Janice Kay

Developmental Surface Dyslexia and Dysgraphia: An Orthographic Processing Impairment:

This study presents a detailed investigation of a young man in his early twenties who has suffered from a severe spelling impairment since childhood, and currently has a spelling age of only 9 years and 2 months. In contrast with the developmental phonological dyslexics reported by Campbell and Butterworth (1985) and Funnell and Davison (1989), his performance on tests of phonological awareness is good. In addition, he can read and spell non-words competently and, unlike normal 9-year-old children, virtually all of his spelling errors are phonologically appropriate. Further analysis of these errors reveals that he has knowledge of many of the different ways in which a given phoneme can be written, and that he uses phoneme-to-grapheme correspondences at the end of a word that are different from those he uses earlier in a word. However, he finds it difficult to spell words that contain uncommon phoneme-to-grapheme correspondences, which is compatible with the view that he has not developed an orthographic spelling lexicon. Although his oral reading of words is prompt and generally accurate, analysis of his lexical decision performance and the way that he defines homophones indicate that he does not have fully specified lexical entries available for reading either. We suggest that he suffers from a general orthographic processing deficit, and relies instead upon the combination of sub-lexical phonology and a lexicon that contains only partial information about way in which words are spelt. This leads to reasonably competent reading, even of many irregular words, but produces very poor spelling. It is argued that qualitatively different types of developmental dyslexia do genuinely exist, but that reading impairments are likely to be much more pronounced in children who have a phonological rather than an orthographic processing deficit.

Psycholinguistic assessments of language processing in aphasia (PALPA): An introduction

PALPA has been designed as a comprehensive psycholinguistic assessment of language processing in adult acquired aphasia. Intended both as a clinical instrument and research tool, PALPA is a set of resource materials enabling the user to select language tasks that can be tailored to the investigation of an individual patients impaired and intact abilities. The detailed profile that results can be interpreted within current cognitive models of language. The materials consist of sixty rigorously controlled tests of components of language structure such as orthography and phonology, word and picture semantics and morphology and syntax. The tests make use of simple procedures such as lexical decision, repetition and picture naming and have been designed to assess spoken and written input and output modalities. Particular attention has been paid to practical use of the tests in the clinic and comprehensive guides have been included that help to suggest which selection of test may be appropriate for each aphasic person. Each test is also accompanied by detailed instructions of how and why it was constructed, how to use it, and by presenters forms and marking sheets.

Anomia for common names and geographical names with preserved retrieval of names of people: a semantic memory disorder.

This paper describes the case of an anomic patient (FH) who is impaired at naming pictures of objects but has no difficulties in recalling the names of familiar people. Even though his performance on McKennas (1997) Category Specific Naming Test was at the first percentile, he consistently recalled the names of familiar people as successfully as controls. It is argued that the pattern of performance displayed by FH represents a much clearer double dissociation with proper name anomia than any case previously reported (Cipolotti et al., 1993; Semenza and Sgaramella, 1993). FH is unable to provide detailed semantic information about many of the objects that he cannot name, even though he can recall semantic information about familiar people. Consequently his case appears to represent the mirror image of the proper name anomic patient (APA) described by Miceli et al. (2000) who was unable to recall detailed semantic information about many of the people she was unable to name. Further investigation of FHs anomia revealed impairments in retrieving both common nouns and verbs, and difficulties in retrieving and comprehending geographical names. It is argued that FHs preserved ability to name and recall biographical information about people supports the view that knowledge about familiar people may be subserved by its own dedicated neural subsystem (Kay and Hanley, 1999; Miceli et al., 2000; Gentileschi et al., 2001).

Simultaneous Form Perception and Serial Letter Recognition in a Case of Letter-by-letter Reading

Abstract This paper examines the performance of a letter-by-letter reader, PD, on tests which involve the perception of words and letter-strings under tachistoscopic presentation conditions. Unlike the patients recently reported by Bub, Black, and Howell (1989) and Reuter-Lorenz and Brunn (1990), PD shows no evidence of processing the letters of a word in an “ends-in” fashion. Instead, letters appear to be recognised serially from left to right. Furthermore, PD does not show an advantage of words over pseudowords when asked to report the letters from briefly presented letter-strings. In addition, unlike control subjects, he does not show a word superiority effect in same/different judgements about two simultaneously presented letter-strings (Friedrich, Walker, & Posner, 1985). A final experiment reveals that his ability to recognise letters under sequential processing conditions is relatively unimpaired, as is his ability to match letters on the basis of physical features with simultaneous presentation. I...

Evidence for the involvement of a nonlexical route in the repetition of familiar words: A comparison of single and dual route models of auditory repetition

Abstract In this paper, we attempt to simulate the picture naming and auditory repetition performance of two patients reported by Hanley, Kay, and Edwards (2002), who were matched for picture naming score but who differed significantly in their ability to repeat familiar words. In Experiment 1, we demonstrate that the model of naming and repetition put forward by Foygel and Dell (2000) is better able to accommodate this pattern of performance than the model put forward by Dell, Schwartz, Martin, Saffran, and Gagnon (1997). Nevertheless, Foygel and Dells model underpredicted the repetition performance of both patients. In Experiment 2, we attempt to simulate their performance using a new dual route model of repetition in which Foygel and Dells model is augmented by an additional nonlexical repetition pathway. The new model provided a more accurate fit to the real-word repetition performance of both patients. It is argued that the results provide support for dual route models of auditory repetition.

