Klaus Poeck

Text comprehension in aphasia.

Abstract The semantic and pragmatic strategies in the comprehension of spoken texts are investigated in four subgroups of aphasic patients and in normal and brain-damaged controls. Short texts of similar linguistic structure were read to the subjects, who were required to choose the picture, from a multiple choice set of five, that was appropriate to the story. Besides a picture showing the main event of the story, one picture depicted the literal sense of a metaphorical comment, and the others misrepresented semantic functions expressed in the text. With respect to these types of responses, both aphasics and controls exhibited the same pattern of reaction. It is concluded that the redundancy of texts makes up for the difficulties aphasics have in comprehending isolated words and sentences.

The concept of the body schema: A critical review and some experimental results.

Summary The concept of the body schema is widely used, in clinical neurology and in neuropsychological research, to explain a great variety of disturbances. A historical review demonstrates that the classical authors have by no means developed an unequivocal, let alone unitary concept. Subsequent use and misuse has virtually emptied the theoretical construct of its previous meaning. The most important clinical signs and symptoms which are termed “disturbances of the body schema” are discussed in detail, on the basis of experimental results. Neither autotopagnosia, nor finger agnosia, nor “right-left disorientation” are unitary in nature. All of these disturbances appear in various types, brought about by varying underlying neuropsychological deficit, such as aphasia, spatial disorientation or general mental disorder.

Visuo-cognitive performances in patients with unilateral hemispheric lesions

SummaryThree factorial reference tests for Speed of Visual Closure (Cs), Flexibility of Visual Closure (Cf) and Perceptual Speed (P) were given to 41 patients with unilateral retro-rolandic brain lesions. The tests were: the Street Test (for Cs), the Gottschaldt Test (for Cf) and the test Form Perception from the GATB (for P). By means of analyses of variance the influence of hemispheric side and intrahemispheric locus of lesion, of aphasia and of visual field defect (VFD) was studied.Aphasia was related only to impairment in Gottschaldts test. In none of the experimental tests an independent main effect of side or intrahemispheric locus of lesion or of VFD was found. However, in Streets test as well as in Form Perception, patients with right-sided lesion plus VFD were more impaired than any other subgroup. It could be demonstrated that neither VFD per se nor hemispheric side of lesion alone could account for this finding. It is suggested that the presence of VFD in the patients with right-sided lesions does not act on test performance as a defect in visual function but stands for a critical localization of lesion.ZusammenfassungEine Gruppe von 41 Patienten mit einseitigen retrorolandischen Großhirnläsionen wurde mit drei faktoriellen Referenztests für „Speed of Visual Closure“ (Cs), „Flexibility of Visual Closure“ (Cf) und „Perceptual Speed“ (P) untersucht. Es wurden verwendet: der Street-Test (für Cs), der Gottschaldt-Test (für Cf) und der Test „Form Perception“ aus der GATB (für P). Mittels Varianzanalysen wurden die Auswirkungen von Seitigkeit und intrahemisphärischer Lokalisation sowie von Aphasie und Gesichtsfelddefekten auf die Testleistungen geprüft.Aphasie beeinflußte nur die Leistung im Gottschaldt-Test. Selbständige Haupteffekte für Seitigkeit und intrahemisphärische Lokalisation der Läsionen sowie für Gesichtsfelddefekte wurden nicht gefunden. Sowohl im Street-Test als auch im Test Form Perception waren jedoch Patienten mit rechtsseitigen Läsionen, die zugleich Gesichtsfelddefekte hatten, signifikant schlechter als jede andere Untergruppe. Es konnte gezeigt werden, daß weder der Gesichtsfelddefekt für sich noch die rechtsseitige Hirnschädigung allein dieses Ergebnis erklären. Nach diesen Befunden muß man annehmen, daß bei den rechtsseitig geschädigten Patienten die Gesichtsfeld-einschränkung nicht unmittelbar die Testleistungen beeinflußt, sondern vielmehr eine für diese Leistungen kritische Lokalisation der Hirnläsion anzeigt.

Die Wernicke-Aphasie

SummaryDespite the variability of its behavioral manifestations Wernickes aphasia is considered to be a unitary syndrome. According to the criteria of intelligibility, phonemic and semantic paraphasias in spontaneous speech, 4 forms of Wernickes aphasia are differentiated: 1) with predominantly semantic paraphasias, 2) with semantic jargon, 3) with predominantly phonemic paraphasias and 4) with phonemic jargon. A severe deficit in language understanding is common to all 4 forms. In addition to phonemic and semantic paraphasias paragrammatism is an outstanding feature of the language production in Wernickes aphasia. After a survey of views about the localization of the lesion and of earlier descriptive models a neurolinguistic explanation of the characteristic symptoms of Wernickes aphasia is suggested.ZusammenfassungDie Wernicke-Aphasie ist bei aller Variabilität des Sprach-verhaltens als einheitliches Syndrom zu beschreiben. Nach den Kriterien: Verständlichkeit, phonematische und semantische Paraphasien in der Spontansprache lassen sich 4 Erscheinungsformen unterscheiden:Wernicke-Aphasie mit vorwiegend semantischen Paraphasien,Wernicke-Aphasie mit semantischem Jargon,Wernicke-Aphasie mit vorwiegend phonematischen Paraphasien,Wernicke-Aphasie mit phonematischem Jargon.Allen 4 Formen sind schwere Störungen im Sprachverständnis gemeinsam. In der Sprachproduktion tritt neben den phonematischen und semantischen Paraphasien als wesentliches Merkmal der Paragrammatismus auf. Nach einem Überblick über die Lokalisation der Schädigung und frühere Beschreibungsmodelle werden für die charakteristischen Symptome der Wernicke-Aphasie neurolinguistische Erklärungen vorgeschlagen.Despite the variability of its behavioral manifestations Wernickes aphasia is considered to be a unitary syndrome. According to the criteria of intelligibility, phonemic and semantic paraphasias in spontaneous speech, 4 forms of Wernickes aphasia are differentiated: 1) with predominantly semantic paraphasias, 2) with semantic jargon, 3) with predominantly phonemic paraphasias and 4) with phonemic jargon. A severe deficit in language understanding is common to all 4 forms. In addition to phonemic and semantic paraphasias paragrammatism is an outstanding feature of the language production in Wernickes aphasia. After a survey of views about the localization of the lesion and of earlier descriptive models a neurolinguistic explantation of the characteristic symptoms of Wernickes aphasia is suggested.

