Competing Frames of Reference Using Vibrotactile Stimuli for Stimulus-Response Mapping Effects

The implementation of vibrotactile stimuli has grown in necessity where visual and auditory modalities are overloaded. However, how attention is oriented using vibrotactile information has been minimally investigated compared to other modalities, such as visual and auditory stimuli. The ability to elicit an appropriate mapping between a response from a specific vibrotactile stimulus can be explained in three different frames of reference accounts: internal, external, or remapping. Previous research has answered questions relating to the ability to use different reference frames but have yet to agree which frame orients attention for creating an automatic response. Using various stimulus-response mapping effects, the current study investigated how competing frames of reference are used to orient attention to select a response based on specific characteristics of vibrotactile stimuli. Experiment 1 validated the novel apparatus developed for this study by obtaining a stimulus-response compatibility effect. Experiment 2 investigated if an external or internal reference frame is used to orient attention automatically. The uncrossed-hands condition provided a replication of Experiment 1 and confirmed that a stimulus-response compatibility effect was present. For the crossed-hands condition, a diminished, reverse stimulus-response compatibility effect was present. Experiment 3 found no meaningful difference between a magnitude aligned (i.e., left associated with low frequency) versus misaligned (i.e., left associated with high frequency) conditions for frequency of vibrotactile stimuli, suggesting vibrotactile stimuli do not hold a mental magnitude line. Overall, the results from Experiments 1 and 2 provide evidence that processing of vibrotactile information is not reliant on only an internal reference frame but instead the external frame has some influence on selecting a motor response. Experiment 3 also suggests that task context influenced the stimulus and response mapping provided in the instructions, rather than the intrinsic, anatomical representation of vibrotactile stimuli.