If you see it, then you know it. If you heard about it, then you know it. mental states vocabulary: see, heard, think, smell, taste, know, remember.5 senses words revision.This product works best on students with Autism / ASD to learn about social thinking, making inference and taking perspectives.**********************************************************************The Picture Communication Symbols ©1981–2017 by Mayer-Johnson LLC a Tobii Dynavox company. All Rights Reserved Worldwide. Used with