In standard flanker tasks, incongruent distractors impair performance more strongly when the flankers are presented shortly in advance of the target. This SOA effect has been ascribed to a “head start” of flanker-related response activation compared to target-related response activation (e.g., Eriksen & Schultz, 1979; Mackenzie et al., 2022). In the current study, we presented both symmetrical letter strings (e.g., HHH, XHX) and asymmetrical letter strings (e.g., HHX, XHH) and asked participants, in separate blocks of trials, to identify the central letter (i.e., flanker task) or to indicate whether the peripheral letters were identical or not (reversing the relationship of central and peripheral letters as targets and distractors compared with the flanker task). Distractors and targets were presented with SOAs of -200 ms, -100 ms, 0 ms, 100 ms, and 200 ms. Our results replicated previous flanker task findings of more pronounced response impairment by incongruent stimuli (i.e., XHX, HXH) when distractor onset preceded target onset than when the SOA was 0 ms. In the same/different task, response impairment by incongruent stimuli was considerably larger than in the flanker task, but appeared to be at maximum when stimuli were presented simultaneously. While the former result is consistent with the notion that centrally presented distractors (i.e., between target stimulus elements) are particularly difficult to ignore, the latter result suggests that distractor-based response activation in the same/different task does depend on a rather simultaneous presentation of all stimulus elements.