The influence of situational context on naming performance in aphasic syndromes

Are single-word picture naming assessments a valid measure of word retrieval in connected speech?

Purpose: Picture naming assessments are one of the most common methods of examining word retrieval in aphasia. However, currently, it is unclear whether these assessments are able to accurately predict word retrieval in "real-life" communication. This paper aims to explore the evidence in the current literature regarding the relationship between picture naming and word retrieval in connected speech in people with aphasia.Method: Literature was reviewed that examined the correlation between picture naming and word retrieval in connected speech. The literature search was limited to articles that were English language, participants with aphasia, and that were not therapy studies.Result: The existing studies showed mixed findings. However, comparison of study outcomes was complicated by inconsistency in the research methods used, including in word retrieval measures and connected speech elicitation.Conclusion: While there is some evidence of a relationship between picture naming and word retrieval in connected speech, correlation outcomes were mixed with possible influences from participant characteristics, assessment method and speech sample type. We therefore suggest that clinical decision-making would benefit from supplementing picture naming tests with an analysis of word retrieval in connected speech. Further research is required with a focus on natural conversation and the development of standard testing procedures for connected speech.

What is Functional Communication? A Theoretical Framework for Real-World Communication Applied to Aphasia Rehabilitation

Aphasia is an impairment of language caused by acquired brain damage such as stroke or traumatic brain injury, that affects a person’s ability to communicate effectively. The aim of rehabilitation in aphasia is to improve everyday communication, improving an individual’s ability to function in their day-to-day life. For that reason, a thorough understanding of naturalistic communication and its underlying mechanisms is imperative. The field of aphasiology currently lacks an agreed, comprehensive, theoretically founded definition of communication. Instead, multiple disparate interpretations of functional communication are used. We argue that this makes it nearly impossible to validly and reliably assess a person’s communicative performance, to target this behaviour through therapy, and to measure improvements post-therapy. In this article we propose a structured, theoretical approach to defining the concept of functional communication. We argue for a view of communication as “situated language use”, borrowed from empirical psycholinguistic studies with non-brain damaged adults. This framework defines language use as: (1) interactive, (2) multimodal, and (3) contextual. Existing research on each component of the framework from non-brain damaged adults and people with aphasia is reviewed. The consequences of adopting this approach to assessment and therapy for aphasia rehabilitation are discussed. The aim of this article is to encourage a more systematic, comprehensive approach to the study and treatment of situated language use in aphasia.

Language mixing patterns in a bilingual individual with non-fluent aphasia

BACKGROUND

Language mixing in bilingual speakers with aphasia has been reported in a number of research studies, but the reasons for the mixing and whether it reflects typical or atypical behaviour has been a matter of debate.

AIMS

In this study we tested the hypothesis that language mixing behaviour in bilingual aphasia reflects lexical retrieval difficulty.

METHODS & PROCEDURES

We recruited a Hebrew-English bilingual participant with mild-moderate non-fluent agrammatic aphasia and assessed his languages at three timepoints. We analysed the participant's Hebrew and English production for retrieval during single-word naming, sentences, and discourse, and identified all instances of language mixing.

OUTCOMES & RESULTS

We found that there was a greater frequency of language mixing during production of more difficult lexical items, namely the post-morbidly less proficient language (compared to the more proficient language), function words (compared to content words), and single-word naming (compared to retrieval in the context of connected speech tasks), but not for verbs (compared to nouns).

CONCLUSIONS

In this bilingual participant with non-fluent aphasia, language mixing behaviour closely resembles lexical retrieval difficulty. Thus, we suggest that bilingual speakers with aphasia may mix their languages as a strategy to maximise communication.

Response Time Inconsistencies in Object and Action Naming in Anomic Aphasia

PURPOSE

The effect of repeated naming on both object and action picture naming in individuals with anomic aphasia is explored. We asked whether repeatedly naming the same items leads to improved accuracy and reduced response latency.

METHOD

Ten individuals with anomic aphasia and 6 healthy adults, 3 young and 3 old, named a set of 27 object pictures and a set of 27 action pictures presented 1 at a time on a computer screen. We examined accuracy and response times (RTs) across the 2 blocks of 10 repeated trials.

RESULTS

Results demonstrated higher accuracy and faster RTs for object than for action naming for all participants, with lower accuracy rates and slower RTs for the people with aphasia (PWA) compared with the healthy individuals, and diverging patterns of change across trials. Unlike the healthy participants, whose RTs decreased across trials, PWA continued to demonstrate variability in response latencies across the trials.

