Labels as features (not names) for infant categorization: a neurocomputational approach

A substantial body of experimental evidence has demonstrated that labels have an impact on infant categorization processes. Yet little is known regarding the nature of the mechanisms by which this effect is achieved. We distinguish between two competing accounts: supervised name-based categorization and unsupervised feature-based categorization. We describe a neurocomputational model of infant visual categorization, based on self-organizing maps, that implements the unsupervised feature-based approach. The model successfully reproduces experiments demonstrating the impact of labeling on infant visual categorization reported in Plunkett, Hu, and Cohen (2008) . It mimics infant behavior in both the familiarization and testing phases of the procedure, using a training regime that involves only single presentations of each stimulus and using just 24 participant networks per experiment. The model predicts that the observed behavior in infants is due to a transient form of learning that might lead to the emergence of hierarchically organized categorical structure and that the impact of labels on categorization is influenced by the perceived similarity and the sequence in which the objects are presented. The results suggest that early in development, say before 12 months old, labels need not act as invitations to form categories nor highlight the commonalities between objects, but they may play a more mundane but nevertheless powerful role as additional features that are processed in the same fashion as other features that characterize objects and object categories.     

Perceptual Bias in Speech Error Data Collection: Insights from Spanish Speech Errors

This paper studies the reliability and validity of naturalistic speech errors as a tool for language production research. Possible biases when collecting naturalistic speech errors are identified and specific predictions derived. These patterns are then contrasted with published reports from Germanic languages (English, German and Dutch) and one Romance language (Spanish). Unlike findings in the Germanic languages, Spanish speech errors show many patterns which run contrary to those expected from bias: (1) more phonological errors occur between words than within word; (2) word-initial consonants are less likely to participate in errors than word-medial consonants, (3) errors are equally likely in stressed and in unstressed syllables, (4) perseverations are more frequent than anticipations, and (5) there is no trace of a lexical bias. We present a new corpus of Spanish speech errors collected by many theoretically naïve observers (whereas the only corpus available so far was collected by two highly trained theoretically informed observers), give a general overview of it, and use it to replicate previous reports. In spite of the different susceptibility of these methods to bias, results were remarkably similar in both corpora and again contrary to predictions from bias. As a result, collecting speech errors “in the wild” seems to be free of bias to a reasonable extent even when using a multiple-collector method. The observed contrasting patterns between Spanish and Germanic languages arise as true cross-linguistic differences.     

Processing of Syllables in Production and Recognition Tasks

Empirical evidence for a functional role of syllables in visual word processing is abundant, however it remains rather heterogeneous. The present study aims to further specify the role of syllables and the cognitive accessibility of syllabic information in word processing. The first experiment compared performance across naming and lexical decision tasks by manipulating the number of syllables in words and non-words. Results showed a syllable number effect in both the naming task and the lexical decision task. The second experiment introduced a stimulus set consisting of isolated syllabic and non-syllabic trigrams. Syllable frequency was manipulated in a naming and in a decision task requiring participants to decide on the syllabic status of letter strings. Results showed faster responses for syllables than for non-syllables in both tasks. Syllable frequency effects were observed in the decision task. In summary, the results from these manipulations of different types of syllable information confirm an important role of syllabic units in both recognition and production.     

Spoken and gestural production in a naming task by young children with Down syndrome

Lexical production in children with Down syndrome (DS) was investigated by examining spoken naming accuracy and the use of spontaneous gestures in a picture naming task. Fifteen children with DS (range 3.8-8.3 years) were compared to typically developing children (TD), matched for chronological age and developmental age (range 2.6-4.3 years). Relative to TD children, children with DS were less accurate in speech (producing a greater number of unintelligible answers), yet they produced more gestures overall and of these a significantly higher percentage of iconic gestures. Furthermore, the iconic gestures produced by children with DS accompanied by incorrect or no speech often expressed a concept similar to that of the target word, suggesting deeper conceptual knowledge relative to that expressed only in speech.     

