Memory In Aphasia Research Articles

Effects of Time Interval and Interference Manipulations on Word-Level Repetition and Naming Performance in Persons with Aphasia

Objectives: The purpose of this paper is to investigate the impact on the repetition and naming ability of Korean aphasia patients by controlling their working memory load through time intervals and interference effects using the Temple Assessment of Language and verbal Short-term memory in Aphasia (TALSA) protocol. In addition, we examined the phonological and lexical-meaning processing abilities of persons with aphasia through word repetition tasks, nonword repetition tasks, and picture naming tasks to examine phonological and lexical-meaning production abilities. Methods: Thirteen native Korean speakers with aphasia participated in the study, along with twelve control group participants. The word and nonword repetition tasks were conducted under three conditions to examine the time delay and interference effects. Each condition entailed listening to each ten words of two and three syllables. Similarly, the picture naming tasks were carried out under three conditions involving viewing ten pictures of two and three syllables each. Results: This study examined how the repetition and naming ability of persons with aphasia, i.e., the ability to producing phonemes and lexical-meaning of persons with aphasia, varies when adjusting the working memory load under time interval and interference effect conditions. This study found that the difference in performance between groups was significant for both tasks. In particular, the larger the time interval, the greater the interference effect; that is, the greater the load of working memory, the lower the performance of aphasia subjects compared to the control group. Conclusion: Since the aphasia subjects have poor working memory ability, the results of this study indicate that as the cognitive load increases, they are more affected by the ability to process phonological and semantic activations.

Revealing linguistic and verbal short-term and working memory abilities in people with severe aphasia

ABSTRACT Background The assessment of aphasia in people with severe deficits is hampered by a paucity of tests that are appropriate for this population and that are sensitive to their underlying linguistic and short-term and working memory (STM/WM) strengths and weaknesses. The Temple Assessment of Language and Short-Term Memory in Aphasia (TALSA) provides a means of assessing people with severe aphasia (PWSA). Aims The aim of this paper is to demonstrate the sensitivity of the TALSA to the underlying linguistic and STM/WM strengths and weaknesses in PWSA. We assessed eight PWSA on selected subtests of the TALSA and found that 1) the TALSA is sensitive to the underlying linguistic and verbal STM/WM abilities of PWSA, 2) the TALSA reveals a wide variety of linguistic and verbal STM/WM profiles in PWSA and, 3) the TALSA can potentially demonstrate common patterns of performance in PWSA. Main contributions The TALSA allows researchers to include more PWSA in the study of aphasia and enables clinicians to establish more accurate prognoses, create precisely targeted treatment plans and document incremental progress in therapy. Conclusions The TALSA is an important addition to the assessment of severe aphasia. It provides an in-depth evaluation of underlying linguistic and verbal STM/WM strengths and weaknesses of PWSA.

Telepractice in speech-language pathology: Assessing remote speech discrimination

PurposeTo evaluate adult remote performance in speech discrimination on the Temple Assessment of Language and Short-term Memory in Aphasia (TALSA), and to compare to remote performance in NU-6 word repetition and participant ratings of self-perceived hearing ability obtained via remote session. MethodSixty older adults completed TALSA speech discrimination of concrete, low frequency words and of non-words via telephone. Remote repetition of words controlled for sound frequency was assessed using the Northwestern University (NU-6) word lists administered in live voice and recorded voice conditions. Forty-six of the participants completed questionnaires about their hearing via Zoom videoconference. ResultsMean performance in TALSA speech discrimination for words was similar to performance in NU-6 word repetition. Word repetition of NU-6 lists did not differ significantly for live voice versus recorded voice conditions. TALSA non-word speech discrimination was significantly worse than TALSA speech discrimination for words and was associated with age and self-reported hearing ability. ConclusionsTALSA speech discrimination can be administered remotely to evaluate potential perceptual influences on auditory comprehension. In remote assessment, participants demonstrated the expected pattern of more accurate speech discrimination for word stimuli than for non-words. The non-word TALSA condition may be particularly useful for detecting speech perception impairment, both in face-to-face and telepractice sessions. Similar performance of participants in both live voice and recorded conditions of the NU-6 word lists suggests that recordings used in SLP receptive language or memory assessment, including the TALSA, need not be abandoned in favor of live voice to support audition during telepractice.

