Lexical Competition Effects in Aphasia

<p>Some aphasic patients show single word production deficits in some situations where object naming is required (e.g., they perform well when objects are presented in unrelated groups (e.g., Cat, Fork, Bread...), but deteriorate when the same items are presented in semantically related groups (e.g., Cat, Cow, Dog...)) (see Wilshire & McCarthy, 2002). We investigated whether context-sensitive single-word production impairments reflect an impaired ability to resolve lexical competition. Three groups of participants (non-fluent aphasics, fluent aphasics, and older controls) completed four tasks that manipulated lexical competition: 1) A category exemplar task, where a high competition condition involved generating items from broad categories (e.g., Animals: "Cat. Dog" etc.), and a low competition condition involved generating items from narrow categories (e.g., Pets: Cat. Dog" etc); 2) A verb generation task, where participants were presented with objects and were required to generate related verbs. The high competition objects were related to a range of verbs (e.g., Penny: Spend"/"Pay"/"Buy" etc), and the low competition objects were related to one dominant verb (e.g., Scissors: "Cut"); 3) A name agreement task where a high competition condition involved naming low name agreement objects (e.g., Artist/Painter), and a low competition condition involved naming of high name agreement objects (e.g., Anchor), and; 4) A sentence completion task, where extrinsic competition was introduced via presentation of auditory distracters. The low competition distracters did not make sense (e.g., Barry wisely chose to pay the RANGE: "Bill"/"Cashier" etc), whereas the high competition distracters did (e.g., Barry wisely chose to pay the FINE: "Bill"/Cashier" etc). Our first hypothesis was that all participants would show high competition costs in increased response latencies and/or decreased accuracy. At the group level, this hypothesis was supported in all four tasks. At the individual level, there was mixed support as some participants showed predicted effects on the verb generation, name agreement, and sentence completion tasks. The second hypothesis was that exaggerated competition costs would occur in some or all non-fluent aphasics. At the group level this hypothesis was not clearly supported on any task. At the individual level there was mixed support, with some indications that non-fluents may be more likely to show significant competition effects than fluents. The third hypothesis was that non-fluent aphasics with relatively well preserved single word production but relatively impaired sentence production may be most likely to show exaggerated lexical competition effects. There was little support for this hypothesis. It was concluded that the data do not support the hypothesis that context-sensitive single-word production impairments are symptomatic of an impaired ability to resolve lexical competition. However, we have gained information on how heterogeneous aphasics perform on tasks that manipulate lexical competition, and we have gained some insights that may direct future research down a path towards more informative results, and increased knowledge on the complex process of speech production.</p>

Lexical Competition Effects in Aphasia

<p>Some aphasic patients show single word production deficits in some situations where object naming is required (e.g., they perform well when objects are presented in unrelated groups (e.g., Cat, Fork, Bread...), but deteriorate when the same items are presented in semantically related groups (e.g., Cat, Cow, Dog...)) (see Wilshire & McCarthy, 2002). We investigated whether context-sensitive single-word production impairments reflect an impaired ability to resolve lexical competition. Three groups of participants (non-fluent aphasics, fluent aphasics, and older controls) completed four tasks that manipulated lexical competition: 1) A category exemplar task, where a high competition condition involved generating items from broad categories (e.g., Animals: "Cat. Dog" etc.), and a low competition condition involved generating items from narrow categories (e.g., Pets: Cat. Dog" etc); 2) A verb generation task, where participants were presented with objects and were required to generate related verbs. The high competition objects were related to a range of verbs (e.g., Penny: Spend"/"Pay"/"Buy" etc), and the low competition objects were related to one dominant verb (e.g., Scissors: "Cut"); 3) A name agreement task where a high competition condition involved naming low name agreement objects (e.g., Artist/Painter), and a low competition condition involved naming of high name agreement objects (e.g., Anchor), and; 4) A sentence completion task, where extrinsic competition was introduced via presentation of auditory distracters. The low competition distracters did not make sense (e.g., Barry wisely chose to pay the RANGE: "Bill"/"Cashier" etc), whereas the high competition distracters did (e.g., Barry wisely chose to pay the FINE: "Bill"/Cashier" etc). Our first hypothesis was that all participants would show high competition costs in increased response latencies and/or decreased accuracy. At the group level, this hypothesis was supported in all four tasks. At the individual level, there was mixed support as some participants showed predicted effects on the verb generation, name agreement, and sentence completion tasks. The second hypothesis was that exaggerated competition costs would occur in some or all non-fluent aphasics. At the group level this hypothesis was not clearly supported on any task. At the individual level there was mixed support, with some indications that non-fluents may be more likely to show significant competition effects than fluents. The third hypothesis was that non-fluent aphasics with relatively well preserved single word production but relatively impaired sentence production may be most likely to show exaggerated lexical competition effects. There was little support for this hypothesis. It was concluded that the data do not support the hypothesis that context-sensitive single-word production impairments are symptomatic of an impaired ability to resolve lexical competition. However, we have gained information on how heterogeneous aphasics perform on tasks that manipulate lexical competition, and we have gained some insights that may direct future research down a path towards more informative results, and increased knowledge on the complex process of speech production.</p>

