People with a diagnosis of Alzheimer’s may not always experience memory loss as their first symptom of the disease, with younger people more likely to have problems with judgement, language or visual and spatial awareness than older people.
People living with dementia can have difficulties with vision and perception which causes them to misinterpret the world. The process of seeing is complicated and there are many points where things can go wrong.
Disturbances in vision and perception can cause emotional responses and even safety risks.
Visuospatial function refers to cognitive processes necessary to “identify, integrate, and analyze space and visual form, details, structure and spatial relations” in more than one dimension.
Visuospatial skills are needed for movement, depth and distance perception, and spatial navigation. Impaired visuospatial skills can result in, for example, poor driving ability because distances are not judged correctly or difficulty navigating in space such as bumping into things.
Visuospatial processing refers to the “ability to perceive, analyze, synthesize, manipulate and transform visual patterns and images”. Visuospatial working memory is involved in recalling and manipulating images to remain oriented in space and keep track of the location of moving objects.
Visual Awareness problems:
- being less sensitive to differences in contrast, such as black and white, and contrast between objects and background
- being less able to detect movement
- changes to the visual field (how much you can see around the edge of your vision, while looking straight ahead)
- being less able to detect different colours. For example, a person may have problems telling the difference between blue and purple
- changes to how the pupil reacts to light
- problems directing or changing gaze
- problems with the recognition of objects, faces and colours
- losing the ability to say what has been seen
- double vision
- problems with depth perception (judging the distance of objects from the person).
- Difficulties with orientation
Spacial Awareness problems:
- at its most simplistic it is an awareness of where your body is in relation to everything else, and there may also be a time factor involved (i.e what is likely to happen in the next few moments).
- having trouble judging distances e.g. when going up and down steps
- bumping into things
- swerving to avoid door frames
- difficulties reaching for things , such as a cup of tea or door handle
- getting lost or disorientated, even in familiar environments.
- reaching out for things and missing them
- A hallucination can involve seeing, hearing, smelling, feeling, tasting (or a combination of them all) something that isn’t there.
- Hallucinations are caused by changes in the brain.
- Hallucinations experienced by people with dementia can involve any of the senses, but are most often either visual (seeing something that isn’t really there) or auditory (hearing noises or voices that do not actually exist)
- They seem real to the person experiencing them but cannot be verified by anyone else.
- a visual hallucination could be seeing bugs crawling over the bed that aren’t actually there.