Tener el encefalograma plano.

Question

What does it mean "tener el encefalograma plano"? It is a colloquial expression. It doesn't have to do with medicine.

Answer 1

I can say: no sé qué le pasa. Nunca tiene ideas interesantes. Creo que le falta imaginación. A lo mejor, tiene el encefalograma plano. (Humorous comment).

I am insinuating that his lack of imagination is because either he can't think properly at the moment or perhaps he is a bit silly. But this is not necessarily this way. In fact, most times this is said jokingly.

It is better to have the doubt.

Answer 2

To be braindead