When it pays off to take a look: Infants learn to follow an object’s motion with their gaze — Especially if it features eyes

Social cues and instrumental learning are two aspects potentially fostering early gaze following. We systematically investigated the influence of social features (schematic eyes vs. reverse-contrast eyes) and gaze-contingent reinforcement (elicited vs. not elicited) on 4-month-olds' learning to attend to gaze-cued objects. In 4 experiments, we tested infants' (N = 74) gaze following of a turning block with schematic or reverse-contrast eyes. In Experiments 1 and 2, infants could elicit an attractive animation in a training phase via interactive eye tracking by following the turning of the block. Experiments 3 and 4 were yoked controls without contingent reinforcement. Infants did not spontaneously follow the motion of the block. Four-month-olds always followed the block after training when it featured schematic eyes. When the block featured reverse-contrast eyes, the training phase only affected infants' looking behavior without reinforcement. While speaking to a certain degree of plasticity, findings stress the importance of eyes for guiding infants' attention

Effects of reinforcement learning on gaze following of gaze and head direction in early infancy: An interactive eye‐tracking study

The current four experiments investigated gaze following behavior in response to gaze and head turns in 4‐month‐olds and how reinforcement learning influences this behavior (N = 99). Using interactive eye tracking, infants’ gaze elicited an animation whenever infants followed a person’s head or gaze orientation (Experiment 1.1, 2.1 and 2.2) or looked at the opposite side (Experiment 1.2). Infants spontaneously followed the direction of a turning head with and without simultaneously shifted gaze direction (Cohen’s d: 0.93–1.05) but not the direction of isolated gaze shifts. We only found a weak effect of reinforcement on gaze following in one of the four experiments. Results will be discussed with regard to the impact of reinforcement on the maintenance of already existing gaze following behavior

Corrigendum: Reduced mu power in response to unusual actions is context-dependent in 1-year-olds

During social interactions infants predict and evaluate other people’s actions. Previous behavioral research found that infants’ imitation of others’ actions depends on these evaluations and is context-dependent: 1-year-olds predominantly imitated an unusual action (turning on a lamp with one’s forehead) when the model’s hands were free compared to when the model’s hands were occupied or restrained. In the present study, we adapted this behavioral paradigm to a neurophysiological study measuring infants’ brain activity while observing usual and unusual actions via electroencephalography. In particular, we measured differences in mu power (6 – 8 Hz) associated with motor activation. In a between-subjects design, 12- to 14-month-old infants watched videos of adult models demonstrating that their hands were either free or restrained. Subsequent test frames showed the models turning on a lamp or a soundbox by using their head or their hand. Results in the hands-free condition revealed that 12- to 14-month-olds displayed a reduction of mu power in frontal regions in response to unusual and thus unexpected actions (head touch) compared to usual and expected actions (hand touch). This may be explained by increased motor activation required for updating prior action predictions in response to unusual actions though alternative explanations in terms of general attention or cognitive control processes may also be considered. In the hands-restrained condition, responses in mu frequency band did not differ between action outcomes. This implies that unusual head-touch actions compared to hand-touch actions do not necessarily evoke a reduction of mu power. Thus, we conclude that reduction of mu frequency power is context-dependent during infants’ action perception. Our results are interpreted in terms of motor system activity measured via changes in mu frequency band as being one important neural mechanism involved in action prediction and evaluation from early on

From co-regulation to self-regulation: Maternal soothing strategies and self-efficacy in relation to maternal reports of infant regulation at 3 and 7 months

This study, conducted in Germany, examines the role of maternal soothing strategies to explain the association of maternal self-efficacy with infant regulation (crying and sleeping behavior). Questionnaire data of 150 mothers, living in Germany, with mixed ethnic and educational backgrounds were collected when infants were 3 and 7 months old. Two types of maternal soothing strategies were distinguished: close soothing, involving close physical and emotional contact, and distant soothing, involving physical and emotional distancing from the infant. A cross-sectional SEM at 3 months indicated that maternal self-efficacy is associated with reported infant regulation through distant soothing strategies. Low maternal self-efficacy was associated with frequent maternal use of distant soothing, which in turn was related to reported infant regulation problems, that is, non-soothability and greater crying frequency. Frequent use of close soothing was associated with reported infant sleeping behavior, that is, frequent night-time awakenings. A longitudinal SEM further indicated that the effects of close soothing persisted at least until the infants' age of 7 months. The study showed how low maternal self-efficacy, increased use of distant soothing, and reported early infant regulation problems are intertwined and that, due to their persisting positive effect on infant soothability, close soothing better supports infant development

Time reversal in thermoacoustic tomography - an error estimate

The time reversal method in thermoacoustic tomography is used for approximating the initial pressure inside a biological object using measurements of the pressure wave made on a surface surrounding the object. This article presents error estimates for the time reversal method in the cases of variable, non-trapping sound speeds.Comment: 16 pages, 6 figures, expanded "Remarks and Conclusions" section, added one figure, added reference

Consciousness, Action Selection, Meaning and Phenomenic Anticipation

Phenomenal states are generally considered the ultimate sources of intrinsic motivation for autonomous biological agents. In this article, we will address the issue of the necessity of exploiting these states for the design and implementation of robust goal-directed artificial systems. We will provide an analysis of consciousness in terms of a precise definition of how an agent "understands" the informational flows entering the agent and its very own action possibilities. This abstract model of consciousness and understanding will be based in the analysis and evaluation of phenomenal states along potential future trajectories in the state space of the agents. This implies that a potential strategy to follow in order to build autonomous but still customer-useful systems is to embed them with the particular, ad hoc phenomenality that captures the system-external requirements that define the system usefulness from a customer-based, requirements-strict engineering viewpoint