Comparing apples to manzanas and oranges to naranjas: A new measure of English-Spanish vocabulary for dual language learners.

The valid assessment of vocabulary development in dual-language-learning infants is critical to developmental science. We developed the Dual Language Learners English-Spanish (DLL-ES) Inventories to measure vocabularies of U.S.

From description to generalization, or there and back again.

In his target article, Yarkoni prescribes descriptive research as a potential antidote for the generalizability crisis. In our commentary, we offer four guiding principles for conducting descriptive research that is generalizable and enduring: (1) prioritize context over control; (2) let naturalistic observations contextualize structured tasks; (3) operationalize the target phenomena rigorously and transparently; and (4) attend to individual data.

(Hyper)active Data Curation: A Video Case Study from Behavioral Science.

Video data are uniquely suited for research reuse and for documenting research methods and findings. However, curation of video data is a serious hurdle for researchers in the social and behavioral sciences, where behavioral video data are obtained session by session and data sharing is not the norm. To eliminate the onerous burden of curation at the time of publication (or later), we describe best practices in data curation-where data are curated and uploaded immediately after each data collection to allow instantaneous sharing with one button press at any time.

Infants plan prehension while pivoting.

Skilled object retrieval requires coordination of the perceptual and motor systems. Coordination is especially challenging when body position is changing and visual search is required to locate the target. In three experiments, we used a "pivot paradigm" to induce changes in body position: Participants were passively pivoted 180° toward a target placed at varied locations to the left and right of the center of a reaching board.

The Multisensory Attention Assessment Protocol (MAAP): Characterizing individual differences in multisensory attention skills in infants and children and relations with language and cognition.

Multisensory attention skills provide a crucial foundation for early cognitive, social, and language development, yet there are no fine-grained, individual difference measures of these skills appropriate for preverbal children. The Multisensory Attention Assessment Protocol (MAAP) fills this need. In a single video-based protocol requiring no language skills, the MAAP assesses individual differences in three fundamental building blocks of attention to multisensory events-the duration of attention maintenance, the accuracy of intersensory (audiovisual) matching, and the speed of shifting-for both social and nonsocial events, in the context of high and low competing visual stimulation.

Assessing individual differences in the speed and accuracy of intersensory processing in young children: The intersensory processing efficiency protocol.

Detecting intersensory redundancy guides cognitive, social, and language development. Yet, researchers lack fine-grained, individual difference measures needed for studying how early intersensory skills lead to later outcomes. The intersensory processing efficiency protocol (IPEP) addresses this need.

Behavioral flexibility in learning to sit.

What do infants learn when they learn to sit upright? We tested behavioral flexibility in learning to sit-the ability to adapt posture to changes in the environment-in 6- to 9-month-old infants sitting on forward and backward slopes. Infants began with slant at 0°; then slant increased in 2° increments until infants lost balance. Infants kept balance on impressively steep slopes, especially in the forward direction, despite the unexpected movements of the apparatus.

A new twist on old ideas: how sitting reorients crawlers.

Traditionally, crawling and sitting are considered distinct motor behaviors with different postures and functions. Ten- to 12-month-old infants were observed in the laboratory or in their homes while being coaxed to crawl continuously over long, straight walkways (Study 1; N = 20) and during spontaneous crawling during free play (Study 2; N = 20). In every context, infants stopped crawling to sit 3-6 times per minute.

Postural position constrains multimodal object exploration in infants.

Recent research has revealed the important role of multimodal object exploration in infants' cognitive and social development. Yet, the real time effects of postural position on infants' object exploration have been largely ignored. In the current study, 5- to 7-month-old infants ( = 29) handled objects while placed in supported sitting, supine, and prone postures, and their spontaneous exploratory behaviors were observed.

Dynamic reaching in infants during binocular and monocular viewing.

This study examined reaching in 6-, 8-, and 10-month-olds during binocular and monocular viewing in a dynamic reaching situation. Infants were rotated toward a flat vertical board and reached for objects at one of seven positions along a horizontal line at shoulder height. Hand selection, time to contact the object, and reaching accuracy were examined in both viewing conditions.

Development of Three-Dimensional Completion of Complex Objects.

Three-dimensional (3D) object completion, the ability to perceive the backs of objects seen from a single viewpoint, emerges at around 6 months of age. Yet, only relatively simple 3D objects have been used in assessing its development. The present study examined infants' 3D object completion when presented with more complex stimuli.

On the other hand: overflow movements of infants' hands and legs during unimanual object exploration.

Motor overflow is extraneous movement in a limb not involved in a motor action. Typically, overflow is observed in people with neurological impairments and in healthy children and adults during strenuous and attention-demanding tasks. In the current study, we found that young infants produce vast amounts of motor overflow, corroborating claims of symmetry being the default state of the motor system.

Head-mounted eye tracking: a new method to describe infant looking.

Despite hundreds of studies describing infants' visual exploration of experimental stimuli, researchers know little about where infants look during everyday interactions. The current study describes the first method for studying visual behavior during natural interactions in mobile infants. Six 14-month-old infants wore a head-mounted eye-tracker that recorded gaze during free play with mothers.

Systems in development: motor skill acquisition facilitates three-dimensional object completion.

How do infants learn to perceive the backs of objects that they see only from a limited viewpoint? Infants' 3-dimensional object completion abilities emerge in conjunction with developing motor skills--independent sitting and visual-manual exploration. Infants at 4.5 to 7.

Development of three-dimensional object completion in infancy.

Three-dimensional (3D) object completion was investigated by habituating 4- and 6-month-old infants (n= 24 total) with a computer-generated wedge stimulus that pivoted 15 degrees , providing only a limited view. Two displays, rotating 360 degrees , were then shown: a complete, solid volume and an incomplete, hollow form composed only of the sides seen during habituation. There were no reliable preferences for either test display by 4-month-olds.