Jennifer M. Gurd

Illiteracy and brain damage—1. Aphasia testing in culturally contrasted populations (control subjects)

One hundred neurologically healthy adults were tested for their pointing (choosing one of four or six line drawings as the match to an auditorily presented linguistic stimulus), naming (from line drawings), and repetition abilities. All subjects were unilingual adult right-handers. Fifty-seven subjects were totally unschooled illiterates and 43 were fluent readers. Statistically significant differences were found to exist between the scores of the illiterate and literate subpopulations across all tasks. With the focus being placed on these cultural differences, the discussion bears on: (a) the interaction between linguistic and iconographic factors in certain types of naming and pointing tasks currently used in clinical and research aphasiology, (b) some of the linguistic parameters which are apparently at stake in repetition behavior, and (c) the circumstances in which aphasiological research dealing with groups of patients cannot yield reliable data without reference to neurologically healthy controls. It is argued that, when testing brain-damaged patients of different cultural backgrounds, one runs the risk of over- or underestimating the frequency of aphasia if one does not refer to norms which explicitly take educational level into account.

Illiteracy and brain damage. 3: A contribution to the study of speech and language disorders in illiterates with unilateral brain damage (initial testing).

This report bears on the behavior of 188 unilateral stroke subjects when administered an aphasia screening test comprising a short interview as well as naming, repetition, word-picture matching and sentence-picture matching tasks. All subjects were unilingual lusophone adult (40 yr of age or older) right-handers. Furthermore, they were either totally unschooled illiterates or they had received school education and thereafter retained writing skills and reading habits. Subjects were tested less than 2 months after a first unilateral stroke. In all tasks, global error scores were greater among left and right brain-damaged illiterate and literate subjects than among their controls. In repetition and matching, these differences were statistically significant for the left but not for the right-stroke groups, irrespective of the literacy factor. In naming, on the other hand, significant differences were found not only for the two left-stroke groups but also for the right-stroke illiterate group although not for the right-stroke literate one. Likewise, some degree of word-finding difficulty and of reduction in speech output as well as sizeable production of phonemic paraphasias were observed in the interviews of several right-stroke illiterates, clearly less in those of right-stroke literates. These findings lead us to suggest that cerebral representation of language is more ambilateral in illiterates than it is in school educated subjects although left cerebral dominance remains the rule in both.

Retrieval from semantic and letter-initial categories in patients with Parkinson's disease

We report the impaired performance by a group of 27 patients with Parkinsons disease (vs matched controls) on semantic and letter-initial verbal fluency tasks, carried out in both single and alternating category conditions. Individual differences in fluency were significantly correlated with confrontation picture naming scores in the patient group, but not in control subjects. However, the PD patients showed no significant correlation between verbal fluency scores, and rate of reciting days of the week as rapidly as possible. Both controls and patients produced more items when retrieving words from a single category than when alternately retrieving words from two categories. The magnitude of the decrement was nonetheless no greater in the patient than in the control population. This finding shows that task switching per se is not impaired in PD. We suggest that the verbal fluency deficit, while it may in part be attributed to motor-speech factors, primarily reflects an underlying cognitive disorder.

Illiteracy and brain damage. 2. Manifestations of unilateral neglect in testing "auditory comprehension" with iconographic materials.

This report concerns the sentence-picture matching behavior of 100 neurologically healthy and 169 brain-damaged subjects, all of whom were unilingual adult right-handers. Within this population, 144 subjects were totally unschooled illiterates and the remaining 125 had received school education and thereafter had retained writing skills and reading habits. Brain-damaged subjects were tested less than 2 months after a first left- or right-hemisphere stroke. All subjects were administered an aphasia screening battery including, among other subtests, a set of six sentence-picture matching stimuli. For each of these six stimuli, subjects heard a sentence uttered by the examiner and were then requested to match this sentence with one of four drawings presented within a single display divided into four quadrants of equal surface. Three sentences were syntactically simple (noun subject + verb) and three were relatively more complex (noun subject + verb + one or two noun complements). Evidence of unilateral neglect was found in both left- and right-brain-damaged illiterates and literates. Moreover, the right neglect of left-brain-damaged subjects was manifest mostly when target sentences were relatively complex whereas the left neglect of right-brain-damaged subjects was manifest irrespective of the syntactic complexity of target sentences. Our data are interpreted as indicative of an interaction between two cognitive disorders resulting from dysfunctions of asymmetrically represented cognitive mechanisms. The implications of these findings with respect to clinical and research aphasia testing are discussed.

