Hadamard(1945/1954) later undertook his own informal inquiry among mathematician in America, querying such mathematician as George Birkhoff, Norbert Wiener, George Polya, and Albert Einstein about the mental image they used in doing mathematics. David and Hersh (1981, p.308) use the term cognitive style in mathematics to characterize the difference in approach to sovling problems that Hadamard indentified. Indeed, Hadamard's investigation, casually conducted and incompletely reported as it was, did anticipate a subsequent body of reseach into cognitive styles and their relation to mathematical thinking, albeit the thinking of less gifted doers of mathematics.