Neuropsychology
Three classic tasks, five fictional profiles, and one question worth getting right: is this person not attending to the left, or not seeing it?
Simulated — invented profiles, generated performance, original graphics
By the end you should be able to say why neglect is not blindness on one side, and what task signature distinguishes them.
About 30 minutes. Nothing you do here is saved or sent anywhere.
You are not being assessed and nothing here can assess anybody. Every result is generated from a rule for that fictional profile, and the tasks are simplified originals rather than clinical instruments. Real assessment of neglect uses a battery of tasks, observation of everyday behaviour, and a clinician.
Two fictional people both leave food on the left of the plate and both bump into door frames on their left.
| Item | Result | Reading |
|---|
| Profile | Unprompted | Prompted |
|---|
Someone with left field loss has a hole in the visual input and knows it. They move their eyes into the missing region, they can tell you what they have not seen, and given time and a prompt they find everything. Someone with neglect has the input and does not attend to it. They do not report anything missing, they do not spontaneously search the neglected side, and a prompt helps only while it lasts. The two can occur together, which is one of several reasons a single task is not enough.
Asked to mark the middle of a line, neglect produces a mark to the right of centre - the left of the line is under-weighted, so the perceived middle shifts towards the attended side. Field loss without neglect tends to produce a small error in the other direction, towards the blind side. Two people who both "miss things on the left" therefore err in opposite directions on the same task, which is a good demonstration that the surface description was hiding two different problems.
The copying task separates two patterns that look similar in casual description. One person leaves out everything on the left of the page: the space around them is what is neglected. Another draws every object but leaves the left half off each of them, including objects sitting on the right-hand side of the page. That second pattern is hard to explain as a failure to look far enough left, because the omitted parts are not on the left of anything except the object they belong to. Both frames occur, often together and to different degrees.
A prompt rescues field loss completely: the strategy was already available and only needed the time. It improves neglect and does not abolish it, and for object-centred neglect an instruction about the page does nothing at all, because the page is not the frame that is failing. Improvement with cueing is therefore informative about mechanism, and is not a measure of severity.
Neglect is not one thing with one location. It follows damage in several right-hemisphere sites, and the argument about which matters most has run for decades: inferior parietal cortex, the temporo-parietal junction, superior temporal cortex, frontal regions, and - on the evidence that most changed the debate - the white matter connecting them. Neglect after damage confined to a tract is precisely the disconnection case, and it is one of the reasons "the neglect area" is not a useful phrase.