The effects of multiple linguistic variables on picture naming in American Sign Language

Picture naming tasks provide critical data for theories of lexical representation and retrieval and have been performed successfully in sign languages. However, the specific influences of lexical or phonological factors and stimulus properties on sign retrieval are poorly understood. To examine lexical retrieval in American Sign Language (ASL), we conducted a timed picture naming study using 524 pictures (272 objects and 251 actions). We also compared ASL naming with previous data for spoken English for a subset of 425 pictures. Deaf ASL signers named object pictures faster and more consistently than action pictures, as previously reported for English speakers. Lexical frequency, iconicity, better name agreement, and lower phonological complexity each facilitated naming RTs. RTs were also faster for pictures named with shorter signs (measured by average response duration). Target name agreement was higher for pictures with more iconic and shorter ASL names. The visual complexity of pictures slowed RTs and decreased target name agreement. RTs and target name agreement were correlated for ASL and English, but agreement was lower for ASL, possibly due to the English bias of the pictures. RTs were faster for ASL, which we attributed to a smaller lexicon. Overall, the results suggest that models of lexical retrieval developed for spoken languages can be adopted for signed languages, with the exception that iconicity should be included as a factor. The open-source picture naming dataset for ASL serves as an important, first-of-its-kind resource for researchers, educators, or clinicians for a variety of research, instructional, or assessment purposes.

Normative ratings for 111 Swedish nouns and corresponding picture stimuli

Normative ratings are a means to control for the effects of confounding variables in psycholinguistic experiments. This paper introduces a new dataset of normative ratings for Swedish encompassing 111 concrete nouns and the corresponding picture stimuli in the MultiPic database (Duñabeitia et al. 2017). The norms for name agreement, category typicality, age of acquisition and subjective frequency were collected using online surveys among native speakers of the Finland-Swedish variety of Swedish. The paper discusses the inter-correlations between these variables and compares them against available ratings for other languages. In doing so, the paper argues that ratings for age of acquisition and subjective frequency collected for other languages may be applied to psycholinguistic studies on Finland-Swedish, at least with respect to concrete and highly imageable nouns. In contrast, norms for name agreement should be collected from speakers of the same language variety as represented by the subjects in the actual experiments.

