claim: Serotonin induces neuromodulation by binding to receptors.
evidence: Player versus environment , or PvE -LRB- also known as player versus monster , or PvM in some communities -RRB- , is a term used in online games , particularly MMORPGs , CORPGs , MUDs , and other online role-playing video games , to refer to fighting computer-controlled enemies -- in contrast to PvP -LRB- player versus player -RRB- .. MMORPGs. Massively multiplayer online role-playing game. computer-controlled enemies. Mob ( video gaming ). player versus player. player versus player. Usually a PvE mode can be played alone , with human companions or with AI companions .. Artificial intelligence. The PvE mode may contain a storyline that is narrated as the player progresses through missions .. It may also contain missions that may be done in any order .. For example , Guild Wars narrates its story by displaying in-game cut scenes and dialogue with non-playable characters -LRB- NPCs -RRB- .. Guild Wars. Guild Wars. To enhance replayability , missions can often be completed many times .. Characters playing in this mode are often protected against being killed by other players and / or having their possessions stolen .. killed by other players. Player killer. An example of a game where this is not the case is Eve Online , where players can be , and often are , ambushed by other human players player versus player while attempting to complete a quest .. player versus player. player versus player. Eve Online. Eve Online. Some games , such as World of Warcraft , offer the player the choice of participating in open-world PvP combat or doing quests without PvP interruption through use of specialty servers and temporary player flags .. World of Warcraft. World of Warcraft