School Papers

The al., 2011). Two years after his initial

The following
is related to the case study of a 68 year old man, G. F. who showed neurological
and neuropsychological side-effects after suffering an internal capsular
stroke. One of the symptoms experienced was persistent left unilateral mirror-writing.
This is an analysis of the original case study along with a discussion on the
author’s claims and their limitations in clarifying the nature of mirror
writing.

G.F is a retired 68 year old man who in July 2006, at age
66, suddenly manifested right sided motor-difficulties after a spontaneous
stroke due to an intracerebral-hematoma. On his assessment on the Edinburgh
Handedness Inventory (1971), he resulted to be left-handed (handedness score:
-63/100). However, it was imposed on him as a child to write with his right
hand and he had never used his left hand for writing since. The patient’s
neuropsychological state was assessed twenty days after the occurrence of the
incident. G.F. was found to be generally cooperating and well orientated in
time and space. However, his neurological examinations showed a right
hemiparesis (unilateral paresis) without somatosensory or visual field defects.
A frontal and sagittal MRI scans show a left subcortical lesion infringing upon
the thalamus, internal capsule and putamen (Angelino et al., 2010). The patient
although fully communicative with verbal comprehension when speaking
spontaneously his speech sounded mildly dysarthric and anomic (Token Test 26/52:
Huber Poeck Weingier & Willmes, 1991). The initial neuropsychological
battery of tests concluded that the patient showed no sign of cognitive
defects, apart from his left handed writing. During the neuropsychological
assessment G.F involuntarily started writing from the right and then proceeding
towards the left. The syndrome is named mirror writing (MW) as in the mirroring
image of canonical writing (right to left), and often appears as a side effect
in stroke but does not persist (Maurizo wt al., 2011). Two years after his
initial assessment, the patient was recovering motor skills in his right arm,
however he did retain involuntary MW in his left.

G. F’s case of persistent involuntary MW
was analysed by the authors through a dichotomy of two theoretical MW
explanations: general aspects of spatial cognition and graph-motor. The tests
administered analysed cognitive flexibility (Trait Marking Test, Wisconsin Card
Sort Test), spatial cognition with mirror reading tasks (Ciurli, Marangolo &
Basso, 1996), right-left confusion task (Heilman et al., 1980), spatial
discrimination defect (Heilman et al., 1980) or motor production processes, using
mirror errors in non-graphic tasks (Della Sala & Cubelli, 2007), writing to
dictation in left and right hemisphere (Bauxbaum et al. 1993) and effects of
verbal cue (Kim et al., 2008). The literature suggests that everyday objects
are stored in engrams using only one dominant hemisphere (right) and storing
mirror-images in the non-dominant hemisphere (left) (Nas, 1987). G.F. was able to voluntarily manipulate hand motor programs and write in
canonical fashion with his left hand after receiving precise instructions from
the researchers. The authors suggested that the lesion determined an impairment
of autonomic transformation and interfered not with visual strategies. The patient also showed signs of
defective cognitive flexibility, anosognosia (lack of insight) and
anosodiaphoria (lack of concern) (e.g. Angelillo et al., 2010). This was
interpreted by the authors as the explanation for the persistence of his M.W. The results of this case study support a
graph-motor explanation meaning that MW is a defect of motor skills that
persisted through a defective cognitive flexibility.

The explanation however, seems one
sided. As there have been cases where analogues phenomena are known to affect
perception. A parietal lobe damage can induce an inability to tell apart
mirror-images, even though the patient retains the ability to spot subtle
changes in shape and rotation (Davidof & Warrington, 2001; Turnbull &
McCarthy, 1996). This type of mirror-confusions at times co-occur with
mirror-writing (Heilan et al., 1980; Wade & Hart, 1991). The motor explanation
of WM, does not entitle an advantage for reading mirrored texts. However, in some
accounts perception was entirely reversed enabling fluent mirror-reading and
showing involuntary MW (Gottfried et al., 2003; Lambon-Ralph et al., 1997). One
such case, is the unusual report of a polyglot woman who after suffering a
concussion, mirror-read and wrote only her first language, Hebrew but not
Polish or German (Streifler & Hofman, 1976). She exhibited involuntary
mirror writing, affecting the dominant left hand and displayed a range of other
forms of perceptual confusion (inside/outside, above/beneath). A parallel
between her reading and writing suggests that involuntary mirror-writing can be
in some cases a perceptual or conceptual problem. However, deliberate mirror
writing can also hold vital information regarding the mechanism behind
involuntary mirror writing in brain damaged adults. A recent study attempted to
address this question in KB’s study. An ambidextrous German artist who
practiced various forms of mirror writing with experience of more than 50 years.
Using a technique, he developed to half the time spent drawing lines by writing
forwards with his right hand and simultaneously backwards with his left.
Although some of the patient’s characters matched the motor hypothesis, KB also
showed a specific impairment in hand (right and left) discrimination (McIntosh & Salsa, 2012). The author’s interpreted K.B.’s
facility had entailed an abnormal degree of overall neural motor
representations of the hands in the brain. Meaning he could rotate his hands
mentally to match a picture but would have problems to introspectively recognise
which hand made the match. Simply put KB would have difficulty in
distinguishing right from left.