Research Interests

Broadly speaking, my research investigates the underpinnings of perception-action processes and interpersonal coordination. This work is motivated by a long-standing interest in embodied cognition and the realization that the body constitutes the necessary interface between mental processes and events taking place in the environment. I study perception-action processes at different scales spanning individuals, dyads, and small groups through the use of behavioral paradigms that capture discrete responses and changes in online performance (e.g., movement kinematics, postural control, eye-tracking, finger tapping, and drumming). The methodological tools I apply in my work are varied; I use from traditional psychophysics and experimental techniques to non-linear time-series analyses (e.g., cross-recurrence quantification, fractal scaling, principle components analyses). While I have investigated mainly young adults, I also have experience working with developmental and clinical populations (adolescents and adults with autism, and dementia patients).

Action Perception and Prediction

In one line of research, I investigate the informational bases of our ability to predict other people’s possibilities for action. Several of the projects I have conducted are representative of this work. I have determined that we can predict the action boundaries of others by detecting changes in their movement kinematics; specifically, perceivers can estimate a walker's jumping abilities by watching their encumbered or unencumbered walking (Ramenzoni et al, 2008b). Follow-up findings showed that learning to perceive what others can do depends on the nature of the kinematic information available; we learn by watching others perform related but not irrelevant actions (Ramenzoni et al., 2010). I have also found that predicting other’s actions is influenced by changes in the perceiver’s fit with the environment (i.e., optic array: Ramenzoni et al, 2008c) and, most surprisingly, in the perceiver’s own action capabilities (i.e., encumbering the perceiver leads them to perceive other people as less capable jumpers; Ramenzoni et al, 2008a).

Action-Scaling & Body-Scaling

The notion of action scaling proposes that our perception of the environment (and the agents and objects that populate it) is contingent on our ability to act within it. In a collaboration project with Sally Linkenauger (Linkenauger, Ramenzoni, & Proffitt, 2010), we expanded on this idea by demonstrating that changes in object size are experienced in terms of the perceiver’s own body: a magnified object is perceived as shrinking when the perceiver places his/her hand next to it, but not when a familiar object or somebody else’s hand is placed by it. In an extension of this work to individuals within the Autism Spectrum Disorder (Linkenauger et al., 2012), we showed that ADS adults and adolescents have marked difficulties in estimating their action boundaries for the performance of simple actions, such as reaching, grasping, and fitting their hands through an aperture. More recently (with Ulf Liszkowski, under review), I have explored the developmental underpinnings of social perception-action abilities in 8-month-old infants—before the ‘social revolution’ and the emergence of triadic attention. The study found that infants take into account information about the possibilities of action of others in planning their own reaching actions, which suggest an early developmental trajectory for social perception-action abilities. Combined with my previous work, these results strengthen the possibility that information about our fit and other people’s fit with the environment might be at the roots of our ability to enter and maintain social interactions. In the future, I intend to continue building on this work by investigating whether individuals with ADS (particularly high functioning Asperger) can detect information about other people’s possibilities for action and whether difficulties in social perception help account for some of the symptomatology currently associated with the disorder.

Interpersonal Synergies

In a parallel line of research, I study the nature of coordinative processes during joint task performance. During a dyadic interaction individuals integrate visual information about online changes in the partner behavior with proprioceptive information about their own behavior. As a result, the behavior of both partners becomes coordinated (interpersonalcoordination). One of the mechanisms that allows for the emergence of interpersonal coordination is mutual adaptation: when information about an individual’s behavior triggers compensatory mechanisms in the partner's performance (intrapersonalcoordination) and vice versa. In one project, I studied the hand, arm, and postural sway motion of two individuals working together in a simple suprapostural task (i.e., 'keep a stick within a circle without touching its borders for 60 seconds'). Using non-linear dynamics analyses (principle components analyses together with cross-recurrence quantification analyses), I identified different coordinative modes when individuals performed the task alone or jointly (Ramenzoni et al., 2011; 2012; Riley et al., 2011). These findings indicate that our body coordinates within itself (builds flexible synergies) to adapt to the changing demands arising from the other person’s performance.

Joint & Collective Action

In my recent work, I have built on this line of research by exploring other compensatory mechanisms used in joint performance. Specifically, I have been working towards an approach that interfaces predictive modeling and coordination dynamics mechanisms during the performance of rhythmic tasks. Initial findings show that interacting individuals compensate online for changes in the context of the task (i.e., number of individuals involved) by activating distinct forward models to predict the outcome of joint vs. individual actions (Ramenzoni, Sebanz, & Knoblich, in revision). I am currently working on an extension of this work to more complex tasks (i.e., joint imitation of polyrhythms) to investigate whether compensatory mechanisms might help individuals learn a joint task. In a parallel project, I am collaborating with the BabyBRAIN group to study the development of compensatory coordination mechanisms in early childhood (Endedijk et al., in preparation). We studied the joint spontaneous drumming of dyads of 2-, 3-, and 4-year-olds (cross-sectional and longitudinal) and identified that, as children gain in their drumming ability (more stable and predictable), their joint drumming becomes more coordinated. Finally, I am also working in collaboration with computational physicists looking at how dynamic interactions within large communities shape individuals behavior and how individuals organize their knowledge of social events (Lee, Ramenzoni, & Holme, 2010; Karimi, Ramenzoni, & Holme, 2014).