Lewis P. Shapiro

Agrammatic and non-brain-damaged subjects' verb and verb argument structure production

This study examined verb and verb argument structure production in 10 agrammatic aphasic and 10 non-brain-damaged subjects. Production of six types of verbs was examined in two conditions-a confrontation and an elicited condition; and production of verb arguments was examined in a sentence condition in which each target verb was elicited with all possible argument structure arrangements. Results showed statistically significant differences between the aphasic and non-brain-damaged subjects in all conditions, but no significant differences were found between confrontation and elicited labelling conditions for either subject group. The aphasic subjects, however, produced obligatory one-place verbs correctly significantly more often than three-place or complement verbs in the elicited condition and a consistent hierarchy of verb difficulty was found in both the confrontation and elicited conditions, For both subject groups sentence production was influenced by the number of arguments or participant roles and by the type of arguments required by the verb. In addition, the complexity of the verb (i.e. the number of possible argument structure arrangements) influenced sentence production with simple verbs produced correctly with their arguments more often than complex ones. Finally, obligatory arguments were produced correctly more often than optional ones, even when production of the optional arguments was requested. These data indicate that the argument structure properties of verbs are important dimensions of lexical organization that influence both verb retrieval and sentence production in agrammatic aphasic subjects.

Real-Time Examinations of Lexical Processing in Aphasics

We argue that the lesion localizing value of disruptions to modular information processing systems emerges most clearly from on-line analyses of processing. In this respect we seek to show that left anterior (but not left posterior) damage causes slowed information access and we discuss the manner in which this slowing might yield some of the specific syntactic limitations charted in Brocas aphasia. The general possibility we raise is that the cortical area implicated in Brocas aphasia is not necessarily the locus of syntactic representations, but rather sustains particular time-based operating characteristics that in turn sustain normal real-time parsing.

Treatment of sentence production deficits in aphasia: A linguistic-specific approach to wh-interrogative training and generalization

Abstract The present research examines the effects of a linguistic-specific treatment on acquisition and generalization of wh-interrogative structures in two aphasic subjects presenting with deficit patterns consistent with agrammatism. The underlying linguistic representation of sentence structures selected for treatment and generalization was considered based on aspects of Chomskys (1981) Government Binding (GB) theory, and a linguistic-based, wh-movement treatment strategy was implemented. Using a single-subject multiple-baseline design across behaviours and subjects, the effects of treatment were explored by examining generalization patterns across wh question forms requiring wh-movement (movement of a direct object NP to COMP). Within question form generalization also was evaluated by examining formulation of untrained sentences of varied complexity—with complexity defined in terms of the number of phrasal nodes in the d-structure representation of sentences. Results indicated that for both subjects...

Treating agrammatic aphasia within a linguistic framework: Treatment of Underlying Forms

Background : Formal linguistic properties of sentences—both lexical, i.e., argument structure, and syntactic, i.e., movement —as well as what is known about normal and disordered sentence processing and production, were considered in the development of Treatment of Underlying Forms (TUF), a linguistic approach to treatment of sentence deficits in patients with agrammatic aphasia. TUF is focused on complex, non-canonical sentence structures and operates on the premise that training underlying, abstract, properties of language will allow for effective generalisation to untrained structures that share similar linguistic properties, particularly those of lesser complexity. Aims : In this paper we summarise a series of studies focused on examining the effects of TUF. Methods & Procedures : In each study, sentences selected for treatment and for generalisation analysis were controlled for their lexical and syntactic properties, with some structures related and others unrelated along theoretical lines. We use single-subject experimental designs—i.e., multiple baseline designs across participants and behaviours—to chart improvement in comprehension and production of both trained and untrained structures. One structure was trained at a time, while untrained sentences were tested for generalisation. Participants included individuals with mild to moderately severe agrammatic, Brocas aphasia with characteristic deficits patterns. Outcomes & Results : Results of this work have shown that treatment improves the sentence types entered into treatment, that generalisation occurs to sentences which are linguistically related to those trained, and that treatment results in changes in spontaneous discourse in most patients. Further, we have found that generalisation is enhanced when the direction of treatment is from more to less complex structures, a finding that led to the Complexity Account of Treatment Efficacy (CATE, Thompson, Shapiro, Kiran, & Sobecks, 2003). Finally, results of recent work showing that treatment appears to affect processing of trained sentences in real time and that treatment gains can be mapped onto the brain using functional magnetic resonance imaging (fMRI) are discussed. Conclusions : These findings indicate that TUF is effective for treating sentence comprehension and production in patients who present with language deficit patterns like those seen in our patients. Patients receiving this treatment show strong generalisation effects to untrained language material. Given the current healthcare climate, which limits the amount of treatment that aphasic patients receive following stroke, it is important that clinicians deliver treatment that results in optimal generalisation in the least amount of time possible.

