Fourteen-month-olds selectively search for and use information depending on the familiarity of the informant in both laboratory and home contexts.

Infants are selective in their learning from others. However, there is only very limited research on the possible factors that shape this selectivity, especially when it comes to the impact of infants' familiarity with the informant and the context. The current study investigated whether 14-month-olds preferred to receive and use information provided by an unfamiliar informant (experimenter) compared with a familiar informant (parent) and whether this pattern depended on the context (home vs. laboratory). We tested infants either in the laboratory (n = 67) or in their home (n = 70). When both informants presented a novel object with positive or negative emotions, we measured infants' gaze behavior as an indicator for information search. When infants acted on the novel object themselves, we measured their exploratory behavior as an indicator of information use. Results revealed no effect of context on infants' information search and use. Rather, we found that the familiarity of informant had distinct effects on infant attention and object exploration. Namely, infants looked longer at the unfamiliar informant across contexts, but they explored more when the familiar informant presented the object compared with when the unfamiliar informant did so. Thus, during information search, 14-month-olds paid most attention to an unfamiliar source of information. However, participants explored the objects more when they came from a familiar source than when they came from an unfamiliar one. Possible explanations for these findings are discussed.

Infant and adult pupil dilation in response to unexpected sounds.

Surprisingly occurring sounds outside the focus of attention can involuntarily capture attention. This study focuses on the impact of deviant sounds on the pupil size as a marker of auditory involuntary attention in infants. We presented an oddball paradigm including four types of deviant sounds within a sequence of repeated standard sounds to 14-month-old infants and to adults. Environmental and noise deviant sounds elicited a strong pupil dilation response (PDR) in both age groups. In contrast, moderate frequency deviants elicited a significant PDR in adults only. Moreover, a principal component analysis revealed two components underlying the PDR. Component scores differ, depending on deviant types, between age groups. Results indicate age effects of parasympathetic inhibition and sympathetic activation of the pupil size caused by deviant sounds with a high arousing potential. Results demonstrate that the PDR is a sensitive tool for the investigation of involuntary attention to sounds in preverbal children.

Infants' and adults' looking behavior does not indicate perceptual distraction for constrained modelled actions - An eye-tracking study.

When observing a novel action, infants pay attention to the model's constraints when deciding whether to imitate this action or not. Gergely et al. (2002) found that more 14-month-olds copied a model's use of her head to operate a lamp when she used her head while her hands were free than when she had to use this means because it was the only means available to her (i.e., her hands were occupied). The perceptional distraction account (Beisert et al., 2012) claims that differences between conditions in terms of the amount of attention infants paid to the modeled action caused the differences in infants' performance between conditions. In order to investigate this assumption we presented 14-month-olds (N=34) with an eye-tracking paradigm and analyzed their looking behavior when observing the head-touch demonstration in the two original conditions. Subsequently, they had the chance to operate the apparatus themselves, and we measured their imitative responses. In order to explore the perceptional processes taking place in this paradigm in adulthood, we also presented adults (N=31) with the same task. Apart from the fact that we did not replicate the findings in imitation with our participants, the eye-tracking results do not support the perceptional distraction account: infants did not statistically differ - not even tendentially - in their amount of looking at the modeled action in both conditions. Adults also did not statistically differ in their looking at the relevant action components. However, both groups predominantly observed the relevant head action. Consequently, infants and adults do not seem to attend differently to constrained and unconstrained modelled actions.