Elizabeth Warrington


 - selected references on reading and alexia



Kinsbourne, M. & Warrington, E. K. (1962). A variety of reading disability associated with right hemisphere lesions. Journal of Neurology, Neurosurgery and Psychiatry, 25, 339-344.
Notes: (6 cases of left neglect due to right parietal lobe lesions. All six made visual errors on the leftmost letters of words in reading, even when the entire word fell within the patient's right visual field)

Kinsbourne, M. & Warrington, E. K. (1963). The localizing significance of limited simultaneous visual form perception. Brain, 86, 697-702.
Notes: A patient presenting with an isolated "spelling dyslexia" and impairment in picture interpretation (simultanagnosia) was shown by tachistoscopic studies to have a pathological limitation of simultaneous form perception. At autopsy a localized lesion was found within the inferior part of the left occipital lobe. The findings are discussed in relation to the problem of the disorder of function underlying "agnosic alexia"

Shallice, T. & Warrington, E. K. (1975). Word recognition in a phonemic dyslexic patient. Quarterly Journal of Experimental Psychology, 27, 187-199.

Shallice, T. & Warrington, E. K. (1977). The possible role of selective attention in acquired dyslexia. Neuropsychologia, 15, 31-41.
Notes: Literal dyslexia, the inability to read letters within a word which itself could be read, was analysed in two patients. Their impairment was found not to be specific to letters but to stimui in which more than one item of the same category was simultaneously present in the visual field. Thus a letter surrounded by numbers could be read more easily than if surrounded by other letters. Explanations in terms of visual disorientation or implicit response interference were rejected. It is suggested that their impairment arises from a specific defect at the level at which visual input is selected for meaningful analysis

Warrington, E. K. & Shallice, T. (1979). Semantic access dyslexia. Brain, 102, 43-63.
Notes: An analytical investigation of the residual reading capacities of a single patient with dyslexia without dysgraphia is reported. Both his ability to name and to comprehend letters and words were severely impaired. The major finding of this investigation was AR's striking capacity for categorizing words he could not read. In addition there was evidence of semantic priming effects. Thus AR was frequently able to achieve partial comprehension of words he could not read. The orthodox interpretation of the dyslexia without dysgraphia in terms of a disconnection syndrome is shown to be inappropriate, at least for the present case, where the deficit appears to be within the semantic domain; it is argued that this type of dyslexia is due to an impairment in accessing semantic information

Warrington, E. K. & Shallice, T. (1980). Word-form dyslexia. Brain, 103, 99-112.
Notes: In this study we have reported our investigation of two patients with an acquired dyslexia characterized by letter-by-letter reading, whole word reading being apparently impossible. It has been shown that this phenomenon of letter-by-letter reading cannot be accounted for by visual or perceptual factors nor by impairment of visual span of apprehension. The exceptionally slow speed of reading was documented and a clear relationship between word length and reading speed established. Performance on tasks considered to maximize whole word reading which at the same time prevent the possibility of letter-by-letter reading, namely, reading script and reading with tachistoscopic presentation, was impaired. The satisfactory performance of these two patients on tasks of picture interpretation suggests that the two components of the syndrome simultanagnosia, letter-by-letter reading and piecemeal perception of complex scenes, are dissociable. Three alternative explanations of letter-by-letter reading are considered and we conclude that in this type of acquired dyslexia there is damage to the system through which a visual word-form is attained

Shallice, T., Warrington, E. K., & McCarthy, R. (1983). Reading without semantics. Quarterly Journal of Experimental Psychology A,Human Experimental Psychology, 35, 111-138.
Notes: Analysis of the reading of a neurological patient (HTR) indicates that it is based on the operation of a relatively unimpaired phonological route. Quantitative investigations of type of error, reading speed and the effects of lexicality and spelling-to-sound regularity all support this conclusion. Spelling-to-sound regularity is shown to influence reading not only through regular words being read better than irregular, but also through mildly irregular words being better read than very irregular ones. A model is presented of the operation of the phonological route and of its progressive impairment in certain types of neurological disease

