Assessing Relative Linguistic Impairment With Model-Based Item Selection.

Purpose: A picture naming test is presented that reveals impairment to specific mechanisms involved in the naming process, using accuracy scores on curated item sets. A series of psychometric validation experiments are reported.

Method: Using a computational model that enables estimation of item difficulty at the lexical and sublexical stages of word retrieval, two complimentary sets of items were constructed that challenge the respective psycholinguistic levels of representation.

Predicting Outcomes of Language Rehabilitation: Prognostic Factors for Immediate and Long-Term Outcomes After Aphasia Therapy.

Background: Aphasia therapy is an effective approach to improve language function in chronic aphasia. However, it remains unclear what prognostic factors facilitate therapy response at the individual level. Here, we utilized data from the POLAR (Predicting Outcomes of Language Rehabilitation in Aphasia) trial to (a) determine therapy-induced change in confrontation naming and long-term maintenance of naming gains and (b) examine the extent to which aphasia severity, age, education, time postonset, and cognitive reserve predict naming gains at 1 week, 1 month, and 6 months posttherapy.

The Severity-Calibrated Aphasia Naming Test.

Purpose: We present a 20-item naming test, the Severity-Calibrated Aphasia Naming Test (SCANT), that can serve as a proxy measure for an aphasia severity scale that is derived from a thorough test battery of connected speech production, single-word production, speech repetition, and auditory verbal comprehension.

Method: We use lasso regression and cross-validation to identify an optimal subset from a set of 174 pictures to be named for prediction of aphasia severity, based on data from 200 participants with left-hemisphere stroke who were quasirandomly selected to represent the full impairment scale. Data from 20 healthy controls (i.

Beyond Percent Correct: Measuring Change in Individual Picture Naming Ability.

Purpose: Meaningful changes in picture naming responses may be obscured when measuring accuracy instead of quality. A statistic that incorporates information about the severity and nature of impairments may be more sensitive to the effects of treatment.

Method: We analyzed data from repeated administrations of a naming test to 72 participants with stroke aphasia in a clinical trial for anomia therapy.

Defining the Neurobiological Mechanisms of Action in Aphasia Therapies: Applying the Rehabilitation Treatment Specification System Framework to Research and Practice in Aphasia.

The Rehabilitation Treatment Specification System (RTSS) was developed as a systematic way to describe rehabilitation treatments for the purpose of both research and practice. The RTSS groups treatments by type and describes them by 3 elements: the treatment (1) ingredients and (2) the mechanisms of action that yield changes in the (3) target behavior. Adopting the RTSS has the potential to improve consistency in research, allowing for better cross-study comparisons to strengthen the body of research supporting various treatments.

Demystifying the Complexity of Aphasia Treatment: Application of the Rehabilitation Treatment Specification Systemx.

A considerable body of research supports the use of behavioral communication treatment as the standard of care for aphasia. In spite of robust progress in clinical aphasiology, many questions regarding optimal care remain unanswered. One of the major challenges to progress in the field is the lack of a common framework to adequately describe individual treatments, which, if available, would allow comparisons across studies as well as improved communication among researchers, clinicians, and other stakeholders.

Disentangling the Psycholinguistic Loci of Anomia with Cognitive Psychometric Models.

This article reviews advanced statistical techniques for measuring impairments in object naming, particularly in the context of stroke-induced aphasia. Traditional testing strategies can be challenged by the multifaceted nature of impairments that arise due to the complex relationships between localized brain damage and disruption to the cognitive processes required for successful object naming. Cognitive psychometric models can combine response-type analysis with item-response theory to yield accurate estimates of multiple abilities using data collected from a single task.

Effect of Bilateral Opercular Syndrome on Speech Perception.

Speech perception ability and structural neuroimaging were investigated in two cases of bilateral opercular syndrome. Due to bilateral ablation of the motor control center for the lower face and surrounds, these rare cases provide an opportunity to evaluate the necessity of cortical motor representations for speech perception, a cornerstone of some neurocomputational theories of language processing. Speech perception, including audiovisual integration (i.

A Cognitive Psychometric Investigation of Word Production and Phonological Error Rates in Logopenic Progressive Aphasia.

Purpose This study investigated the relationship between word production rates (WPRs) and phonological error rates (PERs) in generative and responsive tasks in logopenic progressive aphasia (lvPPA). We examined whether a portion of the reduced WPR during generative tasks related directly to phonological impairments affecting PER on all tasks, irrespective of other task differences that contributed to WPR. Method Two cognitive psychometric models were hypothesized and fit to the total number of words produced and the number of phonological errors produced by 22 participants on 10 tasks.

