Neural regions underlying object and action naming: Complementary evidence from acute stroke and primary progressive aphasia

A preliminary investigation on core lexicon analysis in dementia of the Alzheimer's type

BACKGROUND

Core lexicon (CL) analysis is a time efficient and possibly reliable measure that captures discourse production abilities. For people with aphasia, CL scores have demonstrated correlations with aphasia severity, as well as other discourse and linguistic measures. It was also found to be clinician-friendly and clinically sensitive enough to capture longitudinal changes in aphasia. To our knowledge, CL has never been investigated in individuals with neurologically progressive disease.

AIMS

As a preliminary investigation, we sought to investigate (1) whether CL scores correlate with dementia severity, (2) whether CL scores correlate with measures of discourse quality, and (3) whether CL scores correlate with other measures of lexical/semantic access.

METHODS & PROCEDURES

Twelve participants with a cognitive impairment associated with dementia of the Alzheimer's type (DAT) completed several measures of language and cognitive ability, as well as provide a language sample from the wordless picture book, Picnic.

RESULTS & CONCLUSION

Results are informative, as they provide insight into characteristics of CL and provide support for potential use of CL in individuals with neurologically progressive disease. The results indicated that CL scores do correlate with dementia severity and several measures of language ability, indicating they may provide a useful measure of language abilities in DAT, but more research is needed.

WHAT THIS PAPER ADDS

What is already known on the subject Core lexicon (CL) analysis is an assessment measure of discourse ability, most closely related to informativeness or productivity, used in aphasiology that is easier to use and less time consuming than previous measures of informativeness, such as correct information units or type-token ratio (TTR). For people with aphasia, CL analysis correlates with aphasia severity, measures of informativeness, as well as other measures of discourse quality. It has also been shown to be faster and more reliable between scorers than other informativeness measures. What this study adds Core lexicon analysis is a new simple and online method for assessing the informativeness of a discourse sample without the need to record or transcribe the language sample. CL is receiving a lot of attention in aphasia, correlating with everything from aphasia severity to measures of productivity and lexical access, as well as measures of informativeness. Unfortunately, no one has investigated CL analysis in dementia. The study demonstrates the first evidence that CL analysis may be a useful measure for determining dementia severity and language quality in people with dementia. What are the clinical implications of this work? Core lexicon analysis may provide clinicians and researchers with an easy method for assessing the discourse of people with a cognitive impairment associated with dementia of the Alzheimer's type. This will improve initial assessment, as well as improve ongoing language assessment that may provide clues into their functional ability to communicate effectively.

The role of cognitive control and naming in aphasia

The classical aphasia literature has placed considerable emphasis on the language-centered understanding of aphasia and failed to consider the role of executive functions (EFs) regarding different aspects of patients' performance. Many current studies suggest deficits in EFs in individuals with aphasia, however, the available data is still limited. Here, our aim was to investigate the impairment of EFs and its potential negative effects on naming (slower performance, increased reaction time and/or decreased accuracy). We sought to determine whether the poor performance observed in word fluency task correlated with similar outcomes in naming. Our study involved five Hungarian post stroke aphasic patients (2 males and 3 females) between the ages of 60 and 70, as well as a control group matched for age and gender. The participants were diagnosed with different types of aphasia (global, Wernicke's, anomic and conduction). This study employed various neuropsychological and linguistic batteries. By comparing the patients' performance to that of the control group, we aimed to investigate the impacts of stroke. Within the aphasia group, we observed difficulties in following complex commands and a connection between general slowness and reduced accuracy in naming. We concluded that impairment of executive functions may have a negative impact on naming, comprehension, and fluency. Therefore, it is important to consider functional variations in neural networks, and to base our interpretations on the available psychophysiological data in literature. Our findings provide an alternative perspective to the traditional assessment of aphasia and highlight the importance of considering the role of executive functions.

Shave, shear, shred, or cut: PPA variant differentially impacts erroneous responses produced in a confrontation naming test of verbs

Background

All common variants of primary progressive aphasia (PPA) exhibit naming deficits. Variants are distinguished by relative deficits in repetition (logopenic; lvPPA), object knowledge (semantic; svPPA), and agrammatism or articulation (non-fluent/agrammatic; nfavPPA; Gorno-Tempini et al., 2011). The Hopkins Action Naming Assessment (HANA) is a 30-item verb naming task that can distinguish between variants (Stockbridge et al., 2021). Item-level accuracy is driven by target verb frequency, semantic information density, and conceptual concreteness of the target word (Stockbridge, Venezia, et al., 2022).

