No abstract

The current study presents both longitudinal behavioral data and functional activation data documenting the effects of early focal brain injury on the development of spatial analytic processing in two children, one with prenatal left hemisphere (LH) injury and one with right hemisphere (RH) injury. A substantial body of evidence has shown that adults and children with early, lateralized brain injury show evidence of spatial analytic deficits. LH injury compromises the ability to encode the parts of a spatial pattern, while RH injury impairs pattern integration. The two children described in this report show patterns of deficit consistent with the site of their injury. In the current study, their longitudinal behavioral data spanning the age range from preschool to adolescence are presented in conjunction with data from a functional magnetic resonance imaging (fMRI) study of spatial processing. The activation results provide evidence that alternative profiles of neural organization can arise following early focal brain injury, and document where in the brain spatial functions are carried out when regions that normally mediate them are damaged. In addition, the coupling of the activation with the behavioral data allows us to go beyond the simple mapping of functional sites, to ask questions about how those sites may have come to mediate the spatial functions. (JINS, 2003, 9, 604–622.)

Minimising the use of animals in experiments is universally recognised by scientists, governments and advocates as an ethical cornerstone of research. Yet, despite growing public opposition to animal experimentation, mounting evidence that animal studies often do not translate to humans, and the development of new research technologies, a number of countries have reported increased animal use in recent years. In the USA--one of the world's largest users of animals in experiments--a lack of published data on the species most commonly used in laboratories (eg, mice, rats and fish) has prevented such assessments. The current study aimed to fill this gap by analysing the use of all vertebrate animals by the top institutional recipients of National Institutes of Health research funds over a 15-year period. These data show a statistically significant 72.7% increase in the use of animals at these US facilities during this time period-driven primarily by increases in the use of mice. Our results highlight a need for greater efforts to reduce animal use. We discuss technical, institutional, sociological and psychological explanations for this trend.

The effect of sentence priming on picture naming was investigated across the lifespan, from age 3 to 87 years. Names that are normally acquired before 3 years of age were presented in auditory contexts that were semantically congruent, incongruent, or neutral in relation to each picture and its name. Sentential priming was present at all age levels. Facilitation (neutral vs. congruent) was significant by 4 years of age and did not vary significantly with age. Interference (incongruent vs. neutral) was significant at all age levels, but changed nonmonotonically with age (largest in the youngest children, stable from young adulthood through age 70, with a small increase in the oldest participants). We conclude that picture naming is a useful tool for the investigation of sentential priming effects across the lifespan and that it can reveal potentially interesting developmental changes in the effects of sentential context on word retrieval.The terms language acquisition and language loss have been used to describe changes in language ability at opposite ends of the human lifespan. These terms imply discrete moments of gain or loss, with knowledge held in a constant and unchanging form across the intervening years. And yet, we know that there are continuous changes throughout the lifespan in the native speaker's ability to access and deploy this knowledge. To increase our understanding of the mechanisms responsible for this kind of developmental change, we need methods that are sensitive to variations in the timing of language use, holding linguistic knowledge constant. In the present study, we explore picture naming in a sentence context as a measure oflexical access, in subjects from 3 to 87 years ofage. Our focus is on developmental changes in the time taken by speakers to access picture names, which were words usually acquired (in the discrete and static sense) by 30 months of age.The procedure in this study was a variant of picturenaming methods that have been used by other investigators (e.g., Griffin & Bock, 1998;Potter, Kroll, Yachzel, Carpenter, & Sherman, 1986), with children as well as adults (Kail & Leonard, 1986), but it was modified for use over a broader age range than any tested before. A substantial1iterature shows that single-word contexts (visual or auditory) can facilitate or interfere with picture-naming and/or picture-viewing times (for reviews, see Duchek, Balota, Faust, & Ferraro, 1995;Glaser, 1992;Humphreys, Lloyd-Jones, & Fias, 1995;Levelt, 1992; Wheeldon & Monsell, 1994). Potter and colleagues have shown that at the sentence level, naming times are reliably faster when the picture represents a good continuation of a visual sentence context (Potter & Faulconer, 1975;Potter et al., 1986; see also Gernsbacher, 1990, for effects of context on picture-viewing times). Our own ongoing studies with young adults show that picture naming yields robust phrasal and/or sentential priming effects (Bentrovato, Devescovi, D'Amico,

A spatial/nonspatial functional dissociation between the dorsal and ventral visual pathways is well established and has formed the basis of domain-specific theories of prefrontal cortex (PFC). Inconsistencies in the literature regarding prefrontal organization, however, have led to questions regarding whether the nature of the dissociations observed in PFC during working memory are equivalent to those observed in the visual pathways for perception. In particular, the dissociation between dorsal and ventral PFC during working memory for locations versus object identities has been clearly present in some studies but not in others, seemingly in part due to the type of objects used. The current study compared functional MRI activation during delayed-recognition tasks for shape or color, two object features considered to be processed by the ventral pathway for perceptual recognition. Activation for the shape-delayed recognition task was greater than that for the color task in the lateral occipital cortex, in agreement with studies of visual perception. Greater memory-delay activity was also observed, however, in the parietal and superior frontal cortices for the shape than for the color task. Activity in superior frontal cortex was associated with better performance on the shape task. Conversely, greater delay activity for color than for shape was observed in the left anterior insula and this activity was associated with better performance on the color task. These results suggest that superior frontal cortex contributes to performance on tasks requiring working memory for object identities, but it represents different information about those objects than does the ventral frontal cortex.