The right uncinate fasciculus supports verbal short-term memory in aphasia

Verbal short-term memory (STM) deficits are associated with language processing impairments in people with aphasia. Importantly, the integrity of STM can predict word learning ability and anomia therapy gains in aphasia. While the recruitment of perilesional and contralesional homologous brain regions has been proposed as a possible mechanism for aphasia recovery, little is known about the white-matter pathways that support verbal STM in post-stroke aphasia. Here, we investigated the relationships between the language-related white matter tracts and verbal STM ability in aphasia. Nineteen participants with post-stroke chronic aphasia completed a subset of verbal STM subtests of the TALSA battery including nonword repetition (phonological STM), pointing span (lexical-semantic STM without language output) and repetition span tasks (lexical-semantic STM with language output). Using a manual deterministic tractography approach, we investigated the micro- and macrostructural properties of the structural language network. Next, we assessed the relationships between individually extracted tract values and verbal STM scores. We found significant correlations between volume measures of the right Uncinate Fasciculus and all three verbal STM scores, with the association between the right UF volume and nonword repetition being the strongest one. These findings suggest that the integrity of the right UF is associated with phonological and lexical-semantic verbal STM ability in aphasia and highlight the potential compensatory role of right-sided ventral white matter language tracts in supporting verbal STM after aphasia-inducing left hemisphere insult.

Aphasia Assessment: Translation of a Research Test Battery To A Practical Clinical Tool

<h3>Research Objectives</h3> To translate a research-based test of aphasia to a clinical version that maintains the theoretical and psychometric aspects of the research version and addresses the practical constraints of a busy health care setting. <h3>Design</h3> Based on the principles of implementation science we used a survey to elicit clinician input throughout the creation of a clinical version of the Temple Assessment of Language and Short-term Memory in Aphasia (TALSA). The survey was active for 15 months and was one component of a larger researcher-clinician partnership that included focus groups, case discussions, and training sessions. <h3>Setting</h3> Five clinical settings including one rehabilitation hospital, two acute care hospitals and two university clinics. <h3>Participants</h3> Clinical speech language pathologists. <h3>Interventions</h3> Not applicable. <h3>Main Outcome Measures</h3> Survey responses including Likert scale question data and short answers to the prompt, "Tell us about your experience with the TALSA." <h3>Results</h3> Survey results – 122 responses Likert scale questions: High level of satisfaction with test instructions (M = 6.56 on a 7-point Likert scale) and test administration (M = 6.54). Lower satisfaction reported for the usefulness of the TALSA in understanding individual patients' aphasia (M = 5.85) and the perceived value of the TALSA in setting therapy goals (M = 5.67). Open ended prompt – percentage of responses by topic: 34% quality of audio stimuli; 21% value of the TALSA; 13% quality of visual stimuli; 12% instructions; 5% interpretation. <h3>Conclusions</h3> Clinicians report that administration of the TALSA is quick and easy. High quality of audio stimuli and visual stimuli are important to clinicians. Higher audio and visual standards will be used in the creation of the second iteration of the Clinical TALSA. Guidance on interpretation of results needs further development. In partnership with clinicians, a treatment guide was created. This issue will be further addressed in a future implementation study. <h3>Author(s) Disclosures</h3> No conflicts of interest.

Short term memory in aphasia: effects of modality and relationship with Western Aphasia Battery-R performance

ABSTRACT Background Producing and comprehending language requires maintenance of linguistic units in short term memory (STM). While there is evidence of verbal STM impairments in persons with aphasia (PWA), there are unresolved questions about other aspects of STM in aphasia, particularly the role of input and output modalities on STM performance. This includes the extent to which visual STM abilities are impaired in PWA and if the modality of eliciting responses (verbal versus pointing) influences STM performance. A better understanding of the relationship between STM performance and clinical language assessments of PWA will inform test interpretation. Aims This study investigated three questions about short term memory (STM) performance in post-stroke aphasia: 1) whether visual STM is impaired in PWA given that a common neural network subserves encoding-recall of both verbal and visual STM, 2) whether the response modality (verbal vs pointing) impacts STM score, 3) the relationship between STM and language performance, specifically on the Western Aphasia Battery-Revised (WAB-R). Methods & Procedures Verbal and visuo-spatial performance on a STM battery was compared between 45 PWA and a representative neurotypical sample (N=40). For PWA, individual performance across STM subtasks was examined to identify dissociations and correlated with language performance on the WAB-R. Outcomes & Results PWA scored lower than neurotypical controls on verbal but not visual STM tasks. At the individual level, about one-half of PWA were impaired on the three verbal STM tasks, and one-third had dissociations among the three verbal STM tasks. There was no effect of response modality (verbal versus pointing) on verbal STM performance. There was a strong association between verbal STM and individual subtests of the WAB-R. In general, the relative phonological and semantic demands of the task (e.g. repetition) influenced the association strength with digit recall versus picture recall scores. Conclusions Verbal STM deficits are: 1) more prevalent than visual-spatial STM deficits in PWA, 2) strongly associated with WAB-R performance in a pattern that is consistent with the phonological and semantic demands of the tasks. The clinical implications of this study are that it is crucial to assess STM performance in PWA and examine its potential impact on language assessments. Further, a verbal or pointing response modality can be used for STM measurement without negatively impacting the score (unless there are clear motoric contra-indications). This study provides performance data for a set of aphasia-friendly STM tasks that can serve as future reference.

