The impact of novel labels on visual processing during infancy

The impact of novel labels on visual processing was investigated across two experiments with infants aged between 9 and 21 months. Infants viewed pairs of images across a series of preferential looking trials. On each trial, one image was novel, and the other image had previously been viewed by the infant. Some infants viewed images in silence; other infants viewed images accompanied by novel labels. The pattern of fixations both across and within trials revealed that infants in the labelling condition took longer to develop a novelty preference than infants in the silent condition. Our findings contrast with prior research by Robinson and Sloutsky (e.g., Robinson & Sloutsky, 2007a ; Sloutsky & Robinson, 2008 ) who found that novel labels did not disrupt visual processing for infants aged over a year. Provided that overall task demands are sufficiently high, it appears that labels can disrupt visual processing for infants during the developmental period of establishing a lexicon. The results suggest that when infants are processing labels and objects, attentional resources are shared across modalities.     

Pregnancy-specific stress, prenatal health behaviors, and birth outcomes

OBJECTIVE: Stress in pregnancy predicts earlier birth and lower birth weight. The authors investigated whether pregnancy-specific stress contributes uniquely to birth outcomes compared with general stress, and whether prenatal health behaviors explain this association. DESIGN: Three structured prenatal interviews (N = 279) assessing state anxiety, perceived stress, life events, pregnancy-specific stress, and health behaviors. MAIN OUTCOME MEASURES: Gestational age at delivery, birth weight, preterm delivery (<37 weeks), and low birth weight (<2,500 g). RESULTS: A latent pregnancy-specific stress factor predicted birth outcomes better than latent factors representing state anxiety, perceived stress, or life event stress, and than a latent factor constructed from all stress measures. Controlling for obstetric risk, pregnancy-specific stress was associated with smoking, caffeine consumption, and unhealthy eating, and inversely associated with healthy eating, vitamin use, exercise, and gestational age at delivery. Cigarette smoking predicted lower birth weight. Clinically-defined birth outcomes were predicted by cigarette smoking and pregnancy-specific stress. CONCLUSION: Pregnancy-specific stress contributed directly to preterm delivery and indirectly to low birth weight through its association with smoking. Pregnancy-specific stress may be a more powerful contributor to birth outcomes than general stress.     

TSUNAMI: Simultaneous Understanding,Answering, and Memory Interaction for Questions

Question processing involves parsing, memory retrieval, question categorization, initiation of appropriate answer-retrieval heuristics, answer formulation, and output. Computational and psychological models have traditionally treated these processes as separate, sequential, independent, and in pursuit of a single answer type at a time. Here this view is challenged and the implications of a theory in which question processes operate simultaneously on multiple question interpretations are explored. A highly interactive model is described in which an expectation-driven parser generates multiple question candidates, including partially-specified candidates. Question candidates act as constraints for a matcher which activates memory items. An answer retrieval process examines question candidates and the active portions of memory in an attempt to generate answer candidates. Answer candidates are examined by an output process that derives the final answer. These processes run simultaneously and interact. Three experiments on human question answering are also described which provide evidence that working memory load during question reading is affected by processes related to answer retrieval.