Browsing by Subject "synchrony"
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Item Dynamic Flexibility in Infancy: Moment-by-Moment Biobehavioral Organization and Synchrony Across System and Context(2022-06) Stallworthy, IsabellaAs humans, our sophisticated interpersonal capacities emerge from neural, biological, and behavioral systems that are intricately coordinated, both internally and with other people. However, research to date has allocated comparatively little focus to the dynamic processes of how social interactions emerge across levels of analysis, especially early in development. Second-person neuroscience (SPN) and dynamic systems approaches together offer an integrative framework for studying the development of social interactions in infancy, through quantifying flexible biobehavioral organization, interactivity within and between people, and dynamic sensitivity to context. This study builds on previous work by using a novel study design that capitalizes on the ubiquity of personal technology and leverages newly adapted methodologies for capturing the dynamic unfolding of real-time, moment-by-moment social processes. The current study quantified continuous heart rate and behavior (~360 observations per system, per person) from 44 mothers and their typically developing infants (M= 9 months) during face-to-face interaction, a perturbation (unexpected series of text messages), and recovery. Aim 1 results revealed a flexible, putative self-organizational structure for the unfolding of both infants’ behavior and their physiology, with relatively less rigid organization associated with more positive social engagement across the entire task. Results from Aim 2 found dynamic, positive linkages between infants’ parasympathetic nervous system activity and their social engagement at the subsequent second, but only while their caregiver was actively attending to them. Lastly, Aim 3 results revealed moment-by-moment parasympathetic synchrony between mothers and infants in the form of a co-regulatory feedback loop. Mothers’ parasympathetic activity positively predicted that of their infant at the subsequent second, a linkage that decreased during the task perturbation and did not fully recover upon reunion. Conversely, infant parasympathetic activity negatively predicted that of their mother at the subsequent second, a linkage that was not sensitive to social context. Together, these findings offer new ways of capturing flexibility in social interactions –through the unfolding of moment-by-moment, flexible midrange organization; cross-system linkages; and asymmetric dyadic synchrony –reflecting both stability and adjustment in the face of changing contexts. Findings from this study contribute to both basic science knowledge and potential targets for monitoring and intervention to better support adaptive social development across the lifespan.Item Effects of winter temperatures, spring degree-day accumulation, and insect population source on phenological synchrony between forest tent caterpillar and(Elsevier, 2016) Uelmen, Johnny A.; Lindroth, Richard L; Tobin, Patrick C.; Reich, Peter B; Schwartzberg, Ezra G; Raffa, Kenneth FGlobal climate change has the potential to dramatically alter multiple ecosystem processes, including herbivory. The development rates of both plants and insects are highly sensitive to temperature. Although considerable work has examined the effects of temperature on spring phenologies of plants and insects individually, few studies have examined how anticipated warming will influence their phenological synchrony. We applied elevated temperatures of 1.7 and 3.4 °C in a controlled chamberless outdoor experiment in northeastern Minnesota, USA to examine the relative responses in onset of egg eclosion by forest tent caterpillar (Malacosoma disstria Hübner) and budbreak of two of its major host trees (trembling aspen, Populus tremuloides Michaux, and paper birch, Betula papyrifera Marshall). We superimposed four insect population sources and two overwintering regimes onto these treatments, and computed degree-day models. Timing of egg hatch varied among population source, overwintering location, and spring temperature regime. As expected, the development rates of plants and insects advanced under warmer conditions relative to ambient controls. However, budbreak advanced more than egg hatch. The degree of phenological synchrony between M. disstria and each host plant was differentially altered in response to warming. The interval by which birch budbreak preceded egg hatch nearly doubled from ambient to +1.7 °C. In the case of aspen, the sequence changed from egg hatch preceding, to following, budbreak at +3.4 °C. Additionally, under temperature regimes simulating future conditions, some insect populations currently south of our study sites became more synchronous with the manipulated hosts than did currently coexisting insect populations. These findings reveal how climate warming can alter insect-host plant interactions, through changes in phenological synchrony, possibly driving host shifts among tree species and genotypes. They also suggest how herbivore variability, both among populations and within individual egg masses, may provide opportunities for adaptation, especially in species that are highly mobile and polyphagous.Item How dynamical regime and neuronal network structure influence synchronous events(2019-06) Baker, BrittanySynchronization of spiking neuronal activity plays a role in many important processes in the human body. In 2011, Zhao, Beverlin, Netoff, and Nykamp explored the relationship between synchrony and network structure by developing the SONET model where one can modulate the microstructure of the network by adjusting frequencies of pairs of directed connections between nodes, which correspond to the second order statistics of the network. We extended the SONET framework to allow for the prescription of probabilities of neuronal connections based on location to modulate spatial macrostructure. We used this spatial SONET model to explore how both network microstructure (SONET motif frequencies) and macrostructure influence the emergence of synchrony. To enable a consistent analysis of synchrony across a wide range of networks, we developed a novel measure of synchrony based on the rate of synchronous events. We discovered that the microstructure played the dominant role in shaping synchrony. Moreover, we found that the influence of the microstructure can depend on the dynamics of the inputs to the network.Item Second Order Networks with spatial structure(2016-06) Fuller, SamanthaSynchronization of spiking activity across neurons plays a role in many processes in the brain. Using the framework of Second Order Networks (SONETs) paired with a global ring structure, we looked at the relationships between the connectivity statistics and two key eigenvalue quantities related to the synchrony of the network - the largest eigenvalue of the connectivity matrix and the variance of the eigenvalues of the Laplacian. Previously, Zhao et al. (2011) examined these relationships in the case of homogeneous SONETs, in which there is no spatial variation in the network. In this work, we broaden our view to SONETs where we allow the connection probabilities to depend on the spatial structure of the network. First, we develop an algorithm to generate SONETs which allows us to specify both the global and local geometry of the network. We then randomly generated a wide range of SONETs to examine the relationships between the connectivity statistics and the eigenvalue quantities of the resulting networks. We find that two of the second order statistics, namely those corresponding to the frequency of convergent connections and to the frequency of chain connections, primarily influence the values of the two eigenvalue quantities. Our results are remarkably similar to those of the homogeneous case, indicating that the qualitative relationship we see between synchrony and second order statstics should extend to a larger class of networks. We also find that for the networks we considered, the parameters used to describe the overall geometry of the network had a minimal influence on the two key eigenvalue quantities.