Figure 1.

The multiple-location fast-adaptation paradigm. (A) Examples of the low, neutral, and high numerosity stimuli used in the experiments. Because the neutral stimulus was equal in numerosity to the standard (40 dots) there was no change in numerosity perception when it was used as an adapter. This meant adaptation to 40 dots could also be used as a neutral control. (B) Participants fixated on a central fixation point while the adaptation and test procedure occurred sequentially at each of the paired locations. This allowed multiple spatial locations to be tested sequentially within the same paradigm. (C) In the 1-second adapter condition each sequence comprised of a 1-s adaptation period, followed by a 1-s ISI pause, and then 0.25 s of the test stimuli. Afterwards participants were required to respond within 1.25 s which of the test stimuli (left or right) had been perceived as more numerous. The sequence then immediately repeated at the next paired location, regardless of whether participants had responded, to ensure regular timing across the task. This meant that there was a 9.5-s delay before adapter stimuli were shown again at any given spatial location. (D) the 5-second adapter condition was identical to the 1-second adapter condition, with the exception that the duration of the adapter increased to 5 s. As the other variables remained the same, this meant that there was now a 17.5-s delay before adapter stimuli were shown again at the same spatial location.