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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
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