CONCLUSIONS

Our preliminary results suggest that measuring RT may be useful in characterizing retrieval difficulty in anomic aphasia and that the retrieval processes in PWA, even in those who experience mild anomia, may be less efficient or different from those processes in neurologically healthy individuals.

Do age-related word retrieval difficulties appear (or disappear) in connected speech?

We conducted a comprehensive literature review of studies of word retrieval in connected speech in healthy aging and reviewed relevant aphasia research that could shed light on the aging literature. Four main hypotheses guided the review: (1) Significant retrieval difficulties would lead to reduced output in connected speech. (2) Significant retrieval difficulties would lead to a more limited lexical variety in connected speech. (3) Significant retrieval difficulties would lead to an increase in word substitution errors and in pronoun use as well as to greater dysfluency and hesitation in connected speech. (4) Retrieval difficulties on tests of single-word production would be associated with measures of word retrieval in connected speech. Studies on aging did not confirm these four hypotheses, unlike studies on aphasia that generally did. The review suggests that future research should investigate how context facilitates word production in old age.

Verb production tasks in the measurement of communicative abilities in aphasia

BACKGROUND

The neurofunctional correlates of verbs and nouns have been the focus of many theoretically oriented studies. In clinical practice, however, more attention is typically paid to nouns, and the relative usefulness of tasks probing nouns and verbs is unclear. The routine administration of tasks that use verbs could be a relevant addition to current batteries. Evaluating performance on both noun and verb tasks may provide a more reliable account of everyday language abilities than an evaluation restricted to nouns.

AIMS

To assess the benefits of administering verb tasks in addition to noun tasks, and their relation to three functional measures of language.

METHOD AND PROCEDURE

Twenty-one subjects with poststroke language disorders completed four picture-naming tasks and a role-playing test (Communicative Abilities in Daily Living, Second Edition, CADL-2), commonly used as measure of everyday language abilities. Two questionnaires (Communicative Effectiveness Index, CETI, and Communicative Activity Log, CAL) were completed by caregivers. Picture-naming tasks were matched for psycholinguistic variables to avoid lexicosemantic and morphosyntactic confounds.

RESULTS

No significant differences emerged across picture-naming tasks. Scores on the role-playing test and the two questionnaires differed; scores between the two questionnaires did not. The four naming tasks correlated significantly with CADL-2, CETI, and CAL. The strength of the correlation with CADL-2 was significantly greater for Naming Finite Verbs than for Object Naming. Thirteen participants showed no differences in performance between tasks, 6 fared significantly worse on verb tasks than on Object Naming, 1 fared better at Naming Finite Verbs though his performance was poor overall, and 1 was significantly more impaired on verbs.

CONCLUSIONS

Performance on tasks that use verbs, and especially Naming Finite Verbs, may provide a more accurate estimate of language abilities in daily living than Object Naming alone. Administering both verb and noun tasks may be recommended in clinical practice.

Effects of context and word class on lexical retrieval in Chinese speakers with anomic aphasia

BACKGROUND

Differences in processing nouns and verbs have been investigated intensely in psycholinguistics and neuropsychology in past decades. However, the majority of studies examining retrieval of these word classes have involved tasks of single word stimuli or responses. While the results have provided rich information for addressing issues about grammatical class distinctions, it is unclear whether they have adequate ecological validity for understanding lexical retrieval in connected speech which characterizes daily verbal communication. Previous investigations comparing retrieval of nouns and verbs in single word production and connected speech have reported either discrepant performance between the two contexts with presence of word class dissociation in picture naming but absence in connected speech, or null effects of word class. In addition, word finding difficulties have been found to be less severe in connected speech than picture naming. However, these studies have failed to match target stimuli of the two word classes and between tasks on psycholinguistic variables known to affect performance in response latency and/or accuracy.

AIMS

The present study compared lexical retrieval of nouns and verbs in picture naming and connected speech from picture description, procedural description, and story-telling among 19 Chinese speakers with anomic aphasia and their age, gender, and education matched healthy controls, to understand the influence of grammatical class on word production across speech contexts when target items were balanced for confounding variables between word classes and tasks.

METHODS & PROCEDURES

Elicitation of responses followed the protocol of the AphasiaBank consortium (http://talkbank.org/AphasiaBank/). Target words for confrontation naming were based on well-established naming tests, while those for narrative were drawn from a large database of normal speakers. Selected nouns and verbs in the two contexts were matched for age-of-acquisition (AoA) and familiarity. Influence of imageability was removed through statistical control.