Treatment of sound errors in aphasia and apraxia of speech: Effects of phonological complexity

Background: Recent research suggests that the complexity of treatment stimuli influences the effectiveness of treatment. However, no studies have examined the role of complexity on sound production treatment in adult individuals with sound production impairments. Aims: This study examines effects of syllable complexity on treatment outcome in two patients with acquired sound production problems. Complexity is defined in terms of syllable structure: clusters are more complex than singletons. Using a single-subject multiplebaseline design, we address the question: Is treatment of complex syllables more effective than treatment of simple syllables? Methods & Procedures: Two patients with aphasia and apraxia of speech were trained to produce complex or simple syllables (using modelling). Improvement was measured by percent correct on a word and nonword repetition test. Outcomes & Results: We found that both treatment on simple syllables and treatment on complex syllables led to improved production of simple syllables, while treatment of complex syllables also led to improvement on some complex syllables for one of the two patients. Conclusions: These results suggests that training complex items is more effective than training simple items, at least for some patients. Possible reasons for lack of stronger effects are discussed, as well as directions for future research.

Prosody and the Processing of Filler-Gap Sentences

This study was designed to explore the effects of linguistic prosody on the processing of “filler-gap” sentences. We designed two experiments to determine first whether the sentence processor uses information contained in the prosodic contour of an utterance during on-line processing, and second the form that information may take. In Experiment 1, we found that prosody apparently influences when listeners posit gaps on-line. In Experiment 2, we obtained acoustic evidence that gaps are represented in the prosodic contour of an utterance. The results of this study support a view in which prosody contributes very early to on-line structure building mechanisms during sentence processing.

Prosodic influences on the resolution of temporary ambiguity during on-line sentence processing

We present three experiments designed to investigate the role of prosody during sentence processing. The first investigated the question of whether an utterances prosodic contour influences its comprehension on-line. We spliced the beginning and end portions of direct object and embedded clause sentences and observed the consequent effects on comprehension using a dual-task procedure to measure processing load. Our second experiment sought to determine-whether the constituent structure of these sentences could be reliably predicted using prosodic information. We found that the duration and F0 contour associated with the main-clause verb and the following NP reliably distinguished between the direct object and embedded clause constructions. In the final experiment, we manipulated the duration of the main-clause verb and found that subjects used this information to guide their initial parse during on-line sentence comprehension. The need for a model of sentence processing that addresses the use of prosodic information is discussed.

The role of syntactic complexity in training wh-movement structures in agrammatic aphasia: optimal order for promoting generalization.

This study examined the postulate that training production of syntactically complex sentences results in generalization to less complex sentences that have processes in common with treated structures. Three agrammatic aphasic patients were trained to produce wh-movement structures, object clefts and/or object extracted who-questions, while generalization between these structures was tested. One NP-movement structure, passive sentences, also was tested for control purposes. Wh-movement occurs from the direct object position to specifier position in the complementizer phrase [SPEC, CP] for both wh-movement structures. In who-questions movement occurs in the matrix sentence, whereas, in object clefts movement occurs within an embedded relative clause, rendering them the most complex. Results showed robust generalization effects from object clefts to matrix who-question for 1 participant (D.L.); however, no generalization was noted from who-questions to object clefts for another (F.P.), and 1 participant (C.H.) showed acquisition of who-questions, but not object clefts, during the baseline condition without direct treatment. As expected, none of the participants showed improved production of passives. These findings supported those derived from our previous studies, indicating that generalization is enhanced not only when target structures are related along dimensions articulated by linguistic theory, but also when the direction of treatment is from more to less complex structures. The present findings also support proposals that projections of higher levels in the syntactic treatment are dependent on successful projection of lower levels. For our participants, training movement within CP in a lower (embedded) clause resulted in their ability to project to CP at higher levels.

On-Line Comprehension of VP-Ellipsis: Syntactic Reconstruction and Semantic Influence

We describe two experiments that explored the on-line processing of coordinated (e.g.,The policeman defended himself and the fireman did [e] too, according to someone who was there) and subordinated VP-ellipsis (e.g.,The policeman defended himself because the fireman did [e], according to someone who was there). Such constructions have two possible interpretations: The “sloppy” reading is thatthe fireman defended himself, wherehimself corefers withthe fireman. The “strict” reading is thatthe fireman defended him, wherehim corefers withthe policeman. In our experiments we examined the strict reading, and found different time courses of processing the coordinated and subordinated structures. In coordination we found immediate reaccess of the nonlocal subject at the gap. In subordinated structures we found the reaccess effect only downstream from the gap. We interpret these patterns as reflecting the automatic nature of gap filling in coordinated ellipsis, but in subordinated ellipsis a causal relation must be computed between the two clauses, “drawing out” reaccess of the filler.

Online Examination of Language Performance in Normal and Neurologically Impaired Adults

This article describes how we and others have exploited online methodology to investigate normal and disordered language processing in adults. Online tasks can be used to measure effects occurring ...