In numerous experiments, after completing demanding cognitive tasks, a walk in a park or forest restored attention significantly more effectively than a walk along city streets. These results formed the basis of Stephen and Rachel Kaplan's Attention Restoration Theory. Now, a researcher from The Ohio State University, Richard Jagacinski, has proposed a mathematical hypothesis that could explain this effect through the mechanism of a travelling wave of attention.
According to the new model, distributed attention can be represented as a wave propagating at a constant speed, but capable of altering its spatial and temporal frequency. When a person is in a spacious natural environment, the wavelength increases, and both frequencies decrease. This creates a slower perceptual mode characteristic of natural landscapes with their fractal structure, smooth transitions, and unhurried rhythms.
In an urban environment, the situation is the opposite. Numerous rapidly changing objects, signs, traffic, and signals correspond to higher attention frequencies. According to the author's hypothesis, it is this high-frequency operation that requires greater voluntary control and leads to cognitive fatigue more quickly.
To support his model, Jagacinski uses results from studies showing that during sustained attention, the brain exhibits rhythmic oscillations in approximately the 3–8 Hz range.
Further support comes from visual search experiments, where a person can simultaneously process multiple objects, which aligns better with a distributed wave organization of attention than with the idea of sequentially scanning the environment.
The assumption of a constant wave propagation speed also helps explain a well-known visual effect: when objects move slowly, we perceive them as a single trajectory, but as the speed increases, we begin to distinguish multiple independent moving objects. The author interprets this boundary as the natural limit of focal attention processing speed.
Kaplan's classic theory explained the restorative effect of nature by qualities such as 'soft fascination,' a sense of spaciousness, and mystery. The new model proposes translating these subjective characteristics into quantitative parameters. Instead of the difficult-to-measure feeling of 'fascination,' a potentially measurable quantity emerges—the spatio-temporal frequency of the attention wave.
Imagine ripples on the surface of a calm lake. The longer the waves, the slower they move across the water, and the calmer the motion appears. By analogy, natural landscapes can shift attention to a lower-frequency mode, reducing the load on voluntary control systems. Conversely, a rich urban environment sustains higher frequencies of attention switching, contributing to the accumulation of cognitive fatigue.
If this model receives experimental confirmation, it could become an important step towards a quantitative description of how environmental characteristics influence attention and subjective perception. This would open new possibilities not only for consciousness research but also for urban design, cognitive rehabilitation programs, and recovery after prolonged use of digital devices.
