Infants

The mobile conjugate reinforcement (MCR) paradigm, made famous by Carolyn Rovee-Collier and her colleagues (Rovee & Rovee, 1969), has long been used to study infant learning and memory. In MCR studies, the infant's foot is tethered to a mobile hanging overhead, and the mobile responds directly to the infant's kicking. Infant kicking rate triples within a few minutes of interacting with the mobile. This result was classically interpreted as evidence of reinforcement learning. Kelso and Fuchs (2016) reinterpreted it as evidence that a coordinative structure, or functional synergy, forms between infant and mobile, triggering a positive feedback loop between the two. Positive feedback is proposed to give rise to an `Aha!' moment as the (prelinguistic) infant suddenly realizes it is an agent in control of the mobile's motion. While some have theorized the realization of self as causal agent emerges from organism-environment interactions, Kelso and Fuchs (2016) developed a mathematical model of the coordination dynamics between the infant and mobile, providing mechanistic explanations for the formation of agency. The current study was the first to measure movement of the mobile and analyze how dynamics of coordination between infant and mobile relate to possible transitions from spontaneous to intentional action. Novel measures of infant and mobile dynamics were used to test model predictions. Infant activity dropped drastically in response to non-contingent mobile movement and remained suppressed at the start of infant~mobile contingency, suggesting that mobile movement triggers a qualitatively different context for infants. This finding challenges the widely held assumption that mobile movement rewards and stimulates infant movement and calls into question the sufficiency of standard contingency detection cut-offs and explanations of conjugate reinforcement learning. Assessing coordination dynamics on a fine time scale using new analytical techniques made it possible to identify moments of agentive realization. Approaching agency as a relational phenomenon allowed for detailed characterization of the infant~mobile relationship and its role in the emergence of causal agency. In addition, the results revealed a number of surprising insights into agency formation such as the critical role of inactivity for agentive discovery and the possibility of intermediary stages or quasi-agentive states.

Robotics have advanced to include highly anthropomorphic (human-like) entities. A novel eye-tracking paradigm was developed to assess infants’ sensitivity to communicative gestures by human and robotic informants. Infants from two age groups (5-9 months, n = 25; 10-15 months, n = 9) viewed a robotic or human informant pointing to locations where events would occur during experimental trials. Trials consisted of three phases: gesture, prediction, and event. Duration of looking (ms) to two areas of interest, target location and non-target location, was extracted. A series of paired t-tests revealed that only older infants in the human condition looked significantly longer to the target location during the prediction phase (p = .036). Future research is needed to tease apart what components of the robotic hand infants respond to differentially, and whether a robotic hand can be manipulated to increase infants’ sensitivity to social communication gestures executed by said robotic hand.

Studies have shown that human infants can integrate the multisensory attributes of their world and, thus, have coherent perceptual experiences. Multisensory attributes can either specify non-arbitrary (e.g., amodal stimulus/event properties and typical relations) or arbitrary properties (e.g., visuospatial height and pitch). The goal of the current study was to expand on Walker et al.'s (2010) finding that 4-month-old infants looked longer at rising/falling objects when accompanied by rising/falling pitch than when accompanied by falling/rising pitch. We did so by conducting two experiments. In Experiment 1, our procedure matched Walker et al.'s (2010) single screen presentation while in Experiment 2 we used a multisensory paired-preference procedure. Additionally, we examined infants' responsiveness to these synesthetic-like events at multiple ages throughout development (four, six, and 12 months of age). ... In sum, our findings indicate that the ability to match changing visuospatial height with rising/falling pitch does not emerge until the end of the first year of life and throw into doubt Walker et al.'s (2010) claim that 4-month-old infants perceive audiovisual synesthetic relations in a manner similar to adults.