Warrington, E. K. & Shallice, T. (1984). Category specific semantic impairments. Brain, 107, 829-854.
Notes: We report a quantitative investigation of the visual identification and auditory comprehension deficits of 4 patients who had made a partial recovery from herpes simplex encephalitis. Clinical observations had suggested the selective impairment and selective preservation of certain categories of visual stimuli. In all 4 patients a significant discrepancy between their ability to identify inanimate objects and inability to identify living things and foods was demonstrated. In 2 patients it was possible to compare visual and verbal modalities and the same pattern of dissociation was observed in both. For 1 patient, comprehension of abstract words was significantly superior to comprehension of concrete words. Consistency of responses was recorded within a modality in contrast to a much lesser degree of consistency between modalities. We interpret our findings in terms of category specificity in the organization of meaning systems that are also modality specific semantic systems

McCarthy, R. & Warrington, E. K. (1986). Phonological reading: phenomena and paradoxes. Cortex, 22, 359-380.
Notes: We report a single case study of a patient with an acquired dyslexia. KT had no difficulty in reading regular words and non- words at a normal speed, but he made numerous errors in reading irregular words. These were characterised by "regularisation" of the letter string. We have documented his residual reading abilities and in addition have investigated other aspects of his residual reading skills. We found that his performance on visual lexical processing tasks was very satisfactory, there was no effect of priming from a correctly read irregular word and his reading of polysyllabic words was remarkably good. In particular his assignment of word stress was usually accurate. We consider our findings in relation to current models of phonological reading and conclude that they provide further evidence for a multiple levels computation of the transcoding between print and phonology

Costello, A. D. & Warrington, E. K. (1987). The dissociation of visuospatial neglect and neglect dyslexia. Journal of Neurology, Neurosurgery and Psychiatry, 50, 1110-1116.
Notes: A right-handed man with a left hemisphere lesion extending into the right hemisphere, with evidence of both a left-sided neglect dyslexia and right-sided visuospatial neglect is reported. When copying simple geometric designs he omitted to copy figures on the right-hand side of the page, when bisecting lines he tended to bisect the line to the left of the line's actual centre. He had a neglect dyslexia which was characterised by paralexic errors affecting the beginning (that is, left) of words. The occurrence of these two phenomena provides evidence of a dissociation of these forms of neglect. The findings are discussed in relation to the possible mechanisms of unilateral neglect

Shallice, T. & Warrington, E. K. (1987). Single and multiple component central dyslexic syndromes. In M.Coltheart, K. Patterson, & J. C. Marshall (Eds.), Deep dyslexia (2 ed., pp. 119-145). London: Routledge & Kegan Paul.

Baxter, D. M. & Warrington, E. K. (1990). A comment on Hillis and Caramazza's (1989) paper "The graphemic buffer and attentional mechanisms". Brain and Language, 38, 615-616.
Notes: (Comments on case ORF, originally described by Baxter & Warrington in 1983, who showed gross spelling errors affecting the beginning of words. He did not, however, show similar neglect errors in his reading)

Warrington, E. K. (1991). Right neglect dyslexia: A single case study. Cognitive Neuropsychology, 8, 193-212.
Notes: A single case study of a right neglect dyslexic is reported. The patient's (RYT) single word reading difficulty was characterised by paralexic errors that affected word endings. An analysis of the error corpus demonstrates the maintenance of word length in his error responses and a gradient of accuracy across individual words irrespective of their length. The actual neglect point was found to be a function of word length. It is concluded that right neglect dyslexia is a reading-specific deficit in which there is activation of an inappropriate visual word form.

