A memory expert is expected to testify in the trial of Adelaide Archbishop Philip Wilson, the most senior Catholic official in the world to be charged with concealing child sexual abuse.
The 67-year-old this week declared under oath in Newcastle Local Court that two former altar boys never told him they'd been sexually abused by a fellow priest in the 1970s.
Wilson, who's been diagnosed with the early stages of Alzheimer's disease, claims he would have remembered a discussion because he would have been horrified.
But the archbishop said he had no memory of one of the former altar boys, Peter Creigh, telling him in 1976 he'd been sexually abused by priest James Fletcher five years earlier when he was 10.
Magistrate Robert Stone has previously rejected a "no case to answer" submission.
On Thursday the trial will hear from a memory expert - the last defence witness to give evidence.