Refractoriness and the healthy brain: A behavioural study on semantic access

While many behavioural studies on refractory phenomena in lexical/semantic access have focused on the mechanisms involved in the oral production of names, comprehension tasks have been almost exclusively used in neuropsychological studies on brain damaged patients. We report the results of two experiments on healthy participants conducted by means of speeded word to picture matching tasks. They assess the effects of the same variables examined in the study of refractory access dysphasic patients: semantic distance and word frequency (experiment 1) and presentation rate and serial position effects (experiment 2). Semantic access patients usually show little effect of word frequency but a large semantic distance effect. However, critical in characterising the syndrome as ‘refractory’, effects of presentation rate and serial position should also be present. The experiments involved the use of a deadline response procedure. The critical manipulation was the absence of a Response Stimulus Interval (RSI) in the fast presentation rate conditions; slower presentation rates involved 1 s RSI. With these manipulations the typical behavioural pattern of performance provided by semantic access dysphasic patients was reproduced. Semantic distance effects were more powerful than word frequency effects (experiment1). Presentation rate effects were found and, most important for a “refractory” account of the effects, a serial position effect was obtained (experiment 2). These results provide the first evidence of such a broad range of refractory effects at the same time in comprehension tasks in healthy subjects and support a purely semantic account for the locus of refractoriness. Moreover, error analysis showed a predominance of perseverative errors with subsequent representations of the same target, supporting a failure of cognitive control mechanisms as the cause of refractory behaviour. The findings are discussed in the light of current models of lexical and semantic processing.     

Learning language from the input: why innate constraints can't explain noun compounding

Do the production and interpretation of patterns of plural forms in noun-noun compounds reveal the workings of innate constraints that govern morphological processing? The results of previous studies on compounding have been taken to support a number of important theoretical claims: first, that there are fundamental differences in the way that children and adults learn and process regular and irregular plurals, second, that these differences reflect formal constraints that govern the way the way regular and irregular plurals are processed in language, and third, that these constraints are unlikely to be the product of learning. In a series of seven experiments, we critically assess the evidence that is cited in support of these arguments. The results of our experiments provide little support for the idea that substantively different factors govern the patterns of acquisition, production and interpretation patterns of regular and irregular plural forms in compounds. Once frequency differences between regular and irregular plurals are accounted for, we find no evidence of any qualitative difference in the patterns of interpretation and production of regular and irregular plural nouns in compounds, in either adults or children. Accordingly, we suggest that the pattern of acquisition of both regular and irregular plurals in compounds is consistent with a simple account, in which children learn the conventions that govern plural compounding using evidence that is readily available in the distribution patterns of adult speech.     

What is the deficit in phonological processing deficits: auditory sensitivity, masking, or category formation?

Although children with language impairments, including those associated with reading, usually demonstrate deficits in phonological processing, there is minimal agreement as to the source of those deficits. This study examined two problems hypothesized to be possible sources: either poor auditory sensitivity to speech-relevant acoustic properties, mainly formant transitions, or enhanced masking of those properties. Adults and 8-year-olds with and without phonological processing deficits (PPD) participated. Children with PPD demonstrated weaker abilities than children with typical language development (TLD) in reading, sentence recall, and phonological awareness. Dependent measures were word recognition, discrimination of spectral glides, and phonetic judgments based on spectral and temporal cues. All tasks were conducted in quiet and in noise. Children with PPD showed neither poorer auditory sensitivity nor greater masking than adults and children with TLD, but they did demonstrate an unanticipated deficit in category formation for nonspeech sounds. These results suggest that these children may have an underlying deficit in perceptually organizing sensory information to form coherent categories.     

Linguistic correlates of asymmetric motor symptom severity in Parkinson’s Disease

Asymmetric motor severity is common in Parkinson’s Disease (PD) and provides a method for examining the neurobiologic mechanisms underlying cognitive and linguistic deficits associated with the disorder. In the present research, PD participants (N = 31) were assessed in terms of the asymmetry of their motor symptoms. Interviews with the participants were analyzed with the Linguistic Inquiry and Word Count (LIWC) program. Three measures of linguistic complexity – the proportion of verbs, proportion of function words, and sentence length – were found to be affected by symptom asymmetry. Greater left-side motor severity (and hence greater right-hemisphere dysfunction) was associated with the production of significantly fewer verbs, function words, and shorter sentences. Hence, the production of linguistic complexity in a natural language context was associated with relatively greater right hemisphere involvement. The potential neurobiological mechanisms underlying this effect are discussed.     

