What is dyslexia? What is the difference between developmental and acquired dyslexia?
- Inability to read
- Acquired = Due to brain damage after learning to read
- Developmental = Acquired just before/after birth
What are some symptoms of dyslexia?
- Hyperactivity
- Motor-perceptual impairments
- Emotional lability
- Coordination deficits
- Impulsivity
What skills are required for reading?
- Letter identification
- Phonological skills (letters –> sounds based on rules)
- Grapheme skills (use visual gestalt of word to access previously learned sound)
- Sequencing skills (sounds are analyzed and combined into sequences)
- Short-term memory (retain information as it is sequentially extracted from written material)
- Lexicon (knowledge of words)
What are the two types of reading?
- Phonological reading (decode by sounds of words)
- Graphemic reading (word is memorized)
What are the four causes of reading disabilities?
- Phonological deficiency (impairments with sound awareness)
- Attentional deficiency (attention cannot be easily shifted, problem with association areas of the parietal lobe)
- Sensory deficiency (individuals with reading disabilities need longer interval between tones to discriminate them, remediation-discrimination training)
- Motor deficiency (cerebellar theory - cerebellum controls movement timing and coordination)
What tests do individuals with reading disabilities perform poorly on?
- IQ tests (low scores on arithmetic, coding, information, and digit span - ACID profile)
- Perform at chance on left-right differentiation tasks
- Verbal fluency is almost static in dyslexics (unchanging)
What is hyperactive child syndrome?
- ADD and ADHD
- Diagnostic criteria: Hyperactivity or restlessness, deficit in sustained attention, impulsive behaviour, duration of at least one year
What are the suggested causes for hyperactivity?
- Brain damage
- Encephalitis
- Genetics
- Allergies
- Lead
- Environment
What is the treatment for hyperactivity?
- Structured environment
- Pharmacological
- Dietary supplements/changes
What is cerebral palsy? What are the motor symptoms? What is it associated with? Where are the brain abnormalities?
- Primary characteristic = motor abnormalities
- Cognitive impairments may occur
- Motor symptoms: spastic, athetoid, rigidity, ataxic
- Associated with: difficult labour, premature birth
- Brain abnormalities: Corticospinal tracts, basal ganglia, brainstem, cerebellum
What is hydrocephalus?
- Increase volume of CSF
- Results from shrinking brain tissue around ventricles, obstruction of flow of CSF results in expansion of ventricles, overproduction of CSF?
- Sudden or gradual onset
- Can cause vision loss, dementia
What is autism? What is the autism spectrum?
- Refers to children without obvious focal cerebral disease. Impaired social interactions, bizarre and narrow interests, language and communication abnormalities. May have preserved intellect
- Spectrum = mild and severe symptoms
What are pervasive developmental disorders not otherwise specified?
- Do not meet criteria for autism
- Show some, but not all, symptoms
What is thought to cause autism?
- Genetics
- Viruses (rubella in first trimester)
- Toxins and environmental pollutants
What are the brain abnormalities of children with autism?
- Larger head and brain size
- Failure of von Economo neurons to develop (associated with rapid communication in the brain)
- Brainstem abnormalities
- Synaptic pruning does not seem to occur
What is Asperger’s syndrome?
- Less severe than autism
- Hyperplexia (precocious development of reading abilities)
What is savant syndrome?
- Narrow range of special abilities
- Triad of retardation, blindness, and musical genius
- Special skill can appear or disappear quickly
- Exceptional memory
What is fragile X syndrome?
- Characterized by facial abnormalities, mental retardation
- May be associated with attention deficits, hyperactivity, anxiety, and unstable moods
- Numerous but poorly formed dendritic spines
- Thin cortex
- Increase in ventricular size
- More common and more severe in men
What is fetal alcohol syndrome? What are the brain abnormalities?
- Physical malformation and mental retardation
- Brain abnormalities: Small brains, abnormal gyri, abnormal clusters of cells
- Learning disabilities, low IQ, hyperactivity, and social problems
- Mild or severe
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The Temporal Lobe32
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Cerebral Asymmetry34
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Language30
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Emotion15
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Neocortical Function6
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The Occipital Lobe19
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The Parietal Lobes19
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Organization of the Motor System19
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Spatial Behaviour29
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Learning and Memory46
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Brain Development and Plasticity26
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Learning Disabilities19
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Plasticity, Recovery, and Rehabilitation of the Adult Brain25
