We aimed to investigate the working memory (WM) and language separate contributions to verbal learning and memory in patients with unilateral drug-resistant temporal lobe epilepsy (drTLE); additionally, we explored the mediating role of WM on the relationship between the number of antiepileptic drugs (AEDs) and short-term verbal memory. We retrospectively enrolled 70 patients with left (LTLE; n = 44) and right (RTLE; n = 26) drTLE. About 40 similar (age and education) healthy controls were used to determine impairments of groups at WM, language (naming and verbal fluency), and verbal learning and memory (five trials list-learning, story memory—immediate recall). To disentangle the effect of learning from the short-term memory, we separately analyzed performances at the first trial, last trial, and delayed-recall list-learning measures, in addition to the total learning capacity (the sum of the five trials). Correlation and regression analyses were used to assess the contribution of potential predictors while controlling for main clinical and demographic variables, and ascertain the mediating role of WM. All patients were impaired at WM and story memory, whereas only LTLE showed language and verbal learning deficits. In RTLE, language was the unique predictor for the most verbal learning performances, whereas WM predicted the results at story memory. In LTLE, WM was the sole predictor for short-term verbal learning (list-learning capacity; trial 1) and mediated the interaction between AED number and the performance at these measures, whereas language predicted the delayed-recall. Finally, WM confounded the performance at short-term memory in both groups, although at different measures. WM is impaired in drTLE and contributes to verbal memory and learning deficits in addition to language, mediating the relationship between AED number and short-term verbal memory in LTLE. Clinicians should consider this overlap when interpreting poor performance at verbal learning and memory in drTLE.

Purpose: Canonical sentence structures are the most frequently used in a given language. Less frequent or non-canonical sentences tend to be more challenging to process and to induce a higher cognitive load. To deal with this complexity several authors suggest that not only linguistic but also non-linguistic (domain-general) mechanisms are involved. In this study, we were interested in evaluating the relationship between non-canonical oral sentence comprehension and individual cognitive control abilities.Method: Participants were instructed to perform a sentence-picture verification task with canonical and non-canonical sentences. Sentence structures (i.e., active or passive) and sentence types (i.e., affirmative or negative) were manipulated. Furthermore, each participant performed four cognitive control tasks measuring inhibitory processes, updating in working memory, flexibility and sustained attention. We hypothesized that more complex sentence structures would induce a cognitive cost reflecting involvement of additional processes, and also that this additional cost should be related with cognitive control performances.Results: Results showed better performances for canonical sentences compared to non-canonical ones supporting previous work on passive and negative sentence processing. Correlation results suggest a close relationship between cognitive control mechanisms and non-canonical sentence processing.Conclusion: This study adds evidence for the hypothesis of a domain-general mechanism implication during oral language comprehension and highlights the importance of taking task demands into consideration when exploring language comprehension mechanisms.

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