Sensory and perceptual problems

Damage to the right side of the brain or the parietal and occipital lobes of the brain can cause sensory and perceptual problems. These areas of the brain process the input from our senses.

For example, when eating an apple our brain will report on the following:

• Touch (round and smooth)
• Taste (sweet and ripe)
• Sound (crunchy)
• Smell (fresh)
• Sight (red)

Brain disorders such as traumatic brain injury (TBI) can disrupt our senses as well as our perception of what our senses tell us. Our sensory and perceptual systems include:

• auditory (sound)
• visual (colour, shape, size, depth and distance)
• tactile (touch relating to pain, pressure and temperature)
• olfactory (smells)
• gustatory (taste).

While problems can occur with our sensory systems, visuospatial problems are often more noticeable. Possible issues include:

• drawing objects
• recognising objects (agnosia)
• telling left from right
• mathematics (discalculia)
• analysing and remembering visual information
• manipulating or constructing objects
• awareness of the body in space (e.g. climbing stairs)
• perception of the environment (e.g. following directions).

A well-known problem is neglect, where the brain ignores one side of all it perceives – usually the left-hand side. For example, a person may ignore food on the left side of a plate or fail to copy aspects on the left side of a picture.

Elsie

Elsie was a 52-year-old woman who had a stroke three years ago and since then had problems with sideswiping parked cars and posts on the left side of her car. Elsie visited her doctor to have her eyesight checked. She was referred to a neuropsychologist who diagnosed the problem as left-sided neglect. When asked how she managed to drive, Elsie said she stayed in the left lane and would know to steer right when she heard her tires going off the road.

Lincoln

After a car accident Lincoln could not even recognise a photo of himself. If separated from his family in a large crowd he was unable to find them again. One of the biggest problems he faced was that others could not understand his ability to see and recognise objects, but not other faces.

A person with neglect might be unaware of the issue, and hence it’s important to identify during rehabilitation and provide them with education.

Retraining skills is one way to manage visuospatial problems and usually involves repetitive and intensive exercises for a specific skill or task (e.g. drawing an object while receiving feedback).

Changing the environment or expectations involves modifying the environment to provide more support or reducing the demands of a particular skill. Reducing the demands of a skill can be as simple as shifting furniture at home so that walking around the house is easier and support might be fitting a handrail to make climbing stairs easier.

Compensatory strategies are very important in rehabilitation as they are designed to improve areas of difficulty post brain injury. For example, Elsie may be taught to turn her head or body to scan the environment properly due to her neglect of things on her left side.

A range of specialised equipment is available to fit into a person’s home or assist with community access.

External prompts are things like:

• colour stickers for object recognition
• bright lights on the floor
• musical or sound prompts
• stencils or transparent paper for copying
• handrails and other safety devices.

Recognising objects could involve the person shutting their eyes and relying more on other senses like touch, hearing and smell.

The rehabilitation strategies described may be developed by a neuropsychologist, occupational therapist or physiotherapist.