Measuring the velocity of spatio-temporal attention waves

•Participants viewed a rectangular sequential pattern of lights.•Boundaries between streamed and integrated percepts were measured.•Linear patterns of rectangle height vs. light duration indicated two velocity boundaries.•The slopes are interpreted as integer multiples of a constant attentional velocity.•A traveling wave model of distributed attention includes an adjustable wavelength. A sequence of visual or auditory events may be perceived as a single continuing sequence or as two or more separate sequences occurring in parallel. The latter percept occurs when the perceived distance between events is large, and the timing is fast, and is referred to as “streaming.” Several researchers have previously argued that streaming indicates a velocity constraint on the movement of attention. To test this hypothesis the present experiment measured tradeoffs between distance and timing for the onset or loss of streaming in a rectangular pattern of displayed lights. Two linear tradeoffs were found, one corresponding to the loss of streaming when the light pattern was slowed down, and one corresponding to the onset of streaming when the light pattern was sped up. The slopes of these linear relations are interpreted as integer multiples of the velocity of spatio-temporal attention waves. A process model postulates that participants adjust the wavelength of their spatio-temporal attentional traveling wave to match the height of the displayed rectangle. Streaming is assumed to occur when peaks in the attentional traveling wave coincide with the onsets of lights at the top and bottom of the displayed rectangle. Additional supporting evidence for temporal and spatial attention waves is reviewed. This model may be useful for understanding some forms of attentional deficits as well as expert attentional skills arising in musical performance, sports, meditation, and other tasks.