Facilitation by Variation: Right-to-Left Learning of English Yes/No Questions

This study advances the hypothesis that optional structural variation in language facilitates syntactic learning (facilitation‐by‐variation). Support for this is provided by a right‐to‐left‐elaboration acquisition model for English yes/no questions (YNQs). Previous studies have focused on the acquisition of ‘‘inverted’’ YNQs, a cornerstone of nativist theories of language development. Data from five American children (1;3 to 5;1) and their parents show that children hear a range of adult questions (Coming?You coming?Are you coming?), not all inverted. These variants are ordered from structurally least complex noncanonical forms to complex canonical inverted forms. I use state‐of‐the‐art econometric techniques to estimate breakpoints in YNQ time series and show that noncanonical questions emerge early in children’s speech and facilitate acquisition of canonical ones. This incremental structure‐building process relies on an adjunction strategy that augments noncanonical questions with initial auxiliaries and subjects. Development proceeds incrementally from right to left to derive auxiliary‐initial structures.     

A combined fMRI and DTI examination of functional language lateralization and arcuate fasciculus structure: Effects of degree versus direction of hand preference

The present study examined the relationship between hand preference degree and direction, functional language lateralization in Broca’s and Wernicke’s areas, and structural measures of the arcuate fasciculus. Results revealed an effect of degree of hand preference on arcuate fasciculus structure, such that consistently-handed individuals, regardless of the direction of hand preference, demonstrated the most asymmetric arcuate fasciculus, with larger left versus right arcuate, as measured by DTI. Functional language lateralization in Wernicke’s area, measured via fMRI, was related to arcuate fasciculus volume in consistent-left-handers only, and only in people who were not right hemisphere lateralized for language; given the small sample size for this finding, future investigation is warranted. Results suggest handedness degree may be an important variable to investigate in the context of neuroanatomical asymmetries.     

Form follows function: Learning about function helps children learn about shape

Object functions help young children to organize new artifact categories. However, the scope of their influence is unknown. We explore whether functions highlight property dimensions that are relevant to artifact categories in general. Specifically, using a longitudinal training procedure, we assessed whether experience with functions highlights shape as important for categorization. Seventeen-month-olds were provided experience with novel categories of similarly shaped objects. In Study 1, the function group learned about the objects’ shape-based functions; a control group did not. In Study 2, 17-month-olds were trained on the same categories, but the objects’ shapes and functions were no longer causally related. Only the function group in Study 1 subsequently used shape reliably when categorizing novel objects. These results suggest that function is instrumental in establishing a ‘shape bias’ in early categorization and that it does so via conceptually based processes.     

想象未来的认知加工成分及其脑网络

合理预期和想象未来事件或场景, 有利于个体做出适应性反应, 促进生存与发展。近年来, 研究者对想象未来的认知加工成分和神经机制进行了深入探讨, 提出了想象未来的相关概念和理论。我们首先概述了想象未来实验常用的思维采样范式和词语-线索范式, 接着介绍了想象未来的自我参照加工、心理场景构建等认知加工成分。此外, 特别介绍了想象未来的默认网络模型以及与之相关的其他大尺度脑网络, 并进一步提出了想象未来的脑网络研究框架。未来的研究可从想象未来的动态脑网络、复杂脑网络以及与疾病的关系等角度入手, 深入探究想象未来的神经机制。     

主动性控制在语言转换线索加工阶段的作用

利用ERP技术,考察个体的主动性控制在语言转换线索加工阶段的作用。实验采用线索化的语言转换范式,要求汉–英双语者根据线索使用汉语或英语对图片进行命名,记录线索加工阶段的脑电成分。采用AX连续执行测验（AX-Continuous Performance Test）中AY试次的错误率作为主动性控制参与程度的指标。结果发现,在线索呈现后的200-350 ms和350-500 ms两个时间窗口,转换试次比重复试次诱发了更负的N2波幅和晚期负波,而且AY试次的错误率可以显著地预测转换试次的N2和晚期负波的波幅。结果表明,语言转换的线索加工可区分为由主动性控制调节的两个阶段,即“与非目标语言任务图式的分离”和“转入目标语言任务图式”的阶段。本研究为主动性控制参与语言转换过程提供了直接的实验证据。     

Predicting the Vote: Implicit Attitudes as Predictors of the Future Behavior of Decided and Undecided Voters

Two studies assessed the predictive validity of implicit political attitudes in relation to voting behavior. In Study 1 , we demonstrated the validity of the adopted measure (i.e., the IAT; Greenwald, McGhee, & Schwartz, 1998 ) with a sample of voters who clearly sided with one of the opposing parties. In Study 2 , implicit political preferences were measured in a sample of undecided voters one month before the election, and actual voting behavior was assessed immediately after the election. Results demonstrated that implicit political attitudes were good predictors of future voting behaviors. These findings support the hypothesis of the presence of embryonic attitudes even in the case of those voters who at the explicit and conscious level deny any preference for one of the two opposing candidates.