Dementia is a condition that changes the way a person’s brain works. It can make it hard for someone to remember things, think clearly, or do everyday tasks. One of the hardest things for families to see is when a loved one with dementia starts to forget the faces of friends and family. This is not just about forgetting names or details. It is about losing the ability to recognize people who have been close for years. This loss can be confusing and painful for everyone involved.
The reason dementia affects the ability to recognize friends is because of changes that happen deep inside the brain. Scientists have found that a part of the brain called the hippocampus plays a big role in memory, especially social memory. Social memory is what helps us remember who people are, how we know them, and why they matter to us. When dementia starts to take hold, this part of the brain begins to break down in a way that makes it harder to hold onto those memories[1].
Researchers at the University of Virginia School of Medicine have discovered something important about how this happens. They found that there are special protective “nets” in the brain called perineuronal nets, or PNNs. These nets wrap around certain nerve cells in the hippocampus and help keep connections between brain cells stable. When these nets are strong, memories stay strong. But in people with Alzheimer’s disease, which is the most common form of dementia, these nets start to break down. When that happens, the brain loses the ability to keep memories of friends and family in place[1][2][4].
In studies done with mice, scientists saw that when these nets were damaged, the animals could no longer tell the difference between a familiar mouse and a new one. They stopped spending more time with mice they knew, which is a sign that they had lost their social memory. When the researchers used a drug that helped protect these nets, the mice were able to keep their memories of other mice and still recognized them as familiar[1]. This shows that the breakdown of these nets is directly linked to the loss of the ability to recognize friends and family.
The same thing happens in people. When the perineuronal nets in the hippocampus break down, it becomes harder for someone with dementia to recognize the faces and voices of people they have known for years. This is not because they do not care about those people anymore. It is because the brain’s ability to store and recall those memories is damaged[2][4]. The loss of these nets means that the brain can no longer hold onto the details that make someone familiar.
Other research has shown that a specific area of the hippocampus, called the CA2 region, is especially important for social memory. When this area is affected by dementia, it becomes much harder to remember who people are and how they fit into your life[7]. This is why someone with dementia might look at a close friend and not know who they are, even if they have known each other for decades.
It is not just about memory loss. Dementia can also affect the way the brain processes emotions and social cues. People with dementia may have trouble understanding facial expressions, tone of voice, or body language. This makes it even harder to recognize friends, because they rely on more than just memory to know who someone is. They also use emotional and social signals, and when those are lost, it becomes much harder to feel connected to others[5].
The breakdown of perineuronal nets and the damage to the hippocampus are not the only factors. Dementia can also cause changes in other parts of the brain that are involved in recognizing faces and processing social information. These changes can make it harder for someone to put together all the pieces that make a person familiar. It is like trying to solve a puzzle with missing pieces. The brain can no longer see the full picture, so it cannot recognize the person in front of them[7].
Even though there is no cure for dementia yet, scientists are working hard to find ways to slow down or stop the damage to the brain. Some studies are looking at drugs that could protect the perineuronal nets and keep them from breaking down. If these drugs work in humans, they could help people with dementia keep their memories of friends and family for longer[1]. Other research is focused on finding ways to support the brain and help it work better, even when it is damaged by dementia[5].
For families and caregivers, it is important to understand that the loss of recognition is not a choice. It is a result of changes in the brain that are beyond the person’s control. Being patient, kind, and supportive can make a big difference. Familiar music, routines, and gentle reminders can help someone with dementia feel more connected, even when they cannot recognize faces[3]. Technology is also being used to help families capture life stories and memories, so that even if someone forgets, their story is not lost[3].
Dementia changes the way the brain works, and that includes the ability to recognize friends. The breakdown of protective nets in the brain, damage to the hippocampus, and changes in how the brain processes social information all play a role. Scientists are learning more every day about how these changes happen and what can be done to help. For now, the best thing families can do is to be there, to offer love and support, and to help their loved ones feel connected, even when memories fade[1][2][3][4][5][7].
[1] https://cvillerightnow.com/news/208802-uva-researchers-find-family-forgetfulness-cause-in-alzheimers-patients/
[2] https://www.mcknights.com/news/degradation-in-brain-contributes-to-loss-of-social-cognition-memory-among-alzheimers-patients-study-finds/
[3] https://nursing.gmu.edu/news/2025-11/caregivers-invisible-backbone-dementia-care
[4] https://www.news-medical.net/news/20251110/Scientists-pinpoint-a-reason-Alzheimere28099s-patients-forget-loved-ones.aspx
[5] https://pmc.ncbi.nlm.nih.gov/articles/PMC12627961/
[7] https://www.sciencealert.com/we-may-now-know-why-alzheimers-erases-memories-of-our-loved-ones
