Psychology 2410A/B Lecture Notes - Lecture 2: Retina, Synaptic Pruning, Visual Acuity

• School: Western University
• Department: Psychology
• Course: Psychology 2410A/B
• Professor: Lynne Zarbatany

Document Summary

100 billion neurons created during prenatal development. Each neuron is associated w/10 000 synapses; synaptogenesis occurs throughout life. Synaptic pruning (removing connections) begins 24 weeks prenatal; why is this needed: eventually 1000 trillion connections, we don"t keep around things we don"t need. Myelination (white matter) encloses axons; fatty insulating material. Increases nerve impulse speed by 100x: sensory motor areas myelinated first; prefrontal cortex last. Part of nervous system that detects input from the enviro. Involves brain sensory receptors, neural pathways &parts of brain: eyes, ears. Pull them apart for convenience, but the divide is fuzzy &sometimes arbitrary. Sensory &perception provide building blocks for higher level cognitive processing. Much of perceptual development happens in infancy. If dishabituation occurs, the baby can discriminate: show one colour until infant gets bored (habituates, show new colour and see if infant reorients (dishabituates) If baby detects change they will show interest again. Requires a behavioural response; eye movement; head turn.