https://www.selleckchem.com/products/bovine-serum-albumin.html In this study, we explored whether variability in children's physiological reactivity-respiratory sinus arrhythmia and electrodermal activity-predict concurrent and subsequent levels of children's observed help-seeking (HS) from their mothers during a failure task. In addition, we tested whether children's perceptions of maternal positivity pre-task (CPMP) and children's fearful temperament moderate these effects. In a community sample of 101 mother-child dyads, children (8-12 years of age) underwent a repeated failure task while their respiratory sinus arrythmia and electrodermal activity were monitored; their HS behaviors were later coded. Multilevel path analyses indicated that high-fearful children increased their HS at the same time as and following increased physiological reactivity regardless of CPMP pre-task. Low-fearful children showed increases in HS at the same time as and following increased physiological reactivity only when they perceived their mothers' affect to be positive. This study demonstrates children's individual differences in the physiological underpinning of time-linked HS behaviors.The light-from-above prior enables observers to infer an object's three-dimensional shape-from-shading information. Young, Western adults implicitly assume the light source is placed not only above, but also to the left of, the observer. Previous evidence reached conflicting conclusions regarding the development of the assumed light source direction. In the present study, we measured the light source prior cross-sectionally in children aged 5-11 years, using an explicit shape judgement task. The light-from-above prior, and the left bias, were present as soon as children became sensitive to shading information, regardless of their age. Global processing preference was not related to the ability to perform the task. Similarly, scanning habits, as measured by reading proficiency and starting position in