Table 3.

Response rates in Experiment 3: Not crowded. Similar or dissimilar

	Identical Trial	Similar Trial	Dissimilar Trial
Target	63% ± 2%	52% ± 3%	60% ± 8%
Flanker	n/a	22% ± 1%	10% ± 3%
Absent	37% ± 2%	27% ± 3%	33% ± 4%
Total	100%	100%	100%

Experiment 3: Much like Experiment 2 (Table 2), except that the stimulus (target and flankers) was at fixation instead of in the periphery. Shown are the average (±standard error across 2 observers) frequencies of the three kinds of responses produced by the observer when asked to identify the target letter: the target, the flanker, or an absent letter (neither target nor flanker). Unlike in Experiment 2, the target was not crowded, because it was presented at fixation. To restore difficulty, despite the central presentation, the stimulus was presented briefly (70 or 80 ms), and was followed by a post-mask. Substitution accounted for 92% of the trials that produced these results (see the Results section and the Appendix, Eq. 22)