Effect of Working Memory Load and Typicality on Semantic Processing in Aphasia.

This study evaluated the effects of a linguistic characteristic, typicality, and a processing variable, working memory on the abilities of people with aphasia (PWA) and neurologically intact adults to process semantic representations. This was accomplished using a newly developed assessment task, the Category Typicality Test, which was created for the Temple Assessment of Language and Short-Term Memory in Aphasia. A post hoc quasi-experimental design was used. Participants included 27 PWA and 14 neurologically intact adults who completed the picture and word versions of the Category Typicality Test, which required them to determine if two items are in the same category. Memory load was altered by increasing the number of items to be compared, and the typicality of items was altered to increase linguistic complexity. A four-way mixed analysis of covariance was conducted. There was a significant interaction between working memory load and category typicality with performance accuracy decreasing as working memory load increased and category typicality decreased. There was also a significant interaction for typicality and stimuli with better performance in the picture condition and a significant interaction for working memory and group with lower performance accuracy for PWA. Post hoc pairwise comparisons revealed differences between memory load, typicality, stimuli conditions, and group. PWA also showed greater magnitude of change than neurologically intact adults when comparing high and low working memory load conditions, but not typicality conditions. Increasing working memory load had the most substantial impact on the accuracy of category judgments in PWA, but the interaction between increased working memory load and decreased category typicality of items to be compared resulted in reduced accuracy in both groups. These findings suggest that manipulation of processing and linguistic variables in assessment will provide insight into the nature of linguistic breakdown in aphasia. Supplemental Material https://doi.org/10.23641/asha.14781996.

Identifying Verbal Short-Term Memory and Working Memory Impairments in Individuals With Latent Aphasia.

Purpose This study was undertaken to explore whether measures of verbal short-term memory and working memory are sensitive to impairments in people with latent aphasia, who score within normal limits on typical aphasia test batteries. Method Seven individuals with latent aphasia and 24 neurotypical control participants completed 40 tasks from the Temple Assessment of Language and Short-term Memory in Aphasia (TALSA) that assess various aspects of verbal short-term memory, working memory, and language processing. Subtests were identified that differentiated between the two groups of participants. Results Twenty-one TALSA tasks were identified on which the participants with latent aphasia had significantly different performance than the typical control participants. All of these subtests engaged verbal short-term memory, and some involved working memory as well. Furthermore, the TALSA detected individual differences in linguistic profiles among participants with latent aphasia. Conclusions People with latent aphasia may be identified by tests that tap verbal short-term memory and working memory. In addition, the TALSA was found to be sensitive to the heterogeneity of this population. Further development of these measures will improve identification and treatment of this challenging population.

