Hierarchical forms processing in adults and children

Two experiments examined child and adult processing of hierarchical stimuli composed of geometric forms. Adults (ages 18-23 years) and children (ages 7-10 years) performed a forced-choice task gauging similarity between visual stimuli consisting of large geometric objects (global level) composed of small geometric objects (local level). The stimuli spatial arrangement was manipulated to assess child and adult reaction times and predisposition toward local or global form categorization under two distinct trial conditions, with varied density of the local forms comprising the global forms. In Experiment 1, children and adults were presented with common, simple geometric shape hierarchical forms composed of ovals and rectangles. In Experiment 2, adults were presented with hierarchical forms composed of the simple geometric shapes, ovals and rectangles, and additional novel complex geometric shapes, “posts” and “arches.” Results show a clear increase of global processing bias across the age ranges of the individuals in the study, with children at 10 years performing similarly to adults on the simple stimuli. In addition, adults presented with the novel complex geometric shapes showed a significant reduction in global processing bias, indicating that form novelty and complexity lead to additional attention to local features in categorization tasks.     

Two-year-olds exclude novel objects as potential referents of novel words based on pragmatics

Many studies have established that children tend to exclude objects for which they already have a name as potential referents of novel words. In the current study we asked whether this exclusion can be triggered by social-pragmatic context alone without pre-existing words as blockers. Two-year-old children watched an adult looking at a novel object while saying a novel word with excitement. In one condition the adult had not seen the object beforehand, and so the children interpreted the adult’s utterance as referring to the gazed-at object. In another condition the adult and child had previously played jointly with the gazed-at object. In this case, children less often assumed that the adult was referring to the object but rather they searched for an alternative referent - presumably because they inferred that the gazed-at object was old news in their common ground with the adult and so not worthy of excited labeling. Since this inference based on exclusion is highly similar to that underlying the Principle of Contrast/Mutual Exclusivity, we propose that this principle is not purely lexical but rather is based on children’s understanding of how and why people direct one another’s attention to things either with or without language.     

On the segmentation of Chinese words during reading

Given that there are no spaces between words in Chinese, how words are segmented when reading is something of a mystery. Four Chinese characters, which either constituted one 4-character word or two 2-character words, were shown briefly to subjects. Subjects were quite accurate in reporting the 4-character word, but could usually only report the first 2-character word, demonstrating that word segmentation influences character recognition. The results suggest that even with these simple 4-character strings, there is an element of seriality in reading Chinese words: processing is initially focused at least to some extent on the first word. We also found that the processing of characters that are not consistent with the context is inhibited, suggesting inhibition from word representations to character representations. A simple model of Chinese word segmentation and word recognition is presented to account for the data.     

Word processing in the parafoveal region

This study examined the role of words viewed in the parafoveal region during reading. In contrast to previous work, the present experiments used a reading-aloud paradigm that was postulated to encourage letter-to-sound processing, as is typical for beginning readers and for skilled readers who are reading difficult material. The three experiments in this study examined the role of orthographic and semantic information in the parafoveal region on the processing of a word in the foveal region. For this, two words, one in the foveal region and the other in the parafoveal region, were presented side by side to resemble normal reading. Participants were instructed to read aloud the word on the left side, ignoring the word on the right side. Experiments 1 and 2 showed that the presence of a word in the parafoveal region slowed naming of target words, and that this delay was attributable to linguistic interference. This pattern indicates that the information in the parafoveal region affect the processing of the target. Experiment 3 showed an effect of parafoveal semantic information on processing of the target word. In sum the results of the current study suggest that information in the parafoveal region appears to be linguistically processed but to a weaker degree than the focused word. In sum, the results of the experiments in the current study indicate that the influence of parafoveal information is quite lexical and semantic information in the parafoveal region affects processing of the target in the foveal region.     

The cerebellum and language: Evidence from patients with cerebellar degeneration

Clinical and imaging studies suggest that the cerebellum is involved in language tasks, but the extent to which slowed language production in cerebellar patients contributes to their poor performance on these tasks is not clear. We explored this relationship in 18 patients with cerebellar degeneration and 16 healthy controls who completed measures of verbal fluency (phonemic and semantic), word stem completion, and oral naming speed. Cerebellar patients showed significantly slower response times when naming common nouns, which correlated with their degree of motor impairment. Patients were significantly impaired on both phonemic and semantic fluency measures compared to controls (p < 0.001), even when naming speed was entered as a covariate (p = 0.03). On the word stem completion task, patients were significantly less accurate (p < 0.001), had more errors due to non-responses (p = 0.008), and were slower to respond (p = 0.036) than controls; group effects were significant for overall accuracy, but not response time, when the effects of naming speed were covaried (p = 0.014). These findings suggest that cerebellar patients’ poorer performance on language tasks cannot be explained solely by slower language production, and that the integrity of cerebellar-prefrontal loops might underlie poorer performance on measures of executive function in cerebellar patients.     

