Effortful verb retrieval from semantic memory drives beta suppression in mesial frontal regions involved in action initiation

The contribution of the motor cortex to the semantic retrieval of verbs remains a subject of debate in neuroscience. Here, we examined whether additional engagement of the cortical motor system was required when access to verbs semantics was hindered during a verb generation task. We asked participants to produce verbs related to presented noun cues that were either strongly associated with a single verb to prompt fast and effortless verb retrieval, or were weakly associated with multiple verbs and more difficult to respond to. Using power suppression of magnetoencephalography beta oscillations (15–30 Hz) as an index of cortical activation, we performed a whole‐brain analysis in order to identify the cortical regions sensitive to the difficulty of verb semantic retrieval. Highly reliable suppression of beta oscillations occurred 250 ms after the noun cue presentation and was sustained until the onset of verbal response. This was localized to multiple cortical regions, mainly in the temporal and frontal lobes of the left hemisphere. Crucially, the only cortical regions where beta suppression was sensitive to the task difficulty, were the higher order motor areas on the medial and lateral surfaces of the frontal lobe. Stronger activation of the premotor cortex and supplementary motor area accompanied the effortful verb retrieval and preceded the preparation of verbal responses for more than 500 ms, thus, overlapping with the time window of verb retrieval from semantic memory. Our results suggest that reactivation of verb‐related motor plans in higher order motor circuitry promotes the semantic retrieval of target verbs.     

Phonological facilitation effects on naming latencies and viewing times during noun and verb naming in agrammatic and anomic aphasia

Background: Phonological priming has been shown to facilitate naming in individuals with aphasia, as well as healthy speakers, resulting in faster naming latencies. However, the mechanisms of phonological facilitation (PF) in aphasia remain unclear.

Aims: Within discrete vs. interactive models of lexical access, this study examined whether PF occurs via the sub-lexical or lexical route during noun and verb naming in agrammatic and anomic aphasia.

Methods & Procedures: Thirteen participants with agrammatic aphasia and 10 participants with anomic aphasia and their young and age-matched controls (n = 20/each) were tested. Experiment 1 examined noun and verb naming deficit patterns in an off-line confrontation naming task. Experiment 2 examined PF effects on naming both word categories using eyetracking priming paradigm.

Outcomes & Results: Results of Experiment 1 showed greater naming difficulty for verbs than for nouns in the agrammatic group, with no difference between the two word categories in the anomic group. For both participant groups, errors were dominated by semantic paraphasias, indicating impaired lexical selection. In the phonological priming task (Experiment 2), young and age-matched control groups showed PF in both noun and verb naming. Interestingly, the agrammatic group showed PF when naming verbs, but not nouns, whereas the anomic group showed PF for nouns only.

Conclusions: Consistent with lexically mediated PF in interactive models of lexical access, selective PF for different word categories in our agrammatic and anomic groups suggest that phonological primes facilitate lexical selection via feedback activation, resulting in greater PF for more difficult (i.e., verbs in agrammatic and possibly nouns in anomic group) lexical items.     

Semantic feature analysis targeting verbs in a quadrilingual speaker with aphasia

Background: Semantic feature analysis (SFA) is a treatment approach aimed at enhancing lexical retrieval by improving access to the semantic network in speakers with aphasia. Although there are promising results on trained items, previous studies exploring the impact of SFA on verb production in monolingual speakers have shown mixed results for generalisation to untrained items and discourse. There are few published studies investigating SFA and action naming in multilingual speakers.

Aims: The study explores the impact of SFA on trained and untrained verbs, semantics and syntax, and narrative production in the trained and untrained languages of a multilingual speaker (Japanese–English–German–Norwegian) with moderate non-fluent aphasia. Treatment was conducted in a late-acquired language (Norwegian).

Methods & Procedures: SFA was provided during an intensive schedule of about 22 hr of therapy, with approximately 10 hr per week over two and a half weeks. The treatment focused on the production of verbs in sentence contexts.

Outcomes & Results: Outcome measures include the Bilingual Aphasia Test, an action-naming test, and production of semi-spontaneous narratives.

Outcomes in the treated language: Overall, the participant responded positively to the SFA treatment. The trained verbs improved significantly, but no transfer was observed to untrained verbs. There were no changes in the formal testing of semantics or syntax, but improvements were noted in narrative production.

Cross-linguistic outcomes: Transfer to verbs in untreated German was evident. There were significant increases in the semantics and syntax in both English and German. The participant showed an improvement in discourse in English and German, although not in Japanese.

