Gertrude Stein (1874–1946) was an American modernist author. From 1893 to 1897 she was a student of psychologist William James. She experimented with stream of consciousness and results from such experiments were seen by others as examples of automatic writing. However, the Wikipedia article's section on her literary style says,
Despite Stein's work on "automatic writing" with William James, she did not see her work as automatic, but as an 'excess of consciousness'.
The statement has no source. The same claim can be found in Hanna J. Batoréo's paper Was the Birth of Modern Art Psycholinguistically Minded? (Studies in the Psychology of Language and Communication. Warszawa: Matrix 2010), which does not provide a source, either:
(…) her writing process was misunderstood, in 1934, by B. F. Skinner as an example of the “normal motor automatism”. As a matter of fact, Stein had never really accepted the theory of automatic writing, as she did not see her own work as automatic, more as an “excess of consciousness” of someone who worked with words as his/her material.
Where did Gertrude Stein say she saw her work as an "excess of consciousness"?