OUTCOMES & RESULTS

When AoA and familiarity were balanced, nouns were retrieved better than verbs, and performance was higher in picture naming than connected speech. When imageability was further controlled for, only the effect of task remained significant.

CONCLUSIONS

The absence of word class effects when confounding variables are controlled for is similar to many previous reports; however, the pattern of better word retrieval in naming is rare but compatible with the account that processing demands are higher in narrative than naming. The overall findings have strongly suggested the importance of including connected speech tasks in any language assessment and evaluation of language rehabilitation of individuals with aphasia.

Test-retest stability of word retrieval in aphasic discourse

PURPOSE

This study examined the test-retest stability of select word-retrieval measures in the discourses of people with aphasia who completed a 5-stimulus discourse task.

METHOD

Discourse samples across 3 sessions from 12 individuals with aphasia were analyzed for the stability of measures of informativeness, efficiency, main concepts, noun and verb retrieval, word-finding difficulty, and lexical diversity. Values for correlation coefficients and the minimal detectable change score were used to assess stability for research and clinical decision making.

RESULTS

Measures stable enough to use in group research studies included the number of words; the number of correct information units (CIUs); the number of accurate-complete, accurate-incomplete, and absent main concepts; the percentage of T-units that had word-finding behaviors of any kind; the percentage of T-units that contained empty words; and a lexical diversity measure. Words per minute, CIUs per minute, and the percentage of T-units that contained time fillers or delays were sufficiently stable to use when making clinical decisions about an individual.

CONCLUSION

Although several of the measures demonstrated acceptable stability for group research studies, relatively few were sufficiently stable for making clinical decisions about individuals on the basis of a single administration.

Evidence for a context-sensitive word retrieval disorder in a case of nonfluent aphasia

We describe a patient (BM) with nonfluent aphasia who presents with sparse, fragmented spontaneous speech but normal or near-normal performance on standard naming tasks. However, more detailed investigation revealed some unusual features to BM's naming: On a task involving repeated naming of a small set of targets, his performance degenerated when the targets were semantically blocked, particularly at fast rates of presentation. This semantic blocking effect was not observed in an analogous wordpicture matching task. Also, it was not present on a task where a set of words had to be named repeatedly in a fixed, predictable sequence. Finally, a fluent aphasic patient who presented with a classic "output" anomia failed to show the semantic blocking and predictability effects. It is suggested that BM suffers from a context-sensitive word retrieval disorder. The disorder is attributed to a difficulty in modulating activation within the lexical network. Implications for nonfluent aphasia, as well as for models of lexical retrieval, are discussed.

Selection for position: the role of left ventrolateral prefrontal cortex in sequencing language

Patients with damage involving left ventrolateral prefrontal cortex (left VLPFC) often show syntactic deficits. They also show exaggerated interference effects during a variety of non-syntactic tasks, including picture naming and working memory. Conceivably, both deficits could arise from inadequate biasing of competitive interactions during language production. To test this hypothesis, we manipulated "positional" interference during multi-word naming by priming one of the nouns in the same or different position. Experimental case studies of four left VLPFC patients revealed that two of the patients showed exaggerated positional interference, greater number of errors, including omissions during multi-word production, increased production difficulty when the order of nouns did not match the predominant English pattern, as well as impaired comprehension of non-canonical reversible sentences. These results suggest that these two patients had an impairment in "selection for position". Different from the other two, their lesions included a subregion of frontal cortex (BA 44/6) that has been shown in neuroimaging studies to play a role in sequencing.

A linguistic communication measure for monitoring changes in Chinese aphasic narrative production

This study investigated the usefulness of the Cantonese Linguistic Communication Measure (CLCM) in monitoring changes of narrative production in five Chinese adults with aphasia in the period of spontaneous recovery (SR group) and four who underwent anomia therapies (Tx group). Language samples elicited from a picture description task were collected among SR participants at regular intervals within the first 6 months post-onset and among Tx participants before and after treatment. Results showed that the CLCM indices could reflect changes of language production in these individuals over time. The changes of index values were consistent with the expectations of performance during early stages after stroke for the SR participants and treatment outcomes of the Tx participants. While the CLCM has previously been shown to be useful in measuring aphasic narratives on a single occasion, this study has provided further evidence of its capability to monitor changes of language production over time.