Warrington, E. K., Cipolotti, L., & McNeil, J. (1993). Attentional dyslexia: a single case study. Neuropsychologia, 31, 871-885.
Notes: AD: National Hospital for Neurology and Neurosurgery, London, U.K AB: A single case study of an attentional dyslexic is reported. The patient B.A.L. was able to read single letters and single words presented in isolation without difficulty. However, his reading of prose was very disrupted and his ability to read rows of letters and words was significantly impaired. A "flanking" procedure, in which there was a single target item, flanked by other stimuli, was used in a series of experiments to analyse his dyslexic impairment. First it was established that his attentional deficit was specific to reading in so far as the patient did not have comparable difficulties with pictorial material. His performance in the flanking experiments was consistently impaired; and furthermore was unaffected by speed of presentation, the number of flanking stimuli, and the spatial arrangement of the flanking stimuli. The important exception was when the flanking stimuli were of a different category. There was no decrement in performance when target letters were flanked by words or when words were flanked by letters. This study both corroborates and extends the original account of attentional dyslexia (Shallice and Warrnington, Neuropsychologia 15, 31-41, 1977) in terms of a damaged "filter" mechanism controlling the transition from a parallel to a serial stage of reading processing. The categorical effects reported here indicate that such a filter must be post lexical and suggest further that there are multiple filters in the reading system

McNeil, J. E. & Warrington, E. K. (1994). A dissociation between addition and subtraction with written calculation. Neuropsychologia, 32, 717-728.
Notes: AD: National Hospital, London, U.K AB: A patient with a severe dyscalculia and a mild arabic number dyslexia is described. He could perform simple addition and subtraction sums with oral presentation. However with written arabic number sums he was impaired with addition but not with subtraction. These findings require modifications to current models of arithmetic processing which have suggested that numerical inputs are converted into abstract internal representations before arithmetical processing can occur

Warrington, E. K. & Langdon, D. (1994). Spelling dyslexia: a deficit of the visual word-form. Journal of Neurology, Neurosurgery and Psychiatry, 57, 211-216.
Notes: AD: National Hospital for Neurology and Neurosurgery, London, UK AB: A patient with spelling dyslexia read both words and text accurately but slowly and laboriously letter by letter. Her performance on a test of lexical decision was slow. She had great difficulty in detecting a 'rogue' letter attached to the beginning or end of a word--for example, ksong--or in parsing two unspaced words, such as applepeach. By contrast she was immune to the effects of interpolating extraneous coloured letters in a word, a manipulation that affects normal readers. Therefore it is argued that this patient had damage to an early stage in the reading process, to the visual word form itself

Cipolotti, L. & Warrington, E. K. (1995). Semantic memory and reading abilities: A case report. Journal of the International Neuropsychological Society, 1, 104-110.
Notes: We document the unexpected dissociation of preserved reading skills in a patient with severely impaired semantic memory. The common co-occurrence between impairment of word meaning and surface dyslexia has not been observed. The patient (hereafter called DRN) had marked naming and word comprehension difficulties. A strong word frequency effect was observed on tests of word comprehension but was absent in a test of word reading. DRN's ability to read to both regular and exception words that he failed to comprehend was remarkably well preserved. We will argue that these findings provide further support for the independence of semantic and phonological processing

Cipolotti, L., Warrington, E. K., & Butterworth, B. (1995). Selective impairment in manipulating Arabic numerals. Cortex, 31, 73-86.
Notes: National Hospital for Neurology and Neurosurgery, London This paper describes an acalculic patient (B.A.L.) with an unusual selective deficit in manipulating arabic numerals. The patient was unimpaired in reading aloud letters, words and written number names but unable to read aloud single arabic numerals. Furthermore, his ability to produce the next number in the sequence and his ability to produce answers to simple addition and subtraction was relatively spared when the stimuli were presented as number names but impaired when the stimuli were presented as arabic numerals. Using magnitude comparison tasks it was demonstrated that his knowledge of cardinal values of arabic numerals was preserved. His impairment in manipulating arabic numerals was interpreted in terms of a deficit in the connection between format specific number codes and the verbal numeral production system 9509

Manning, L. & Warrington, E. K. (1995). The role of familiar letter combinations in phonological dyslexia. Neurocase, 1, 239-249.
Notes: We report two cases of acquired phonological dyslexia. JW and MRF read competently real words including not only nouns but parts of speech, function words, irregular words and abstract words. JW was also able to read inflected words and unfamiliar surnames at the same level of competence. MRF had difficulties reading these latter categories of words. Neither patient was able to read non-words accurately. Both patients were significantly affected by the familiarity of non-word letter combinations. We interpret our findings within a dual-route model for reading and we consider that both patients' reading performance was carried out by the semantic route. We discuss some implications of this postulation


Anders Gade