Exploring Treatment Fidelity in Persons With Aphasia Autonomously Practicing With Computerized Therapy Materials.

Purpose: Current computer technologies permit independent practice for people with cognitive-communicative disorders. Previous research has investigated compliance rates and outcome changes but not treatment fidelity per se during practice. Our aim was to examine adherence to procedures (treatment fidelity) and accuracy while persons with aphasia independently practiced word production using interactive, multimodal, user-controlled, word-level icons on computers. Method: Four persons with aphasia independently practiced single-word production after stimulation via user-initiated interactions in 3 conditions: (I) auditory stimulus with static representational drawing; (II) auditory stimulus with synchronized articulation video; and (III) users' choice between the 2 prior conditions. Sessions were video-recorded for subsequent analysis, which established emergently refined behavioral taxonomies using an iterative, mixed-methods approach. Results: In independent practice, users only sometimes adhere to modeled behaviors, other times improvising novel behaviors. The latter sometimes co-occurred with successful productions. Differences in success rates were noted between Conditions I and II across behaviors with Condition II generally favored. In Condition III, participants tended to choose the stimulus that resulted in highest success rates. Conclusions: During independent practice with technology, persons with aphasia do not necessarily comply with clinicians' practice instructions, and treatment fidelity does not determine success. Autonomy and choice in practice may reveal unanticipated dimensions for computerized aphasia treatment.

Alteraciones del procesamiento preléxico en pacientes hispanohablantes con afasias sensoriales: evidencias neurolingüísticas / Prelexical processing alterations in hispanophone patients with sensitive aphasias: neurolinguistic evidences

La verificación empírica de modelos de conversión acústico-fonémica es una necesidad de la práctica de la neurolingüística en cualquier contexto para optimizar la explicación del patrón neurocognitivo de pacientes con alteraciones del procesamiento preléxico. Por tal razón, en esta investigación se caracterizan los procesos de conversión acústico-fonémica en pacientes hispanohablantes, con el objetivo de obtener y acumular evidencias empíricas que permitan verificar en esta población lingüística el modelo de procesamiento preléxico más aceptado actualmente. Para ello se realizó un estudio descriptivo-transversal, con la participación de 72 pacientes con afasia de comprensión pertenecientes a los Servicios de Logofoniatría de la ciudad de Santiago de Cuba, con edades de 20 a 65 años, y entre 60 y 180 días de recuperación del daño cerebral. Estos fueron sometidos al Test de discriminación fonológica, que es una adaptación local de la «Prueba de discriminación» del Test DIFO de Benedet y Cortés-del-Solar. Se obtuvo que las alteraciones del procesamiento de las características distintivas de los sonidos del habla se distinguen de las alteraciones de la integración perceptual de fonemas. En el primer caso, se registran fallos estables en la ejecución de tareas que implican el procesamiento de unos u otros rasgos distintivos de los sonidos consonánticos del habla, mientras se conserva el procesamiento de rasgos distintivos de los sonidos vocálicos, y viceversa. En el segundo caso, se observan fallos en el procesamiento, tanto de todos los rasgos distintivos de los sonidos consonánticos del habla, como de los rasgos distintivos de los sonidos vocálicos (AU)

The empirical verification of prelexical processing models is necessary for the neurolinguistic practices in any context for optimizing the explanations of neurocognitive model in aphasic patients with disorder in prelexical processing. For this reason, the present investigation shows the characterization of acoustic-phonemic conversion process in aphasic hispanophone patients. The study was executed with the purpose to accumulate and to obtain empirical evidences in this linguistic population, for the practical verification of the most accepted prelexical processing model. A descriptive-transversal study was conducted with the participation of 72 patients with sensitive aphasia, localized in the Phoniatry Services of Santiago de Cuba City, with ages between 20 and 65 years, and not more of 60 to 180 days of brain injury recovery period. The participants performed the Test de discriminación fonológica, that is a contextual adaptation of the task «Prueba de discriminación» of the Test DIFO of Benedet and Cortés-del-Solar. Results revealed that disorders in distinctive characteristics of speech sounds processing are different of phoneme perceptual integration disorders. In the first, affectation in the execution of tasks that implies the processing of some distinctive characteristics of consonant speech sounds was recorded, whereas the processing of other distinctive characteristics of vowel speech sounds are preserved. In the second affectation in the processing of all distinctive characteristics of speech sounds was observed (AU)

Fundamental deficits of auditory perception in Wernicke's aphasia.

