In socially shared regulation of learning, adaptation is a key process for overcoming collaborative learning challenges. Monitoring the learning process allows learners to recognize the situations that require a need to change, revise, or optimize the current learning process. This can be done through adapting their strategies, task perception, goals, or standards for monitoring their progress. This process is called small-scale adaptation. It is not yet clear how shared monitoring in groups activates small-scale adaptation "on the fly" or how this phenomenon can be detected using multimodal data. The aim of this study is to explore how small-scale adaptation emerges during collaboration. Video and heart rate data were collected from four groups of three high-school students (age 16-17) who worked together during six 75-min advanced physics lessons. The results show small-scale adaptation occurs most often when groups switch from enacting tasks to defining them. Physiological synchrony occurred throughout the collaboration and was not significantly more prevalent before or after adaptation occurred. The opportunities and challenges of combining video observation to identify monitoring and adaptation events, and physiological synchrony as a possible indicator of "sharedness," are discussed, contributing to the literature about using multimodal data to study learning processes.