Connections and selections: Comparing multivariate predictions and parameter associations from latent variable models of picture naming.

Connectionist simulation models and processing tree mathematical models of picture naming have complementary advantages and disadvantages. These model types were compared in terms of their predictions of independent language measures and their associations between model components and measures that should be related according to their theoretical interpretations. The models were tasked with predicting independent picture naming data, neuropsychological test scores of semantic association and speech production, grammatical categories of formal errors, and lexical properties of target items.

Disease risk analysis in sea turtles: A baseline study to inform conservation efforts.

The impact of a range of different threats has resulted in the listing of six out of seven sea turtle species on the IUCN Red List of endangered species. Disease risk analysis (DRA) tools are designed to provide objective, repeatable and documented assessment of the disease risks for a population and measures to reduce these risks through management options. To the best of our knowledge, DRAs have not previously been published for sea turtles, although disease is reported to contribute to sea turtle population decline.

A cognitive psychometric model for assessment of picture naming abilities in aphasia.

Picture naming impairments are a typical feature of stroke-induced aphasia. Overall accuracy and rates of different error types are used to make inferences about the severity and nature of damage to the brain's language network. Currently available assessment tools for picture naming accuracy treat it as a unidimensional measure, while assessment tools for error types treat items homogenously, contrary to findings from psycholinguistic investigations of word production.

Evaluating quantitative and conceptual models of speech production: how does SLAM fare?

In a previous publication, we presented a new computational model called SLAM (Walker & Hickok, Psychonomic Bulletin & Review doi: 10.3758/s13423-015-0903 ), based on the hierarchical state feedback control (HSFC) theory (Hickok Nature Reviews Neuroscience, 13(2), 135-145, 2012). In his commentary, Goldrick (Psychonomic Bulletin & Review doi: 10.

Bridging computational approaches to speech production: The semantic-lexical-auditory-motor model (SLAM).

Speech production is studied from both psycholinguistic and motor-control perspectives, with little interaction between the approaches. We assessed the explanatory value of integrating psycholinguistic and motor-control concepts for theories of speech production. By augmenting a popular psycholinguistic model of lexical retrieval with a motor-control-inspired architecture, we created a new computational model to explain speech errors in the context of aphasia.

Short-form Philadelphia naming test: rationale and empirical evaluation.

Purpose: To create two matched short forms of the Philadelphia Naming Test (PNT; Roach, Schwartz, Martin, Grewal, & Brecher, 1996) that yield similar results to the PNT for measuring anomia.

Method: In Study 1, archived naming data from 94 individuals with aphasia were used to identify which PNT items should be included in the short forms. The 2 constructed sets of 30 items, PNT30-A and PNT30-B, were validated using archived data from a separate group of 56 individuals with aphasia.

A large, searchable, web-based database of aphasic performance on picture naming and other tests of cognitive function.

Many research questions in aphasia can only be answered through access to substantial numbers of patients and to their responses on individual test items. Since such data are often unavailable to individual researchers and institutions, we have developed and made available the Moss Aphasia Psycholinguistics Project Database: a large, searchable, web-based database of patient performance on psycholinguistic and neuropsychological tests. The database contains data from over 240 patients covering a wide range of aphasia subtypes and severity, some of whom were tested multiple times.

Neuroanatomical dissociation for taxonomic and thematic knowledge in the human brain.

It is thought that semantic memory represents taxonomic information differently from thematic information. This study investigated the neural basis for the taxonomic-thematic distinction in a unique way. We gathered picture-naming errors from 86 individuals with poststroke language impairment (aphasia).

Support for anterior temporal involvement in semantic error production in aphasia: new evidence from VLSM.

Semantic errors in aphasia (e.g., naming a horse as "dog") frequently arise from faulty mapping of concepts onto lexical items.

Anterior temporal involvement in semantic word retrieval: voxel-based lesion-symptom mapping evidence from aphasia.

Analysis of error types provides useful information about the stages and processes involved in normal and aphasic word production. In picture naming, semantic errors (horse for goat) generally result from something having gone awry in lexical access such that the right concept was mapped to the wrong word. This study used the new lesion analysis technique known as voxel-based lesion-symptom mapping to investigate the locus of lesions that give rise to semantic naming errors.