Intellectually, Ben S. Bernanke was prepared to tackle the gravest economic crisis since the 1930s as chairman of the Federal Reserve. A Princeton University economics professor, he was an expert on the causes of the Great Depression. He was a practitioner as well as economic historian, serving on the Fed’s Board of Governors and as chairman of President George W. Bush’s Council of Economic Advisers. Yet in other ways, from dealings with reporters to bankers and members of Congress, there was little that could have prepared Bernanke for the challenges to come. Here are some highlights of his eight-year term