An evaluation of statistical procedures for comparing an individual's performance with that of a group of controls.

The single case methodology that is widely used in cognitive neuropsychology often requires a comparison of data from a single individual (the patient) with that from a group of controls, in order to ascertain whether the patients mean score can be viewed as significantly different from that of controls. This article reviews methods that have been used to deal with such data. Although Analysis of Variance (ANOVA) provides one possible solution of comparing group means, unequal group sizes and differences in variability between patient and controls can violate the assumptions of the test. Using Monte Carlo simulations, it was found that differences in group size and a group of N = 1 did not significantly affect the reliability of the analysis. In contrast, unacceptably high Type I errors were obtained when, in addition to unequal group sizes, there were relatively modest differences between the variance of the patient and that of the controls. We suggest that ANOVA can be used for the comparison of the mean score of an individual with that of a group of controls, but that when there is a difference in variability between the two groups, revised F criteria should be used in order to make the analysis reliable. A table of modified F values is given, which can be used for various departures from homogeneity of variance.

Visuoperceptual deficits in letter-by-letter reading?

A longstanding and controversial issue concerns the underlying mechanisms that give rise to letter-by-letter (LBL) reading: while some researchers propose a prelexical, perceptual basis for the disorder, others postulate a postlexical, linguistic source for the problem. To examine the nature of the deficit underlying LBL reading, in three experiments, we compare the performance of seven LBL readers, matched control participants and one brain-damaged patient, OL, with no reading impairment. Experiment 1 revealed that the LBL patients were impaired, relative to the controls and to OL, on a same/different matching task using checkerboards of black and white squares. Given that the perceptual impairment extends beyond abnormalities with alphanumeric stimuli, the findings are suggestive of a more general visual processing deficit. This interpretation was confirmed in Experiments 2 (matching words and symbol strings) and 3 (visual search of letter and symbol targets), which compared the processing of linguistic and non-linguistic written stimuli, matched for visual complexity. In both experiments, the LBL patients displayed qualitatively similar effects of length and left-to-right sequential ordering on linguistic and non-linguistic stimuli. Moreover, there was a clear association between the perceptual impairments on these tasks and the slope of the reading latency function for the LBL patients. Taken together, these findings are consistent with a significant visuoperceptual impairment in LBL that adversely affects reading performance as well as performance on other non-reading tasks.

PERSON-SPECIFIC KNOWLEDGE AND KNOWLEDGE OF BIOLOGICAL CATEGORIES

We report new findings from a neurological case described by Hanley, Young, and Pearson (1989). In the original study, the patient, BD, had impaired biographical knowledge of people which appeared to extend to a general impairment of knowledge of “ living things” . In more recent work, we present evidence which confirms Hanley et al.’ s finding that BD has impaired person-specific knowledge, but we suggest that this is not associated with a more general impairment to do with knowledge of biological categories. We propose that an artefactual explanation of the original account is more likely based on differences in “ age of acquisition” between items from “ living” and “ nonliving” categories. We conclude that biographical knowledge of people is represented separately from knowledge of biological categories in semantic memory.

Proper name anomia and anomia for the names of people: functionally dissociable impairments?

This paper reviews the performance of 10 previously reported patients who have deficits in recalling the names of people, but whose performance in recalling common names is relatively well preserved. An analysis of face naming ability in these 10 patients reveals that the proportion of faces that a patient can name is closely related to whether or not the patient has a retrieval problem that also extends to the recall of other types of proper names such as the names of towns. This analysis suggests that names of faces are particularly difficult to recall relative to other types of proper names, and provides no support for the view that a specialised brain mechanism is involved in the retrieval of peoples names.

Neuropsychological and psychiatric profiles in acute encephalitis in adults

Acute encephalitis is an inflammation of brain tissue that can result from activity in the central nervous system (CNS) of a number of viruses. Although the neurological and psychiatric effects of encephalitis in the acute phase of the illness are well-known (Caroff, Mann, Gliatto, Sullivan, & Campbell, 2001), larger scale studies of the pattern of neuropsychological and psychiatric impairment following recovery from the acute inflammatory phase are less apparent. This paper reports the results of neuropsychological testing with a range of standardised cognitive measures in a case series of long-term post-acute participants. Psychiatric abnormality is examined using the SCL-90-R self-report scale of distress (Derogatis, 1983). We also examined the role of emerging insight in the aetiology of depression in this population. Two clusters of cognitive dysfunction were observed, one group of primarily herpes simplex cases showing a severe generalised deficit across a number of cognitive domains and a second cluster showing a variety of more isolated disorders of executive function. Abnormally high levels of distress were reported by participants, with depression, obsessive-compulsive symptoms, interpersonal sensitivity and phobic anxiety most significantly increased. Depression was found to be least severe in those with most accurate insight into their problems. Examining the correlations between cognitive and psychiatric test results demonstrates a relationship between depression and interpersonal anxiety and specific cognitive measures. Obsessive-compulsive behaviour and phobic anxiety, however, appear to exist independently of the assessed cognitive deficits.