Clinician perspectives on the assessment of short-term memory in aphasia

ABSTRACT Background: Verbal short-term memory (STM) and the related ability, working memory (WM), are widely understood to be integral components of language production and comprehension. However, assessment of these abilities in people with aphasia is hampered by a lack of valid, standardized measures that are clinically appropriate. Focusing primarily on verbal STM, we held a series of five focus groups with speech-language pathologists (SLPs) to understand better their current clinical practices and their beliefs and attitudes regarding assessment of verbal STM in aphasia. Aims: The purpose of this study was to explore the attitudes, beliefs and preferences of clinical SLPs to determine: (1) current practices related to verbal STM assessment; (2) the extent to which practices reflect current theories of aphasia and the role of verbal STM in language processing; and (3) practical considerations regarding aphasia assessment in clinical practice. Methods & Procedures: Five focus groups were conducted using a semi-structured interview protocol with a total of 44 SLPs. Grounded theory methodology was used to collect, code and analyse the data. Codes were reviewed to identify emerging themes. Themes were compared to explore meta-themes, connections and potential theoretical frameworks. Outcomes & Results: Five main themes were identified: (1) The theoretical understanding that clinical SLPs have regarding the role of verbal STM in aphasia is not always consistent with clinical practice; (2) Clinical SLPs highly value functionally relevant assessments; (3) The intense time constraints in clinical practice affect all aspects of assessment; (4) Clinical SLPs feel that there is a lack of appropriate tests for assessment of STM in aphasia; and (5) Clinical SLPs prefer tests that are comprehensive, easy to administer and psychometrically sound. Conclusions: Clinical SLPs report a lack of standardized measures to assess STM in individuals with aphasia. Researchers are met with several challenges in the development of these tests including effective communication with clinicians regarding the benefit of verbal STM assessments, especially as it relates to functional skills, and the creation of a test that is comprehensive yet simple, quick and easy to administer.

Evaluating the Contribution of Executive Functions to Language Tasks in Cognitively Demanding Contexts

Purpose The purpose of this study was to determine the degree to which the executive functions of attention switching and inhibition predicted performance on language subtests from the Temple Assessment of Language and (Verbal) Short-Term Memory in Aphasia (TALSA; N. Martin, Minkina, Kohen, &Kalinyak-Fliszar, 2018) across 3 interval conditions (no delay, 5-s delay, and 5-s filled delay), which was designed to add a memory and executive load to language tasks. Method This study was a post hoc experimental design. Participants included 27 people with aphasia who were administered 5 subtests from the TALSA (Naming, Word Repetition, Nonword Repetition, Category Judgment, and Rhyming Judgment), which were selected to evaluate input and output levels of processing in the 3 interval conditions listed above. Three executive tasks were administered to evaluate inhibition (Simon and Flanker tasks) and attention switching (number-letter shifting). Results Independent variables were proportion correct on each TALSA task in 3 separate time conditions, and predictor variables were efficiency on the Simon task and number-letter shifting task. Linear regression modeling was completed, which revealed that inhibition was a significant predictor of proportion correct for Word Repetition and Category Judgment in the 5-s filled interval condition. Conclusions Our findings indicate that inhibition plays a role in completing tasks that require lexical and/or semantic processing in cognitively demanding conditions. Attention switching was not a significant predictor for any task. These results are an important step toward creating methods to evaluate executive skills in the context of language production. Supplemental Material https://doi.org/10.23641/asha.9765107.

Short-term memory span in aphasia: Insights from speech-timing measures.

Auditory-verbal short-term memory impairments are part and parcel of aphasia and interfere with linguistic processing. To date, the science about short-term memory impairments in aphasia has been generated and dominated by studying measures of accuracy, that is, span length. Because accuracy is expressed through speech, examining the speech-timing characteristics of persons with aphasia as they engage in spoken recall could reveal insights about the manner in which accuracy is achieved. Six speech-timing measures (e.g., response durations, pause durations) were elicited from the speech waveform of word span tasks from twelve people with aphasia. Speech-timing measures were compared to neuro-typical control participants. Speech-timing performance between erroneous and correct responses in the aphasia group was also examined. Across all measures, people with aphasia produced considerably longer speech-timing patterns in comparison to control participants. Memory load affected some measures in people with aphasia and control participants. Speech-timing in correct response trials was shorter than responses in erroneous trials. Memory span correlated only with one measure, namely, speech time (defined as the sum of each individual word duration in a response). Speech time also correlated with the following measures: Aphasia severity (Aphasia Quotient of the Western Aphasia Battery), spontaneous speech, and language comprehension (also measured by the Western Aphasia Battery). Some protracted speech-timing patterns in the aphasia group may be explained by a deregulation of activation-decay patterns. However, in the absence of further evidence from people with aphasia, possible issues around the sensitivity of some speech-timing measures limit firmer conclusions. Speech-timing measures are response-time measures, which have not been systematically studied in studies of short-term or working memory in aphasia and as such, can push the current boundaries of knowledge of short-term and working memory impairments in aphasia, not only in stroke related aphasia but also other neurological conditions.

Working Memory in Aphasia: Considering Discourse Processing and Treatment Implications.

