brain activities

I don't understand your question. Can you give some examples of these "activities" please?

For example working with computers.
I think "brain based activities" can conveys the meaning, doesn't it?

I still don't get you. I mean even making a cup of tea requires some brain activity, doesn't it?!

teechrI still don't get you. I mean even making a cup of tea requires some brain activity, doesn't it?!

That's right; but in the context I've used it, it refers to the activities in a workplace.

gillyflowerCan I use "brain activities" to refer to physical activities which need brain to be done?

A more usual term is "mental activity", but normally a distinction is made between mental activity and physical activity.