Blog Archives

Regional differences in the listener’s phonemic inventory affect semantic processing: A mismatch negativity (MMN) study

Using the mismatch negativity (MMN) response, we examined how Standard French and Southern French speakers access the meaning of words ending in /e/ or /ε/ vowels which are contrastive in Standard French but not in Southern French. In Standard French speakers, there was a significant difference in the amplitude of the brain response after the deviant-minus-standard subtraction between the frontocentral (FC) and right lateral (RL) recording sites for the final-/ε/ word but not the final-/e/ word. In contrast, the difference in the amplitude of the brain response between the FC and RL recording sites did not significantly vary as a function of the word’s final vowel in Southern French speakers. Our findings provide evidence that access to lexical meaning in spoken word recognition depends on the speaker’s native regional accent.

from Brain and Language

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Regional differences in the listener’s phonemic inventory affect semantic processing: A mismatch negativity (MMN) study

Using the mismatch negativity (MMN) response, we examined how Standard French and Southern French speakers access the meaning of words ending in /e/ or /ε/ vowels which are contrastive in Standard French but not in Southern French. In Standard French speakers, there was a significant difference in the amplitude of the brain response after the deviant-minus-standard subtraction between the frontocentral (FC) and right lateral (RL) recording sites for the final-/ε/ word but not the final-/e/ word. In contrast, the difference in the amplitude of the brain response between the FC and RL recording sites did not significantly vary as a function of the word’s final vowel in Southern French speakers. Our findings provide evidence that access to lexical meaning in spoken word recognition depends on the speaker’s native regional accent.

from Brain and Language

Semantic access dysphasia resulting from left temporal lobe tumours

Unlike semantic degradation disorders, the mechanisms and the anatomical underpinnings of semantic access disorders are still unclear. We report the results of a case series study on the effects of temporal lobe gliomas on semantic access abilities of a group of 20 patients. Patients were tested 1–2 days before and 4–6 days after the removal of the tumour. Their semantic access skills were assessed with two spoken word-to-picture matching tasks, which aimed to separately control for rate of presentation, consistency and serial position effects (Experiment 1) and for word frequency and semantic distance effects (Experiment 2). These variables have been held to be critical in characterizing access in contrast to degraded-store semantic deficits, with access deficits characterized by inconsistency of response, better performance with slower presentation rates and with semantically distant stimuli, in the absence of frequency effects. Degradation deficits show the opposite pattern. Our results showed that low-grade slowly growing tumours tend not to produce signs of access problems. However, high-grade tumours especially within the left hemisphere consistently produce strong semantic deficits of a clear access type: response inconsistency and strong semantic distance effects in the absence of word frequency effects were detected. However, effects of presentation rate and serial position were very weak, suggesting non-refractory behaviour in the tumour patients tested. This evidence, together with the results of lesion overlapping, suggests the presence of a type of non-refractory semantic access deficit. We suggest that this deficit could be caused by the disconnection of posterior temporal lexical input areas from semantic system.

from Brain

Semantic access dysphasia resulting from left temporal lobe tumours

Unlike semantic degradation disorders, the mechanisms and the anatomical underpinnings of semantic access disorders are still unclear. We report the results of a case series study on the effects of temporal lobe gliomas on semantic access abilities of a group of 20 patients. Patients were tested 1–2 days before and 4–6 days after the removal of the tumour. Their semantic access skills were assessed with two spoken word-to-picture matching tasks, which aimed to separately control for rate of presentation, consistency and serial position effects (Experiment 1) and for word frequency and semantic distance effects (Experiment 2). These variables have been held to be critical in characterizing access in contrast to degraded-store semantic deficits, with access deficits characterized by inconsistency of response, better performance with slower presentation rates and with semantically distant stimuli, in the absence of frequency effects. Degradation deficits show the opposite pattern. Our results showed that low-grade slowly growing tumours tend not to produce signs of access problems. However, high-grade tumours especially within the left hemisphere consistently produce strong semantic deficits of a clear access type: response inconsistency and strong semantic distance effects in the absence of word frequency effects were detected. However, effects of presentation rate and serial position were very weak, suggesting non-refractory behaviour in the tumour patients tested. This evidence, together with the results of lesion overlapping, suggests the presence of a type of non-refractory semantic access deficit. We suggest that this deficit could be caused by the disconnection of posterior temporal lexical input areas from semantic system.

from Brain