Re: On Luria's "Z" (by JC)

From: Stevan Harnad (harnad@cogsci.soton.ac.uk)
Date: Sun Feb 25 1996 - 14:38:40 GMT


> From: "Chatwin Judy" <JAC295@psy.soton.ac.uk>
> Date: Sun, 18 Feb 1995 18:45:44 GMT
>
> A similar example was written about by Oliver Sacks when referring
> to a stroke patient who could see nothing on her left side and would
> complain whilst in the hospital that she did not have enough food on
> her plate. She could only see half of the portion she overcame this
> by acquiring a rotating wheelchair that enabled her to move round to
> the right in a circle until the plate became visible and she was
> able to eat a further half of what was on the plate. Her natural
> tendencies were movements to the right, she had no understanding or
> concept of what was meant by left in either the world or her body.
> This meant that she became quite upset and distressed when mirrors
> enabled her to see her left side because it had no feeling and so in
> her mind did not exist. Luria does not mention any attempts to
> overcome this difficulty with "Z" but as his problems were many-fold
> it would not have been so straightforward to correct a single
> symptom.

Besides, there is not a lot that can be done about a persistent
one-sided neglect if it does not men of its own accord. Patients can
adopt "strategies" for reminding themselves about the ignored or
forgotten half of space, but the neglect mechanism itself is conspiring
to keep them unaware of or inattentive to it.

> his reading ability was severely affected by his memory loss.
> Initially, he was presented as being illiterate, when he looked at a
> letter it was unfamiliar to him and therefore he could not recognise
> words in his unstable world. he tried to learn to read again but
> associating visual images with letters. His verbal-motor function
> was unaffected as he retained the ability to recite the alphabet, he
> used this to locate letter when he was trying to identify letters and
> words. His visual limitation also restricted his reading as he could
> only see three letters on the page at any one time which meant that
> once those 3 letters had been `read' and they moved out of the visual
> field they were soon forgotten again. His difficulties with reading
> increased rather than improved, he developed blocks and the pace got
> slower.

You should discuss how the way he read was unlike the way we read, or
the way he read before his injury. Many compensations that neurological
patients learn involve performing the same task in a very different
way.

> Despite his loss of reading ability he retained the ability to
> write. Initially he lost this, along with many other things, and
> could not even hold a pencil, gradually he tried to learn to write
> again in the same way that children learn to write but this did not
> prove successful. However, time revealed that the way to overcome
> this particular ability was to write as he did as any adult,
> spontaneously and without thinking. This strange concept of being
> able to write but not read was an unusual one and may bring to the
> fore the debate of how interlinked the two functions are. "Z" could
> write but he could not read what he had written. Six months
> intensive training enabled him to read and write again although
> there were no grammatical rules involved in his work.

This is a bit of a vague description of "automatic writing," where the
patient is encouraged to set aside his conviction that he cannot do it,
and simply launches himself into writing. The usual visual feedback and
even the conscious, cognitive monitoring is absent, yet Z manages to
write.

> Grammar fell into that category of his memory involved with
> knowledge and his inability to remember what he had previously
> learnt. He began by writing down single words and then trying to
> make sense of them, problems arose for him when the order of words
> in a sentence seriously affected their meaning, i.e. brother's
> father or father's brother. Also in this category came the studies
> he had undertaken at school and college - all this had gone. When
> someone later spent a great deal of time going over mathematical
> formulas which were previously known to him, he still could not
> remember them, he could not even remember how to count or do basic
> arithmetic. He needed to constantly recall information or it was
> instantly forgotten.

Some of these disabilities seem to be very language-specific: Word order
and word endings are no longer noticed as they used to be. Much more
recent evidence (from Myrna Gopnik) on a rare genetic disorder of
language suggest that there may be genes that code for capacities like
these, and that the are parts of the brain specialised for them. It is
odd that some kinds of patterns are easier to notice than others --
except if you lose the genetic disposition to see them, or the brain
structure that enables you to do so.

> Yet another frustrating problem he faced may be described as the
> `tip-of-the-tongue' phenomena, whereby he had great difficulty
> recalling words and associating them with objects, as was described
> when discussing his `bodily peculiarities". He would see an object
> which he recognised but he could not recall the name of the object
> concerned. The converse also happened whereby he could hear a word
> that was familiar to him but was unable to associate any meaning
> with it. He lacked the ability to link word with meaning or meaning
> with word.
>
> Sacks' patient, Dr P., also suffered from this type of disability.
> he could not recognise people, at least not by their faces only by
> their body movement (or "body-music" as he called it) or if they had
> a particularly distinguishing feature, e.g. a birthmark or a beard.
> There is no account of how "Z" reacted to people but Dr P. also had
> difficulty associating objects with names and relied on other senses
> as well as vision, e.g. when shown a red rose, he described it and
> suggested that may be a flower, but when he was able to touch and
> smell it, he recognised it immediately as a rose. If conversation
> helps to unlock "Z"s memories it may well be that by introducing
> other senses, his ability to name objects may have been enhanced.

But even if we just stay within the sense of vision, it is odd, is it
not, that he almost has to DEDUCE that something is a rose, based on the
evidence of his senses, whereas we automatically see it?

> "Z"s problems mirrored those of Dr P. in that the latter did not
> know what he had lost, he could be described as being blissfully
> unaware of his deficiencies whereas "Z" "fought to regain lost
> faculties with indomitable tenacity of the damned." This leads to
> the question of who suffers more - he who knows or he who does not?

Remember that the neurological term for unawareness of your handicap is
"anosognosia." In weighing whether it's better to be aware or not,
consider that if you are unaware that you are blind on one side, you may
bump into things and injure yourself. With less obtrusive deficits, it
may seem preferable not to know you have them, but if the situation ever
comes around that it is crucial that you know you have a certain
handicap, anosognosia could get you into trouble.

Good summary, and good comparisons with Oliver Sacks's patients.



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