Psyc 2012 1st Edition Lecture 9Outline of Last Lecture I. Neural Development: developmental neurogenesis, brain development and environmentA. Today’s lecture goalII. The Human BrainA. Developmental NeurogenesisIII. Gross Development of the human nervous system- early stages of developmentA. ZygoteB. Blastula or blastocystC. GastrulaIV. Formation of the NS in 6 main processesA. Cell proliferationi. Neural stem cell proliferationii. PNET- primitive neuroectodermal tumorB. Cell migrationi. Neural cell migration1. Tangential migration of neural crest cellsC. Cell differentiation i. Two types of differentiation1. Chemical differentiation2. Morphological differentiationa. Chemoattractantsb. Cell adhesion moleculesD. Synaptogenesisi. Cellular activities in both neurons create proper synaptic structureE. Cell death and synaptic pruningi. Key pointii. Neural cell death and neurotrophinsF. Myelinationi. Does not progress evenly throughout the brainOutline of Current Lecture II. Neural development II: effects of postnatal maturation and the environment on neural developmentA. Today’s lecture goalIII. Grasping motor behaviorsA. Neural changes and grasping motor behaviorsIV. Language developmentThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.A. Neural changes and language developmenti. Increased cortical thickness in speech areas for the language the child is hearing and speakingii. We prune neurons and synapses in speech sound areas of other languages that we don’t hear or speakV. Problem solving- Piagetian stages of developmentA. Sensorimotor stagei. Object permanenceB. Preoperational stageC. Concrete operationsi. Conservation of mass uses inductive reasoningD. Formal operations: abstract reasoningi. Deductive reasoningVI. Brain development and the environment- experience, imprinting, and neural plasticityA. Enriched environments and neural development in animalsB. Enriched environments and neural development in humansC. Neural changes due to enriched environments and neural complexity in animalsi. Adult neurogenesisVII. Developmental disorders- autism spectrum disorder and mental retardationA. Autism spectrum disorderi. Symptomsii. Key neural changes in autism1. Undergrowth/underconnectivitya. Hippocampus & amygdalab. Insular cortexc. Brainstem nuclei2. Overgrowth/over-connectivitya. Basal ganglia & motor cortexb. Sensory cortexc. Frontal cortexB. Mental retardationi. Causesii. Neural changes in mental retardationCurrent LectureWeek 6- Lecture 9- 2/12Neural Development II: effects of postnatal maturation and the environment on neural developmentToday’s lecture goal: to explain how postnatal maturation and experiences are associated with change sin neural structure and function.The formation of synapses is key to child development, so, how does behavior correlate with brain development, and how are these brain developmental processes influence by postnatal events?Grasping motor behaviorsAt around 2 months- the hand orients toward an object and gropes to hold itAt around 4 months- baby grasps with entire hand and fingers work together like a clawAt around 6-8 months- “mature” grasp using fingers individually or in groupsAt around 10 months- baby has a fine pincer grasp for holding small objects like cheeriosNeural changes and grasping motor behaviorsWe see increased dendritic maturation in motor cortex neurons because we’re forming more connectionsWe see increased myelination of motor cortex neurons at the last two stages of hand grasp developmentMyelination starts at birth and is the highest during early developmentDecreases in cortical thickness in the hand region of the motor cortex can reflect pruning of ineffective motor neurons and synapses, as well as selection of the strongest connections. Studying this depends on imaging, autopsies, and other indirect methodsLanguage developmentIncreases post-birth12 months- vocabulary starts to form, around 5-10 words24 months- 200-300 words36 months- 500-1000 words, can now use them in sentences72 months- 2500 wordsNeural changes and language developmentIncreased cortical thickness in speech areas for the language the child is hearing and speaking. This may mean:There’s an increase of glial cells; thickness DOES NOT mean new neurons formed. There’s an increase in dendritic branching and synaptogenesisMyelination has occurredSide note- hearing someone talk stimulates neuronsWe prune neurons and synapses in speech sound areas of other languages that we don’t hear of speak; but children who are raised bilingual will retain more speech sound synapses.Loss of these synapses makes it hard but not impossible to learn new languages as an adult, it just requires forming new synapses instead of strengthening old ones. Problem solving- Piagetian Stages of Development1) Sensorimotor stage- birth-2 years old:Object permanence: the idea of “out of sight out of mind”; if babies don’t see it then it doesn’t exist.Focus on sensory information; understanding and responding to it. Understanding cause-and-effectPreoperational stage- 2-6 years old: form mental, word, and drawing/figurative representations of the world. We see creativity through drawing and playingEgocentrismAnimism: attributing human intentions to naturally occurring events. Concrete operations- 7-11 years old: mentally manipulate dimensions, mathematics, strict adherence to rulesConservation of mass uses inductive reasoning- just because something is a different size doesn’t mean its mass changes. Example- taller/thinner glass verses shorter/widerglass. Formal operations: abstract reasoningDeductive reasoning- kids use this to learn strategy. Example- the concept of taking one step back in order to take two steps forward.Neural changes and Piagetian stagesSpurts of brain growth accompany or preceded changes in Piagetian developmentNumber of neurons doesn’t change, but glial cells and synaptic density probably increase. Myelination increases. Brain development and the environment- experience, imprinting, and neural plasticityEnriched environments and neural development in animalsRats raised in an enriched environment performed better on cognitive tasks like solving mazes than rats in standard cages. These experiments looked at how our environments influence our ability to think. Enriched environments and neural development in humansChildren in