After having read Music and Psychophysiology (1896), in which Marie Jaëll used his own scientific works, the eminent physiologist Charles Féré, head doctor at the Kremlin-Bicêtre Hospital in Paris, proposed his collaboration. Marie had thus, from 1897 to 1907, year of the death of Féré, the benefit of the competence of a friend and of the laboratory of a specialist.

« From 1897 to 1907, I did not work alone, Doctor Féré communicated all his search to me as I communicated mine to him. It is at the 14, rue de Tournon, that we have made the repeated prints of a same chord. He compared between them the touches carried out by each finger and said to me : they are similar, therefore it is conclusive. I continued the work with a passionate interest, which made me find what you know...

« I sought the right movements and, by these movements, I found the harmony of the touch, the musical memory, the improvement of the ear, all faculties which seem sleep in each one of us. These movements were unceasingly controlled in experiments at the laboratory of Dr. Féré in Bicêtre. Continued through ten years, these chronometric experiments established the unforeseen fact that the movements of the automated fingers undergo delays which make some pianists be like backward or deficient people - while on the contrary, the thought movement, the right movement, accelerates, as it improves, the response times so as to allow my pupils, to answer the signal of the chronometer with a precision only acquired by strong intelligences ».

Quotation from H. KIENER, Marie Jaëll, Problèmes d'esthétique et de pédagogie musicales, Paris, 1952, p. 72 n. 1.