OBJECTIVE: This work investigates the nature of the comprehension impairment in Wernicke's aphasia (WA), by examining the relationship between deficits in auditory processing of fundamental, non-verbal acoustic stimuli and auditory comprehension. WA, a condition resulting in severely disrupted auditory comprehension, primarily occurs following a cerebrovascular accident (CVA) to the left temporo-parietal cortex. Whilst damage to posterior superior temporal areas is associated with auditory linguistic comprehension impairments, functional-imaging indicates that these areas may not be specific to speech processing but part of a network for generic auditory analysis. METHODS: We examined analysis of basic acoustic stimuli in WA participants (n = 10) using auditory stimuli reflective of theories of cortical auditory processing and of speech cues. Auditory spectral, temporal and spectro-temporal analysis was assessed using pure-tone frequency discrimination, frequency modulation (FM) detection and the detection of dynamic modulation (DM) in "moving ripple" stimuli. All tasks used criterion-free, adaptive measures of threshold to ensure reliable results at the individual level. RESULTS: Participants with WA showed normal frequency discrimination but significant impairments in FM and DM detection, relative to age- and hearing-matched controls at the group level (n = 10). At the individual level, there was considerable variation in performance, and thresholds for both FM and DM detection correlated significantly with auditory comprehension abilities in the WA participants. CONCLUSION: These results demonstrate the co-occurrence of a deficit in fundamental auditory processing of temporal and spectro-temporal non-verbal stimuli in WA, which may have a causal contribution to the auditory language comprehension impairment. Results are discussed in the context of traditional neuropsychology and current models of cortical auditory processing.

Action and object processing in aphasia: from nouns and verbs to the effect of manipulability.

The processing of words and pictures representing actions and objects was tested in 21 aphasic patients and 20 healthy controls across three word production tasks: picture-naming (PN), single word reading (WR) and word repetition (WRP). Analysis 1 targeted task and lexical category (noun-verb), revealing worse performance on PN and verb items for both patients and control participants. For Analysis 2 we used data collected in a concurrent gesture norming study to re-categorize the noun-verb items along hand imagery parameters (i.e., objects that can/cannot be manipulated and actions which do/do not involve fine hand movements). Here, patients displayed relative difficulty with the 'manipulable' items, while controls displayed the opposite pattern. Therefore, whereas the noun-verb distinction resulted simply in lower verb accuracy across groups, the 'manipulability' distinction revealed a 'double-dissociation' between patients and control participants. These results carry implications for theories of embodiment, lexico-semantic dissociations, and the organization of meaning in the brain.

Subcortical aphasia.

We critically review the literature on subcortical aphasia, suggest that a number of traditional concepts regarding mechanisms of aphasia are inconsistent with now abundant data, and propose several new hypotheses. The absence of aphasia in 17 reported cases of dominant hemisphere striatocapsular infarction and the finding of nearly every conceivable pattern of language impairment in 33 different reported cases of striatocapsular infarction provide strong evidence against a major direct role of the basal ganglia in language and against disconnection or diaschisis as mechanisms of nonthalamic subcortical aphasia. However, detailed consideration of the vascular events leading to striatocapsular infarction strongly suggests that associated linguistic deficits are predominantly related to sustained cortical hypoperfusion and infarction not visible on structural imaging studies. Thalamic disconnection, as may occur with striatocapsular infarcts with extension to the temporal stem and putamenal hemorrhages, may also contribute to the language deficits in some patients. Review of the literature on thalamic infarction, in conjunction with previously unreported anatomic details of four cases, suggests that what infarcts in the tuberothalamic artery territory and the occasional infarcts in the paramedian artery territory associated with aphasia have in common is damage to the frontal lobe-inferior thalamic peduncle-nucleus reticularis-center median system that may be involved in regulating the thalamic gate in attentional processes. Disruption of attentional gating in the pulvinar and lateral posterior nuclei resulting from such lesions may impair selection of specific neuronal networks in the projection field of these nuclei that serve as the substrate for lexical-semantic function, which is in effect a disruption of a type of working memory, as defined by Goldman-Rakic. We define this as a defect of selective engagement.