Evidence suggests that persons with aphasia (PWAs) present with working memory impairments that affect a variety of language tasks. Most of these studies have focused on the phonological loop component of working memory and little attention has been paid to the episodic buffer component. The episodic buffer, as a limited capacity, multimodal system that binds and integrates information from the phonological loop, visuospatial sketchpad, and long-term memory would likely be involved in discourse processing. The purposes of this article were to (1) review discourse level deficits associated with aphasia, (2) describe how a deficit at the level of the episodic buffer could cause such deficits, (3) to review discourse treatment approaches for PWAs, and (4) present preliminary results from a novel discourse treatment study for PWAs.

Assessment and treatment of short-term and working memory impairments in stroke aphasia: a practical tutorial.

Aphasia following stroke refers to impairments that affect the comprehension and expression of spoken and/or written language, and co-occurring cognitive deficits are common. In this paper we focus on short-term and working memory impairments that impact on the ability to retain and manipulate auditory-verbal information. Evidence from diverse paradigms (large group studies, case studies) report close links between short-term/working memory and language functioning in aphasia. This evidence leads to the hypothesis that treating such memory impairments would improve language functioning. This link has only recently been acknowledged in aphasia treatment but has not been embraced widely by clinicians. To examine the association between language, and short-term and working memory impairments in aphasia. To describe practical ways of assessing short-term and working memory functioning that could be used in clinical practice. To discuss and critically appraise treatments of short-term and working memory reported in the literature. Taking a translational research approach, this paper provides clinicians with current evidence from the literature and practical information on how to assess and treat short-term and working memory impairments in people with aphasia. Published treatments of short-term and/or working memory in post-stroke aphasia are discussed through a narrative review. This paper provides the following. A theoretical rationale for adopting short-term and working memory treatments in aphasia. It highlights issues in differentially diagnosing between short-term, working memory disorders and other concomitant impairments, e.g. apraxia of speech. It describes short-term and working memory assessments with practical considerations for use with people with aphasia. It also offers a description of published treatments in terms of participants, treatments and outcomes. Finally, it critically appraises the current evidence base relating to the treatment of short-term and working memory treatments. The links between short-term/working memory functioning and language in aphasia are generally acknowledged. These strongly indicate the need to incorporate assessment of short-term/working memory functioning for people with aphasia. While the supportive evidence for treatment is growing and appears to highlight the benefits of including short-term/working memory in aphasia treatment, the quality of the evidence in its current state is poor. However, because of the clinical needs of people with aphasia and the prevalence of short-term/working memory impairments, incorporating related treatments through practice-based evidence is advocated.

Measuring working memory in aphasia: Comparing performance on complex span and N-back tasks

Measuring working memory in aphasia: Comparing performance on complex span and N-back tasks

Copy and Recall Therapy for Dysgraphia and Memory in Aphasia

Copy and Recall Therapy for Dysgraphia and Memory in Aphasia

Verbal and non-verbal working memory in aphasia: What three n-back tasks reveal

Background: Researchers have found that many individuals with aphasia (IWA) present with cognitive deficits that may impact their communication, and perhaps underlie their language-processing deficits (e.g., Erickson et al., 1996; Murray et al., 1997; Wright et al., 2003). However, many investigations of cognitive ability in aphasia have included measures that may be considered “language heavy”; they require overt lexical, semantic, and/or phonological processing to follow the task instructions and/or formulate a response. Few have considered the amount of linguistic processing required to perform the task. Subsequently, it is not clear if poorer performance by IWA on cognitive tasks compared to neurologically intact (NI) participants is due to a deficit in the respective cognitive domain or due to the inability of IWA to perform the task because of their language difficulties. Aims: The purpose of the current study was to explore the effect of varying linguistic processing demands in the context of a dynamic working memory task—an n-back task for participants with and without aphasia. Method & Procedures: This study compared differences on three different n-back tasks within and across groups for individuals with aphasia and NI matched peers. Participants completed three different n-back tasks; stimuli for the tasks varied in “linguistic load”. For each n-back task participants completed two levels of difficulty: 1-back and 2-back. Outcomes & Results: The aphasia group performed significantly worse than the NI participants across the n-back tasks. All participants performed significantly better with the stimuli that carried a higher linguistic load (i.e., the fruit), than with the fribbles (semi-linguistic) and blocks (non-linguistic). All participants performed significantly better on the 1-back than the 2-back working memory task. Unlike the NI participants, IWA performed equally poorly with the fribbles and the blocks in the 2-back task. Conclusions: Overall, the performance of individuals with aphasia on working memory tasks that varied in their linguistic load was similar to the control group but reduced. However, unlike the NI participants, IWA were less skilled at rapidly utilising linguistic knowledge to increase performance on the fribbles, demonstrating the further decrement in working memory that results from a decreased ability to utilise a linguistic strategy to increase performance on verbal working memory tasks. The results of this study indicate that language ability has a significant influence on performance on working memory tasks and should be considered when discussing cognitive deficits in aphasia.