A case of foreign accent syndrome, with follow-up clinical, Neuropsychological and phonetic descriptions

We report a comparatively pure case of foreign accent syndrome (FAS) in a right-handed patient who sustained a small, isolated, left basal ganglia infarct. At 3 weeks post-onset FAS persisted in the absence of aphasic disorder. Phonetic analysis of the patients speech was undertaken at that time and a further, more detailed acoustic and phonetic investigation, was undertaken at 8 months. The validity and significance of the term FAS is discussed.

Aspects of non-native pronunciation in a case of altered accent following stroke (foreign accent syndrome)

Foreign accent syndrome (FAS) refers to a disorder that involves foreign sounding speech, usually following stroke. This paper presents a case study of an English patient allegedly speaking with a Scottish English accent after right-hemisphere stroke. The results of detailed impressionistic and acoustic analyses are reported, based on a direct comparison of the patients pre-stroke and post-stroke speech samples. The emphasis is on a comparison of the typical features of Scottish English and phonetic features actually found in the patients post-stroke speech. The respective roles of prosodic and segmental features in the post-stroke speech sample are also discussed. Rather untypically, prosodic features seem to be affected to a much lesser extent than segmental phonetic features in the patients post-stroke speech. They are, therefore, less likely to contribute to the perception of a foreign accent.

Hand preference and performance in 20 pairs of monozygotic twins with discordant handedness.

The differences between right (RH) and left (LH) handers reported in the literature on fine motor tasks, has traditionally been interpreted relative to purported functioning of the cerebral hemispheres. However, conclusive evidence for performance differences which are intrinsic to handedness per se is difficult to obtain unless left and right handers are compared who are similar in their genetic and environmental background. The present study therefore, employed a monozygotic (MZ) twin design which minimizes differences in genetic variation between the two groups. Forty female monozygotic twins (20 pairs) were selected on the basis of discordance of writing hand. Their laterality preferences were assessed and they were tested for differences on hand performance tasks (dot filling, finger tapping, and peg moving). The results revealed that on the hand and foot preference inventories, the right-handers were more strongly lateralized than their left-handed sisters, and that the left-handers had greater variation in their laterality scores. There were substantial correlations between preference and performance scores. The analyses not only revealed the obvious strong main effects of writing hand on performance tasks, but interaction effects of handedness on the peg-moving task. The dot filling task differentiated the writing versus non-writing hand considerably better than either of the other two performance tasks. However, no evidence was found to indicate that twins who wrote with their left hands showed poorer performance than their right-handed twin sisters.

Organic or Functional? A New Case of Foreign Accent Syndrome

We describe a patient who presented with a French-sounding accent, although she only spoke English. In previous cases of foreign accent syndrome (FAS), neurological causes were clearly identifiable (Moen, 2000). Here the diagnostic picture is unclear. The case illustrates that voice disorders are: “a prototype of disorders which reflect the intricate interplay of emotional, cognitive and physiological functions” (Matas, 1991).

Frontal dissociations: evidence from Parkinson's disease

Abstract Control subjects and patients with Parkinsons disease were tested on three tasks that have often been held to implicate functions of frontal cortex. The tasks were verbal fluency, continuous series, and the Stroop test. In the patient group, there was no significant correlation between performance on verbal fluency and continuous series, or between verbal fluency and the Stroop test. The results are interpreted in terms of the fractionation of the Supervisory Attentional System.

Motor speech versus digit control in Parkinson's disease: A cognitive neuropsychology investigation

Motor speech and digit tapping deficits are well-documented in idiopathic Parkinsons Disease (PD); this study focuses on the relationship between the two. Despite the fact that motor aspects are present in both tasks, significant dissociations between them are reported. Parkinsons Disease patients were slow at finger tapping and rapid syllable repetition. They also showed reduced fundamental frequency ranges when humming. Performance on verbal fluency ranged from intact to impaired, and dissociated doubly with rapid articulation. Finger tap values correlated significantly with disease severity, but not with single syllable repetition, or with verbal fluency rates.