Management of anomia

Anomia is a complex, commonly occurring symptom of aphasia with different underlying causes. A number of behavioral approaches to rehabilitation of anomia have been described. Some are restitutive in nature and attempt to reactivate lexical-semantic or phonological representations to improve word retrieval. Others are intended to reorganize language functions by engaging alternative cognitive systems to mediate word retrieval or by exploiting residual abilities to circumvent the impairment. A better appreciation of the characteristics of an individual's naming deficit may assist the clinician in selecting appropriate interventions for restitution or substitution of function in the management of this disorder.

Phonological neighborhood effects in aphasic speech errors: spontaneous and structured contexts

The current study investigates the influence of phonological neighborhoods on the accuracy of speech production in aphasia by examining errors produced in both spontaneous and structured speech tasks. Characteristics of the phonological neighborhoods of spontaneously produced aphasic errors are compared to the neighborhood characteristics of correctly produced targets in a picture description task. Accuracy of picture naming is also examined with reference to the phonological neighborhood characteristics of the stimuli. Results show that frequency of occurrence and neighborhood density play a facilitative role in speech production, replicating findings from recent studies with normal subjects. It is argued that the results are most parsimoniously explained within an interactive activation framework of lexical access.

The effects of varying attentional demands on the word retrieval skills of adults with aphasia, right hemisphere brain damage, or no brain damage

Adults with mild aphasia, right hemisphere brain damage (RBD), or no brain damage (NBD) provided one-word phrase completions under isolation, focused attention, and divided attention conditions and in response to relatively constrained or unconstrained phrase stems. Despite comparable word retrieval accuracy among groups during the isolation condition, aphasic and RBD groups performed less accurately than the NBD group during focused and divided attention conditions. Across conditions, there were no significant differences between aphasic and RBD groups. Only aphasic subjects demonstrated a significant effect of phrase type, responding more accurately when completing constrained versus unconstrained stimuli. For aphasic and RBD groups, error type analysis indicated that semantic and phonological aspects of word retrieval were influenced by increased attentional demands. These findings suggest that for adults with aphasia or RBD, there is a negative relation between attention impairments and word retrieval abilities.

The boston corpus of aphasic naming errors

This report provides verbatim error responses to picture naming given by 30 aphasic patients (10 Broca's aphasics, 6 Wernicke's aphasics, 7 conduction aphasics, and 7 anomic aphasics). The error corpus is intended to supply a rich set of raw data for investigators interested in the characteristics of aphasic word-finding problems as well as those interested in general models of lexical retrieval.

Evolution of oral and written confrontation naming errors in aphasia. A retrospective study on vascular patients

Impaired naming is a common finding in aphasia but while it is known that naming errors diminish over time, longitudinal studies are rare. In this retrospective study, naming errors of 84 vascular aphasic patients are studied. Errors in oral and written confrontation naming tasks in two successive evaluations are tabulated and coded into one of 10 error types. No Response, Word-Finding Difficulty, Semantic Paraphasia, Unrelated Paraphasia, Phonemic/Orthographic Paraphasia, Neologism, Paraphasic Jargon, Phonemic/Neologistic Jargon, Stereotypy, and Other. All analyses were carried out on the difference scores, that is, the score in the second examination minus the score in the first examination. Results indicate that there is a significant decrease of No Responses (in oral and written naming) and Neologisms (in oral naming), and a significant increase of Orthographic Paraphasias in written naming. Moreover, the difference score for Phonemic/Orthographic Paraphasias was higher in written than oral naming. The difference scores for the other types of error were not statistically significant.

Word retrieval in fluent and nonfluent dysphasia: utilization of pictogram

Connected speech samples were elicited from 10 nonfluent and 10 fluent dysphasic subjects utilizing two contexts, picture and pictogram descriptions. Incidences of word retrieval problems were identified and assigned to nine word retrieval categories. Results revealed pictogram elicited a greater incidence of word retrieval problems, and therefore, proved as a more informative context for identifying word retrieval problems in mild dysphasia. Also, certain word retrieval categories were selectively used by specific dysphasic classification categories and severity levels.

On the nature of naming difficulties in aphasia

An extensive naming battery was administered to ten patients representing classical aphasia syndromes. The battery included traditional performance measures and error scoring, phonological cuing, multiple-choice tasks tapping semantic and phonological knowledge, and word repetition tests. Differences in the patients' performance profiles were interpreted as reflecting lexical-phonological, phoneme assembly or multiple deficits. The results suggest that the hypothesized naming deficits have complex relationships to classical aphasia syndromes.

