Which section of the insect's body is specialized for sensory function?

The head is the section of an insect's body that is specialized for sensory functions.

Specifically, the section in question is top- or upper-most in an insect. It joins to the thorax (middle region), which segues into the abdomen (last region). It will be the location of the insect's antennae for sensing, eyes for seeing, and mouth parts for tasting.