An experimental investigation of finger agnosia

THE SYMPTOM of finger agnosia has been the subject of extensive theoretical considerations. The controversial positions defended by various investigators have been recently reviewed by Bentonl and by Kinsbourne and Warrington.2 It appears from the literature that there does not exist an uncontested definition of this peculiar symptom, nor is there agreement on the appropriate method of testing for it. The original concept suggested by Gerstman

Facet theory applied to the construction and validation of the Aachen Aphasia Test

implies that the essential feature is the inability to differentiate single fingers, either on the patient’s own hand or on the hand of another person. Testing procedures include verbal and nonverbal tasks. Most of these have been assembled by Benton‘ into a comprehensive battery of finger tests. Recently, Kinsbourne and Warrington2 have proposed five new tests, four of which are nonverbal in nature. These tasks require the awareness of the order of the fingers and of the structure of the hand. Apparently, however, these methods are not fully comparable with the clinical methods used to test the identification of single fingers. Previous studies of this problem have been based on single cases or on highly selected groups. The latter holds true also for the 32 subjects examined by Kinsbourne and Warrington. Therefore, it appeared useful to carry out another investigation of finger agnosia using various finger tests, verbal and nonverbal, with a large group of unselected braindamaged patients. The starting point was a study of the so-called Gerstmann ~yndrome.~ In agreement with Benton,s we reached the conclusion that the common denominator of these symptoms is an aphasic disturbance. This view has been corroborated in another study of right-left disorientation,G which is another component of the Gerstmann syndrome.

Functional disconnection in pure alexia and color naming deficit demonstrated by facilitation methods

The linguistic performance of 120 aphasic patients of the four standard syndromes assessed by the Aachen Aphasia Test (AAT) is analyzed by a nonmetric (ordinal) multidimensional scaling procedure (Smallest Space Analysis, SSA1). The linguistic structure of the test items is characterized within the framework of L. Guttmans facet theory. Three systematic components (facets) are discerned: linguistic modality, unit, and regularity. Properties of the facets as well as their relations are assessed and tested empirically by analyzing the interrelations among different items or sets of items. The spatial configurations obtained by the scaling procedure fit only partially the expectations derived from the facet-theory model. The modality facet was found to have a strong overriding influence on the aphasic test performance. The facets unit and regularity were only found for the most rigorously designed subtests. Written Language and Comprehension. The results suggest the introduction of a new combined facet linguistic complexity which reflects the dependency of the facets regularity and unit.

A cross-validation study on the token test

Abstract The authors suggest that the possible combinations of pure alexia with concomitant neuropsychological symptoms form a continuum determined by the extent and severity of the brain lesion. The disconnection mechanism underlying these syndromes is demonstrated by the facilitating effect of unblocking methods (in the tactile, somesthetic, auditory, and visual modality) on the reading performance of a pertinent case. In the unblocking situation, other pathways than the one impaired by the brain lesion are used. It is proposed that the color naming deficit is associated with defective verbal identification of graphemic stimuli because of their common linguistic features. The delineation from aphasic color naming and reading deficit is discussed.

A Quantitative Study on Language Understanding in Fluent and Nonfluent Aphasia

Abstract The cut-off score of 11 errors on the Token Test, proposed by O RGASS and P OECK (1966), was applied to a larger sample of brain damaged patients. Whilst 93% of aphasics were correctly identified, 22 per cent of non-aphasic patients were misclassified. Therefore, this cut-off score proved to be unsatisfactory. The discriminating power of the TT, however, was again confirmed: Applying the cut-off score optimal for this sample (23 errors), 91 per cent of aphasics were correctly classified and only 5% of the non-aphasics were misclassified. A moderate influence of age and PIQ on the TT-scores was found. The implication of this results is discussed.

Impairment in visual recognition of geometric figures in patients with circumscribed retrorolandic brain lesions.

Summary Language understanding, as tested by the Token Test, was compared in two groups of non-fluent (N = 13) and fluent (N = 21) aphasics. No difference between the distribution for the two sub-groups was found. The mean scores were not significantly different for each part of the test and for the total score. Thus, language understanding is impaired to an equal extent in non-fluent and fluent aphasics. The theoretical implications of this finding are discussed.