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 four types of metamorphism. Contact metamorphism is a result of heat generated from a nearby magma source. Regional metamorphism consists of change through intense heat and pressure. Hydrothermal metamorphism is a chemical change that occurs when hot fluids circulate through out the rock.etamorphism occurs under the influence of extreme heat, pressure, and/or chemical fluids. A rock undergoing metamorphism changes the texture and mineral composition of the rock but never leaves solid form.