On predicting others’ words: Electrophysiological evidence of prediction in speech production

The present study investigated whether lexical processes that occur when we name objects can also be observed when an interaction partner is naming objects. We compared the behavioral and electrophysiological responses of participants performing a conditional go/no-go picture naming task in two different conditions: individually and jointly with a confederate participant. To obtain an index of lexical processing, we manipulated lexical frequency, so that half of the pictures had corresponding names of high-frequency and the remaining half had names of low-frequency. Color cues determined whether participants should respond, whether their task-partner should respond, or whether nobody should respond. Behavioral and ERP results showed that participants engaged in lexical processing when it was their turn to respond. Crucially, ERP results on no-go trials revealed that participants also engaged in lexical processing when it was their partner’s turn to act. In addition, ERP results showed increased response inhibition selectively when it was the partner’s turn to act. These findings provide evidence for the claim that listeners generate predictions about speakers’ utterances by relying on their own action production system.     

Verbal working memory predicts co-speech gesture: Evidence from individual differences

Gesture facilitates language production, but there is debate surrounding its exact role. It has been argued that gestures lighten the load on verbal working memory (VWM; Goldin-Meadow, Nusbaum, Kelly, & Wagner, 2001), but gestures have also been argued to aid in lexical retrieval (Krauss, 1998). In the current study, 50 speakers completed an individual differences battery that included measures of VWM and lexical retrieval. To elicit gesture, each speaker described short cartoon clips immediately after viewing. Measures of lexical retrieval did not predict spontaneous gesture rates, but lower VWM was associated with higher gesture rates, suggesting that gestures can facilitate language production by supporting VWM when resources are taxed. These data also suggest that individual variability in the propensity to gesture is partly linked to cognitive capacities.     

图词间隔时间影响口语词汇产生中语义效应的机制：图词干扰范式研究

口语词汇产生过程中存在语义抑制和语义促进效应, 可能发生在概念准备和词汇选择或者后词汇水平阶段。本研究采用图画-词汇干扰实验任务, 变化图画与词汇出现点之间的时间间隔(stimulus onset asynchrony, SOA), 运用脑电技术考察口语词汇产生中语义效应发生的时间进程。结果显示, 当SOA为0 ms时表现出语义抑制效应, 语义效应发生在词汇选择阶段(344~418 ms); 当SOA为-400 ms时, 语义效应发生在概念准备阶段(0~76 ms)和词汇选择阶段(274~390 ms); 460~594 ms时间窗口内的语义效应可能表明讲话者对语义信息的自我监测。词汇产生中存在语义促进效应和抑制效应的权衡, 影响了行为结果中语义效应的方向, 上述发现支持了口语词汇产生的词汇竞争假说。     

Structural priming as structure-mapping: children use analogies from previous utterances to guide sentence production

What mechanisms underlie children’s language production? Structural priming—the repetition of sentence structure across utterances—is an important measure of the developing production system. We propose its mechanism in children is the same as may underlie analogical reasoning: structure‐mapping. Under this view, structural priming is the result of making an analogy between utterances, such that children map semantic and syntactic structure from previous to future utterances. Because the ability to map relationally complex structures develops with age, younger children are less successful than older children at mapping both semantic and syntactic relations. Consistent with this account, 4‐year‐old children showed priming only of semantic relations when surface similarity across utterances was limited, whereas 5‐year‐olds showed priming of both semantic and syntactic structure regardless of shared surface similarity. The priming of semantic structure without syntactic structure is uniquely predicted by the structure‐mapping account because others have interpreted structural priming as a reflection of developing syntactic knowledge.     

