Architectural affordance systematically alter parieto-occipital alpha-band desynchronization

Transitions are among the most fundamental architectural elements, as they distinguish between inside and outside (1). Over millennials, architectural transitions have been shaped by human beings in various forms, making them both ar­chitecturally and biologically attractive. Because transitions extend in time and space and depend on the human body’s capabilities to propel itself through space, we used a Mobile Brain/Body Imaging approach (MoBI; 2–4) with high-density electrocenphalography (EEG) synchronized to head mounted virtual reality to investigate the animate human transition from one space to another with varying affordances. As a continuation of previous enticing results (5), we performed a time-frequency analysis on the source-level of recorded in-actio brain activity. By varying the width of the passage, we regulated the affordances, i.e. narrow or wide openings, which allowed exploring the animate body towards transitions and to investigate how such processes are expressed in the time-frequency domain of human brain dynamics. As the alpha-band oscillations have been implicated to regulate the responsivity in sensorimotor areas, particularly as a function of predicted spatial attention (6), we hypothesized to find event-related desynchronization (ERD) in the alpha-band. Specifically, the attenuations within the alpha-band were expected to co-vary with the architectural affordances both upon perceiving the opening and well as while approaching the transition. The hypothesis retrieved from active inference (7–9) suggests that during movement, the continuous affordances are expressed as suppression of proprioceptive prediction-errors while the embodied brain becomes more certain of the environment and, thus, planned movements. Affordances in the context of the subject in this experiment can thus be interpreted as a function of top-down attention expressed in the alpha-band oscillation. Given the dependence on sensorimotor activity, e.g. action-perception, these results are particularly appealing to active inference and enactivism. Our study investigates to which extent affordances are reflected in the neuronal responses and how architecture is embedded in cortical processes.