So far, it is really interesting to notice that lower frequency peaks occur most when subjects look at ‘space establishing elements’, particularly where nothing interesting happens in terms of changing building volumes in the composition of the visual field. Peaks that occur in the alpha band are in sync with quick-scans of the street, looking towards a vanishing point or the end of the street, and quick-scanning edges of paths and shapes of buildings.
Peaks in the Beta band seem to occur the most in what Thiel calls “place-quality agents”. These are spatial elements that form places from spaces. Common peaks occur in perceiving objects such as public art, trees, or lamp posts. Apart from objects, elements on façades such as coloured rain pipes, detailed window frames, aedicules and other façade ornaments that stand out from the rest of the visual field also occur in the beta band. Apart from object recognition, another reoccurring perturbation pattern in the Beta band is in discontinuing spatial elements in the figure-ground composition of the visual field. Examples are asymmetrical building shapes, chamfers in building volumes, visual portals, small arcades, and overhangs.
Encountering signs, or numbers or texts on a surface shows a longer gaze position, where Beta peaks occasionally are followed by peaks in higher frequency domains. The peaks in higher frequency area also seem to occur when focussing on distant objects that are not clear in the video.
What was striking is the difference how people perceive trees that have a large green crown, leafless trees (that are almost like abstract art), and trees with blossoming pink flowers. The effect of a tree with green leafs seems to have a less perturbative effect than a tree with bright colours, or a cut-off tree branch.
To be continued…