The bivalency effect: adjustment of cognitive control without response set priming

One could argue that there may still be a potential overlap in the non-overlapping response set depending on how responses are coded (see Druey & Hübner, 2008; Hübner & Druey, 2008). For example, participants in the non-overlapping response set condition might code responses according to the anatomical features of the finger types or according to the spatial features of the response keys. Accordingly, they would have coded the responses according to the three finger types (i.e., index, middle, ring) or to the spatial features of the response keys (i.e., left, middle, right). If participants would code responses according to the three finger types, the index, middle, and ring fingers for both hands would be mapped to the parity, colour, and case decisions, respectively, in Experiment 1, and to the colour, parity, and case decisions, respectively, in Experiment 2. As bivalent stimuli always appeared in the case decisions, bivalent stimulus features would be linked to the response features of the ring fingers. However, they would never be linked to the response features of the index or middle fingers. As a consequence, even when responses are coded according to anatomical features of the finger types, the response set would not overlap between univalent and bivalent stimuli for the parity and colour decisions.

Alternatively, if participants would code responses according to the spatial features of the response keys, the response features left, middle, and right would be mapped in Experiment 1 to the case, colour, and parity decisions, respectively, for the left hand and to the parity, colour, and case decisions, respectively, for the right hand. Similarly, in Experiment 2, the response features left, middle, and right would be mapped to the case, parity, and colour decisions, respectively, for the left hand and to the colour, parity, and case decisions, respectively, for the right hand. In this case, bivalent stimulus features would be linked to the response features left and right. Therefore, the response set would overlap between univalent and bivalent stimuli for the parity and case decisions in Experiment 1 and for the colour and case decisions in Experiment 2. In contrast, it would never overlap for the colour decision in Experiment 1 and for the parity decision in Experiment 2 as these tasks were mapped to the response feature middle. Accordingly, even if participants would have coded responses according to the spatial features of the response keys, the response set would still not overlap for at least one of the three tasks. Therefore, it does not matter how the responses are coded because for both types of response codes (finger vs. spatial), negative priming of bivalent stimulus features via common response features would not be sufficient to account for the present results.