Web-based language production experiments: Semantic interference assessment is robust for spoken and typed response modalities.

For experimental research on language production, temporal precision and high quality of the recorded audio files are imperative. These requirements are a considerable challenge if language production is to be investigated online. However, online research has huge potential in terms of efficiency, ecological validity and diversity of study populations in psycholinguistic and related research, also beyond the current situation. Here, we supply confirmatory evidence that language production can be investigated online and that reaction time (RT) distributions and error rates are similar in written naming responses (using the keyboard) and typical overt spoken responses. To assess semantic interference effects in both modalities, we performed two pre-registered experiments (n = 30 each) in online settings using the participants' web browsers. A cumulative semantic interference (CSI) paradigm was employed that required naming several exemplars of semantic categories within a seemingly unrelated sequence of objects. RT is expected to increase linearly for each additional exemplar of a category. In Experiment 1, CSI effects in naming times described in lab-based studies were replicated. In Experiment 2, the responses were typed on participants' computer keyboards, and the first correct key press was used for RT analysis. This novel response assessment yielded a qualitatively similar, very robust CSI effect. Besides technical ease of application, collecting typewritten responses and automatic data preprocessing substantially reduce the work load for language production research. Results of both experiments open new perspectives for research on RT effects in language experiments across a wide range of contexts. JavaScript- and R-based implementations for data collection and processing are available for download.

Semantic Interference through Multiple Distractors in Picture Naming in People with Aphasia.

When we refer to an object or concept by its name, activation of semantic and categorical information is necessary to retrieve the correct lexical representation. Whereas in neurotypical individuals it is well established that semantic context can interfere with or facilitate lexical retrieval, these effects are much less studied in people with lesions to the language network and impairment at different steps of lexical-semantic processing. Here, we applied a novel picture naming paradigm, where multiple categorically related and unrelated words were presented as distractors before a to-be-named target picture. Using eye tracking, we investigated preferential fixation on the cohort members versus nonmembers. Thereby, we can judge the impact of explicit acknowledgment of the category and its effect on semantic interference. We found that, in contrast to neurotypical participants [van Scherpenberg, C., Abdel Rahman, R., & Obrig, H. A novel multiword paradigm for investigating semantic context effects in language production. PLoS One, 15, e0230439, 2020], participants suffering from mild to moderate aphasia did not show a fixation preference on category members but still showed a large interference effect of ∼35 msec, confirming the implicit mechanism of categorical interference. However, preferential fixation on the categorically related cohort words correlated with clinical tests regarding nonverbal semantic abilities and integrity of the anterior temporal lobe. This highlights the role of supramodal semantics for explicit recognition of a semantic category, while semantic interference is triggered if the threshold of lexical cohort activation is reached. Confirming psycholinguistic evidence, the demonstration of a large and persistent interference effect through implicit lexico-semantic activation is important to understand deficits in people with a lesion in thelanguage network, potentially relevant for individualized intervention aiming at improving naming skills.

A novel multi-word paradigm for investigating semantic context effects in language production.

Semantic context modulates precision and speed of language production. Using different experimental designs including the Picture-Word-Interference (PWI) paradigm, it has consistently been shown that categorically related distractor words (e.g., cat) inhibit retrieval of the target picture name (dog). Here we introduce a novel variant of the PWI paradigm in which we present 8 words prior to a to be named target picture. Within this set, the number of words categorically related was varied between 3 and 5, and the picture to be named was either related or unrelated to the respective category. To disentangle interacting effects of semantic context we combined different naming paradigms manipulating the number of competitors and assessing the effect of repeated naming instances. Evaluating processing of the cohort by eye-tracking provided us with a metric of the (implicit) recognition of the semantic cohort. Results replicate the interference effect in that overall naming of pictures categorically related to the distractor set was slower compared to unrelated pictures. However, interference did not increase with increasing number of distractors. Tracking this effect across naming repetitions, we found that interference is prominent at the first naming instance of every picture only, whereby it is stable across distractor conditions, but dissipates across the experiment. Regarding eye-tracking our data show that participants fixated longer on semantically related items, indicating the identification of the lexico-semantic cohort. Our findings confirm the validity of the novel paradigm and indicate that besides interference during first exposure, repeated exposure to the semantic context may facilitate picture naming and counteract lexical interference.

The relationship between response consistency in picture naming and storage impairment in people with semantic variant primary progressive aphasia.

OBJECTIVE: The progressive loss of stored knowledge about word meanings in semantic variant primary progressive aphasia (svPPA) has been attributed to an amodal "storage" deficit of the semantic system. Performance consistency has been proposed to be a key characteristic of storage deficits but has not been examined in close detail and larger participant cohorts. METHOD: We assessed whether 10 people with svPPA showed consistency in picture naming across 3 closely consecutive sessions. We examined item-by-item consistency of naming accuracy and specific error types, while controlling for the effects of word-related variables such as word frequency, familiarity, and age of acquisition. RESULTS: Participants were very consistent in their accurate and inaccurate responses over and above any effects of the word-related variables. Analyses of error types that compared consistency of semantic errors, correct responses, and other error types (e.g., phonologically related errors, unrelated errors) revealed lower consistency. CONCLUSIONS: Our findings support the assumption that semantic features constituting semantic representations of objects are progressively lost in people with svPPA and are therefore consistently unavailable during naming. Variability in the production of error types occurs when distinctive features of an object are lost, resulting in the selection of semantically or visually similar items or in the failure to select an item and a response omission. The assessment of performance consistency sheds light on the underlying impairment of people with semantic deficits (semantic storage vs. access deficit). This can support the choice of an appropriate treatment technique to maintain or reteach semantic information. (PsycINFO Database Record (c) 2019 APA, all rights reserved).