Define and give real-life examples of top-down processing and bottom-up processing. Explain how top-down processing and bottom-up processing are related to sensation and perception.

A. describe the model of urban structure most often observed in mega-cities in developing countries. explain how this model differs from common urban structures in north america. b. describe at least two factors leading to the growth of mega-cities in developing or least-developed countries. c. identify and explain two factors that led to the formation of squatter settlements in mega-cities in developing countries.