Drain artichokes, reserving marinade; chop artichokes coarsely. In a 2- or 4-cup electric slow cooker, combine artichokes, chiles, mayonnaise, and cheese. Cover and heat until cheese is melted (45 minutes to 1 hour). Stir gently to mix ingredients, then blend in 1/2 to 1 tablespoon of the reserved artichoke marinade to give mixture a good dipping consistency. Serve hot. Makes about 1.5 cups.