Are complex attentional templates restricted to a single location?

It is debated whether complex attentional templates spanning multiple potential target values and feature dimensions—demanded by real-world visual search tasks—can truly guide attention, or if they are instead simulated by cycling through a series of simpler attentional templates. We recently (Racioppo & Tamber-Rosenau, OPAM, 2022) asked participants to simultaneously search for targets defined in one or two feature dimensions using continuously changing dynamic multivalent stimuli in two separate locations. We observed costs in response time and accuracy for dual-dimension compared to single-dimension search tasks. Within the dual-dimension task, we observed further costs when targets alternated vs. repeated dimensions: more responses were omitted and, of the responses, more were erroneous following a switch. These initial results are more consistent with the simple template account than the complex template account. However, by using multiple locations that could have required serial attention, we may have inadvertently incentivized an overall strategy that could have favored cycling simple templates. Here we present a similar experiment except that all stimuli were presented in a single location. Participants responded to extreme values in a grating stimulus that gradually and continuously varied in spatial frequency and orientation. In single-dimension blocks, participants responded to one of either spatial frequency or orientation; in dual-dimension blocks, they responded to both kinds of targets. In contrast to the two-location experiment, there was evidence against dimension switch costs for both omitted and erroneous response accuracies. However, response time data remain inconclusive in the present sample. Overall, it may be possible to use a complex attentional template to search for multiple target values in multiple feature dimensions at the same time—but perhaps only in a single location.