The document discusses brain development in children and the interaction between genes and environment. It notes that the brain develops rapidly in the first two years of life and that both genes and environment influence this development. Genes determine the basic structure of the brain, but the environment determines which neural connections and cells survive based on use. Early experiences and stimulation can affect the brain by strengthening certain connections.

1. Brain Development in Children Genes vs. Environment

2. Development of the human brain is crucial in the first 2 years of a person’s life. Genes + Environment = Full development

3. The Development of the Brain The Brain weighs 3 lbs 100 billion neurons 60 trillion connections Trees in the Amazon Rainforest Right Hemisphere & Left Hemisphere connected by a fibre bundle

4. Grey Matter  Cell Bodies of Neurons White Matter  Axons Surface of the Brain = Neocortex 47 sub-areas of the Neocortex

5. Development Foetus  Adult Almost all of neurons are generated during the first half of pregnancy Produce 200 000 Neurons / minute during early pregnancy

6. Until first year of life, baby has almost 2x amount of Neurons & Connections as an adult Cells that are part of functioning networks have access to nerve growth factor . Cells compete to survive. Make Connections  survive . No Connection  Die Peak varies with Each area of the brain, but same pattern

7. Nature vs. Nurture Fight between Nature vs. Nurture . Actually, Nature + Nurture Nature  Interaction  Nurture Brain : -Plan governed by genetic expression - Influenced by experience of the organism

8. Genes Structure Base Compound = Letter in alphabet in the genetic code 4 Letters (A,C,G,U) Some have few letters. Some are very long

9. Function Genes Contribute to talent, language, eye color, disease, etc. Very rare that a gene is solely responsible for a particular structure or function

10. Pax6 & Emx2 Pax6 and Emx2: genes that control regionalization of the Pre-neuronogenic Cortical Primordium Pax6: high concentration in Back & Middle of brain Emx2: high concentration in Front & Sides of brain.

11. Gene Mutation Expressed in the embryonic neo-cortex region very early in development . (First 2 months of pregnancy) Compete with each other suppressing the one with mutation

12. Environment Plays an essential role in determining which cells & connections are lost or stabilized . Big effect on the brain’s development

13. Effects on the Brain’s Development Rat Study 2 different settings 1- One rat/cage No activity , contact, input or companionship 2- Many rats/cage Toys , nicely decorated, visitors Some rats started as babies & some as adults

14. Results Rats in CEs had more synapses per neuron than those in ICs in both cases

15. Auditory Study 2 types of kids 1- Kids deaf since birth 2- Kids with good hearing Deaf kids: Something visual and respond Regular kids: Something auditory and respond

16. Results When deaf kids did the visual task , they activated the auditory cortex This happens when people have never heard anything before. Doesn’t work with someone Normally, in the beginning of who became deaf later in life development, the structures of the body fight for the response from certain parts of the brain. Eyes and ears fight for the response from the auditory cortex In these cases, the ear doesn’t activate a response because no sound is heard, so the eyes take over the function of this area X