Dynamic thematic maps allow the communication of complex real-world phenomena through comprehensive spatio-temporal virtual displays. Our research applies Event Segmentation Theory (EST) to investigate their perception and processing. EST describes an automated cognitive process dividing continuous experiences into meaningful event units based on perceptual and conceptual cues. These segmented events modulate higher-order cognitive processes such as attention and memory.
We present a preregistered experiment designed to differentiate the effects of map design as perceptual clues and semantic framing as conceptual clues on segmentation behavior in the context of dynamic maps. 125 participants performed a segmentation task on dynamic maps displaying insect population changes on fictional islands by pressing a key when they perceived the start or end of an event unit. Three independent variables were orthogonally varied in creating the stimuli: The slope of the population development, the framing of the species as either invasive or endangered, and the mapping of the values to either a hue- or saturation-based color scale.
We found that segmentation agreement between participants was higher if the depicted slope matched the expectation encouraged by the framing, but only if the color scale made the direction of change salient. These results replicate prior findings that event segmentation is influenced both top-down by expectations and bottom-up by the salience of visual features for the special case of dynamic maps. Understanding viewer segmentation aids in leveraging dynamic maps for effective communication.
Subsequent research will explore the impact of the spatial distribution of the depicted change on segmentation agreement.