Not many of us think about how our body automatically adjusts to the space around us, preventing us from bumping into things. We can also automatically locate our limbs without thought, such as our hands or feet. This function changes with dementia progression.
Our sense of body positioning in space is called Proprioception. This perception makes us aware of where our body is relative to objects around us and allows us to move and adjust within our environment. Orienting ourselves in space usually accompanies actions, such as moving around, looking for something, or avoiding 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 our sense of space is primarily visual, it's also perceived with the other senses: kinesthetic (body movement), our sense of balance, gravity, and particular cues. These must work together 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 our body's posture, even with our eyes closed.
As dementia progresses, the individual experiences a profound loss of the mind-body connection.
Simple tasks become challenging-asking them to lift their hand might result in them lifting their foot. They struggle to recognize or pinpoint pain, often indicating an unaffected area as the source of pain. Their limbs become unresponsive, making walking a difficult task. This loss of connection can lead to an overload of the physical nervous system, causing chaotic signals to the brain and triggering panic.
When panic sets in, it triggers the out-of-control fight-or-flight response. Whatever reasoning abilities the person retains shut off as they struggle to escape perceived danger, real or imaginary.
Years ago, I accompanied an elderly husband and wife on a plane trip to Chicago. The wife had Alzheimer's, and with the exhaustion of the airports and claustrophobia of the plane seats, she became sensory overloaded and panicked during the bustle of passengers getting their carry-on bags and crowding the aisles after landing. She struggled to escape her seat, screaming in terror, and worse yet, her legs stopped functioning, and she fell wedged between seats. It took five attendants to help get her off the plane while I continually attempted to calm her down.
As dementia progresses, the individual's hand-eye coordination is often affected, as the brain struggles to recognize the hand to send signals to it. This loss of connection with the body leads to a loss of balance and an increased risk of falling. They may not be able to feel their feet on the floor or their buttocks while sitting in a chair, further complicating their sense of space and safety.
Also, during dementia progression, changes to their vision complicate their sense of space. They progressively lose peripheral vision, which creates tunnel vision. Depth perception is also affected, creating a monovision effect. They can't tell the distance of people or objects or the height of stairs or curbs.
Imagine losing touch with your body. If you can't connect with your physical self to anything around you, it might seem like floating in space.
Every day, we take for granted that we can automatically move through the space around us without bumping into things or falling. We routinely climb stairs, navigate uneven terrain, and effortlessly move through our homes. We can locate our limbs even with our eyes closed and not have to think about these movements because our body automatically does them.
But a person with dementia feels lost in space.
Katya De Luisa resides in Costa Rica and is a dementia educator, consultant, freelance writer, and author of "Journey through the Infinite Mind, the Science and Spirituality of Dementia. www.dementialearninginstitute.com
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