Toronto: Alzheimer's not only steals the memory but also hinders people's ability to recognise faces -- slowly taking them away from their loved ones, researchers have found. Also known as "holistic perception," visual face perception plays a fundamental role in human communication and is thought to be dependent on the ability to perceive a face as a whole. For the study, the team from the University of Montreal recruited people with Alzheimer's along with healthy participants to test their ability to perceive faces and cars in photos that were either upright or upside down. Compared with the upright faces, people with Alzheimer's were much slower and made more mistakes than the healthy individuals. This led the researchers to believe that "holistic face recognition" becomes impaired in Alzheimer's patients. “People with Alzheimer's disease also demonstrated normal recognition of the upright cars, a task that in theory does not require holistic processing. This suggests that Alzheimer's leads to visual perception problems specifically with faces," noted lead researcher and professor Sven Joubert. This impairment is observed in the early stages of the disease and the findings may help families understand better their loved one's inevitable difficulties and lead to new avenues to postpone this painful aspect of the disease. Overall, the study published in the Journal of Alzheimer's Disease explains the mechanism involved in the problem that people with Alzheimer's have with recognising the faces of family members or celebrities.