Myrna F. Schwartz - US grants

Cognitive neuropsychologists apply the methods and models of cognitive psychology to study disorders resulting from brain damage. Up to now, the concerns have been mostly of a theoretical nature and have had little to do with the therapeutic management of patients. This proposal is aimed at rectifying this situation. Part 1 of the Research Plan deals with acquired aphasia. Recent psycholinguistic studies indicate that some aphasic patients suffer from an inability to assign thematic roles (e.g., agent, patient) to syntactic functions (subject, object) in accordance with lexically-stated mapping rules. This "mapping" impairment has serious consequences for producing and comprehending sentences and underlies at least some aspects of the "agrammatism" of the Broca-type aphasic. A study is therefore proposed to evaluate an original treatment program aimed at strengthening the mapping operations in patients who show the agrammatic pattern in speaking and/or comprehending sentences. The second study is Part 1 proceeds on the assumption that the paraphasia-filled speech of the fluent aphasic is subject to analysis on the model of "slips-of-the-tongue". A method is proposed for classifying patients' "slips" and for interpreting the resulting pattern in accordance with a theory of sentence planning. Some preliminary treatment techniques are proposed which have the goal of modifying the size of the planning units and the speech rate, parameters which, on the theory, exert a critical influence on both the frequency and the character of speech errors. It is possible to view slips-of-the-tongue as a special case of "errors of action" and indeed, more general theories of action have been proposed that speak to the origin of non-verbal, as well as verbal slips. In Part II of the Research Plan, such a theoretical perspective is brought to bear on the problems in planning and executing routine activities (ideational apraxia) shown by patients with traumatic brain injury. An observational study is proposed that involves videotaping selected patients in the performance of routine morning activities and classifying their errors according to an original taxonomic scheme. A proposed diary study assesses whether this scheme reliably classifies the action slips recorded by non-brain damage individuals. Comparisons between the two error corpora are expected to generate hypotheses as to the origin of patients' errors within the conceptual system for action and lead to future treatment studies aimed at remediating or circumventing the underlying disturbance.

Cognitive neuropsychologists apply the methods and models of cognitive psychology to study disorders resulting from brain damage. Up to now, the concerns have been mostly of a theoretical nature and have had little to do with the therapeutic management of patients. This proposal is aimed at rectifying this situation. Part 1 of the Research Plan deals with acquired aphasia. Recent psycholinguistic studies indicate that some aphasic patients suffer from an inability to assign thematic roles (e.g., agent, patient) to syntactic functions (subject, object) in accordance with lexically-stated mapping rules. This "mapping" impairment has serious consequences for producing and comprehending sentences and underlies at least some aspects of the "agrammatism" of the Broca-type aphasic. A study is therefore proposed to evaluate an original treatment program aimed at strengthening the mapping operations in patients who show the agrammatic pattern in speaking and/or comprehending sentences. The second study is Part 1 proceeds on the assumption that the paraphasia-filled speech of the fluent aphasic is subject to analysis on the model of "slips-of-the-tongue". A method is proposed for classifying patients' "slips" and for interpreting the resulting pattern in accordance with a theory of sentence planning. Some preliminary treatment techniques are proposed which have the goal of modifying the size of the planning units and the speech rate, parameters which, on the theory, exert a critical influence on both the frequency and the character of speech errors. It is possible to view slips-of-the-tongue as a special case of "errors of action" and indeed, more general theories of action have been proposed that speak to the origin of non-verbal, as well as verbal slips. In Part II of the Research Plan, such a theoretical perspective is brought to bear on the problems in planning and executing routine activities (ideational apraxia) shown by patients with traumatic brain injury. An observational study is proposed that involves videotaping selected patients in the performance of routine morning activities and classifying their errors according to an original taxonomic scheme. A proposed diary study assesses whether this scheme reliably classifies the action slips recorded by non-brain damage individuals. Comparisons between the two error corpora are expected to generate hypotheses as to the origin of patients' errors within the conceptual system for action and lead to future treatment studies aimed at remediating or circumventing the underlying disturbance.

