Luria’s Neuropsychological and Neurolinguistic Testing

In this paper Luria’s neuropsychological and neurolinguistic theory is briefly reviewed in order to relate it to his neuropsychological testing. Luria’s neuropsychological and neurolinguistic testing is based on his general theory of brain-behaviour relations, which emphasizes the overlap between different functional systems. Luria’s goal was to provide a principled approach to testing and rehabilitation, based upon an understanding of the factors underlying complex psychological activities and derived from observations and studies of normal and pathological populations. A case history illustrates these principles. LURIA’S NEUROPSYCHOLOCICAL AND NEUROLINGUISTIC THEORY In his last manuscript edited and published by Michael Cole “The Making of a Mind” (Luria 1979) Luria argued that different parts of the brain are responsible for different components of verbal activities and that different components of verbal communication suffer as a consequence of different localized brain lesions. Consequently, neuropsychology is valuable not only as a specific branch of science in and of itself, but also as a special means for studying components of verbal communication. New insight may be brought to basic linguistic problems that cannot be solved by pure linguistic analysis, if they are approached from a neuropsychological point of view. 138 Journal of Keurolinguistic~, Volume 4, Number 1 (1989) I.uria’s early work with Vygotsky in the psychology of development and language had given impetus to his medical studies and built the background for his work in neuropsychology. In Luria’s own words, the observations made during the Second World War resulted in a much better understanding of the “morphology” of higher psychological processes in terms of both their inner structure and of the role that separate parts of the brain play in their neural organization. Much insight was gained by way of a new method of investigation that had been developed b) Luria. The goal of the investigation was to understand the symptoms of disturbances of higher cortical functions but also to “qualify the defects”, i.e. to analyze the factors underlying behavioural disturbances. The concept of the higher psychological processes as beingsocial in their origins, structured through initiation of speech and functioning consciously in a selfregulated manner set the framework for the investigation. The observation that separate parts of the brain played specific roles in behaviour was taken into account in building the stages of the investigation. Behavioural acts were considered complex functional systems not localized in narrow circumscribed brain areas, but rather depending upon the coordinated participation of groups of interrelated functional areas. each making its own particular contribution to the entire functional system. A voluntary movement. a visual observation or a speech act represent such functional systems in which cerebral structures participate in an integrated and complex way. Every functional area gives its own contribution to the whole functional system. Depending upon which area is damaged, the specific disturbance of the functional system will manifest itself in different ways and the structure can be identified only after a detailed analysis of the symptom. In concordance with this, Luria’s work represents an attempt to develop a theory of language as a functional system and a concern with the component processes involved in the uses of language. Luria’s approach has much in common with and seems an important precursor of modern neurolinguistic analyses of aphasic language disturbances. Neurolinguists :iew the language capacity as decomposable into components or modules whose nature and interactions are the ob.jects of study (Fodor 1983). In both Luria’s approach and in modern neurolinguistics. dissociations and associations of impairments arising after brain damage constitute data for componential analyses of psychological functions. However. Luria differs from modern neurolinguistics in some important respects. Neurolinguists consider language to be special in the sense that it requires its own descriptive vocabulary and cannot be fully accounted for in sensorimotor or general cognitive terms. Within modern neurolinguistics, hypotheses about the components of language are therefore derived from psycholinguistic models or linguistic theory. While Luria advocated the introduction of linguistic analyses as a powerful tool Luria’s ~europsyehoiogical and ~eurolinguistie Testing 139 in the study of aphasic language deficits, his position regarding the special nature of language appears to be intermediary between the modern neurolinguistic position and so-called holist positions, as exemplified by Goldstein, who viewed language as a second-order symbol system (Arbib and Caplan 1979). In Luria’s theory, psycholinguistic activities (e.g. reading. word recognition, naming, etc.) constitute complex functional systems whose subcomponents can be characterized to a large extent in sensorimotor or general cognitive terms. Although there may be subcomponents which are special to language, Luria’s general approach is to emphasize the association and interaction between linguistic and non-linguistic functional systems. It seems that in the final analysis Luria’s goal was to be able to relate linguistic behaviour to sensorimotor and to cognitive non-language behaviour. However, it may be precarious to do so without an intermediary level of psycholinguistic description, because one is apt to ignore the complex structure of language. Luria has been criticized on this account, i.e. for a preoccupation with sensorimotor aspects and a simplification of linguistic behaviour (Hatfield 1981). Modern neurolinguistics is based on sophisticated models of language and is not likely to be met with the same criticism. However, in the preoccupation with structural descriptions, neurolinguists sometimes neglect the performance or processing perspective on the language capacity which Luria showed a clear awareness of in his writings. In recent years, systematic empirical studies of aphasic subgroups have brought new evidence about the nature of the normal language processing system. As this research progresses, Luria’s neurolinguistic work may be expanded. Luria also differs from modern neurolinguistics on another important question, pertaining to the level of theory construction. In Luria’s theory, the neural substrate of functional systems is a constellation of activated areas and interactions between these. The components of a functional system are psycho-physiological in the sense that they are assumed to have a discrete and specific localization in the brain, Recent developments in neurolinguistics create distances to any specific theory of localization or neurophysiology. The components sought are psychological rather than psycho-physiological and their neural instantiation is considered to be a separate issue, Blood flow studies (Lassen et al. 1978) show that many areas of the brain are activated during complex psychological activities and therefore support Luria’s notion of a whole working brain and dynamic patterns of activity across different cortical zones. However, recent findings concerning neurochemical circuits of cortical areas {Finger and Stein 1982) suggest that changes in our understanding of the relationship between anatomy and function may be under way. As our knowledge in this area increases, Luria’s theory about anatomy and function may have to undergo revisions. 