Something we usually don’t consider is how a healthy brain automatically processes where our body is positioned within the space around us. We are also aware of where our limbs are; how to locate our hand for instance. This ability changes with dementia progression.
Space perception enables us to be aware of our body position and objects around us allowing us to move and adjust to the environment. Orienting ourselves in space usually accompanies our actions; move around, look for something, or avoid injury. This perception of space is processed through our sensory organs, primarily our vision, and gives us a sense of our physical reality.
However, although we might think our sense of space is primarily visual, it’s also perceived with the other senses; kinesthetic (body movement), our sense of balance, gravity, and special cues. All of this must combine to create a unified perception of the body and space around it.
Professor Patrick Haggard, UCL Institute of Cognitive Neuroscience, said, “Our brain constantly keeps track of the movements of the limbs, so that we always know the posture of our body, even with our eyes closed.
This changes with dementia as the individual begins to lose their brain to body connection. If you ask them to lift their hand, they might lift their foot. They eventually can’t recognize or pinpoint pain and often will show you an unaffected area thinking this is the location that hurts. They have trouble getting their limbs to react; like getting legs to work when walking. Their physical nervous system can become overloaded, and the signals to the brain become chaotic or tangled. I cared for a woman that whenever she became confused or upset, her legs stopped functioning. Hand/eye coordination becomes affected when the brain doesn’t recognize the hand and can’t send signals to it. As dementia progresses, the individual completely loses touch with their bodies.
When this happens, they can’t rely on their sensory input to automatically find their position in the space around them. They may not be able to feel their feet on the floor or their buttocks while sitting in a chair. When you lose body connection, you also lose your sense of the environment around you.
Imagine what this is like? It must feel like floating in space if you can’t connect with your physical self or to anything around you.
Every day we take for granted that we can automatically move through the space around us and don’t bump into things or fall. We routinely climb stairs or navigate uneven terrain and effortlessly move through our home, and we can locate our limbs even with our eyes closed. We don’t even think about these movements because our body automatically does it.
But the person with dementia can’t.