The ghost of Christmas future: didn't Scrooge learn to be good? Commentary on Magnuson,McMurray, Tanenhaus,and Aslin (2003)

Magnuson, McMurray, Tanenhaus, and Aslin [Cogn. Sci. 27 (2003) 285] suggest that they have evidence of lexical feedback in speech perception, and that this evidence thus challenges the purely feedforward Merge model [Behav. Brain Sci. 23 (2000) 299]. This evidence is open to an alternative explanation, however, one which preserves the assumption in Merge that there is no lexical–prelexical feedback during on‐line speech processing. This explanation invokes the distinction between perceptual processing that occurs in the short term, as an utterance is heard, and processing that occurs over the longer term, for perceptual learning.     

The Wind Chilled the Spectators, but the Wine Just Chilled: Sense, Structure, and Sentence Comprehension

Anticipation plays a role in language comprehension. In this article, we explore the extent to which verb sense influences expectations about upcoming structure. We focus on change of state verbs like shatter , which have different senses that are expressed in either transitive or intransitive structures, depending on the sense that is used. In two experiments we influence the interpretation of verb sense by manipulating the thematic fit of the grammatical subject as cause or affected entity for the verb, and test whether readers' expectations for a transitive or intransitive structure change as a result. This sense-biasing context influenced reading times in the postverbal regions. Reading times for transitive sentences were faster following good-cause than good-theme subjects, but the opposite pattern was found for intransitive sentences. We conclude that readers use sense-contingent subcategorization preferences during on-line comprehension.     

Do early lexical skills predict language outcome at 3 years? A longitudinal study of French-speaking children

Early language development is considered critical for children’s adjustment in school, for social adaptation and for later educational achievement. Despite the role of children’s receptive skills as a foundation for later productive word use, receptive language skills have received surprisingly little attention. The present research extends recent work on the prediction of preschool language skills by exploring whether a decontextualized measure of lexical comprehension can account for unique variance in preschool language skills above and beyond parent report and how early such a prediction can be made. For this purpose, 65 French-speaking children have been tested at 16, 22, 29 and 36 months.The results of the current study suggest that up to the age of two, although parent reports of lexical comprehension and/or production account for a portion of variance in later receptive, productive or general language outcome, they have less predictive validity than a direct measure of early lexical comprehension. By contrast, after age two, parent reported vocabulary production is the strongest predictor of later language production skills.     

Opposite ERP effects for conscious and unconscious semantic processing under continuous flash suppression

We examined whether semantic processing occurs without awareness using continuous flash suppression (CFS). In two priming tasks, participants were required to judge whether a target was a word or a non-word, and to report whether the masked prime was visible. Experiment 1 manipulated the lexical congruency between the prime-target pairs and Experiment 2 manipulated their semantic relatedness. Despite the absence of behavioral priming effects (Experiment 1), the ERP results revealed that an N4 component was sensitive to the prime-target lexical congruency (Experiment 1) and semantic relatedness (Experiment 2) when the prime was rendered invisible under CFS. However, these results were reversed with respect to those that emerged when the stimuli were perceived consciously. Our findings suggest that some form of lexical and semantic processing can occur during CFS-induced unawareness, but are associated with different electrophysiological outcomes.     

Size matters: Bigger is faster

A largely unexplored aspect of lexical access in visual word recognition is “semantic size”—namely, the real-world size of an object to which a word refers. A total of 42 participants performed a lexical decision task on concrete nouns denoting either big or small objects (e.g., bookcase or teaspoon). Items were matched pairwise on relevant lexical dimensions. Participants' reaction times were reliably faster to semantically “big” versus “small” words. The results are discussed in terms of possible mechanisms, including more active representations for “big” words, due to the ecological importance attributed to large objects in the environment and the relative speed of neural responses to large objects.     

Early use of phonetic information in spoken word recognition: Lexical stress drives eye movements immediately

For optimal word recognition listeners should use all relevant acoustic information as soon as it comes available. Using printed-word eye tracking we investigated when during word processing Dutch listeners use suprasegmental lexical stress information to recognize words. Fixations on targets such as “OCtopus” (capitals indicate stress) were more frequent than fixations on segmentally overlapping but differently stressed competitors (“okTOber”) before segmental information could disambiguate the words. Furthermore, prior to segmental disambiguation, initially stressed words were stronger lexical competitors than noninitially stressed words. Listeners recognize words by immediately using all relevant information in the speech signal.