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.
The two classifications of metamorphic rock are foliated and non-foliated : 1. Foliated metamorphic rock such as gneiss display banding and regrouping of its mineral constituents as a result of enormous pressures and heat. The banding forms perpendicularly to the direction of pressure.The pressure is usually related to tectonic plate collisions.. Foliated metamorphic rock such as gneiss display banding and regrouping of its mineral constituents as a result of enormous pressures and heat. The banding forms perpendicularly to the direction of pressure.