Development of tolerance. Over time, the brain adapts in a way that actually makes the sought-after substance or activity less pleasurable. In nature, rewards usually come only with time and effort. Addictive drugs and behaviors provide a shortcut, flooding the brain with dopamine and other neurotransmitters.
There are two types of metamorphism: contact metamorphism and regional metamorphism. Contact metamorphism is a type of metamorphism where rock minerals and texture are changed, mainly by heat, due to contact with magma.This is an easy name to recall if you remember that these rocks change by actually coming in contact with something very hot, like magma.egional metamorphism is a type of metamorphism where rock minerals and texture are changed by heat and pressure over a wide area or region. Contact and regional metamorphism differ in both the area and pressure involved.
there are three basic types of rocks that planet earth is composed of igneous sedimentary and metamorphic follow these simple guidelines to determine the three types of rocks when looking at various types of rocks in the fieldetamorphic rocks metamorphic rocks are types of existing rocks that have been altered in form as a result of changes in heat and pressure in mountainous regions for example where rock matter is pressed and altered by plate tectonic activity metamorphic rocks are very common