Investigating the influence of semantic factors on word retrieval: Reservations, results and recommendations

The impact of linguistic complexity on feasibility and reliability of language mapping in aphasic glioma patients

BACKGROUND

Reliable language mappings require sufficient language skills. This study evaluated whether linguistic task properties impact feasibility and reliability of navigated transcranial magnetic stimulation (nTMS)-based language mappings in aphasic glioma patients.

METHODS

The effect of linguistic complexity on naming accuracy during baseline testing without stimulation and on the number of errors during nTMS was evaluated for 16 moderately and 4 severely expressive aphasic patients.

RESULT

During baseline, items acquired later in life and used less frequently, a higher amount of multisyllabic, compound, and inanimate items were named inaccurately. Even after removing these more complex items, less frequent and multisyllabic items were more error-prone during stimulation.

CONCLUSION

Higher linguistic item complexity was associated with decreased naming accuracy during baseline and resulted in a potentially higher false positive rate during nTMS in aphasic glioma patients. Thus, tailoring task complexity to individual performance capabilities may considerably support the preservation of residual functionality.

Why is a flamingo named as pelican and asparagus as celery? Understanding the relationship between targets and errors in a speeded picture naming task

Speakers sometimes make word production errors, such as mistakenly saying pelican instead of flamingo. This study explored which properties of an error influence the likelihood of its selection over the target word. Analysing real-word errors in speeded picture naming, we investigated whether, relative to the target, naming errors were more typical representatives of the semantic category, were associated with more semantic features, and/or were semantically more closely related to the target than its near semantic neighbours were on average. Results indicated that naming errors tended to be more typical category representatives and possess more semantic features than the targets. Moreover, while not being the closest semantic neighbours, errors were largely near semantic neighbours of the targets. These findings suggest that typicality, number of semantic features, and semantic similarity govern activation levels in the production system, and we discuss possible mechanisms underlying these effects in the context of word production theories.