Aims

In this investigation, we examined whether word frequency, semantic density, concreteness, and age of acquisition (AoA) also shaped the incorrect responses patients provided. We hypothesised that error responses would vary in these dimensions as a function of PPA variant.

Methods & Procedures

The HANA was administered to 271 participants with PPA, resulting in 443 total administrations and 4,529 analysable error responses. Standardised differences between error and target responses for frequency, density, concreteness, and AoA were calculated and averaged for each patient. Analysis of variance (ANOVA) for correlated samples was used to compare variants and planned post-hoc analyses examined the effect of variant on each response quality.

Outcomes & Results

Participants were similar in age, sex, handedness, and education. There was a significant interaction between PPA variant and the standardised mean differences in lexical qualities (Pillai's Trace=0.11, F(9, 747)=3.19, p<0.001). Univariate ANOVAs revealed significant differences in the semantic density of error responses relative to the target (F(3)=7.91, p<0.001, ηP 2=0.09), as individuals with lvPPA tended to produce error responses with greater semantic density than the target when compared to the words produced by individuals with nfavPPA (mean difference=1.45, 95%CI=[0.60,2.29], p<0.001; Figure 1). PPA variants also differed in the concreteness of their error responses relative to the target (F(3)=5.99, p<0.001, ηP 2=0.07), as error responses produced by individuals with nfavPPA were significantly more concrete than those with lvPPA (mean difference=0.08, 95%CI=[0.02,0.13], p=0.003) or svPPA (mean difference=0.08, 95%CI=[0.02,0.14], p=0.007). Variants did not differ significantly in AoA or frequency of responses relative to their targets. All variants tended to produce more frequent words with a lower AoA than the target verb.

Conclusions

Error responses tended to be more semantically dense, more concrete, higher frequency, and younger AoA than the target verb. However, PPA variants differed significantly in the extent to which these broader trends held true. These distinct patterns may be included as part of a larger diagnostic picture that to distinguish among PPA variants.

Multiple phonological activation in writing: evidence for cascadedness in Chinese written verb production

The dynamics of information transmission through the lexical system during written word production remain underspecified. Existing studies largely come from noun production, relatively less work has explored verb production. Verbs, representing actions or states, are considered more abstract and are found to be more challenging to be produced. The present study investigated phonological involvement and the principles governing information flow during Chinese written verb production. Participants wrote down single verbs and verb phrases while ignoring phonologically related, or unrelated distractor pictures. Results revealed phonological facilitation effects on writing latencies from phonologically related distractors in the verb phrase generation. Findings provide novel chronometric evidence that information transmission during written production involves cascaded activation allowing multiple phonological codes to be activated prior to written output. This phonological facilitation effect signifies the influence of phonology, especially lexical phonology, has been underestimated in writing.

Anomia: Deciphering Functional Neuroanatomy in Primary Progressive Aphasia Variants

Naming decline is one of the most common symptoms of primary progressive aphasia (PPA). Most studies on anomia in PPA are performed without taking into account PPA variants, especially for action naming. Only limited data are available for the neuroanatomical basis of anomia considering differences in the pathogenesis of PPAs. The aim of our study is to investigate the associations between anomia severity for both noun and verb naming and gray matter (GM) atrophy, as well as accompanying functional connectivity (FC) changes in three PPA variants. A total of 17 patients with non-fluent (nfvPPA), 11 with semantic (svPPA), and 9 with logopenic (lvPPA) PPA variants were included in the study and underwent cognitive/naming assessments and brain MRIs. Voxel-based morphometry was performed to evaluate GM volume. A resting-state functional MRI was applied to investigate FC changes in the identified GM areas. The study shows that different brain regions are involved in naming decline in each PPA variant with a predominantly temporal lobe involvement in svPPA, parietal lobe involvement in lvPPA, and frontal lobe involvement in nfvPPA. Separate data for object and action naming in PPA variants are provided. The obtained results mainly correspond to the current understanding of language processing and indicate that the evaluation of language impairments is preferable for each PPA variant separately. A further analysis of larger cohorts of patients is necessary to confirm these preliminary results.