Faroqi-Shah_Verb_Naming_in_Aphasia

Persons with aphasia (PWA) frequently experience difficulties in retrieving verbs. Little is known about mechanisms underlying verb retrieval, both in neurologically healthy adults and PWA. The present study investigated two questions pertaining to action verb naming: 1) if any properties of a verb influence naming efficiency, particularly, somatotopy (bodypart used for the action), and 2) if somatotopic and phonemic primes facilitate action verb naming. Neurologically healthy adults and eight PWA named action videos performed by hand, leg or face under three conditions: neutral, phonemic or somatotopic (same body part) prime. Both groups named hand verbs the fastest and leg verbs the slowest. Somatotopic primes speeded naming for healthy adults, while phonemic facilitation was found for both groups. A multiple regression analysis identified verb frequency, name agreement and somatotopic association rating as significant predictors of verb naming in healthy participants. The findings elucidate the dynamics of verb retrieval and its impairment in aphasia.

Conducting Language Production Research Online: A Web-based Study of Semantic Context and Name Agreement Effects in Multi-Word Production

Few web-based experiments have explored spoken language production, perhaps due to concerns of data quality, especially for measuring onset latencies. The present study highlights how speech production research can be done outside of the laboratory by measuring utterance durations and speech fluency in a multiple-object naming task when examining two effects related to lexical selection: semantic context and name agreement. A web-based modified blocked-cyclic naming paradigm was created, in which participants named a total of sixteen simultaneously presented pictures on each trial. The pictures were either four tokens from the same semantic category (homogeneous context), or four tokens from different semantic categories (heterogeneous context). Name agreement of the pictures was varied orthogonally (high, low). In addition to onset latency, five dependent variables were measured to index naming performance: accuracy, utterance duration, total pause time, the number of chunks (word groups pronounced without intervening pauses), and first chunk length. Bayesian analyses showed effects of semantic context and name agreement for some of the dependent measures, but no interaction. We discuss the methodological implications of the current study and make best practice recommendations for spoken language production research in an online environment.

Lexical Access in Persian Speaking Children With and Without Specific Language Impairment

Introduction: Word retrieval problems are among the limitations observed in children with specific language impairment during the initial schooling years. These restrictions are predictive of reading problems and poor performance at school. Additionally, studies on lexical access in Persian speaking children are scarce. Therefore, this study aimed to investigate and compare naming accuracy and latency in children with and without specific language impairment. Methods: Twenty 7-9-year-old children with specific language impairment and 20 age-matched peers were recruited as the study participants. They were requested to name the 128 black and white line-drawing pictures from a Persian picture naming set for children, as rapidly as possible. We compared the effects of psycholinguistic variables on naming latency in the explored children with and without specific language impairment. Results: Linear mixed-effects modeling presented an interaction between the research groups and the psycholinguistic variables. Significant main effects were found for name agreement (P≤0.00) and the age of acquisition (P=0.05) in children with typical language development; significant effects for name agreement (P≤0.00) and log frequency (P≤0.00) were revealed in children with specific language impairment. Conclusion: The obtained models indicated that psycholinguistic factors could differently affect the naming latency in children with and without specific language impairment. Factors that may have accounted for the findings are discussed in this paper.

IMABASE: A new set of 313 colourised line drawings standardised in French for name agreement, image agreement, conceptual familiarity, age-of-acquisition, and imageability

We provide normative data for a new set of 313 colourised line drawings. The drawings were standardised on name agreement ( N = 60 participants), image agreement ( N = 34), conceptual familiarity ( N = 36), age of acquisition ( N = 35), and imageability ( N = 35). Objective visual complexity measures are given for the pictures, and objective word frequencies are provided for the modal names of the drawings. Reliability measures for the collected norms are very high. There are high levels of agreement between the names given by the participants and the drawings and comparative analyses indicate that the distribution of name agreement scores is very similar in both our own database and the MultiPic database (Duñabeitia et al., 2018). A novel “picture-choice task” used to assess name-image agreement ( N = 30) reveals that the great majority of the IMABASE pictures that are also present in MultiPic are rated as providing better pictorial representations of the corresponding concepts. Finally, most of the correlations are comparable with those reported in other normative studies on colourised drawings. The whole set of pictures is freely available from https://leadserv.u-bourgogne.fr/~lead/imabase/ and the norms are available as Supplementary Material.