Specifying the scope of 13-month-olds'' expectations for novel words

Recent research has documented that for infants as young as 12–13 months of age, novel words (both count nouns and adjectives) highlight commonalities among objects and, in this way, foster the formation of object categories. The current experiment was designed to capture more precisely the scope of this phenomenon. We asked whether novel words (count nouns; adjectives) are linked specifically to category-based commonalities from the start, or whether they also direct infants' attention to a wider range of commonalities, including property-based commonalities among objects (e.g. color, texture). The results indicate that by 12–13 months, (1) infants have begun to distinguish between novel words presented as count nouns versus. adjectives in fluent, infant-directed speech, and (2) infants expectations for novel words accord with this emerging sensitivity.     

Neural correlates of comprehension and production of nouns and verbs in Chinese

This paper reports a conjunction analysis between semantic relatedness judgment and semantic associate generation of Chinese nouns and verbs with concrete or abstract meanings. The results revealed a verb-specific task-independent region in LpSTG&MTG, and task-dependent activation in a left frontal region in semantic judgment and the left SMG in semantic associate production. The observation of word class effects converged on Yu, Law, Han, Zhu, and Bi (2011), but contrasted with null findings in previous reports using a lexical decision task. While word class effects in the left posterior temporal cortices have been described in previous studies of languages with rich inflectional morphology, the significance of this study lies in its demonstration of the effects in these regions in a language known to have little inflectional morphology. In other words, differential neural responses to nouns and verbs can be observed without confounding from morphosyntactic operations or contrasts between actions and objects.     

Adjectives Modulate Sensorimotor Activation Driven by Nouns

We performed three experiments to investigate whether adjectives can modulate the sensorimotor activation elicited by nouns. In Experiment 1, nouns of graspable objects were used as stimuli. Participants had to decide if each noun referred to a natural or artifact, by performing either a precision or a power reach-to-grasp movement. Response grasp could be compatible or incompatible with the grasp typically used to manipulate the objects to which the nouns referred. The results revealed faster reaction times (RTs) in compatible than in incompatible trials. In Experiment 2, the nouns were combined with adjectives expressing either disadvantageous information about object graspability (e.g., sharp) or information about object color (e.g., reddish). No difference in RTs between compatible and incompatible conditions was found when disadvantageous adjectives were used. Conversely, a compatibility effect occurred when color adjectives were combined with nouns referring to natural objects. Finally, in Experiment 3 the nouns were combined with adjectives expressing tactile or shape proprieties of the objects (e.g., long or smooth). Results revealed faster RTs in compatible than in incompatible condition for both noun categories. Taken together, our findings suggest that adjectives can shape the sensorimotor activation elicited by nouns of graspable objects, highlighting that language simulation goes beyond the single-word level.     

A common mechanism in verb and noun naming deficits in Alzheimer’s patients

We tested the ability of Alzheimer’s patients and elderly controls to name living and non-living nouns, and manner and instrument verbs. Patients’ error patterns and relative performance with different categories showed evidence of graceful degradation for both nouns and verbs, with particular domain-specific impairments for living nouns and instrument verbs. Our results support feature-based, semantic representations for nouns and verbs and support the role of inter-correlated features in noun impairment, and the role of noun knowledge in instrument verb impairment.     

A place for nouns and a place for verbs? A critical review of neurocognitive data on grammatical-class effects

It is generally held that noun processing is specifically sub-served by temporal areas, while the neural underpinnings of verb processing are located in the frontal lobe. However, this view is now challenged by a significant body of evidence accumulated over the years. Moreover, the results obtained so far on the neural implementation of noun and verb processing appear to be quite inconsistent. The present review briefly describes and critically re-considers the anatomo-correlative, neuroimaging, MEG, TMS and cortical stimulation studies on nouns and verbs with the aim of assessing the consistency of their results, particularly within techniques. The paper also addresses the question as to whether the inconsistency of the data could be due to the variety of the tasks used. However, it emerged that neither the different investigation techniques used nor the different cognitive tasks employed fully explain the variability of the data. In the final section we thus suggest that the main reason for the emergence of inconsistent data in this field is that the cerebral circuits underlying noun and verb processing are not spatially segregated, at least for the spatial resolution currently used in most neuroimaging studies.     