The interaction of lexical and non-lexical processing mechanisms: evidence from anomia

Patient SF presented with a selective deficit in naming, in the presence of normal auditory, visual and pictorial input processing, and of normal comprehension. The naming disorder was independent of input modality, and resulted in the inability to respond to low-frequency items. The analysis of the patient's performance in the repeated administration of the same set of pictures for oral naming and for written naming demonstrated that both tasks were disrupted to a similar extent--high consistency values were observed both across and within modality. Thus, the profile of the naming disorder observed in this patient was consistent with damage to phonological and orthographic output lexicons. SF's performance in reading and writing was apparently at odds with this account, as he was able to read aloud words with lexically-assigned stress, and to write to dictation words whose spelling is also determined lexically. The co-occurrence of the inability to activate output lexical representations in both oral and written picture naming, in the context of normal ability to activate the same representations in reading and in writing is consistent with the notion that phonological and orthographic output lexicons are distinct, but interact with nonlexical conversion mechanisms.

Aphasic and non-brain-damaged adults' descriptions of aphasia test pictures and gender-biased pictures

Twelve aphasic and 12 non-brain-damaged adult males described the speech elicitation pictures from the Boston Diagnostic Aphasia Examination (BDAE), the Minnesota Test for Differential Diagnosis of Aphasia (MTDDA), the Western Aphasia Battery (WAB), and six pictures representing male-biased or female-biased daily-life situations. For each speech sample we calculated number of words, words per minute, number of correct information units, percentage of words that were correct information units, and percentage of correct information units that were nouns or adjectives (amount of enumeration or naming). The WAB picture elicited more enumeration than the BDAE or MTDDA pictures, and information was produced at a slower rate in response to the WAB picture than the other two pictures. These differences were statistically significant and appear to be clinically important. Gender bias had statistically significant effects on two measures. Male-biased pictures elicited significantly more words and significantly more correct information units than female-biased pictures. However, these differences were small and do not appear to be clinically important. Two of the five measures (words per minute and percentage of words that were correct information units) differentiated non-brain-damaged speakers from aphasic speakers. The magnitude of these differences suggests that these measures provide clinically important information about the problems aphasic adults may have when they produce narrative discourse.

Spontaneous speech in aphasia: a correlational study

Seventeen spontaneous speech measures and scores on a naming test, employed to characterize the expressive performance of 121 aphasics, were subjected to a factor analysis. Five factors were obtained: (1) Syntactic ability, (2) Phonological paraphasia, (3) Neologistic paraphasia, (4) Articulatory impairment, and (5) Vocabulary. Relationships of the factors to naming error types were examined in order to elucidate the nature of some of the factors. Also, the relationships of the expressive factors to auditory comprehension tests were explored, such an exploration being relevant to the issue of the overlap between expressive and receptive functions.

The operativity effect in naming: a re-analysis

According to Howard Gardner (1973), operativity, i.e. the extent to which it is possible to act with or upon an object, influences picture naming by aphasic subjects. In the present study, this influence is analysed with three purposes: (1) to replicate the Gardner's observation, (2) to avoid methodological biases and to extend the analyses, and (3) to look for alternative explanations. Sixty-four pictures corresponding to high- and low-frequency nouns rated as high or low in operativity were presented to 18 aphasic subjects. Frequency and operativity were found to significantly affect naming performance. More particularly, fewer semantic paraphasias were observed in confrontation with operative items and fewer phonemic paraphasias in the production of frequent nouns. However, the influence of operativity on the reduction of errors disappeared when age-of-acquisition and picture familiarity were introduced as co-variables. These dimensions were found to be better predictors of aphasic performance than operativity.

The disconnection in anomic aphasia between semantic and phonological lexicons

PB, a right handed woman aged 26, has developed anomic language disturbances following right frontal and left temporal brain damage due to a road traffic accident. Her anomia shows exceptional features: it occurs in naming tasks in test conditions but not in continuous speech; it involves comprehension deficits but very few semantic errors in expression; it improves with phonemic, but not with semantic cues. These features, it is argued, indicate the disconnection between two intact lexicons: the semantic and the phonological.

Factors influencing naming performance in aphasia: a review of the literature

The naming performance of aphasic patients may vary substantially, depending upon linguistic factors associated with the target words, characteristics of the referent (real or pictured), the manner in which the response is elicited, and the particular situation in which the naming response is produced. Furthermore, the specific influence of certain of these factors on naming performance appears to vary with type of aphasia. This article reviews and evaluates the literature pertaining to factors that influence adult aphasics' naming performances. Implications for future research are discussed.