Processing distinct linguistic information types in working memory in aphasia

Background: Recent investigations have suggested that adults with aphasia present with a working memory deficit that may contribute to their language‐processing difficulties. Working memory capacity has been conceptualised as a single “resource” pool for attentional, linguistic, and other executive processing—alternatively, it has been suggested that there may be separate working memory abilities for different types of linguistic information. A challenge in this line of research is developing an appropriate measure of working memory ability in adults with aphasia. One candidate measure of working memory ability that may be appropriate for this population is the n‐back task. By manipulating stimulus type, the n‐back task may be appropriate for tapping linguistic‐specific working memory abilities. Aims: The purposes of this study were (a) to measure working memory ability in adults with aphasia for processing specific types of linguistic information, and (b) to examine whether a relationship exists between participants' performance on working memory and auditory comprehension measures. Method & Procedures: Nine adults with aphasia participated in the study. Participants completed three n‐back tasks, each tapping different types of linguistic information. They included the PhonoBack (phonological level), SemBack (semantic level), and SynBack (syntactic level). For all tasks, two n‐back levels were administered: a 1‐back and 2‐back. Each level contained 20 target items; accuracy was recorded by stimulus presentation software. The Subject‐relative, Object‐relative, Active, Passive Test of Syntactic Complexity (SOAP) was the syntactic sentence comprehension task administered to all participants. Outcomes & Results: Participants' performance declined as n‐back task difficulty increased. Overall, participants performed better on the SemBack than PhonoBack and SynBack tasks, but the differences were not statistically significant. Finally, participants who performed poorly on the SynBack also had more difficulty comprehending syntactically complex sentence structures (i.e., passive & object‐relative sentences). Conclusions: Results indicate that working memory ability for different types of linguistic information can be measured in adults with aphasia. Further, our results add to the growing literature that favours separate working memory abilities for different types of linguistic information view.

Auditory and Visual Verbal Short-Term Memory in Aphasia

Phonological short-term memory was investigated in 24 aphasic left brain-damaged patients and in 12 matched controls. Aphasic patients have a reduced auditory and visual immediate memory span and show the standard detrimental effect of phonological similarity on immediate retention only when the stimuli are auditorily presented, while in the control group the effect is present with both auditory and visual input. Most patients have phonological processing deficits, but two patients have an impaired immediate verbal memory in the absence of analysis disorders. These results, in line with most individual case studies of patients with selective deficits of verbal short-term memory, are interpreted with reference to a model distinguishing a phonological short-term store component of memory, to which auditory input has direct and automatic access, and a rehearsal component, that, after phonological recoding, conveys visually presented stimuli to the phonological store. This latter system, that appears to become fully operational later in development, is less resistive to brain damage.

Organization of and access to semantic memory in aphasia

Previous experiments with picture sorting and matching tasks have shown aphasics to give more deviant responses than controls when decisions require the identification of single features of concepts, whereas their responses are close to normal whenever decisions have to be based on the relative overlap of broad associative fields. The present experiment was designed to compare picture matching based on single features (property verification) with picture matching based on category membership (category verification). Fifty-five aphasics (14 amnesics, 18 Brocas, 13 Wernickes, 10 global aphasics) and 29 right-brain-damaged control patients served as subjects. Aphasics were poorer than right hemisphere controls on property as well as on category sortings, especially when the sorting criterion was not a dominant property of the object or when the object in question was not a typical member of the criterion category. Contrary to other studies, the “semantic distance” variable did not differentially affect Brocas as compared to Wernickes aphasics. Verbal labels denoting the sorting criterion and added to the picture presentation did not affect the performance of the right hemisphere controls but significantly improved that of the aphasics.

Nonlinguistic Memory in Aphasia

Two experiments were carried out to assess nonlinguistic memory in aphasia. In the first experiment, subjects had to make judgments about the frequency with which words in a study list were repeated, and, in the second, they had to recall the spatial location in which a pictured object had been presented originally. Aphasics were very accurate in both tasks and did not differ from normal controls.It is suggested that a comprehensive account of memory in aphasia requires that we look beyond their omnipresent language deficit to more general processing factors such as attentional capacity.