12-18-2002, 10:45 PM
• Gottfried JA, Sancar F and Chatterjee A (2003). Acquired mirror writing and reading: evidence for reflected graphemic representations. Neuropsychologia 41:96-107. Summary: Mirror writing occurs when individual letters and whole word strings are produced in reverse direction. By analogy, mirror reading refers to the preference to read mirror reversed over normally written words. These phenomena appear rarely after brain damage and offer insight into the nervous system's organization of visual-spatial and visual-motor representations. We present the case of a 51-year-old patient with persistent mirror writing and reading following traumatic brain injury. She preferred to write in the mirror direction with either hand. She drew asymmetric pictures with the same directional bias as normal right-handed subjects, and she did not exhibit left-right confusion regarding other pictures. By contrast, on picture-word matching and lexical decision tasks, she was faster and more accurate with mirrored than normally written words. This pattern of performance suggests that her behavior was not accounted for by reflected motor programs, or by the mirroring of visual-spatial representations in general. Rather, we suggest that her behavior was produced by privileged access to mirrored graphemes. Furthermore, because she seemed better able to read irregular words in mirrored than in normal formats, we suggest that mirrored representations may exist at the whole word level and not simply at the letter level. Department of Neurology, Center for Cognitive Neuroscience, The Hospital of the University of Pennsylvania, 3 West Gates, 3400 Spruce Street, 19104, Philadelphia, PA, USA
09-19-2008, 12:35 PM
I have been automatically mirror-writing with the right hand since age 18. Sometimes if I concentrate, I can write forwards with one hand and backwards with the other at the same time; or write in two languages at the same time. I also can write upside down and backwards, or just upside down. I have no trouble writing normally, and I have never had any dyslexia or other learning difficulties.
My interest is in learning why this happens, and finding others who can do the same thing. Who has information? Thank you.
02-22-2009, 08:05 AM
Neuropsychologia. 2007 May 15;45(9):2078-91.
When left becomes right and vice versa: mirrored vision after cerebral hypoxia.
Pflugshaupt T, Nyffeler T, von Wartburg R, Wurtz P, Lüthi M, Hubl D, Gutbrod K, Juengling FD, Hess CW, Müri RM.
Perception & Eye Movement Laboratory, Department of Neurology, University Hospital, 3010 Bern, Switzerland.
The combination of acquired mirror writing and reading is an extremely rare neurological disorder. It is encountered when brain damaged patients prefer horizontally mirrored over normal script in writing and reading. Previous theories have related this pathology to a disinhibition of mirrored engrams in the non-dominant hemisphere, possibly accompanied by a reversal of the preferred scanning direction. Here, we report the experimental investigation of PR, a patient who developed pronounced mirror writing and reading following septic shock that caused hypoxic brain damage. A series of five oculomotor experiments revealed that the patient's preferred scanning direction was indeed reversed. However, PR showed striking scanpath abnormalities and mirror reversals that cannot be explained by previous theories. Considered together with mirror phenomena she displayed in neuropsychological tasks and everyday activities, our findings suggest a horizontal reversal of visual information on a perceptual level. In addition, a systematic manipulation of visual variables within two further experiments had dramatic effects on her mirror phenomena. When confronted with moving, flickering or briefly presented stimuli, PR showed hardly any left-right reversals. Not only do these findings underline the perceptual nature of her disorder, but also allow interpretation of the pathology in terms of a dissociation between visual subsystems. We speculate that early visual cortices are crucially involved in this dissociation. More generally, her mirrored vision may represent an extreme clinical manifestation of the relative instability of the horizontal axis in spatial vision.
J Neurol. 2007 Apr;254(4):436-41. Epub 2007 Mar 22.Click here to read Links
Mirror writing and reversing single letters in stroke patients and normal elderly.
Balfour S, Borthwick S, Cubelli R, Della Sala S.
Human Cognitive Neuroscience Psychology, University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK.
Mirror writing (MW) refers to the production of individual letters or whole word strings in reversed direction. When held to a mirror, these letters or words can be read normally. We observed MW in a considerable number of stroke patients. Of the 86 patients screened 15 (17.5%) showed at least one instance of mirror writing in any of the tasks. Both right (14% of 36 patients) and left (20% of 50 patients) hemisphere damaged patients produced reversed letters only when writing with their left hand, respectively the contralesional and ipsilesional hand. The dissociated performance between the two hands in brain damaged patients is relevant to the interpretation of MW because, unlike all other peripheral dysgraphias, MW affects the non-dominant hand only. Importantly, healthy elderly also showed MW solely when writing with their left hand (6.9% of 86 participants). MW in controls was less frequent but qualitatively similar to that observed in brain damaged patients. This finding is consistent with the motor interpretation of MW that assumes an inability to transform the stored letter forming programmes for left hand writing. However, several cases have been reported in the literature of a more pervasive form of MW whereby patients mirror reverse entire words or sentences. This pattern has been observed in children learning to write but it has never been observed in healthy adult volunteers. We propose that the diagnosis of MW should be limited to the reversal of whole words, multi-digit numbers and full sentences, which reveal a disorder in coding the correct direction of writing rather than an inability to accomplish the correct spatial orientation of single letters.