The human mind is able to create an imagination of the area around him self. Contrary to animals, humans can imagine places and rooms you can‘t see, just by recalling your experience. You know it from the situation of explaining a route to a tourist. It even helps drawing a little sketch (for example a map with landmarks) to support your verbal navigation instructions. The formation of the inner 'imaginary map' is contingent upon certain abilities of orientation and imagination.
The ability of making inner 'imaginary maps' is called cognitive 'mapping' and it is vital for succeeding a wayfinding process.
Your mind builds the 'imaginary map' from every bits of information received: little information gives poor mapping, much information gives detailed mapping. And information in this case can be everything from what you see to things you know by experience.
Once you have formed a cognitive 'map' inside your head, this map enables you to navigate in the area by using your experience of the location only.
These abilities differ from person to person. Some people form their 'imaginary map' automatically, for others it takes some time, and some do not have the ability at all.
Emotional states and wayfinding
'Mapping' a buildings inside your head is a mental process that is not equally developed for everybody. Certain diseases and emotional states may reduce 'map building' dramatically.
In the healthcare segment some user groups are exposed to certain irrational emotional feelings like stress, fear, anxiety, grief, sorrow, sadness, depression, etc. These feelings can be so overwhelming that they in fact need manual assistance finding their way.
A person visiting a hospital could typically be in a stressed situation and therefore needs clear information as his ability to 'map' the building has gone down dramatically
It might also be useful to use larger type sizes than in an office environment as the user is typically in a hurry, and there is a higher percentage of elderly people who by nature may have increasing levels of visual impairment.
It is for this specific reason that at all time it is recommended to avoid the use of floor plans as an information resource to support the cognitive mapping. Besides the fact that the ability for cognitive mapping differ a lot from person to person, the emotional state of a person affects this process dramatically. Using floor plans as a plain data source, will involve complex spatial processing before the output can be used for the process of cognitive mapping. Instead of reducing complexity, indoor maps will in most cases increase the complexity in the process towards cognitive mapping.
Provide your visitor with clear instructions at key-locations and reduce spatial processing at any time. That is the key to increase the chances for a decent wayfinding experience for viistors of large and complex buildings.