Attention and social functioning in children with malformations of cortical development and stroke

Attention and social functioning and their interrelationships have not been routinely examined in children with early brain insult (EBI). This study aimed to describe attention and social functioning in children with two types of EBI: malformations of cortical development (MCD) and stroke. Children diagnosed with MCD (n = 14, 6 males) or stroke (n = 14, 8 males) aged 8 to 14 years (M = 12 years 11 months) completed neuropsychological assessments to examine attention processes. Primary caregivers completed a questionnaire to assess executive components of children's attention and teachers completed a questionnaire to measure children's social functioning. Brain scans (MRI or CT) were coded by a pediatric neuroradiologist. Higher rates of impairments in attention and social function were found in children with EBI compared with normative expectations. Children with MCD experienced more global and clinically significant levels of impairment than children with stroke; though impairments were present in both groups. A strong association between executive components of attention and social function was observed. In addition, complex attention processes were associated with social function. The findings emphasize the reciprocity between attention, behavior and social outcomes, and the vulnerability of social function following EBI.     

Seeing What We Know, Knowing What We See: Challenging the Limits of Visual Acuity

Ageism has resulted in overstated expectations regarding the inevitable deterioration in human capabilities, such as visual perception, with age (Rowe and Kahn in Science, 237, 143?C149, 1987; Grant in Health and Social Work, 21, 9?C15, 1996). Human visual perception, however, is of a largely constructive nature, evidenced in the complementary interactions between top-down inputs (e.g., expectations) and bottom-up stimuli (Engel et al. in National Review of Neuroscience, 2(10), 704?C716, 2001; Miller and Cohen in, Annual Review of Neuroscience, 24, 167-202, 2001). Based on this constructive nature, we hypothesized that visual perception may be better than is typically expected. In three experiments, we demonstrated the malleability of visual acuity using a conditioning procedure involving manipulations in bottom-up stimuli. Experimental groups read a book excerpt with one letter in decreased font size, while the control groups read the same book excerpt with all letters in the same font size. Experiment 1 (N?=?112) examined whether visual acuity could be enhanced for a specific letter. Experiment 2 (N?=?70) assessed whether visual acuity could be enhanced for a non-conditioned letter, while Experiment 3 (N?=?108) evaluated whether the visual conditioning effects would transfer to all non-conditioned letters. Visual acuity for experimental groups was significantly better than that in the control groups, speaking to the general malleability of our visual sense.     

Bilingualism: consequences for mind and brain

Building on earlier evidence showing a beneficial effect of bilingualism on children's cognitive development, we review recent studies using both behavioral and neuroimaging methods to examine the effects of bilingualism on cognition in adulthood and explore possible mechanisms for these effects. This research shows that bilingualism has a somewhat muted effect in adulthood but a larger role in older age, protecting against cognitive decline, a concept known as 'cognitive reserve'. We discuss recent evidence that bilingualism is associated with a delay in the onset of symptoms of dementia. Cognitive reserve is a crucial research area in the context of an aging population; the possibility that bilingualism contributes to cognitive reserve is therefore of growing importance as populations become increasingly diverse.     

The learning of visually guided action: An information-space analysis of pole balancing

In cart-pole balancing, one moves a cart in 1 dimension so as to balance an attached inverted pendulum. We approached perception-action and learning in this task from an ecological perspective. This entailed identifying a space of informational variables that balancers use as they perform the task and demonstrating that they improve by traversing the space to the loci of more useful variables. We presented a novel information space-including fractional derivatives of pendulum angle (e.g., halfway between angle and angular velocity)-as possible information for balancing. Fourteen college students tried to meet a criterion of balancing the pole for 30 s on 3 of 5 successive trials, up to a maximum of 150 attempts. Loci in the fractional derivative space predicted the time series of force production well. Systematic differences were seen in loci as a function of success, and systematic changes in locus were seen with learning. The fractional derivatives were shown to predict pole angles a short time interval into the future, allowing balancers to prospectively control the action and thereby nullify visuomotor delay. In addition to loci in the information space, we analyzed loci in a calibration space, reflecting the gain relating force to information. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

A rational analysis of the acquisition of multisensory representations

How do people learn multisensory, or amodal, representations, and what consequences do these representations have for perceptual performance? We address this question by performing a rational analysis of the problem of learning multisensory representations. This analysis makes use of a Bayesian nonparametric model that acquires latent multisensory features that optimally explain the unisensory features arising in individual sensory modalities. The model qualitatively accounts for several important aspects of multisensory perception: (a) it integrates information from multiple sensory sources in such a way that it leads to superior performances in, for example, categorization tasks; (b) its performances suggest that multisensory training leads to better learning than unisensory training, even when testing is conducted in unisensory conditions; (c) its multisensory representations are modality invariant; and (d) it predicts ‘‘missing” sensory representations in modalities when the input to those modalities is absent. Our rational analysis indicates that all of these aspects emerge as part of the optimal solution to the problem of learning to represent complex multisensory environments.     

The Role of Structure Versus Individual Agency in Churches�� Responses to HIV/AIDS: A Case Study of Baltimore City Churches

This paper examines the activities of churches in Baltimore, Maryland, concerning the issues of sexuality, whether they potentially stigmatize persons with or at risk for HIV/AIDS, and to what extent individual agency versus institutional forces influence churches in this regard. In-depth interviews were conducted with 20 leaders from 16 churches and analyzed using a grounded theory methodology. Although many churches were involved in HIV/AIDS-related activities, the content of such initiatives was sometimes limited due to organizational constraints. Church leaders varied, however, in the extent to which they responded in accordance with or resisted these constraints, highlighting the importance of individual agency influencing churches?? responses to HIV/AIDS.     

Generalization gradients in human predictive learning: Effects of discrimination training and within-subjects testing

Generalization gradients have been investigated widely in animal conditioning experiments, but much less so in human predictive learning tasks. Here, we apply the experimental design of a recent study on conditioned fear generalization in humans (Lissek et al., 2008) to a predictive learning task, and examine the effects of a number of relevant procedural parameters drawn from the generalization literature in animal conditioning. Experiment 1 shows that prior discrimination learning and steady-state testing procedures sharpen the gradient; Experiment 2 shows that within-subjects testing of the range of generalization stimuli also sharpens the gradient. In addition, Experiment 2 shows that, in case of very flat initial generalization, an orderly gradient can reveal itself through differential rates of extinction learning. Finally, Experiment 2 also evidenced an orderly gradient of generalization-of-extinction. These results suggest that discrimination processes have an important effect on the generalization of predictive learning in humans, and highlight behavioral analogies between animal conditioning and human predictive learning.