Changing Structures in Midstream: Learning Along the Statistical Garden Path

Previous studies of auditory statistical learning have typically presented learners with sequential structural information that is uniformly distributed across the entire exposure corpus. Here we present learners with nonuniform distributions of structural information by altering the organization of trisyllabic nonsense words at midstream. When this structural change was unmarked by low-level acoustic cues, or even when cued by a pitch change, only the first of the two structures was learned. However, both structures were learned when there was an explicit cue to the midstream change or when exposure to the second structure was tripled in duration. These results demonstrate that successful extraction of the structure in an auditory statistical learning task reduces the ability to learn subsequent structures, unless the presence of two structures is marked explicitly or the exposure to the second is quite lengthy. The mechanisms by which learners detect and use changes in distributional information to maintain sensitivity to multiple structures are discussed from both behavioral and computational perspectives.     

Wittgenstein and contemporary theories of word learning

Wittgenstein's positions on word learning, rules of use, and the impossibility of a private language, as expounded in his Philosophical Investigations, are examined in relation to issues of early child word learning. Current theoretical positions in the cognitivist mode are contrasted with the social cultural pragmatic approach, and each is compared to the principles that Wittgenstein advanced. Bloom's [(2000). How children learn the meanings of words. Cambridge, MA: MIT Press] version of the cognitivist theory rejects most of the principles that Wittgenstein advanced, relying on innate cognitive endowments to explain children's success in word learning, using the word-referent mapping paradigm. Nelson's “use without meaning” and Tomasello's [(2003). Constructing a language: A usage-based theory of language acquisition. Cambridge, MA: Harvard University Press] social-pragmatic model of learning from use are presented as representative of Wittgensteinian principles that meaning exists in and is inferred from the uses of words within communal activities (“language games” in “forms of life”).     

Dual-Route and Connectionist Models: A Step Towards a Combined Model

Current models of word recognition are mainly constructed within the frameworks of either dual-route or connectionist theories. The most important test of a word recognition model is how it succeeds in accounting for various reading behaviors. In the present paper dual-route and connectionist word recognition models are briefly described and evaluated. As a further development of these models, a combined framework is proposed. An amalgamation of the two main types of models might give a more satisfactory account of various phenomena within word recognition.     

A simple multivariate probabilistic model for preferential and triadic choices

Multidimensional probabilistic models of behavior following similarity and choice judgements have proven to be useful in representing multidimensional percepts in Euclidean and non-Euclidean spaces. With few exceptions, these models are generally computationally intense because they often require numerical work with multiple integrals. This paper focuses attention on a particularly general triad and preferential choice model previously requiring the numerical evaluation of a 2n-fold integral, wheren is the number of elements in the vectors representing the psychological magnitudes. Transforming this model to an indefinite quadratic form leads to a single integral. The significance of this form to multidimensional scaling and computational efficiency is discussed.The authors would like to thank Jean-Claude Falmagne and Norman Johnson for suggestions and advice concerning quadratic forms.     

Metalexical Awareness: Development, Methodology or Written Language? A Cross-linguistic Comparison

This study explores the ability to access word boundaries of pre-school children, using an on-line methodology (Karmiloff-Smith, Grant, Sims, Jones, & Cockle (1996). Cognition, 58, 197–219.), which has hardly been used outside English-speaking countries. In a cross-linguistic study in the Netherlands and Norway, four and five-year-old children were asked to repeat the last word every time a narrator stopped reading a story. In total 32 target-words were used, both closed and open class words, and both monosyllabic and disyllabic words. The outcomes in both countries were different from those of the original English study (Karmiloff-Smith et al., 1996): four- and five-year-olds were successful in only about 26% of the cases, whereas the success rate in the former English experiment was 75% for the younger and 96% for the older children. No differences were found between age groups and between open and closed class words. This methodology does reveal the ability to access word boundaries, but probably not because of the ease of the on-line methodology in itself, but rather because literacy introduces new representations of language, even in on-line processing. The outcomes implicate that the ability to mark word boundaries does not seem to be a valid indication of who is ready for reading.