What is the piriform lobe or 5th lobe involved in complex emotion behaviors?

A fifth small lobe called the island (insula) hidden deep inside each hemisphere, but it does not involve complex emotion behaviors. (Plural form: insular)

http://www.healthline.com/galecontent/brain-2

However, there is the Limbic lobe (which is really a system not a lobe) that is involved in complex emotional behaviors. http://www.sci.uidaho.edu/med532/limbic.htm