Comparing two picture naming tasks in primary progressive aphasia: Insights from behavioural and neural results

Picture naming tests are widely used to evaluate language impairments in neurodegenerative diseases, especially in Primary Progressive Aphasia (PPA). The available tests differ for many factors affecting the performance, e.g. format of stimuli and their psycholinguistic properties. We aim to identify the most appropriate naming test to be used on PPA according to the clinical and research demands. We investigated the behavioural characteristics, i.e. proportion of correct responses and error type, and their neural correlates in two Italian naming tests, CaGi naming (CaGi) and naming subtest of the Screening for Aphasia in NeuroDegeneration battery (SAND), administered to 52 PPA patients who underwent an FDG-PET scan. We analysed the effectiveness of the tests in distinguishing PPA versus controls and among PPA variants, considering the psycholinguistic variables affecting performance. We explored the brain metabolic correlates of behavioural performance in the tests. SAND, differently from CaGi, has time limits for the response and its items are less frequent and acquired later. SAND and CaGi differed in terms of number of correct responses and error profile, suggesting a higher difficulty to name SAND items compared to CaGi. Semantic errors predominated in CaGi, while anomic and semantic errors were equally frequent in SAND. Both tests distinguished PPA from controls, but SAND outperformed CaGi in discriminating among PPA variants. FDG-PET imaging revealed a shared metabolic involvement of temporal areas associated with lexico-semantic processing, encompassing anterior fusiform, temporal pole, and extending to posterior fusiform in sv-PPA. Concluding, a picture naming test with response time limit and items which are less frequent and acquired later in life, as SAND, may be effective at highlighting subtle distinctions between PPA variants, improving the diagnosis. Conversely, a naming test without time limit for the response, as CaGi, may be useful for a better characterization of the nature of the naming impairment at the behavioural level, eliciting more naming errors than anomia, possibly helping in the development of rehabilitation protocols.

Mary has a little chair: Eliciting noun-modifier phrases in individuals with acute post-stroke aphasia

Background

Aphasia assessment primarily examines an individual's syntax, nouns, and verbs. However, modifiers, such as adjectives and number words, and bound morphemes can be the subject of considerable difficulty for individuals with aphasia. The Morphosyntactic Generation (MorGen) targets nouns, modifiers, and bound inflectional morphemes in two-word phrases among people with aphasia.

Aims

The purpose of this work is to provide the first report of the MorGen in hyperacute-acute aphasia. In doing so, we aim to (1) examine the MorGen's concurrent validity with common assessments of aphasia; (2) describe performance in modifiers by people with acute aphasia; and (3) associate MorGen performance with extent of lesioned vascular territories in acute stroke.

Methods & Procedures

62 adult English speakers within the first 14 days of left hemisphere ischemic stroke and 61 healthy control participants completed the MorGen. In addition to receiving the MorGen, participants with stroke received the Western Aphasia Battery (WAB), Boston Naming Test, and Hopkins Action Naming Assessment. Clinical MRIs were analyzed for the extent of lesion in the vascular territory of the left anterior, medial, and posterior cerebral artery, as well as the left posterior choroidal and thalamoperforator arteries.

Outcomes & Results

Aim 1: Performance on the MorGen demonstrated consistently high, significant correlations with that on the WAB, Boston Naming Test, and Hopkins Action Naming Assessment. Aim 2: Individuals who had a stroke but were within functional limits (WFL) on the WAB performed significantly worse than healthy controls on the MorGen, driven by differences in adjective performance. When controlling for aphasia severity, those with fluent aphasia performed significantly better in their production of nouns, plurals, number, size, and color than those who had non-fluent aphasia, but both groups were similarly inclined to omit genitive marking. Aim 3: Lesions in the territory of the temporal branch of the posterior cerebral artery were associated with poorer performance in nouns, size, and color. Lesions in the territory of the anterior cerebral artery were associated with poorer performance in numbers.

Conclusions

This work highlights the value of the MorGen as a tool for post-stroke language evaluation that complements the skills captured in more widely-used assessments such as the WAB and BNT.

Association of Regional Atrophy With Naming Decline in Primary Progressive Aphasia

BACKGROUND AND OBJECTIVES

Primary progressive aphasia (PPA) is a neurodegenerative condition that predominantly impairs language. Most investigations of how focal atrophy affects language consider 1 time point compared with healthy controls. However, true atrophy quantification requires comparing individual brains over time. In this observational cohort study, we identified areas where focal atrophy was associated with contemporaneous decline in naming in the same individuals.

