New empirical research enhance understanding about human perception in healthy aging
Self-perception is a crucial component to the human experience—one that new research indicates may be more fluid than we think. In recent studies, interdisciplinary researcher Dr. Amir Jahanian-Najafabadi from Constructor University, alongside colleagues from Bremen University and the University of Bielefeld employed a trio of neural, cognitive and behavioral methods to investigate how humans perceive and interact with tools and how that interaction reshapes our understanding of the body in space and time. From everyday tools to specialized sports equipment like golf clubs, their findings show that long-term tool use can alter our body schema (our internal sense of our body’s shape and size), our sense of ownership over our body parts, our sense of control (agency), and even how we perceive space and time. This has resulted in valuable insights into the underlying cognitive and neural mechanisms involved in the way we perceive ourselves.
Tools are an integral part of human life, enhancing our sensory-motor functions and expanding our ability to interact with the environment. Decades ago, researchers proposed that tools could become incorporated into the dynamic neural representation of the body, effectively extending our reach and altering our perception of space. This phenomenon, known as tool embodiment, has since been widely supported by research, demonstrating how tool use modifies the brain's representation of the body and alters spatial perception. Furthermore, tool use has been linked to changes in sensorimotor representations, shaping our sense of ownership and agency depending on the space in which interactions occur.
Together with Constructor University Prof. Dr. Ben Godde; Dr. Dennis Küster and Dr. Felix Putze from Bremen University; and Prof. Dr. Christoph Kayser of Bielefeld University, Dr. Jahanian-Najafabadi, conducted a series of studies in both physical and virtual environments, employing visual and haptic feedback to explore the effects of tool use on sensorimotor representations. These studies enhanced our understanding on how experience with tools reshapes our perception of space, time, and body ownership, offering insights into the underlying neural and behavioral mechanisms of tool embodiment.
In Dr. Jahanian-Najafabadi’s and his team’s research, findings from a series of studies conducted in both physical and virtual environments, involving younger and older adults, shed light on the cognitive and behavioral mechanisms underlying tool embodiment and its deep-rooted connections to space and time perception. Recent research also suggests that tool use not only influences spatial perception but also our perception of time. Studies indicate that time is perceived differently in near and far space and that tool use training can eliminate these perceptual differences. This connection between space and time perception underscores the intricate relationship between cognitive processing and physical interaction with the environment.
Fundamental to our awareness of ourselves and our surroundings, time perception, however, is subjective and can be influenced by movement—whether our own or that of external objects. Philosophers and researchers have long observed the deep interconnection between temporal and spatial information in daily life. Traditional laboratory tasks attempting to separate these dimensions may fail to capture the reality of human perception, as spatial, temporal, and other magnitudes appear to share a common neural representation.
Research suggests that our perception of time is flexible and influenced by the spatial location of stimuli. The space around us is categorized into near-space, which is within our reach, and far-space, which extends beyond our immediate grasp. The use of tools can expand near-space into far-space, effectively remapping our perception of distance. While this adaptation occurs quickly, its duration and extent depend on the frequency and duration of tool use. If time perception is inherently tied to spatial processing, then this remapping of space through tool use implies that our experience of time may also be modulated by tool use.
Dr. Jahanian Najafabadi's work has been featured in various publications, including studies on the ability of the elderly to master new tools and technologies, highlighting his contributions to understanding cognitive aging and neuroplasticity.