The impact of ignoring multiple membership data structures in multilevel models

This study compared the use of the conventional multilevel model (MM) with that of the multiple membership multilevel model (MMMM) for handling multiple membership data structures. Multiple membership data structures are commonly encountered in longitudinal educational data sets in which, for example, mobile students are members of more than one higher-level unit (e.g., school). While the conventional MM requires the user either to delete mobile students' data or to ignore prior schools attended, MMMM permits inclusion of mobile students' data and models the effect of all schools attended on student outcomes. The simulation study identified underestimation of the school-level predictor coefficient, as well as underestimation of the level-two variance component with corresponding overestimation of the level-one variance when multiple membership data structures were ignored. Results are discussed along with limitations and ideas for future MMMM methodological research as well as implications for applied researchers.     

The importance of "what": Infants use featural information to index events

Dynamic spatial indexing is the ability to encode, remember, and track the location of complex events. For example, in a previous study, 6-month-old infants were familiarized to a toy making a particular sound in a particular location, and later they fixated that empty location when they heard the sound presented alone (Journal of Experimental Psychology: General, 2004, Vol. 133, pp. 46-62). The basis and developmental trajectory of this ability are currently unclear. We investigated dynamic spatial indexing across the first year after birth and tested the hypothesis that the structure of visual cues supports infants' learning of sound and location associations. In our study, 3-, 6-, and 10-month-olds were tested in a dynamic spatial indexing eye movement paradigm that paired two sounds with two locations. In one condition, these were reliably paired with two sets of visual features (two toys condition), replicating the original studies. We also presented a single set of visual cues in both locations (one toy condition) and multiple sets of visual features in both locations (six toys condition). Infants from 3months of age onward showed evidence of dynamic spatial indexing in the two toys condition, but only the 10-month-olds succeeded in the one toy and six toys conditions. We argue that this may reflect a broader developmental trajectory, whereby infants first make use of multiple cue integration but with age are able to learn from a narrow set of cues.     

Sound support: intermodal information facilitates infants' perception of an occluded trajectory

In a visual occlusion task, 4-month-olds were given a dynamic sound cue (following the trajectory of an object), or a static cue (sound remained stationary). Infants' oculomotor anticipations were greater in the Dynamic condition, suggesting that representations of visual occlusion were supported by auditory information.     

Early Caregiver–Child Interaction and Children’s Development: Lessons from the St. Petersburg-USA Orphanage Intervention Research Project

Clinical Child and Family Psychology Review - We review a series of interrelated studies on the development of children residing in institutions (i.e., orphanages) in the Russian Federation or...