Analyses flow step 4: We use the automatically detected of gaze hot spots to investigate the gaze transitions within and between hot spots (‘Hot Hops’), which participants make when exploring paintings, to analyse the statistics of their journey through the artwork. In the process we select from the complete saccadic events between subsequent fixations only this which start in an ROI (hot spot) and end in an ROI, and ignore all other which start or end outside of any ROI.
Automatically detected Hot Spots density map for participant BLUE-11. The colour code indicates the order of hot spots determined by the cumulative gaze duration within the region of the corresponding colour circle.
Hot Hops are then sampled in bins which are characterised by the origin and destination of these gaze transitions. The data set can be described by a ‘Hot Hops bi-gram transition matrices’, in which the number of gaze transitions is indicated in colour code.
Hot Hops bi-gram transition matrix for participant BLUE-11, showing the saccadic events between origin and destination ROIs (hot spot) in colour code. Left: Hot Hops within and between ROIs suggest that saccades within a given ROI (hot spot 10, in this case). Right: Hot Hops within are removed, to emphasize transitions between ROIs, suggesting that this participant moved preferentially from hot spot 1 to hot spot 5.
The matrix description of the likelihood of moving from one ROI (hot spot) to another, can be visualised as bi-gram graph where each line between connection between origin and destination ROI is shown as a line with the thickness of the lines indication the likelihood of such a transition. The process of accumulating these statistics over time spent by the participant exploring the ROIs could be interpreted as a Markov chains model, and will need further investigation. These graphs clearly indicate preferred as well as rare or absent transitions.
Hot Hops for the first 16 hotspots (black dots arranged on a circle) visualized for participant BLUE-11 as bi-gram Graph: where thickness of the line is indicating the strength of the connection between origin and destination, and its colour is determined by the colour code of the hot spot of origin.