Alex Grillo

Manual interactions with objects appear early in infancy and are the primary way infants gain information about the world, but these interactions change with postural development. With each novel posture, infants gradually learn about and more readily adapt to the relationship between their new body position and the wider space. In the current study, we investigate how learning to stand affects infants’ manual interactions. We ask, do infants modify their manual interactions with objects when trying to stand while hindered or assisted? Participants will be infants who are capable of standing while leaning on an object (novice standers) or who can stand on their own for at least 20 seconds (experienced standers). So far, we have collected data from 10 infants. Infants were prompted to manipulate an interactive toy on an infant-sized table in three 1- to 2-minute standing conditions: control, supported (infant placed in a standing harness), and hindered (infant stood on foam flooring at a “wobbly” table). Sessions were video-recorded and synchronized for coding in Datavyu. We coded infants’ hand use (e.g., unimanual, bimanual) and manual exploratory behaviors: no contact with the object, rudimentary exploration (e.g., banging, slapping), or sophisticated exploration (e.g., fingering, pushing buttons). We used non-parametric Freidman and Wilcoxon tests to assess differences in manual behaviors within and between conditions. Preliminary analyses from the current sample of 10 infants revealed in all conditions, rudimentary and sophisticated behaviors were the most commonly displayed (ps < .05). However, no contact was displayed significantly more in the control and supported conditions compared to the hindered condition (ps < .05). Rudimentary manual exploration was more commonly displayed in the hindered condition compared to the control (p < .05). All other forms of manual exploration were similar across conditions. In all conditions, infants displayed significantly more unimanual than bimanual behaviors (ps <.05). These results suggest infants’ manual interactions with objects are affected when standing upright becomes more difficult. Gains in postural experience may help infants better control their body and adapt to environmental demands. This could impact object interactions, a main strategy of information gathering, leading to differences in learning opportunities.