Staying Together: A Bidirectional Delay–Coupled Approach to Joint Action

To understand how individuals adapt to and anticipate each other in joint tasks, we employ a bidirectional delay–coupled dynamical system that allows for mutual adaptation and anticipation. In delay–coupled systems, anticipation is achieved when one system compares its own time‐delayed behavior, which implicitly includes past information about the other system’s behavior, with the other system’s instantaneous behavior. Applied to joint music performance, the model allows each system to adapt its behavior to the dynamics of the other. Model predictions of asynchrony between two simultaneously produced musical voices were compared with duet pianists’ behavior; each partner performed one voice while auditory feedback perturbations occurred at unpredictable times during live performance. As the model predicted, when auditory feedback from one musical voice was removed, the asynchrony changed: The pianist’s voice that was removed anticipated (preceded) the actions of their partner. When the auditory feedback returned and both musicians could hear each other, they rapidly returned to baseline levels of asynchrony. To understand how the pianists anticipated each other, their performances were fitted by the model to examine change in model parameters (coupling strength, time‐delay). When auditory feedback for one or both voices was removed, the fits showed the expected decrease in coupling strength and time‐delay between the systems. When feedback about the voice(s) returned, the coupling strength and time‐delay returned to baseline. These findings support the idea that when people perform actions together, they do so as a coupled bidirectional anticipatory system.     

Forced Migration among Latinx Children and their Families: Introducing Trilateral Migration Trauma as a Concept to Reflect a Forced Migratory Experience

ABSTRACT

Forced migration is a process where people must leave their countries of origin due to situations of war, human rights violations, torture, and political reasons, among other factors. This article presents a working definition of forced migration with a focus on the experience of Latinx children and their families. Venezuela and the Northern Triangle of Central America are presented as regional examples and highlight the state of crisis regarding migration in Latin America. The author introduces the concept of trilateral migration trauma as a new model to understand forced migration experiences. Mental health considerations faced by children who forcibly migrate from their homelands are considered. The “push-pull” theory of migration is critiqued in the context of a forced migratory experience.     

Behavioral competition in a case of Rett syndrome

Major behavioral features of Rett syndrome are the loss of instrumental reaching and grasping and the presentation of some variant of hand-hand or hand-mouth stereotypy. As part of an experimental home intervention program, a 3-year-old girl with Rett syndrome was exposed to four types of contingency games designed to elicit instrumental reaching, kicking, vocalization, and eye movement, respectively. Parent and subject performance were videorecorded on seven occasions over the initial 2-month period. Evaluation of these records provided evidence of contingency learning in all but the vocalization games. Stereotypic hand clasping was examined in relation to the performance of instrumental behavior (reaching, kicking, looking). Coincidental (short-term mutual inhibition arising by chance co-occurrence), associative (short-term mutual inhibition arising by having elicitor in common), and foundational (long-term mutual inhibition arising by having neural network in common) forms of specific behavioral competition were defined and examined. Evidence for coincidental and foundational competition was found in the relation between reaching and hand clasping. Implications for the support of functional hand use are discussed.