Abstract 2: Celebrating Eric Roy’s research advances in understanding the performance differences of the two hands: the preferential reaching task.

This talk celebrates Dr. Eric Roy's foundational contributions to motor behaviour and lateralization, focusing on his innovative work on manual asymmetries and the development of the preferential reaching task. The preferential reaching task has become a cornerstone for investigating hand preference and the dynamics of lateralized motor control. By systematically varying object location and observing spontaneous hand choice, the task provides a sensitive and nuanced measure of how spatial, cognitive, and motor factors interact to influence hand selection. Dr. Roy's and his students’ work validated the preferential reaching task methodology and approach, demonstrating its versatility across age groups, task complexities, and experimental contexts. His research showed how handedness is not a fixed trait, but one that situational demands and the spatial layout of the environment can modulate. Over the past 25 years, the preferential reaching task has evolved, incorporating advances in motion tracking and neuroimaging. These developments have deepened our understanding of lateralization in typical and atypical populations, including individuals with neurological conditions or developmental differences. As we reflect on Dr. Roy’s enduring legacy, this presentation will trace the evolution of the preferential reaching task from its inception to its current applications in developmental psychology, neuroscience, and rehabilitation. Dr. Roy’s contributions have shaped a methodological paradigm and inspired generations of researchers to explore the complexities of manual asymmetries with rigour and creativity.