The influence of selection modality, display dynamics and error feedback on patterns of human foraging
In previous studies, we have used an iPad task to explore how humans “forage” through static displays containing multiple targets from two categories. When demands on attention were increased, foraging patterns tended to shift from random category selection to exhaustive category selection. Here, we used the same task on a vertically oriented touch-screen. In separate blocks, static or dynamic target items were selected using different modalities, specifically: (a) mouse (b) touchscreen or (c) infrared hand tracker. Although the different selection modalities varied considerably in terms of familiarity and difficulty of use, there was a minimal effect on the patterns of foraging. While there was a consistent reduction in the number of category switches with increased attentional load, the tendency to use exhaustive runs was much reduced, particularly with dynamic displays. We suggest that this pattern is a consequence of generally slowed response times. These findings indicate that in addition to capacity limits, temporal constraints are likely to be an important determinant of foraging patterns in humans. We introduce the term “foraging tempo” to capture this latter notion and to emphasize the probable role played by the overall pace of the regular, repetitive selections required during multi-target search tasks.