Figure 1.
(A) Outline of the two-step model for the ideomotor principle (see e.g. [21]). Response-effect (R-E) couplings are established between key press and tone in the acquisition phase. This results in response facilitation in the test phase when at stimulus presentation the matching tone (with respect to this stimulus) is sounded, but not when the other tone is sounded. (B) Outline of the alternative model based on stimulus-response (S-R) couplings established between Stimulus and Response component 1 and between Effect and Response component 2. The difference in response latencies between compatible and incompatible trials for both movements is accounted for by cooperation and competition mechanisms between the two response-selection processes (triggered by the S-R couplings). Importantly, the two response components are to be understood as an integrate part of the same ongoing response action. This schematic merely temporally separates them along the time line of the task.
Figure 2.
The observed means (with 95% CI) for the two types of response latency measured in Experiment 1 as a function of S-R Compatibility of the trials. The values of the means, confidence intervals and size of the Compatibility Effect (CE) are reported in Table S1.
Figure 3.
Results of the test phase of the two single-movement response variations of Experiment 2.
The observed means (with 95% CI) for the two types of response latency measured in Experiments 2A and 2B as a function of S-R Compatibility of the trials. The values of the means, confidence intervals and size of the Compatibility Effect (CE) are reported in Table S1. In Experiment 2A participants had to press and hold down the correct key upon stimulus presentation, in Experiment 2B participants had to release the correct key upon stimulus presentation.
Figure 4.
Setup of Experiment 3A and Experiment 3B in terms of the S-R model.
The acquisition phase of both versions of the experiment was identical, consisting of two response components and without an imperative stimulus, such that they were performed in the ideomotor mode (for more details see text). (A) In the test phase of the key-press only version (Experiment 3A), response selection is not facilitated by the S-R coupling between Effect (tone) and Response component 2 (key release). (B) In the test phase of the key-release only version (Experiment 3B), this S-R coupling does influence response selection, leading to differences in response latencies between the compatible and incompatible conditions.
Figure 5.
Results of the test phase of Experiments 3A and Experiment 3B in one graph.
The observed means (with 95% CI) for the two types of response latency measured in Experiments 3A and 3B as a function of S-R Compatibility of the trials. The values of the means, confidence intervals and size of the Compatibility Effect (CE) are reported in Table S1. Experiment 3A was the key-press only version (RT) and Experiment 3B the key-release only (KCD) version. In these experiments, S-R Compatibility was measured between subjects.