Advanced Search Abstract A multiple case study was conducted in order to assess three leading theories of developmental dyslexia: Sixteen dyslexic and 16 control university students were administered a full battery of psychometric, phonological, auditory, visual and cerebellar tests.
Magnocellular Impairment Of late, the magnocellular theory of dyslexia has gained much attention. This theory holds that the visual, learning, and processing issues found in dyslexics may be due to a deficit in the magnocellular pathway.
This is an area of the brain that is sensitive to visual motion and helps focus the direction of our gaze in response to movement. The magnocellular pathway also contributes to the control of eye movement.
For more more info about the flow of visual and motor information and the magnocellular pathway: Cerebellar Impairment In the cerebellar impairment theory, there is a belief that there is a mild dysfunction of the cerebellum.
The cerebellum is needed for timing motor control. Impairment of the cerebellum may lead to an inability to effect the timed eye movements necessary for reading or the phonological processing deficits that are responsible for causing dyslexia.
The cerebellum is also necessary for the fluid interpretation of letters to sounds grapheme-phoneme relationships that are crucial to reading text. For more information about the cerebellum: Phonological Disorder Proponents of the phonological-deficit theory believe that dyslexia is the direct result of impairment in the ability to process and represent speech sounds.
Most scientists in the field of dyslexia favor this theory which asserts that in order to learn a writing system based on an alphabet, the brain must be able to map letters to speech sounds grapheme-phoneme conversion.
Many dyslexics find it hard to retain speech within their short-term memories or to break up this speech into shorter segments of sound phonemes. Learn more about the phonological approach and theory: This is unrelated to hearing impairments.
People with APD tend to have normal hearing ability. But they do find it difficult to process the information they hear. This makes it hard for them to recognize what they hear. This theory holds that the dyslexic finds it hard to process and interpret short segments of sounds within a short span of time.
Visual Processing Disorder Dyslexia as a visual processing disorder is the most traditional way of viewing reading difficulties. This theory believes dyslexia to be the result of a visual impairment that makes it difficult for the dyslexic to process information from the letters and words of a written text.
Visual processing issues include visual crowding the inability to recognize a single object in a crowded environmentproblems with binocular vision coordinating both eyesand poor vergence control both eyes must rotate in opposite directions at the same time to arrive at binocular vision.
Learn more about the visual processing approach and theory:Dyslexia Definition, Five Causal Theories, Research One favored definition of Dyslexia tells us that: “Dyslexia is characterized by an unexpected difficulty in reading in children and adults who otherwise possess the intelligence, motivation, and schooling necessary .
Dyslexia: an overview of recent research. Abridged from Everatt and Reid From Reid, G. (ed.) This has aided explanations of dyslexia and supported policy and practice. the dominant causal viewpoint about dyslexia is the phonological deficit hypothesis.
This perspective has been derived from the substantial evidence that difficulties in. Dyslexia is a common learning issue that affects reading and other skills. Researchers think genes and brain function might play a role in dyslexia.
Find out what could cause dyslexia. Researchers looking into the role of genetics in dyslexia say it can run in families. If your child has dyslexia.
Biological theories of dyslexia. Jump to navigation Jump to search The primary symptoms of dyslexia In , however, the study by Simone Gori et al.
published in Cerebral Cortex (journal) demonstrated a clear causal link between the magnocellular-dorsal pathway deficit and dyslexia. Naming speed deficit and double deficit theories. Dyslexia is a learning disorder that affects your ability to read, spell, write, and speak.
Kids who have it are often smart and hardworking, but they have trouble connecting the letters they see. This model is inﬂuential because it explains both dyslexia and literacy from causal and behavioural perspectives.
The three elements of this model, bio- A framework which offers explanations at different levels, the Dyslexia and Literacy: Theory and Practice.
Edited by Gavin Reid and Janice Wearmouth. C John Wiley & Sons.