METHODS

Cross-sectional analyses-related Boston Naming Test (BNT) performance and volume in 22 regions of interests (ROIs) at each time point using Least Absolute Shrinkage and Selection Operator (LASSO) regression. Longitudinal analysis evaluated changes in BNT performance and change in volume in the same ROIs.

RESULTS

Participants (N = 62; 50% female; mean age = 66.8 ± 7.4 years) with PPA completed the BNT and MRI twice (mean = 343.9 ± 209.0 days apart). In cross-sectional left inferior frontal gyrus pars opercularis, superior temporal pole, middle temporal gyrus, and inferior temporal gyrus were identified as critical for naming at all time points. Longitudinal analysis revealed that increasing atrophy in the left supramarginal gyrus and middle temporal pole predicted greater naming decline, as did female sex and longer intervals between time points.

DISCUSSION

Although cross-sectional analyses identified classic language areas that were consistently related to poor performance at multiple time points, it was not increasing atrophy in these areas that lead to further decline: longitudinal analysis of each person's atrophy over time instead identified nearby but distinct regions where increased atrophy was related to decreasing performance. The results demonstrate that directly examining atrophy (in each individual) over time furthers understanding of decline in PPA and reveal the importance of left supramarginal gyrus and middle temporal pole in maintaining naming when areas normally critical for language degenerate. The novel results provide insight into how the underlying disease progresses to result in the clinical decline in naming, the deficit most common among all 3 PPA variants.

Gesture profiles distinguish primary progressive aphasia variants

Primary progressive aphasia (PPA) is a neurodegenerative syndrome characterized by progressive language deficits. There are three main variants of PPA - semantic (svPPA), logopenic (lvPPA), and nonfluent (nfvPPA) - that can be challenging to distinguish. Limb praxis may also be affected in PPA, but it is unclear whether different variants of PPA are associated with differences in gesture production. Prior research with neurotypical individuals indicates that the left temporal lobe is a critical locus of manipulable object and hand posture representations. Moreover, when imitating gestures, individuals whose strokes include the left temporal lobe show reduced benefit of gesture meaning and disproportionate impairment in hand posture as compared to arm kinematics. We tested the hypothesis that svPPA - who typically exhibit primarily temporal lobe atrophy - would differentially show these expected patterns of gesture imitation performance. Nineteen participants with PPA completed meaningful and meaningless gesture imitation tasks, and performance was scored for hand posture and arm kinematics accuracy. Generalized logistic mixed-effect regression models controlling for dementia severity showed overall benefits from gesture meaning, and greater impairments in hand posture than arm kinematics. We also found that svPPA participants were the most impaired in gesture imitation overall. Critically, there was also a significant three-way interaction of group, meaning, and gesture component: only svPPA participants showed relative impairments of hand posture for meaningful gestures as well as meaningless gestures. Thus, unlike lvPPA and nfvPPA, the hand postures of svPPA failed to benefit from gesture meaning. This research extends prior findings on the role of the temporal lobe in hand posture representations associated with manipulable objects, and is the first to indicate that there may be distinct gesture imitation patterns as a function of PPA variant. Characterizing componential gesture deficits in PPA may help to inform differential diagnosis, compensatory communication strategies, and cognitive praxis models of PPA.

Neural Correlates of Naturally Occurring Speech Errors during Picture Naming in Healthy Participants

Most of our knowledge about the neuroanatomy of speech errors comes from lesion-symptom mapping studies in people with aphasia and laboratory paradigms designed to elicit primarily phonological errors in healthy adults, with comparatively little evidence from naturally occurring speech errors. In this study, we analyzed perfusion fMRI data from 24 healthy participants during a picture naming task, classifying their responses into correct and different speech error types (e.g., semantic, phonological, omission errors). Total speech errors engaged a wide set of left-lateralized frontal, parietal, and temporal regions that were almost identical to those involved during the production of correct responses. We observed significant perfusion signal decreases in the left posterior middle temporal gyrus and inferior parietal lobule (angular gyrus) for semantic errors compared to correct trials matched on various psycholinguistic variables. In addition, the left dorsal caudate nucleus showed a significant perfusion signal decrease for omission (i.e., anomic) errors compared with matched correct trials. Surprisingly, we did not observe any significant perfusion signal changes in brain regions proposed to be associated with monitoring mechanisms during speech production (e.g., ACC, superior temporal gyrus). Overall, our findings provide evidence for distinct neural correlates of semantic and omission error types, with anomic speech errors likely resulting from failures to initiate articulatory-motor processes rather than semantic knowledge impairments as often reported for people with aphasia.