140 Journal of Neurolinguistics, Volume 4, Number 1 (1989) LURIA’S NEUROPSYCHOLOGICAL EXAMINATION Luria’s neuropsychological testing is described in Higher Cortical Functions in Man (Luria 1966) as well as in LuriaS Neuropsychological Investigation (Christensen 1974). His neurolinguistic testing and its theoretical background are also described in Traumatic Aphasia (Luria 1970) and in Basic Problems qf‘ Neurolinguistics (Luria 1976). The first stage of the investigation is a preliminary conversation, In this stage, attention is focused first on the state of consciousness of the patient and his orientation with respect to time and place. The areas of the brain which need to be active in order for these functions to be performed are primarily the reticular formation and the deeper structures. Next, as much information as possible is obtained regarding the patient’s premorbid level. Here mnestic functions play an important role. In the third part of the conversation self-awareness and selfevaluation (primarily frontal lobe functions) are concentrated upon. The fourth part, illuminating the subjective complaints of the patient, has a varied localizing value depending upon the specific symptoms noted by the patient. In the second stage of testing, attention is directed to the primary areas, the motor, the auditory, the visual and the tactile areas. In order to provide the most extensive information. these tests have to be simple and short. The purpose is to clarify the integrated components through a qualitative analysis. In the third stage the testing will be selective. The tests are chosen to illuminate and determine the disturbances that have been shown in the earlier stages of the investigation. In the selection of the tests, awareness of the components is necessary in order to secure the qualitative analysis of the patient’s performance. Thus, the general strategy is to test complex activities and to vary mode of response, rate or mode of stimulus presentation, memory requirements or stress-factors such as time limits on responses in order to establish the circumstances under which the patient fails and succeeds. The final part of the investigation is stage four, where the formulation of a clinical-neuropsychological conclusion is made. The disturbed, as well as the intact functions, have to be discerned. The fundamental defects must be identified; the influence of the defects on various forms of mental activity must be illuminated in order to discriminate the pathopsychological factors underlying the defects. The reliability of the conclusion can be ensured by syndrome analysis, i.e. by a comparative analysis of the results of the group of assorted tests and a determination of the general signs among these results which converge on a specific syndrome. Through this method of administration and analysis, the neuropsychological examination becomes an experiment conducted by the examiner; the results Luria’s Neuropsychological and Neurolinguistic Testing 141 are thus obtained, not only by distinguishing the functional mental defect, but also by demonstrating how this defect manifests itself in changing activities and symptoms. In the investigation of the motor function, first the motor function of the hands is examined. Secondly, an examination of oral praxis follows. The more complex motor functions where speech can regulate the motor act are examined last. The initial tests are simple, i.e. the patient is instructed to touch each finger in turn with his thumb. In a more complex variation of the test the patient can be instructed to count the fingers at the same time. The task of the investigator in this test is to pay attention to the muscle power and tone, to the kinesthetic afferent impulses that direct the motor efferent impulse to its proper destination and to observe the motor control of the movements. Inclusion of coordinates of external space (up, down, right, left, near, far) will provide information about the optic spatial components of the system. The same procedure is followed in the examination of the tongue, lips and face. The main purpose is to differentiate disorders of the peripheral innervation of the articulatory apparatus from aphasic disturbances. Simple movements such as to show the teeth, to puff the cheeks or to frown, kinesthetic movements and dynamic organization as well as integrative oral praxis are examined. An example of a more complex task in the examination of speech regulation of movement is conflict reactions: the patient is asked to show his finger when the examiner shows his fist and vice-versa. The subtests included in the investigation of acoustic-motor organization have to do with perception and reproduction of pitch relationships and rhythmic patterns. Implied in these tasks are a precise serial organization and a “motor” melody, in which the sequence is based on time intervals, acts for which the convexity of the temporal lobe is considered especially important. Investigation of cutaneous sensation, muscle and joint sensation and stereognosis is performed in order to clarify the state of the structures responsible for cutaneo-kinesthetic functions. Usually, vision is excluded to prevent participation of the visual receptors. The investigation of the higher visual functions is not only aimed at the primary visual area but also at the complex processes inherent in visual analysis and synthesis. Included in this section are tests of perception of objects and pictures and of spatial orientation and intellectual operations in space. A number of variations in the testing method can ensure insight into the directions and implications of specific processes taking part in the subject’s performance and in this way the need for a qualitative analysis can be obtained. The examination of language is organized into subtests corresponding to the classical psycholinguistic faculties: impressive speech (auditory comprehension), expressive speech (production), reading and writing. This organization is didactic