A. G. Greenwald and H. G. Shulman (1973) found that 2 tasks characterized by ideomotor (IM) compatibility could be perfectly timeshared (i.e., performed simultaneously without mutual interference). The 2 tasks were pronouncing “A” or “B” in response to hearing those letter names, and making a manual left or right response to seeing a left- or right-positioned arrow. M.-C. Lien, R. W. Proctor, and P. A. Allen (2002) did not replicate Greenwald and Shulman’s result, and concluded that their finding of perfect (...) timesharing of 2 IM-compatible tasks might not be replicable. In the present research, Experiment 1 replicated Greenwald and Shulman’s 1973 finding while also supporting the conclusion that Lien et al.’s nonreplication was due to their not instructing subjects to make 2 responses simultaneously in their timeshared task. Experiment 2 again replicated the perfect timesharing finding, using an alternative control procedure that mixed manual and vocal tasks in the same block. (shrink)

Visual stimuli that are made invisible by masking can affect motor responses to a subsequent target stimulus. When a prime is followed by a mask which is followed by a target stimulus, an inverse priming effect has been found: Responses are slow and frequently incorrect when prime and target stimuli are congruent, but fast and accurate when prime and target stimuli are incongruent. To functionally localize the origins of inverse priming effects, we applied the psychological refractory period paradigm which distinguishes (...) a perceptual level, a central bottleneck, and a level of motor execution. Two dual-task experiments were run with the PRP-paradigm to localize the inverse priming effect relative to the central bottleneck. Together, results of the Effect-Absorption and the Effect-Propagation Procedure suggest that inverse priming effects are generated by perceptual mechanisms. We suggest two perceptual mechanisms as the source of inverse priming effects. (shrink)

Visual stimuli that are made invisible by a following mask can nonetheless affect motor responses. To localize the origin of these target priming effects we used the psychological refractory period paradigm. Participants classified tones as high or low, and responded to the position of a visual target that was preceded by a prime. The stimulus onset asynchrony between both tasks varied. In Experiment 1 the tone task was followed by the position task and SOA dependent target priming effects were observed. (...) When the visual position task preceded the tone task in Experiment 2, with short SOA the priming effect propagated entirely to the tone task yielding faster responses to tones on visually congruent trials and delayed responses to tones on visually incongruent trials. Together, results suggest that target priming effects arise from processing before and at the level of the central bottleneck such as sensory analysis and response selection. (shrink)