Gustaf Gredebäck

The development of joint visual attention: A longitudinal study of gaze following during interactions with mothers and strangers

Two- to 8-month-old infants interacted with their mother or a stranger in a prospective longitudinal gaze following study. Gaze following, as assessed by eye tracking, emerged between 2 and 4 months and stabilized between 6 and 8 months of age. Overall, infants followed the gaze of a stranger more than they followed the gaze of their mothers, demonstrating a stranger preference that emerged between 4 and 6 months of age. These findings do not support the notion that infants acquire gaze following through reinforcement learning. Instead, the findings are discussed with respect to the social cognitive framework, suggesting that young infants are driven by social cognitive motives in their interactions with others.

The development and neural basis of pointing comprehension

The neurological correlates of pointing comprehension in adults and 8-month-old infants are explored. Both age groups demonstrate differential activation to congruent and incongruent pointing gestures over posterior temporal areas. The functional similarity of the adult N200 and the infant P400 component suggests that they might have a common source.

Goal Directedness and Decision Making in Infants.

The term goal directed conventionally refers to either of 2 separate process types-motor processes organizing action oriented toward physical targets and decision-making processes that select these targets by integrating desire for and knowledge of action outcomes. Even newborns are goal directed in the first sense, but the status of infants as decision makers (the focus here) is unknown. In this study, 24-month-olds learned to retrieve an object from a box by pressing a button, and then the objects value was increased. After the objects subsequent disappearance, these children were more likely to press the button to try to retrieve the object than were control 24-month-olds who had learned to retrieve the object but for whom the objects value was unchanged. Such sensitivity to outcome value when selecting actions is a hallmark of decision making. However, 14- and 19-month-olds showed no such sensitivity. Possible explanations include that they had not learned the specifics of the action outcome; they had not acquired the necessary desire; or they had acquired both but did not integrate them to make a decision.

Brain activation during upright and inverted encoding of own- and other-age faces: ERP evidence for an own-age bias.

We investigated the neural processing underlying own-age versus other-age faces among 5-year-old children and adults, as well as the effect of orientation on face processing. Upright and inverted faces of 5-year-old children, adults, and elderly adults (> 75 years of age) were presented to participants while ERPs and eye tracking patterns were recorded concurrently. We found evidence for an own-age bias in children, as well as for predicted delayed latencies and larger amplitudes for inverted faces, which replicates earlier findings. Finally, we extend recent reports about an expert-sensitive component (P2) to other-race faces to account for similar effects in regard to other-age faces. We conclude that differences in neural activity are strongly related to the amount and quality of experience that participants have with faces of various ages. Effects of orientation are discussed in relation to the holistic hypothesis and recent data that compromise this view.

The development of the still-face effect: mothers do matter.

The Face-to-Face Still-Face paradigm (FFSF) has been used to investigate how infants react to stressful events. However, there is little developmental data on the FFSF effect, and whether it connects to a specific relationship (e.g., to a mother versus a stranger). This prospective longitudinal study aims to evaluate developmental changes in infant reaction to the FFSF presented by the mother or a stranger at 2, 4, 6, and 8 months of age (n=39). Results show that infant negativity was expressed less in relation to a stranger, the identity effect. Results further suggest that from 6 to 8 months of age, stranger induced protest flattens out; whereas mother induced protest decreases. The results are discussed in relation to different theories regarding infant responsiveness.

Reduced Prospective Motor Control in 10-Month-Olds at Risk for Autism Spectrum Disorder

Motor impairments are not a part of the diagnostic criteria for autism spectrum disorder (ASD) but are overrepresented in the ASD population. Deficits in prospective motor control have been demonstrated in adults and older children with ASD but have never before been examined in infants at familial risk for the disorder. We assessed the ability to prospectively control reach-to-grasp actions in 10-month-old siblings of children with ASD (high-risk group, n = 29, 13 female) as well as in a low-risk control group (n = 16, 8 female). The task was to catch a ball rolling on a curvilinear path off an inclined surface. The low-risk group performed predictive reaches when catching the ball, whereas the high-risk group started their movements reactively. The high-risk group started their reaches significantly later than the low-risk group (p = .03). These results indicate impaired prospective motor control in infants susceptible for ASD.