Semantic distance effects on object and action naming

Graded interference effects were tested in a naming task, in parallel for objects and actions. Participants named either object or action pictures presented in the context of other pictures (blocks) that were either semantically very similar, or somewhat semantically similar or semantically dissimilar. We found that naming latencies for both object and action words were modulated by the semantic similarity between the exemplars in each block, providing evidence in both domains of graded semantic effects.     

Demonstration of the shape bias without label extension

Existing shape bias research has determined that children generally extend object labels to novel instances on the basis of shape, and this typically occurs by around age 2.5. This research was conducted to further examine the nature of this bias during the second year of life, and determined that by using a more sensitive measure (novelty preference looking time) an emerging shape bias can be found as early as 14 months of age. In addition, demonstration of the shape bias in the current experiment appears to be unrelated to the 50 count noun marker.     

Neural responses to morphological, syntactic, and semantic properties of single words: an fMRI study

Dissociations in the recognition of specific classes of words have been documented in brain-injured populations. These include deficits in the recognition and production of morphologically complex words as well as impairments specific to particular syntactic classes such as verbs. However, functional imaging evidence for distinctions among the neural systems underlying these dissociations has been inconclusive. We explored the neural systems involved in processing different word classes in a functional Magnetic Resonance Imaging study, contrasting four groups of words co-varying morphological complexity (simple, monomorphemic words vs complex derived or inflected words) and syntactic class (verbs vs nouns/adjectives). Subtraction of word from letter string processing showed activation in left frontal and temporal lobe regions consistent with prior studies of visual word processing. No differences were observed for morphologically complex and simple words, despite adequate power to detect stimulus specific effects. A region of posterior left middle temporal gyrus showed significantly increased activation for verbs. Post hoc analyses showed that this elevated activation could also be related to semantic properties of the stimulus items (verbs have stronger action associations than nouns, and action association is correlated with activation). Results suggest that semantic as well as syntactic factors should be considered when assessing the neural systems involved in single word comprehension.     

Adjectives really do modify nouns: the incremental and restricted nature of early adjective acquisition

By 24 months, most children spontaneously and correctly use adjectives. Yet prior laboratory research that has studied lexical acquisition in young children reports that children up to 3-years-old map novel adjectives to object properties only in very limited situations (Child Development 59 (1988) 411; Child Development 64 (1993) 1651; Child Development 71 (2000) 649; Developmental Psychology 36 (2000) 571; Child Development 69 (1998) 1313). In Experiments 1 and 2 we introduced 36-month-olds (Experiment 1) and 24-month-olds (Experiment 2) to novel adjectives while providing rich referential and syntactic information to indicate what the novel words mean. Specifically, we used a given novel adjective to describe multiple familiar objects which shared a salient property; in addition we used the adjectives in full noun phrases, not in conjunction with pronouns. Under these conditions, both groups mapped novel adjectives onto object properties. In Experiment 3 we asked whether the rich referential information was responsible for the successful outcome of the previous two experiments; we introduced novel adjectives to 2- and 3-year-olds as in Experiments 1 and 2, but the adjectives modified nouns of vague (very general) reference ("one", or "thing"). Under these conditions the children failed. We suggest that young word learners require access to the taxonomy of the object type so that the relevant property can be identified. The taxonomically specific nouns of Experiments 1 and 2 accomplish this, whereas the more general, semantically bleached nominals in Experiment 3 do not. Taken together with related findings in the literature, these findings favor an account of lexical acquisition in which layers of information become available incrementally, as a consequence of solving prior parts of the learning problem.     

Infants use known verbs to learn novel nouns: Evidence from 15- and 19-month-olds

Fluent speakers’ representations of verbs include semantic knowledge about the nouns that can serve as their arguments. These “selectional restrictions” of a verb can in principle be recruited to learn the meaning of a novel noun. For example, the sentence He ate the carambola licenses the inference that carambola refers to something edible. We ask whether 15- and 19-month-old infants can recruit their nascent verb lexicon to identify the referents of novel nouns that appear as the verbs’ subjects. We compared infants’ interpretation of a novel noun (e.g., the dax) in two conditions: one in which dax is presented as the subject of animate-selecting construction (e.g., The dax is crying), and the other in which dax is the subject of an animacy-neutral construction (e.g., The dax is right here). Results indicate that by 19 months, infants use their representations of known verbs to inform the meaning of a novel noun that appears as its argument.