A Formula 1 driver is the sole occupant of the cockpit. But they are far from alone.
The radio connects them to their engineers - chiefly, their race and performance engineers - but also a wider selection of senior personnel if a situation requires further input. These voices are key to every driver's session - and some of them, such as Peter Bonnington (Lewis Hamilton's Mercedes race engineer) - or Rob Smedley, who made a famous connection with Felipe Massa at Ferrari, become well-known as a result.
There are other engineers that make up the vital team-within-a-team for every driver - tyre specialists, aerodynamicists, controls engineers, engine engineers, and on it goes. An F1 driver can really never succeed alone.