Verb Frequency and Density Drive Naming Performance in Primary Progressive Aphasia

Background

Recent work has highlighted the utility of the Boston Naming Test and Hopkins Action Naming Assessment (HANA) for distinguishing between semantic (svPPA), logopenic (lvPPA) and non-fluent agrammatic (nfavPPA) variants of primary progressive aphasia (PPA).

Aims

To determine whether item level differences between variants on when naming verbs on the HANA were able to be accounted for using common variables of lexical interest: word frequency, semantic density, concreteness, or valency. We also examined three specific hypotheses: (1) svPPA and lvPPA may result in increased difficulty with decreased semantic density compared to nfavPPA; (2) svPPA may result in increased difficulty with decreased concreteness; and (3) nfavPPA may result in increased difficulty with high syntactic valency.

Methods & Procedures

268 patients with PPA were evaluated using the HANA. A hierarchical Bayesian regression approach was adopted to account for effects of repeated measurement within participants and items.

Outcomes & Results

The main effects of variant and verb trait were significant in all models, as was the interaction for frequency, semantic density, and valency. Increasing frequency, semantic density, and concreteness led to better performance, while increasing valency led to poorer performance. Low semantic density contributed to greater difficulty in svPPA and lvPPA, but low concreteness did not uniquely impact verb naming in svPPA. Those with nfavPPA had no particular difficulty as a result of valency.

Conclusions

Prior studies have identified the independent effects of frequency and semantic density on verb naming in PPA, which were confirmed by our analyses, and the best predictions of the data were achieved by combining these dimensions. This investigation complements our previous work highlighting the value of the HANA for efficiently demonstrating verb performance in PPA.

Neuroanatomical correlates of screening for aphasia in NeuroDegeneration (SAND) battery in non-fluent/agrammatic variant of primary progressive aphasia

Background

Non-fluent/agrammatic variant of Primary Progressive Aphasia (avPPA) is primarily characterized by language impairment due to atrophy of the inferior frontal gyrus and the insula cortex in the dominant hemisphere. The Screening for Aphasia in NeuroDegeneration (SAND) battery has been recently proposed as a screening tool for PPA, with several tasks designed to be specific for different language features. Applying multivariate approaches to neuroimaging data and verbal fluency tasks, Aachener Aphasie Test (AAT) naming subtest and SAND data may help in elucidating the neuroanatomical correlates of language deficits in avPPA.

Objective

To investigate the neuroanatomical correlates of language deficits in avPPA using verbal fluency tasks, AAT naming subtest and SAND scores as proxies of brain structural imaging abnormalities.

Methods

Thirty-one avPPA patients were consecutively enrolled and underwent extensive neuropsychological assessment and MRI scan. Raw scores of verbal fluency tasks, AAT naming subtest, and SAND subtests, namely living and non-living picture naming, auditory sentence comprehension, single-word comprehension, words and non-words repetition and sentence repetition, were used as proxies to explore structural (gray matter volume) neuroanatomical correlates. We assessed univariate (voxel-based morphometry, VBM) as well as multivariate (source-based morphometry, SBM) approaches. Age, gender, educational level, and disease severity were considered nuisance variables.

Results

SAND picture naming (total, living and non-living scores) and AAT naming scores showed a direct correlation with the left temporal network derived from SBM. At univariate analysis, the left middle temporal gyrus was directly correlated with SAND picture naming (total and non-living scores) and AAT naming score. When words and non-words repetition (total score) was considered, a direct correlation with the left temporal network (SBM) and with the left fusiform gyrus (VBM) was also evident.

Conclusion

Naming impairments that characterize avPPA are related to specific network-based involvement of the left temporal network, potentially expanding our knowledge on the neuroanatomical basis of this neurodegenerative condition.

