从给定的一段英文文本中，找出最常用的5个单词。输出这5个单词及对应的出现次数。
文本：
Natural language processing (NLP) is a field of study in artificial intelligence and computational linguistics concerned with the interactions between computers and human languages. As such, NLP is related to the area of human–computer interaction. Many challenges in NLP involve natural language understanding — that is, enabling computers to derive meaning from natural language inputs.
1. "language" - 4 times
2. "natural" - 3 times
3. "NLP" - 2 times
4. "computers" - 2 times
5. "human" - 2 times