Notes: Assignment 4 due next Thursday Will have exam review questions next week Class questions Human Neuropsychology (486 / 686) Lecture Chapter 23 & 24 . “Brain Development and Plasticity” 2 The Development of the Human Brain Neural Tube Developmental Abnormalities - Occur due to genetic program errors, trauma, toxins, disease Stages of Brain Development Neuron Generation Neural Stem Cells - Capacity for selfrenewal - produce progenitor cells Cell Migration and Differentiation Neural Maturation Dendrites Arborization Spine formation Axons Athetosis - http://www.youtube.com/watch?v=gNKKZAfMr8M Dystonia http://www.youtube.com/watch?v=2O014fPXScU&feature=PlayList&p=5F72 AD603D2AD188&index=0 Synapse Formation and Pruning Experience expectant Development depends on the presence of sensory experiences Experience dependent Generation of synapses unique to the individual Glial Development Myelination Imaging Studies of Brain Development Patterns of grey matter loss Developmental disorders Cortical thickness and vocabulary Development of Problem-Solving Ability conservation: http://smedia.depaul.edu/lcamras/water.mpg Growth Spurts in brain during each stage Environmental Influences on Brain Organization Complex environments increase brain size Behavioral advantages Experience: Neural connectivity and Representational plasticity Deprivation - Amblyopia Enrichment - increased representation Brain Injury and Plasticity Kennard Principle Functions are spared when injury occurs early in development Effects of brain injury depend on: Behavior affected Extent and location of damage Age at injury Brain Injury and Plasticity Effects of damage on language Childhood aphasia – 1. Language survives early damage 2. Due to reorganization 3. Right hemisphere damage causes similar deficits to adults. Reorganization of Language Reorganization depends on area of damage (left hemisphere) Special left hemisphere anatomy Mechanisms of Recovery The effects of early brain lesions on behaviors: 1. Complete recovery of function if injury occurs during neurogenesis 2. Injury during migration and differentiation is devastating 3. After migration and differentiation the brain can recover Plasticity and recovery: 1. Generation of new neurons 2. Reoganization 3. Generation of new circuitry Autism Spectrum Disorders Autism – impaired social interaction, unusual and narrow interests, language and communication problems, need for “sameness” without obvious focal cerebral disease Causes: genetic, viruses Various brain abnormalities: Larger head and brain size than normal Frontal lobe – social interaction Cerebellum – coordination and habituation Temporal Lobe - memory Brainstem – facial abnormalities Autism Spectrum Disorders Asperger’s Syndrome Less severe than autism, have language Hyperlexia Savant Syndrome Narrow range of special abilities Kim Peek: http://www.youtube.com/watch?v=jL0SthoRMC8 http://video.google.com/videoplay?docid=-6097787318198018019#