The paradox of moral focus

When we evaluate moral agents, we consider many factors, including whether the agent acted freely, or under duress or coercion. In turn, moral evaluations have been shown to influence our (non-moral) evaluations of these same factors. For example, when we judge an agent to have acted immorally, we are subsequently more likely to judge the agent to have acted freely, not under force. Here, we investigate the cognitive signatures of this effect in interpersonal situations, in which one agent (“forcer”) forces another agent (“forcee”) to act either immorally or morally. The structure of this relationship allowed us to ask questions about both the “forcer” and the “forcee.” Paradoxically, participants judged that the “forcer” forced the “forcee” to act immorally (i.e. X forced Y), but that the “forcee” was not forced to act immorally (i.e. Y was not forced by X). This pattern obtained only for human agents who acted intentionally. Directly changing participants’ focus from one agent to another (forcer versus forcee) also changed the target of moral evaluation and therefore force attributions. The full pattern of judgments may provide a window into motivated moral reasoning and focusing bias more generally; participants may have been motivated to attribute greater force to the immoral forcer and greater freedom to the immoral forcee.     

Perception and production of object-related grasping in 6-month-olds

In this study, 6-month-olds’ perception of an object-related human grasping action was compared with their level of grasping performance using a within-participants design. In the action perception task, infants were presented with the video of an actor’s grasping movement toward an occluded target object. Subsequently, an expected and an unexpected final state of this grasping movement were presented simultaneously, and infants’ looking times were measured. In the action production task, infants were presented with three graspable objects. Infants’ grasping behavior was coded to be either palmar or thumb-opposite grasping. Results indicate that infants who were already able to perform a thumb-opposite grasp differentiated between the two final states in the action perception task by looking longer toward the unexpected final state. In contrast, infants who showed only palmar grasps looked equally long toward both final states. This finding supports the assumption that action perception and action control are already closely related in infants as young as 6 months.     

The contribution of the inferior parietal cortex to spoken language production

This functional MRI study investigated the involvement of the left inferior parietal cortex (IPC) in spoken language production (Speech). Its role has been apparent in some studies but not others, and is not convincingly supported by clinical studies as they rarely include cases with lesions confined to the parietal lobe. We compared Speech with non-communicative repetitive tongue movements (Tongue). The data were analyzed with both univariate contrasts between conditions and probabilistic independent component analysis (ICA). The former indicated decreased activity of left IPC during Speech relative to Tongue. However, the ICA revealed a Speech component in which there was correlated activity between left IPC, frontal and temporal cortices known to be involved in language. Therefore, although net synaptic activity throughout the left IPC may not increase above baseline conditions during Speech, one or more local systems within this region are involved, evidenced by the correlated activity with other language regions.     

Language deficits in pre-symptomatic Huntington's disease: evidence from Hungarian

A limited number of studies have investigated language in Huntington’s disease (HD). These have generally reported abnormalities in rule-governed (grammatical) aspects of language, in both syntax and morphology. Several studies of verbal inflectional morphology in English and French have reported evidence of over-active rule processing, such as over-suffixation errors (e.g., walkeded) and over-regularizations (e.g., digged). Here we extend the investigation to noun inflection in Hungarian, a Finno-Ugric agglutinative language with complex morphology, and to genetically proven pre-symptomatic Huntington’s disease (pre-HD). Although individuals with pre-HD have no clinical, motor or cognitive symptoms, the underlying pathology may already have begun, and thus sensitive behavioral measures might reveal already-present impairments. Indeed, in a Hungarian morphology production task, pre-HD patients made both over-suffixation and over-regularization errors. The findings suggest the generality of over-active rule processing in both HD and pre-HD, across languages from different families with different morphological systems, and for both verbal and noun inflection. Because the neuropathology in pre-HD appears to be largely restricted to the caudate nucleus and related structures, the findings further implicate these structures in language, and in rule-processing in particular. Finally, the need for effective treatments in HD, which will likely depend in part on the ability to sensitively measure early changes in the disease, suggests the possibility that inflectional morphology, and perhaps other language measures, may provide useful diagnostic, tracking, and therapeutic tools for assessing and treating early degeneration in pre-HD and HD.