Flexibility and development of mirroring mechanisms

The empirical support for the SCM is mixed. We review recent results from our own lab and others supporting a central claim of SCM that mirroring occurs at multiple levels of representation. By contrast, the model is silent as to why human infants are capable of showing imitative behaviours mediated by a mirror system. This limitation is a problem with formal models that address neither the neural correlates nor the behavioural evidence directly

Spatial Attention to Social Cues is not a Monolithic Process

Social stimuli are a highly salient source of information, and seem to possess unique qualities that set them apart from other well-known categories. One characteristic is their ability to elicit spatial orienting, whereby directional stimuli like eyegaze and pointing gestures act as exogenous cues that trigger automatic shifts of attention that are difficult to inhibit. This effect has been extended to non-social stimuli, like arrows, leading to some uncertainty regarding whether spatial orienting is specialized for social cues. Using a standard spatial cueing paradigm, we found evidence that both a pointing hand and arrow are effective cues, but that the hand is encoded more quickly, leading to overall faster responses. We then extended the paradigm to include multiple cues in order to evaluate congruent vs. incongruent cues. Our results indicate that faster encoding of the social cue leads to downstream effects on the allocation of attention resulting in faster orientin

A Method for Measuring Dynamic Respiratory Sinus Arrhythmia (RSA) in Infants and Mothers

The measurement of respiratory sinus arrythmia (RSA) in infants, children and adults is critical to the study of physiological regulation, and more recently, interpersonal physiological covariation, but it has been impeded by methods that limit its resolution to 30 s or longer. Recent analytical developments have suggested methods for studying dynamic RSA in adults, and we have extended this work to the study of infants and mothers. In the current paper, we describe a new analytical strategy for estimating RSA time series for infants and adults. Our new method provides a means for studying physiological synchrony in infant-mother dyads that offers some important advantages relative to existing methods that use inter-beat-intervals (e.g. Feldman, Magori-Cohen, Galili, Singer, & Louzoun, 2011). In the middle sections of this paper, we offer a brief tutorial on calculating RSA continuously with a sliding window and review the empirical evidence for determining the optimal window size. In order to confirm the reliability of our results, we briefly discuss testing synchrony by randomly shuffling the dyads to control for spurious correlations, and also by using a bootstrapping technique for calculating confidence intervals in the cross-correlation function. One important implication that emerges from applying this method is that it is possible to measure both positive and negative physiological synchrony and that these categorical measures are differentially predictive of future outcomes

Associations between acoustic features of maternal speech and infants’ emotion regulation following a social stressor

Caregiver voices may provide cues to mobilize or calm infants. This study examined whether maternal prosody predicted changes in infants’ biobehavioral state after the still face, a stressor in which the mother withdraws and reinstates social engagement. Ninety-four dyads participated in the study (infant age 4–8 months). Infants’ heart rate and respiratory sinus arrhythmia (measuring cardiac vagal tone) were derived from an electrocardiogram (ECG). Infants’ behavioral distress was measured by negative vocalizations, facial expressions, and gaze aversion. Mothers’ vocalizations were measured via a composite of spectral analysis and spectro-temporal modulation using a two-dimensional fast Fourier transformation of the audio spectrogram. High values on the maternal prosody composite were associated with decreases in infants’ heart rate (β = −.26, 95% CI: [−0.46, −0.05]) and behavioral distress (β = −.23, 95% CI: [−0.42, −0.03]), and increases in cardiac vagal tone in infants whose vagal tone was low during the stressor (1 SD below mean β = .39, 95% CI: [0.06, 0.73]). High infant heart rate predicted increases in the maternal prosody composite (β = .18, 95% CI: [0.03, 0.33]). These results suggest specific vocal acoustic features of speech that are relevant for regulating infants’ biobehavioral state and demonstrate mother–infant bi-directional dynamics

Is automatic imitation a specialized form of stimulus–response compatibility? Dissociating imitative and spatial compatibilities

In recent years research on automatic imitation has received considerable attention because it represents an experimental platform for investigating a number of inter-related theories suggesting that the perception of action automatically activates corresponding motor programs. A key debate within this research centers on whether automatic imitation is any different than other long-term S-R associations, such as spatial stimulus-response compatibility. One approach to resolving this issue is to examine whether automatic imitation shows similar response characteristics as other classes of stimulus-response compatibility. This hypothesis was tested by comparing imitative and spatial compatibility effects with a two alternative forced-choice stimulus-response compatibility paradigm and two tasks: one that involved selecting a response to the stimulus (S-R) and one that involved selecting a response to the opposite stimulus (OS-R), i.e., the one not presented. The stimulus for both tasks was a left or right hand with either the index or middle finger tapping down. Speeded responses were performed with the index or middle finger of the right hand in response to the finger identity or the left-right spatial position of the fingers. Based on previous research and a connectionist model, we predicted standard compatibility effects for both spatial and imitative compatibility in the S-R task, and a reverse compatibility effect for spatial compatibility but not for imitative compatibility in the OS-R task. The results from the mean response times, mean percentage of errors, and response time distributions all converged to support these predictions. A second noteworthy result was that the recoding of the finger identity in the OS-R task required significantly more time than the recoding of the left-right spatial position, but the encoding time for the two stimuli in the S-R task was equivalent. In sum, this evidence suggests that the processing of spatial and imitative compatibility is dissociable with regard to two different processes in dual processing models of stimulus-response compatibility

Chapter to appear in Data Analytic Techniques for Dynamical Systems,

What is a dynamical system? In simple terms, it is a means to describe the temporal unfolding of a system. It is concerned with two fundamental concepts, change and time. For example, a psychological process, such as memory or cognitive development, unfolds by progressing through a series of discrete states that occurs over time. Every dynamical model has time as a variable, although it is often represented implicitly (Ward, 2002). In more formal terms, a simple dynamical model is a differential equation, such as the following simple linear one dx/dt=at. A somewhat more complex model involves feedback, dx/dt=ax-bx 2, which provides a mechanism by which the system can self organize. (In this latter example,-bx 2 is a negative term and will decrease the rate of change of x at an accelerating rate as x gets larger.) Mathematics is the language of dynamical systems, which is both a strength and a weakness for the psychological sciences. Although the study of dynamical systems has had a long and venerable history in the physical sciences (Abraham, Abraham, & Shaw, 1992), it has yet to have a major impact in the psychological sciences. This seems somewhat paradoxical given tha

Effortful Control of Attention and Executive Function in Preschool Children

Attention is widely considered a core process of Executive Function (EF), but it is not clear if it is a separable or integral component of EF in preschool children. Preschool children (n=137) completed a battery of tasks which included EF (i.e., response inhibition, working memory) and attentional control (AC) processes (i.e., sustained attention, selective attention). Confirmatory Factor Analyses (CFA) indicated that a two-factor model with EF and AC as separate factors fit the data better than a unitary one-factor model. These findings are consistent with the view that EF and AC are developing at different rates during the preschool years, and thus are not yet fully integrated in the processing of information. The implications of how EF and AC should be conceptualized in early childhood are discussed

A Gaze-Contingent Paradigm for Studying Infants’ Social Attention

Presentation given at 2012 IEEE International Conference on Development and Learning and Epigenetic Robotics (ICDL