From Psy3241

Hemineglect is a neurological disorder that is also called hemispatial neglect, unilateral spatial neglect and unilateral inattention. It is characterized by an “unawareness or unresponsiveness to stimuli in the side of space opposite the brain damage” (113). Neglect can come in many varieties. However the most common is visual stimuli and limbs. Neglect results from damage to either the left or right parietal cortex, but damage to the right hemisphere is generally more severe.

In an extreme case, a patient with neglect might fail to eat the food on the left half of their plate, even though they complain of being hungry. If someone with neglect is asked to draw a clock, their drawing might show only the numbers 12 and 1 to 6, the other side being distorted or left blank. Neglect patients may also ignore the contralesional side of their body, shaving or adding make-up only to the non-neglected side. Neglect may also present as a delusional form, where the patient denies ownership of a limb or an entire side of the body. Since this delusion often occurs alone without the accompaniment of other delusions, it is often labeled as a monothematic delusion.

Theories of Causation

Theories of causation fall into two different categories, attentional and representational. The attentional theories seek to describe why right hemisphere damage more often leads to hemineglect. Some propose that it is because the right hemisphere dominates space for both sides and the left is mainly concerned with the right side of space. The basic component of the representational theory is that neglect patients suffer from a loss of one side of their visual imagery. This comes from research which asked patients to recall images from their long term memories and the participants were only able to produce the half of images that were not on their neglected side.

Treatments

Some of the early treatments called for patients to attend to the neglected side of space. For instance, if a patient had right hemisphere damage, to help them read, a red marker might be placed at the top of the left page and the patient is told to look at the red marker when they are done on the right side. Another treatment is based off of observations of neurologically intact people and prisms. When they are worn they distort the view 10 degrees to the right. Researchers attempted to see if this effect would allow individuals with hemineglect to begin to see the neglected side. When the prisms were worn for long periods of time, neglect patients improved for 5-17 weeks. Although there are various different rehabilitation techniques, researchers understand that the key is to get the patient to switch their attention.

References

Ogden, Jenni. Fractured Minds.