Final answer:
The filiform papillae are not taste receptors but instead contain touch receptors that aid in the mechanical manipulation of food in the mouth.
Step-by-step explanation:
The filiform papillae, which cover the surface of the tongue, are a type of papilla found on the tongue that are involved in the mechanical aspect of processing food in the mouth. Contrary to some other papillae on the tongue that contain taste buds sensitive to chemical stimuli, the filiform papillae's primary function is mechanical rather than gustatory. They have touch receptors that help the tongue move and manipulate food, enabling proper chewing and swallowing. Additionally, the abrasive surface of the filiform papillae facilitates in the mechanical processing of food, similar to how a cat's tongue works during grooming. In summary, the filiform papillae are not primarily involved in taste but are essential for the tactile sensation and mechanics of food handling in the mouth.