Subcortical aphasia and the problem of attributing functional responsibility to parts of distributed brain processes.

N&C's discussion is, in places, an exemplar of the sort of rigor and attention to detail that will bring us closer to an understanding of the functional organization of the brain. Indeed, it is this level of work that pushes us to reflect on the assumptions that undergird our research efforts. Our criticisms have developed four main points. First, the level of rigor applied to the consideration of basal ganglionic aphasia should extend to each application of the CPC method (thalamic aphasia included). Second, in our haste to identify specific brain systems with distinct cognitive functions we should not neglect the more basic question of the causal mechanisms by which the brain organizes behavior. Questions of "direct" versus "indirect" involvement of a particular organ in a cognitive function are only likely to distract our attention from this more basic and less inferentially perilous issue. Third, pure cases should no longer be considered touchstones against which all behavioral disturbances are measured. Reifying such ideals is more likely to shroud than reveal the brain's true complexity. Finally, the functions that we enshrine in particular brain regions should explain the particular character of the symptoms observed when they are damaged and should admit of independent verification.

[Relation between defect in comprehension and frontal lobe lesion].

We assessed anatomical findings and language defects in 14 right handed patients who had fluent aphasia following left frontal lobe lesion. From the onset of aphasia all of the patients showed fluent speech and excellent repetition but difficulty in word finding and impairment in language comprehension. We administered to all of the patients the Western Aphasia Battery, a 50-item pointing task using line drawings representing single words selected from among common Japanese words for language training for aphasics, and the Token Test. Anatomical analysis was performed using brain CT and/or MRI. The patients were divided into three groups on the basis of the extent of impairment in comprehension of single words: one group showed no impairment, another showed slight impairment and the other showed severe impairment. The lesion site differed among the groups. Each group had a different lesion site. We concluded the following: first, lesions in Brodmann's areas 6 and 9 produce impairment in comprehension of single words, with lesions extending to anterior to Broca's area producing more impairment than those without the extending lesions. Second, lesions in the frontal lobe produce impairment in comprehension of complex sentences.

Aphasia and infarction of the posterior cerebral artery territory.

Spoken language disorders are rarely mentioned in superficial infarction of the posterior cerebral (PCA) territory. Two clinical types have been reported: transcortical sensory and amnesic aphasia. Between 1979 and 1990, we studied retrospectively 76 patients suffering from an occipitotemporal infarction located in the superficial territory of the posterior cerebral artery, all well documented by CT. Aphasia was one of the first and prominent signs in 18 cases. Middle cerebral artery concomitant infarction could have been the cause of language impairment in 10. In 8 patients aphasia was only explained by a PCA territory infarct. Three patients showed features of transcortical sensory aphasia. CT localization showed internal lobe and thalamic involvement of the dominant hemisphere. Five patients exhibited word finding impairment with various degrees of amnestic syndrome. The dominant internal temporal lobe was always affected. Dominant thalamus involvement was found in one case only. Some correlations between clinical features and anatomical support (vascular supply and anatomical structure) might be suggested in our 8 cases of aphasic disorders due to PCA infarcts. They are discussed and compared with data in the literature.

An on-line analysis of syntactic processing in Broca's and Wernicke's aphasia.

This paper is about syntactic processing in aphasia. Specifically, we present data concerning the ability of Broca's and Wernicke's aphasic patients to link moved constituents and empty elements in real time. We show that Wernicke's aphasic patients carry out this syntactic analysis in a normal fashion, but that Broca's aphasic patients do not. We discuss these data in the context of some current grammar-based theories of comprehension limitations in aphasia and in terms of the different functional commitments of the brain regions implicated in Broca's and Wernicke's aphasia, respectively.