Interactions of reading and semantics along the ventral visual processing stream

Converging evidence supports a distributed-plus-hub view of semantic processing, in which there are distributed modular semantic sub-systems (e.g., for shape, colour, and action) connected to an amodal semantic hub. Furthermore, object semantic processing of colour and shape, and lexical reading and identification, are processed mainly along the ventral stream, while action semantic processing occurs mainly along the dorsal stream. In Experiment 1, participants read a prime word that required imagining either the object or action referent, and then named a lexical word target. In Experiments 2 and 3, participants performed a lexical decision task (LDT) with the same targets as in Experiment 1, in the presence of foils that were legal nonwords (NW; Experiment 2) or pseudohomophones (PH; Experiment 3). Semantic priming was similar in effect size regardless of prime type for naming, but was greater for object primes than action primes for the LDT with PH foils, suggesting a shared-stream advantage when the task demands focus on orthographic lexical processing. These experiments extend the distributed-plus-hub model, and provide a novel paradigm for further research.     

Bilingual infants excel at foreign‐language talker recognition

Bilingual and monolingual infants differ in how they process linguistic aspects of the speech signal. But do they also differ in how they process non‐linguistic aspects of speech, such as who is talking? Here, we addressed this question by testing Canadian monolingual and bilingual 9‐month‐olds on their ability to learn to identify native Spanish‐speaking females in a face‐voice matching task. Importantly, neither group was familiar with Spanish prior to participating in the study. In line with our predictions, bilinguals succeeded in learning the face‐voice pairings, whereas monolinguals did not. We consider multiple explanations for this finding, including the possibility that simultaneous bilingualism enhances perceptual attentiveness to talker‐specific speech cues in infancy (even in unfamiliar languages), and that early bilingualism delays perceptual narrowing to language‐specific talker recognition cues. This work represents the first evidence that multilingualism in infancy affects the processing of non‐linguistic aspects of the speech signal, such as talker identity.     

The vocabulary spurt predicts the emergence of backward semantic inhibition in 18‐month‐old toddlers

The current study examines the relationship between 18‐month‐old toddlers’ vocabulary size and their ability to inhibit attention to no‐longer relevant information using the backward semantic inhibition paradigm. When adults switch attention from one semantic category to another, the former and no‐longer‐relevant semantic category becomes inhibited, and subsequent attention to an item that belongs to the inhibited semantic category is impaired. Here we demonstrate that 18‐month‐olds can inhibit attention to no‐longer relevant semantic categories, but only if they have a relatively large vocabulary. These findings suggest that an increased number of items (word knowledge) in the toddler lexical‐semantic system during the “vocabulary spurt” at 18‐months may be an important driving force behind the emergence of a semantic inhibitory mechanism. Possessing more words in the mental lexicon likely results in the formation of inhibitory links between words, which allow toddlers to select and deselect words and concepts more efficiently. Our findings highlight the role of vocabulary growth in the development of inhibitory processes in the emerging lexical‐semantic system.     

五官完整度对自闭症儿童面孔表情性别识别的影响

摘 要 为探讨自闭症儿童在不同面孔遮蔽部位和不同面孔表情下的性别识别能力,本研究选取自闭症、智力障碍和普通儿童各21名对240张面孔表情图片进行性别识别。结果发现,自闭症儿童的性别识别正确率显著低于普通儿童,且表现出对中性和高兴表情的识别优于生气表情,同时在遮蔽眼睛时正确率最低。研究认为,自闭症儿童的总体性别识别能力偏低,且受面孔遮蔽部位和表情类型的影响显著,在面孔表情加工过程中体现出较为明显的局部加工特征。     

The effect of educational environment on identity recognition and perceptions of within-person variability

Individuals from small communities show impoverished face recognition relative to those from large communities, suggesting that the number of faces to which one is exposed has a measurable effect on face processing abilities. We sought to extend these findings by examining a second factor that influences the population of faces to which one is exposed during childhood: educational setting. In particular, we examined whether formerly home-schooled participants show reduced performance relative to non-homeschoolers on the Cambridge Face Memory Test (CFMT) and on a sorting task in which participants sort photographs of two unfamiliar identities into piles representing the number of identities they believe are present. On the CFMT, there was no effect of educational setting. However, formerly home-schooled participants showed significant deficits on the sorting task. Such results suggest that reduced exposure to faces early in life as a function of home-schooling may have lasting effects on the face processing system.     

Does impaired socioemotional functioning account for behavioral dysexecutive disorders? Evidence from a transnosological study

Behavioral dysexecutive disorders are highly prevalent in patients with neurological diseases but cannot be explained by cognitive dysexecutive impairments. In fact, the underlying mechanisms are poorly understood. Given that socioemotional functioning underlies appropriate behavior, socioemotional impairments may contribute to the appearance of behavioral disorders. To investigate this issue, we performed a transnosological study.

Seventy-five patients suffering from various neurological diseases (Alzheimer’s disease (AD), Parkinson’s disease (PD), frontotemporal lobar degeneration, and stroke) were included in the study. The patients were comprehensively assessed in terms of cognitive and behavioral dysexecutive disorders and socioemotional processes (facial emotion recognition and theory of mind). As was seen for cognitive and behavioral dysexecutive impairments, the prevalence of socioemotional impairments varied according to the diagnosis. Stepwise logistic regressions showed that (i) only cognitive executive indices predicted hypoactivity with apathy/abulia, (ii) theory of mind impairments predicted hyperactivity–distractibility–impulsivity and stereotyped/perseverative behaviors, and (iii) impaired facial emotion recognition predicted social behavior disorders. Several dysexecutive behavioral disorders are associated with an underlying impairment in socioemotional processes but not with cognitive indices of executive functioning (except for apathy). These results strongly suggest that some dysexecutive behavioral disorders are the outward signs of an underlying impairment in socioemotional processes.     

Word recognition in Alzheimer's disease: Effects of semantic degeneration

Impairments of word recognition in Alzheimer's disease (AD) have been less widely investigated than impairments affecting word retrieval and production. In particular, we know little about what makes individual words easier or harder for patients with AD to recognize. We used a lexical selection task in which participants were shown sets of four items, each set consisting of one word and three non‐words. The task was simply to point to the word on each trial. Forty patients with mild‐to‐moderate AD were significantly impaired on this task relative to matched controls who made very few errors. The number of patients with AD able to recognize each word correctly was predicted by the frequency, age of acquisition, and imageability of the words, but not by their length or number of orthographic neighbours. Patient Mini‐Mental State Examination and phonological fluency scores also predicted the number of words recognized. We propose that progressive degradation of central semantic representations in AD differentially affects the ability to recognize low‐imageability, low‐frequency, late‐acquired words, with the same factors affecting word recognition as affecting word retrieval.     

The influence of speech rate and accent on access and use of semantic information

Circumstances in which the speech input is presented in sub-optimal conditions generally lead to processing costs affecting spoken word recognition. The current study indicates that some processing demands imposed by listening to difficult speech can be mitigated by feedback from semantic knowledge. A set of lexical decision experiments examined how foreign accented speech and word duration impact access to semantic knowledge in spoken word recognition. Results indicate that when listeners process accented speech, the reliance on semantic information increases. Speech rate was not observed to influence semantic access, except in the setting in which unusually slow accented speech was presented. These findings support interactive activation models of spoken word recognition in which attention is modulated based on speech demands.