Progressive attenuation of visual global precedence across healthy aging and Alzheimer's disease

In the perception of Navon hierarchical stimuli (e.g., large letters made up of small letters), young adults identify large letters faster than small ones (known as 'global advantage') and identify more slowly small letters when they form a different (or incongruent) large letter (known as 'unidirectional global interference'). Since some global/local perceptual alterations might be occurring with aging, we investigated whether these effects vary across healthy aging and Alzheimer's disease (AD). Here, the Navon letter task was administered to 26 healthy elderly (HE), 21 adults with mild cognitive impairment (MCI), and 26 adults with AD. The same task was administered 1 year later, and different neuropsychological variables were incorporated into the analyses. The cross-sectional study revealed no global advantage but did reveal both global and local interferences in all groups when response times were analyzed. Regarding discrimination sensitivity, HE showed unidirectional global interference, while AD displayed better discrimination of local than global letters in the incongruent condition, which denotes less interference by global distractors than by local ones. The longitudinal study revealed that 1 year later the participants with MCI showed a slowdown in inhibiting local distractors in the global task, revealing a certain bias toward focus in their attention on small stimuli. The elders with AD reflected a generalized slowing of their responses with a clear bias toward local analysis of stimuli, also suggested by their better discrimination in the incongruent local task at the second moment of assessment. Furthermore, all response timing measures in the Navon task were correlated with several neuropsychological indexes of highly sensitive neuropsychological tests, suggesting that performance in this task may also have a potential diagnostic value for differentiating typical from atypical cognitive aging. All these results support the need for a multidomain approach to define neuropsychological markers of progression toward AD, including visual perceptual organization evaluated via measures of performance quality.

When words first fail: Predicting the emergence of primary progressive aphasia variants from unclassifiable anomic performance in early disease

Background

The majority of patients with primary progressive aphasia (PPA) can be distinguished into one of three variants: semantic, non-fluent/agrammatic, or logopenic. However, many do not meet criteria for any one variant.

Aim

To identify aspects of cognitive-linguistic performance that yield an early unclassifiable PPA designation that predicted the later emergence of a given variant.

Methods & Procedures

Of 256 individuals with PPA evaluated, 19 initially were unclassifiable and later met criteria for a variant. Receiver operating characteristic curves were used to evaluate the binary ability of a given task to predict eventual classification as a given variant. Tasks with a high area under the curve were examined using regression analyses to determine their ability to predict variant.

Outcomes & Results

High mean predictive value was observed for multiple naming assessments targeting nouns and verbs. The Boston Naming Test (BNT) was the only test that, in isolation, resulted in a significant model and high classification accuracy.

Conclusions

Although naming impairment is common across PPA variants, very low initial BNT scores emerged as a uniquely accurate basis for predicting eventual semantic variant, and normal BNT scores predicted eventual nonfluent/agrammatic variant. High performance on picture-verb verification was useful in identifying future lvPPA.

Task performance to discriminate among variants of primary progressive aphasia

Primary progressive aphasia can be distinguished into one of three variants: semantic, non-fluent/agrammatic, and logopenic. While a considerable body of work exists characterizing each variant, few prior studies have addressed the problem of optimizing behavioral assessment in a typical outpatient evaluation setting. Our aim is to examine the sensitivity and specificity of a battery of cognitive and linguistic assessments and determine optimal scores for distinguishing patients' subtype based on these instruments. This was a retrospective analysis of outpatient clinical testing of individuals with known or suspected primary progressive aphasia. Evaluations included the National Alzheimer's Coordinating Center frontotemporal lobar degeneration module and additional measures of naming, semantic association, word verification, and picture description. Receiver operating characteristic analysis was used to examine the utility of each task in distinguishing each variant from the others. Logistic regressions were used to examine the combined utility of tasks for distinguishing a given subtype. We examined 435 evaluations of 222 patients retrospectively. The battery was most consistent in distinguishing semantic variant by low scores and non-fluent/agrammatic variant by high scores on a similar subset of tasks. Tasks best distinguishing semantic variant produced a model that correctly classified 86% of cases. Tasks best distinguishing non-fluent/agrammatic variant correctly classified 77% of cases. The battery of tasks was weakest in identifying logopenic variant; only the ratio of sentence reading to sentence repetition performance was identified as a reasonable predictor, and it had predictive accuracy of 67%. Naming assessments were the strongest basis for distinguishing all variants, particularly semantic variant from non-fluent/agrammatic variant. These data illustrate that a number of commonly used assessments perform at chance in distinguishing variant and preliminarily support an abbreviated battery that marginally favors tools not currently included in the frontotemporal lobar degeneration module.