• Samuel Shaki
  • William M. Petrusic
  • Craig Leth-Streensen


In one experiment, participants compared the size of animals from memory and on congruent trials selected the smaller if both were small and the larger if both were large. On incongruent trials, they selected the larger animal if both were small and the smaller if both were large. In a second experiment, participants compared the lengths of lines and the direction of the comparison was contingent on whether the lines were short or long. Response times (RTs) were increased and semantic congruity effects (SCE) were greatly amplified with the category contingent instructions relative to the conventional non-contingent instructions precisely as predicted by the class of evidence accrual models of decisional processing. These findings are not easily accounted for by the single sample, stage models, of the SCE.

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