Former Attorney General John Ashcroft on Thursday disavowed the now-defunct legal reasoning used to justify harshly questioning terrorism suspects, but dug in his heels to defend White House officials who pressured him while he was hospitalized four years ago to approve terror surveillance programs.

For a House Judiciary Committee hearing focused on a somber subject — whether methods used to interrogate al-Qaida plotters amount to torture — the four hours of testimony included moments of humor and repeated problems pronouncing the names of terror suspects.