A body of research-to which the PI and Co-PI have been major contributors-implicates a syntax-to-semantics mapping deficit as a core feature in the grammatical disorder of nonfluent, Broca's aphasics. Consequently, our team of neurolinguists and speech-language pathologists has sought to develop treatment protocols that target mapping operations, along with verb retrieval operations that bear directly on mapping. Our preliminary successes reinforce the belief that treatments motivated by neurolinguistic findings and directed at components deficits have an important role to play in the clinical management of aphasic patients. Properly designed and adequately tested, such treatments may comprise the modular building blocks of programs for the rehabilitation of complex linguistic skills like oral production. This 'modular treatments' theme is elaborated in this 3-part proposal in accordance with the following specific aims: Part I: To compare the efficacy of two treatments for agrammatism-syntax stimulation and mapping therapy-which target different neurolinguistic operations; and to examine the efficacy of ordered combinations of the two treatments. Part II: To continue the development of a verb treatment program which simultaneously encourages lexico-semantic, syntactic, and phonological processing of verbs in sentence contexts; to manipulate 'depth of processing' of verb meaning as an independent variable in such treatment; Part IIl: To promote carry-over of treatment effects, and hence more functional outcomes, by means of a step-wise generalization training module aimed at bridging the gap between constrained and naturalistic oral production tasks;

The topic of this application is acquired disorders of action (apraxia) that impact performance of everyday activities. We seek to develop new analytic tools for describing and understanding the neuro-cognitive systems implicated in neurological conditions like ideational apraxia, frontal apraxia, and the executive disorder of traumatic brain injury. These conditions pose a significant clinical problem for neurological rehabilitationists and may place a heavy financial burden on families and society. We advocate a cognitive neuropsychological approach to the problem, which exploits the many parallels between speech and action. The first step involves analyzing the "syntactic" organization of action, and the nature of action errors, in natural action contexts. The Action Coding System (ACS), developed by our group, embodies a descriptive theory of action syntax and methods for coding errors and other measures of disorganization. Interpreted from the perspective of the cognitive systems supporting action, a patient's ACS error profile suggests hypotheses regarding which components of the cognitive system are impaired, and which are spared. These hypotheses may then be examined by the standard cognitive case-study method. This proposal seeks to apply and advance this general approach to the study of action disorders along three specific lines. Part 1 develops a Multi-level Action Test (MLAT) which requires the subject to perform familiar everyday tasks in contexts and combinations that vary along a continuum of task demands. This test will be used as a screening instrument for action disorders of the ideational and frontal types, in patients with TBI and stroke. Part 2 adapts the ACs to the task environment of the MLAT, in an effort to. examine how variations in task demands and contextual constraints effect the expression of action disorders of various types. Part 3 details a program of longitudinal case studies, in which a specially designed battery of neuropsychological tests is administered at regular intervals to a selected subset of patients, in an effort to further specify the nature of the underlying impairment to conceptual or executive systems, and the nature of the change over time. Together, the three parts of this proposal aim to advance the diagnosis of acquired action disorders and their theoretical analysis. The long term goal is to establish predictors of long-term outcome and new approaches to treatment for these often disabling conditions.

DESCRIPTION (provided by applicant): Our objectives are (1) to account for aphasic deficits in terms of psycholinguistic theory and (2) to test models of language processing by extending them to the phenomena of language breakdown. Section (1) concerns studies of lexical-phonological retrieval: to amass evidence on individual differences in error patterns in naming and repetition, including changes linked to recovery; to strengthen evidence that nonword errors generated in naming are influenced by lexical factors; to analyze how structural and sequential factors influence nonword errors in naming; and to determine whether movement errors in connected speech occur at above chance rates in individual aphasics. (2) concerns context-sensitive naming disorders. The aims are to develop reliable diagnostic procedures for these disorders; and to test and extend the theoretical accounts proposed by investigators who reported them. (3 ) presents studies of sentence processing that focus on aphasic deficits and grammatical processing. Aims include: to evaluate "mapping" and "working memory" accounts of agrammatic comprehension; to determine whether the poor performance of Wernicke's aphasics on grammaticality judgment tests reflects deficits at the single word level or grammatical structures; to replicate with new methods the finding that complexity of meaning facilitates verb access in some patients; and to provide data to test a computational account of this phenomenon that relates it to agrammatism. (4) links computational modeling to the empirical work described above: to compare two models of lexical retrieval for their ability to capture naming, repetition, and recovery data; to extend these models to account for neighborhood density effects, context-sensitive naming disorders and other challenging data; to develop a new connectionist learning model that produces multisyllabic words as true sequences and test this model against nonword phonological errors; and to develop a model of grammatical encoding that can be used to understand impaired access to verbs and multiple word sequences.

