Giuseppe Leonardi

• PhD
• Dean at Vizja University

This book introduces techniques developed in physics and physiology for characterizing and analyzing patterns in time series data to a broad audience of social scientists. In contrast to time-series regression and related techniques, recurrence quantification analysis (RQA) has its background in chaos and nonlinear dynamical systems—theory arguably...

The current article introduces lagged multidimensional recurrence quantification analysis. The method is an extension of multidimensional recurrence quantification analysis and allows to quantify the joint dynamics of multivariate time series and to investigate leader–follower relationships in behavioral and physiological data. Moreover, the method...

The process by which infants move from liquid feeding to caregiver-assisted spoon feeding of semi-solid food is quite a dramatic transition. In previous studies, we observed that in the weeks after the introduction to solid food, mother-infant dyads showed increased co-regulation and synchronization of their respective feeding behaviors (e.g. offer...

Fractal properties in time series of human behavior and physiology are quite ubiquitous, and several methods to capture such properties have been proposed in the past decades. Fractal properties are marked by similarities in statistical characteristics over time and space, and it has been suggested that such properties can be well-captured through...

Recurrence quantification analysis is a widely used method for characterizing patterns in time series. This article presents a comprehensive survey for conducting a wide range of recurrence-based analyses to quantify the dynamical structure of single and multivariate time series, and to capture coupling properties underlying leader-follower relatio...

In this article, we note that despite being a multimodal phenomenon, turn-taking has still been investigated mostly as being unimodal. Based on theoretical positions emphasizing that communication is organized jointly by interaction partners, we identify the challenge of assessing human sequential behavior that is (a) spread across different modali...

This paper provides a practical, hands-on introduction to cross-recurrence quantification analysis (CRQA), diagonal cross-recurrence profiles (DCRP), and multidimensional recurrence quantification analysis (MdRQA) in R. These methods have enjoyed increasing popularity in the cognitive and social sciences since a recognition that many behavioral and...

In this work, I propose a new method for the computation of informational entropy from Recurrence Plots when the analyzed time series are categorical in nature. In such cases, there is typically a simplification in choosing the parameters of the analysis, in the sense that no embedding in multidimensional space is usually assumed and that recurrenc...

Recurrence plots (RPs) have proved to be a very versatile tool to analyze temporal dynamics of time series data. However, it has also been conjectured that RPs can be used to model samples of random variables, that is, data that do not contain any temporal dependencies. In the current paper, we show that RPs can indeed be used to mimic nonparametri...

The analysis of parent-child interactions is crucial for the understanding of early human development. Manual coding of interactions is a time-consuming task, which is a limitation in many projects. This becomes especially demanding if a frame-by-frame categorization of movement needs to be achieved. To overcome this, we present a computational app...

Dynamical systems approaches to social coordination underscore how participants' local actions give rise to and maintain global interactive patterns and how, in turn, they are also shaped by them. Developmental research can deliver important insights into both processes: (1) the stabilization of ways of interacting, and (2) the gradual shaping of t...

A growing number of studies attest to the role of social interaction for the development of infants’ preverbal vocalizations. Warlaumont et al. (2014) suggest a social feedback loop reinforcing infants’ own communicative acts. Goldstein et al. (2009) have shown that phonological properties of infants’ vocalizations are socially guided and Gros-Loui...

Continuous interaction of mother and infant in the first weeks and months of an infant's life entrains the infant on many crucial aspects of how to do things together. Contingencies of gaze, vocalizations, and other movements are slowly routinized; this scaffolds directing of attention to each other and the world and gives to such multimodal intera...

Gaze is one of the first and most important means of communication and coordination in parent–infant dyads. In the present paper we used a novel method, designed to discover patterns in time-series, to investigate the dynamics of gaze in dyads and its developmental change. Using a longitudinal corpus of natural interactions, mutual mother–infant ga...

Although observable behavior happens in time, its actual temporal unfolding has only recently come under closer scrutiny. This focus on time and timing highlights the dynamical connection of the elements giving rise to observable behaviors and to cognition in general, shows their multiple temporal scales, and points out to the fact that they are ra...

Conceptual recurrence analysis is a promising new tool for the study of the dynamics of communication. By taking a dynamical perspective on discourse production and comprehension, we present preliminary results showing how conceptual recurrence can be used to characterize texts at different levels of reading difficulty.

In the last decade we witness an increase in approaching issues in language, and more generally, cognition, from a dynamical standpoint. This theoretical shift necessitates new research methods and statistical / analytical tools. Some of these tools gain popularity and are being applied to language in many of its multifaceted perspectives. Recurren...

This study was aimed at identifying the impaired attentional components in patients who had sustained a severe CHI several years before. A group of 14 CHI patients and a Control group (matched for age, sex and education) were tested. Experiment 1 used a dual-task paradigm (Umiltà et al., 1992). The double task-single task difference was greater for...