Sensory Changes and Challenges

One of the main challenges a person with Dementia may face relates to how sensory information is interpreted by our unravelling brains. It has been long recognised by people with dementia that the way we experience the world though our senses changes (and continues to change) as our disease progresses. Unfortunately, these changes are often dismissed by clinicians, doctors and those around us because they have overlooked the obvious cause (our brains) or dismiss it because they can “do nothing”. This dismissal disempowers us and leads us to doubt ourselves, much to our detriment, and degrades our condition further.

I wish to, over a series of articles address some of the major sensory challenges we may face. But before I begin I would like to point you to an excellent resource produced by our good friends in Scotland, Donna and Agnes Houston. The first is a simple pdf document Sensory Challenges Leaflet and the second is a short video resource Dementia and Sensory Challenges Video. These resources will help you understand some of the challenges and some strategies to overcome them.

Now let us consider the main senses. How many senses do we have? Five right? No wrong! As little tackers we were taught that we had 5 senses.

• Sight
• Taste
• Touch
• Hearing – Sound
• Smell

That’s enough “sense” for any 5 year old (or teacher) but today it is considered that we have at least nine (9) senses – if not up to twenty one senses. When you see the list it will make “sense“.

Now that’s an interesting expression we use all the time “makes sense“. Meaning it logical, but what makes sense when we can’t trust our sensory interpretation?

Following is a list of these senses. When you read though it, it will make sense.

• Sight: Shape, colour etc. What we see with our eyes.
• Taste:  (sweet, salty, sour, bitter, and umami)
• Touch:  This has been found to be distinct from pressure, temperature, pain, and even itch sensors.
• Pressure: Obvious sense is obvious but hard to explain.
• Itch:  Surprisingly, this is a distinct sensor system from other touch-related senses.
• Thermoception:  Ability to sense heat and cold.
• Sound:  Detecting vibrations along some medium, such as air or water that is in contact with your ear drums. This is fundamental to our ability to communicate with others.
• Smell: Our olfactory sense. When combined with taste pretty much describes our food.
• Proprioception:  This sense gives you the ability to tell where your body parts are, relative to other body parts.
• Tension Sensors:  These are found in such places as your muscles and allow the brain the ability to monitor muscle tension.
• Nociception:  In a word, pain It is its own unique sensory system.  There are three distinct types of pain receptors: cutaneous (skin), somatic (bones and joints), and visceral (body organs).
• Equilibrioception:   The sense that allows you to keep your balance and sense body movement in terms of acceleration and directional changes.  This sense also allows for perceiving gravity.  The sensory system for this is found in your inner ears and is called the vestibular labyrinthine system.
• Stretch Receptors:  These are found in such places as the lungs, bladder, stomach, and the gastrointestinal tract.  A type of stretch receptor, that senses dilation of blood vessels, is also often involved in headaches.
• Chemoreceptors:  These trigger an area of the medulla in the brain that is involved in detecting blood born hormones and drugs.  It also is involved in the vomiting reflex.
• Thirst:  This system more or less allows your body to monitor its hydration level and so your body knows when it should tell you to drink.
• Hunger:  This system allows your body to detect when you need to eat something.
• Magnetoception:  This is the ability to detect magnetic fields, which is principally useful in providing a sense of direction when detecting the Earth’s magnetic field.  Unlike most birds, humans do not have a strong magentoception, however, experiments have demonstrated that we do tend to have some sense of magnetic fields.
• Time:  This one is debated as no singular mechanism has been found that allows people to perceive time.  However, experimental data has conclusively shown humans have a startling accurate sense of time, particularly when younger. The mechanism we use for this seems to be a distributed system involving the cerebral cortex, cerebellum, and basal ganglia.  Long term time keeping seems to be monitored by the suprachiasmatic nuclei (responsible for the circadian rhythm).  Short term time keeping is handled by other cell systems.
• Humour: Not defined as a human sense as such but very relevant to us, and last if not as equally important;
• Justice: Again very relevant to our sense of self – our sense of Justice.

This list (19+ senses) makes some sense to most people. I would begin my next article discussing my experiences with the sense of Touch. (Please note: I’m not a touchy-feely type of person).

As a final note I would like to add that I will approach my experience with a sense of humour – to illustrate its importance.

Observations and Challenges:

Post 1: Sensory Challenge – Touch        Post 2: Sensory Challenge – Sound