexia diagnosis better than any test.^[95] In primary school (ages 5–7), the ideal screening procedure consists of training primary school teachers to carefully observe and record their pupils’ progress through the phonics curriculum, and thereby identify children progressing slowly.^[96][97] When teachers identify such students they can supplement their observations with screening tests such as the Phonics screening check^[98] used by United Kingdom schools during Year one.

In the medical setting, child and adolescent psychiatrist M. S. Thambirajah emphasizes that «[g]iven the high prevalence of developmental disorders in school-aged children, all children seen in clinics should be systematically screened for developmental disorders irrespective of the presenting problem/s.» Thambirajah recommends screening for developmental disorders, including dyslexia, by conducting a brief developmental history, a preliminary psychosocial developmental examination, and obtaining a school report regarding academic and social functioning.^[99]

Management

Through the use of compensation strategies, therapy and educational support, individuals with dyslexia can learn to read and write.^[100] There are techniques and technical aids that help to manage or conceal symptoms of the disorder.^[101] Reducing stress and anxiety can sometimes improve written comprehension.^[102] For dyslexia intervention with alphabet-writing systems, the fundamental aim is to increase a child’s awareness of correspondences between graphemes (letters) and phonemes (sounds), and to relate these to reading and spelling by teaching how sounds blend into words. Reinforced collateral training focused on reading and spelling may yield longer-lasting gains than oral phonological training alone.^[103] Early intervention can be successful in reducing reading failure.^[104]

Research does not suggest that specially-tailored fonts (such as Dyslexie and OpenDyslexic) help with reading.^[105] Children with dyslexia read text set in a regular font such as Times New Roman and Arial just as quickly, and they show a preference for regular fonts over specially-tailored fonts.^[105] Some research has pointed to increased letter-spacing being beneficial.^[105]

There is currently no evidence showing that music education significantly improves the reading skills of adolescents with dyslexia.^[106]

Prognosis

Dyslexic children require special instruction for word analysis and spelling from an early age.^[107] The prognosis, generally speaking, is positive for individuals who are identified in childhood and receive support from friends and family.^[1] The New York educational system (NYED) indicates «a daily uninterrupted 90-minute block of instruction in reading» and «instruction in phonemic awareness, phonics, vocabulary development, reading fluency» so as to improve the individual’s reading ability.^[108]

Epidemiology

The prevalence of dyslexia is unknown, but it has been estimated to be as low as 5% and as high as 17% of the population.^[109] Dyslexia is diagnosed more often in males.^[2]

There are different definitions of dyslexia used throughout the world. Further, differences in writing systems may affect development of written language ability due to the interplay between auditory and written representations of phonemes.^[110] Dyslexia is not limited to difficulty in converting letters to sounds, and Chinese people with dyslexia may have difficulty converting Chinese characters into their meanings.^[111][112] The Chinese vocabulary uses logographic, monographic, non-alphabet writing where one character can represent an individual phoneme.^[113]

The phonological-processing hypothesis attempts to explain why dyslexia occurs in a wide variety of languages. Furthermore, the relationship between phonological capacity and reading appears to be influenced by orthography.^[114]

History

Dyslexia was clinically described by Oswald Berkhan in 1881,^[35] but the term dyslexia was coined in 1883 by Rudolf Berlin, an ophthalmologist in Stuttgart.^{[115][116][117]} He used the term to refer to the case of a young boy who had severe difficulty learning to read and write, despite showing typical intelligence and physical abilities in all other respects.^[118] In 1896, W. Pringle Morgan, a British physician from Seaford, East Sussex, published a description of a reading-specific learning disorder in a report to the British Medical Journal titled «Congenital Word Blindness».^[119] The distinction between phonological versus surface types of dyslexia is only descriptive, and without any etiological assumption as to the underlying brain mechanisms. However, studies have alluded to potential differences due to variation in performance.^[120] Over time, we have changed from the intelligence-based model to the age-based model, in terms of those with Dyslexia.^[121][85]

Society and culture

As is the case with any disorder, society often makes an assessment based on incomplete information. Before the 1980s, dyslexia was thought to be a consequence of education, rather than a neurological disability. As a result, society often misjudges those with the disorder.^[102] There is also sometimes a workplace stigma and negative attitude towards those with dyslexia.^[122] If the instructors of a person with dyslexia lack the necessary training to support a child with the condition, there is often a negative effect on the student’s learning participation.^[123]

Since at least the 1960s in the UK, the children diagnosed with developmental dyslexia have consistently been from privileged families.^[124] Although half of prisoners in the UK have significant reading difficulties, very few have ever been evaluated for dyslexia.^[124] Access to some special educational resources and funding is contingent upon having a diagnosis of dyslexia.^[124] As a result, when Staffordshire and Warwickshire proposed in 2018 to teach reading to all children with reading difficulties, using techniques proven to be successful for most children with a diagnosis of dyslexia, without first requiring the families to obtain an official diagnosis, dyslexia advocates and parents of children with dyslexia were fearful that they were losing a privileged status.^[124]

Stigma and success

The stigma surrounding dyslexia is just beginning to be understood.^[125] As awareness increases, it is informative to observe the long list of notable people with dyslexia who have struggled and ended up with successful careers, among them Whoopi Goldberg, who said:

When I was a kid they didn’t call it dyslexia. They called it you know, you were slow, or you were retarded, or whatever. What you can never change is the effect that the words ‘dumb’ and ‘stupid’ have on young people. I knew I wasn’t stupid, and I knew I wasn’t dumb.^[126]

Their success was not without struggle. Henry Winkler said:

You want so badly to be able to do it and you can’t. And no matter how hard you try, it’s not working … I would study my words. I would know them cold. I would know them backwards and forwards. I would go to class. I would pray that I had retained them. Then I would get the test and spend a lot of time thinking about where the hell those words went. I knew them. They must have fallen out of my head … I didn’t have the slightest idea of how to spell the words that I knew a block and a half away in my apartment the night before.^[127]

Research

Most dyslexia research relates to alphabetic writing systems, and especially to European languages.^[128] However, substantial research is also available regarding people with dyslexia who speak Arabic, Chinese, Hebrew, or other languages.^[129] The outward expression of individuals with reading disability, and regular poor readers, is the same in some respects.^[130]

See also

• Dyscalculia, difficulty comprehending numbers and math
• Learning to read
• Orton-Gillingham

References

This article was submitted to WikiJournal of Medicine for external academic peer review in 2018 (reviewer reports). The updated content was reintegrated into the Wikipedia page under a CC-BY-SA-3.0 license (2019). The version of record as reviewed is:
Osmin Anis; et al. (15 October 2019). «Dyslexia». WikiJournal of Medicine. 6 (1): 5. doi:10.15347/WJM/2019.005. ISSN 2002-4436. Wikidata Q73053061.

Further reading

External links