[unreadable] DESCRIPTION (provided by applicant): The PC-based Communication System (CS) was developed for adults with acquired aphasia. It acts as a "processing prosthesis" by taking spoken message creation off-line and minimizing demands for fast retrieval and working memory. Used as an AAC device, the CS has been shown to enhance aphasics' fluency and grammatical expression in narrative production tasks. Used as a therapy tool, it resulted in improved unaided production after independent practice in the home. This proposal will extend the functionality of the CS by making it possible for the user to transfer CS-generated messages appropriate to specific situations onto a hand-held computer, which can be deployed in situ to supplement or cue language production in real-world, real-time, communication. The intention is to create an AAC device that will not only enable the transfer of information appropriate to these situations, but also will allow the user to demonstrate his or her intellectual competence, which may be obscured by the language disability. An experiment is proposed to evaluate whether and how the enhanced system (CS plus handheld: CS-HH) benefits aphasics' communication of messages prepared in anticipation of simulated service encounters (e.g., a medical examination). The experiment will compare a group trained to use CS-HH in these simulated encounters with a second, closely matched group, that is trained to use conventional verbal and nonverbal strategies to compensate for their spoken language deficits (the control group). Experimental and control groups will be compared on a total of five service encounters: three that subjects train for in therapist-led sessions, and two that they prepare for without therapist involvement (the generalization test). The prediction is that the experimental group will use the CS-HH to communicate more effectively both in the encounters they train for and in those they prepare themselves. A second study will use qualitative techniques (focus groups, semistructured interviews) to explore patients' assessment of their communicative competence in service- and other encounters, and their attitudes toward communication aids, both technological and conventional (e.g., picture books, gestures). It is predicted that after using the CS-HH in simulated service encounters, patients will view themselves as more effective communicators than they did at the start and will be positively disposed to using this AAC device in the future. [unreadable] [unreadable]

DESCRIPTION (provided by applicant): This long-running grant deals with the persistent language impairment that results from left hemisphere stroke (chronic aphasia). Over the years, it produced new aphasia assessment tools, experimental methods, and computational and statistical techniques, and made these available to the research community. Unique to our approach is the emphasis on linking data to implemented computational models of individual patients and patient variability that are derived from psycholinguistic and cognitive principles. These data and models now form the backbone of lesion-mapping and learning studies that are the focus of the next cycle. Building on our success in applying group-level, voxel-based lesion-symptom mapping (VLSM) methodology, the next cycle will introduce new enhancements in the form of multivariate lesion-behavior mapping at the level of voxels, regions, and tracks. Coupling these powerful techniques to our model-driven behavioral analysis ensures that the symptoms that are mapped are realistic with respect to psycholinguistic models, and meaningful with respect to patient performance. Specific aims are to identify lesion correlates of impairments at conceptual, lexical-semantic, and lexical-phonological stages of word production. There is consensus on the need to bridge the gap between theory and practice in language rehabilitation. Towards this end, a series of studies are proposed that aim to articulate principles of learning in connection with the learning-based recovery of lexical- semantic and lexical-phonological access to words in aphasia. As in our past work, the innovation is the linking of individual patients and patient variability to theory and models. Specifically, we strive to formulate principles of learning that specify how impairment in the lexical access system affects the system's ability to monitor its own state, strengthen weights through repetition, learn from errors, and so on. Such principles constitute building blocks for effective, individually tailored treatment strategies. They are building blocks, too, for learning-based approaches to recovery of other, more complex language functions.