Executive performance on the preschool executive task assessment in children with sickle cell anemia and matched controls

Executive deficits are commonly reported in children with sickle cell anemia. Earlier identification of executive deficits would give more scope for intervention, but this cognitive domain has not been routinely investigated due to a lack of age-appropriate tasks normed for preschool children. In particular, information relating to patient performance on an executive task that reflects an everyday activity in the classroom could provide important insight and practical recommendations for the classroom teacher at this key developmental juncture as they enter the academic domain. The performance of 22 children with sickle cell anemia was compared to 24 matched control children on the Preschool Executive Task Assessment. Findings reveal that children with sickle cell anemia are performing poorer than their matched peers on this multi-step assessment. In particular, children with sickle cell anemia required more structured support to shift focus after a completed step, as reflected by poorer scores in the quantitative Sequencing and Completion domains. They also required more support to stay on task, as seen by poorer ratings in the qualitative Distractibility domain.

Abbreviations:PETA: Preschool Executive Task Assessment; SCA: Sickle Cell Anemia; EF: Executive Functioning.     

A color-contingent prism displacement aftereffect

Observers were trained to point with feedback to red and blue dots whose images had been laterally displaced in opposite directions by a reversible prism. On pretraining and posttraining trials the red and blue dots were aligned vertically in the absence of visual orientation cues. The alignment was modified by the pointing training on the posttraining trials. The colors were aligned in the direction of their prior prismatic displacement. One control experiment showed that the alignment aftereffect requires feedback during the pointing task. Another experiment in which observers pointed to the red and blue dots with opposite arms showed that pointing to both dots with the same arm was necessary to produce the alignment aftereffect. Changes in the perceived position of objects in the visual field occur when changes in perceived limb position cannot compensate for a sensorimotor conflict. Eye torsion or fixation displacements are proposed as alternative mechanisms mediating the aftereffect.     

Accent trumps race in guiding children's social preferences

A series of experiments investigated the effect of speakers' language, accent, and race on children's social preferences. When presented with photographs and voice recordings of novel children, 5-year-old children chose to be friends with native speakers of their native language rather than foreign-language or foreign-accented speakers. These preferences were not exclusively due to the intelligibility of the speech, as children found the accented speech to be comprehensible, and did not make social distinctions between foreign-accented and foreign-language speakers. Finally, children chose same-race children as friends when the target children were silent, but they chose other-race children with a native accent when accent was pitted against race. A control experiment provided evidence that children's privileging of accent over race was not due to the relative familiarity of each dimension. The results, discussed in an evolutionary framework, suggest that children preferentially evaluate others along dimensions that distinguished social groups in prehistoric human societies.     

Spectral weights and the profile bowl

In these experiments, listeners detected changes in the shape of a complex spectrum that varied in overall level. With multicomponent complexes, a typical finding is that the listeners were more sensitive to changes made in the middle components of the spectrum than to changes made at either edge. We used a technique developed by Berg (1989) to estimate the weight listeners attached to the different components of the spectrum in making these judgements. For reasons not understood, the pattern of spectral weights was nearly optimum for a change made in the middle component of the spectrum and much poorer when the change occurred at either edge.