sentences:  A single cell recording experiment with monkeys demonstrated the different level of activation of mouth mirror neurons when monkey observed mouth movement depending on context (ingestive actions such as sucking juice vs. communicative actions such as lip-smacking or tongue protrusions).An fMRI study also showed that mirror neurons respond to the action of grasping a cup differently depending on context (to drink a cup of coffee vs. to clean a table on which a cup was placed).One criticism of mirror neurons is that since they show that same muscle groups is used for someone watching an action as someone completing an action, they only predict actions, not beliefs or desires.