Conclusions: SFA treatment in a late-acquired language can lead to gains in the treated language and transfer to both stronger and weaker languages, with different patterns for the various languages. This indicates that SFA may be a promising method for treating multilingual speakers with aphasia. The authors further advocate the use of narratives as an assessment tool. In addition to enhancing the ecological validity of the findings, the narratives provided information not obtainable from the other assessment tools for within- and cross-linguistic therapy gains for the participant.     

Neural bases of event knowledge and syntax integration in comprehension of complex sentences

Comprehension of complex sentences is necessarily supported by both syntactic and semantic knowledge, but what linguistic factors trigger a readers’ reliance on a specific system? This functional neuroimaging study orthogonally manipulated argument plausibility and verb event type to investigate cortical bases of the semantic effect on argument comprehension during reading. The data suggest that telic verbs facilitate online processing by means of consolidating the event schemas in episodic memory and by easing the computation of syntactico-thematic hierarchies in the left inferior frontal gyrus. The results demonstrate that syntax–semantics integration relies on trade-offs among a distributed network of regions for maximum comprehension efficiency.     

How do deaf speakers talk about time?

The grammatical and lexical aspects of temporal reference in the expressive language of prelingually deaf speakers in comparison with normally hearing age-matched speakers were examined. Significant differences emerged between groups in the grammaticalization of time. The deaf subjects used fewer verb inflections to mark time and made many errors with inflections. In addition, a significant triple interaction was found between group × verb typology × verb inflection, which suggested that the deaf were using the verb inflections to code the aspectual features of completion and duration inherent in verbs. Lexical aspects of time reference were found to be similar for both groups. The results are discussed with reference to the normal development of linguistic expressions of time in children acquiring language, and the implications for language therapy with the deaf are considered.     

南通话中的“捉”

"捉"在南通话中主要用作动词,词义丰富,常带表受事、结果、原因、方式的宾语;同时,在"捉 O1 V O2"或"捉 O V"结构中,当"捉"的动词性特征减弱、语义虚化时,可以介引后面动词的借助工具、支配对象、施事主体、方位处所等,用作表工具义、处置义、致使义、处所义的介词。     

The link between language and action in aging

ObjectiveMany studies have demonstrated the existence of a link between action verb processing and action. However, little is known about the changes in this relationship with aging.MethodTo assess this point, we compare the performances of younger and older people during a priming task consisting of judging whether an image contains a human after listening to an action verb.ResultsIn accordance with previous literature, the results showed that younger people were faster to detect the presence of a human in the image in congruent conditions, namely, when the action verb and the image refer to the same action. However, this effect was not present in older adults’ participants.ConclusionThese findings suggest that the link between action and language decreases with age. We discuss these findings in the context of the embodied view of cognition.     

Broca's area and inflectional morphology: evidence from broca's aphasia and computer modeling

In a series of articles Ullman (2001, 2004; Ullman et al., 1997) has proposed that regular inflection is critically subserved by Broca's area. This suggestion is motivated by the finding that English speaking Broca's aphasics show selective deficits with regular inflection. Here we argue that this proposal does not hold cross-linguistically but is based on a confound between inflectional suffix and regularity that is specific to the English language. We present data from two experimental studies of participle inflection with 13 German and 12 Dutch Broca's aphasics. None of these aphasic speakers are selectively impaired for regular inflection but instead most of them show selective deficits with irregular inflection. These data suggest that a selective regular deficit is not a characteristic of Broca's aphasia across languages, and that Broca's area is not critically involved in regular inflection. To investigate the nature and localization of the processes underlying inflection we present a connectionist neural network model that accounts for the deficits of the German aphasic speakers. The model implements the view that the inflection of all verb types is based on a single mechanism with multiple representations that emerge from experience-dependent brain development. We show that global damage to this model results in a selective deficit for irregular inflection that is comparable to that of the German aphasic speakers. This finding suggests that a selective impairment of irregular participles as observed by German and Dutch aphasic speakers does not presuppose two distinctly localized mechanisms or processes that can be selectively affected by brain damage.     

医学英语的词法特征

目的 探讨医学英语的词法特征.方法 通过归纳和分析找出医学英语在词法方面的特征.结果 作为一种特殊用途英语,医学英语在词汇来源、两栖词汇、复合词汇、非谓语动词、书面语词汇等的使用方面具有不同于普通英语的词法特征. 结论 了解医学英语的词法特征有利于提高医学英语的教学水平.