Attention is generally defined as "the application of the mind to a mental state.
Accordingly we find that the knowledge of the words of the other person and the meaning thereof results in a mental state agreeable or disagreeable.
A percept, then, while the simplest form of thought, is seen to be a mental state.
From the standpoint of psychotherapy it is important to remember that certain serious organic lesions may show their first signs in the patient's mental state.
The above list will hopefully provide you with a few useful examples demonstrating the appropriate usage of "mental state" in a variety of sentences. We hope that you will now be able to make sentences using this group of words.