Dr. Ilan Shalef, head of medical imaging at Soroka University Medical Center, told CNN on Monday that Sharon's reactions are hard to interpret.

CNN: 'Significant brain activity' in comatose Ariel Sharon

But the team of medical researchers from Israeli and U.S. institutions used recently developed methods to assess his brain's responsiveness at Soroka University Medical Center in Beersheba.

CNN: STORY HIGHLIGHTS

Alon Friedman, a neurological director at Israel's Soroka Medical Centre in Beersheba, said the findings suggested that even in Mr Sharon's comatose state, "he might be listening, and some important information goes into his brain and is being processed".

BBC: Ariel Sharon: Israeli ex-PM in coma 'has brain activity'