In the cell doctrine, what is the first cell also termed?

• A. sensus communis ('common sense')
• B. first ventricle
• C. sensus universalis
• D. common sense area

Answer: (A)

In the cell doctrine, the brain is viewed as built from discrete functional units, each tied to a specific mental function. The very first cell is described as the one that gathers and integrates input from all the senses into a single, coherent perception—the common ground on which other faculties build. That integrating role is captured by the term sensus communis, meaning "common sense." The idea is that this first cell provides a shared, common basis for experience, which is why sensus communis is the label used.

The other terms don’t fit this framework: the first ventricle refers to an anatomical space rather than a functional cell, sensus universalis is a separate philosophical concept about a universal sense rather than the first integrative cell, and common sense area isn’t a recognized term in this doctrine.