Modality-specific effects on crosstalk in task switching: evidence from modality compatibility using bimodal stimulation

Abstract

The present study was aimed at examining modality-specific influences in task switching. To this end, participants switched either between modality compatible tasks (auditory-vocal and visual-manual) or incompatible spatial discrimination tasks (auditory-manual and visual-vocal). In addition, auditory and visual stimuli were presented simultaneously (i.e., bimodally) in each trial, so that selective attention was required to process the task-relevant stimulus. The inclusion of bimodal stimuli enabled us to assess congruence effects as a converging measure of increased between-task interference. The tasks followed a pre-instructed sequence of double alternations (AABB), so that no explicit task cues were required. The results show that switching between two modality incompatible tasks increases both switch costs and congruence effects compared to switching between two modality compatible tasks. The finding of increased congruence effects in modality incompatible tasks supports our explanation in terms of ideomotor "backward" linkages between anticipated response effects and the stimuli that called for this response in the first place. According to this generalized ideomotor idea, the modality match between response effects and stimuli would prime selection of a response in the compatible modality. This priming would cause increased difficulties to ignore the competing stimulus and hence increases the congruence effect. Moreover, performance would be hindered when switching between modality incompatible tasks and facilitated when switching between modality compatible tasks.

Exploring Modality Compatibility in the Response-Effect Compatibility Paradigm

“…The results of Experiment 2 fit well with previous findings suggesting evidence for an influence of modality compatibility in S-R tasks in different paradigms (dual task; see, e.g., Göthe et al, 2016; Greenwald, 1972; Hazeltine et al, 2006; task switching; see, e.g., Stephan & Koch, 2010, 2011, 2018). Interestingly, in our REC experiments, which use single-task conditions, we observed that the REC effect disappeared with the modality incompatible R-E mapping under some conditions, while the influence of modality in multitasking settings has proven to be very robust.…”

“…Interestingly, in our REC experiments, which use single-task conditions, we observed that the REC effect disappeared with the modality incompatible R-E mapping under some conditions, while the influence of modality in multitasking settings has proven to be very robust. This may be an important finding, considering that previous studies on multitasking also found an effect of (S-R) modality compatibility, primarily in mixed-task conditions, but very rarely so in single-task conditions (e.g., Lukas et al, 2010; Schäffner et al, 2016; Stephan & Koch, 2010, 2016). Therefore, given this pattern of results within our study and across other published studies, we speculate that modality compatibility is an even more influential factor determining crosstalk in conditions in which there is uncertainty (i.e., variability, such as in task switching studies) about modality mappings.…”

“…Thus, in this experiment, the same S-R modality mappings were considered compatible (visual-manual and auditory-vocal) and incompatible (visual-vocal and auditory-manual), as defined earlier by Greenwald (1972). Stephan and Koch (2010) found reduced switch costs when switching between tasks involving compatible modality mappings compared to switching between tasks with incompatible modality mappings, reflecting less between-task crosstalk when participants had to switch between two compatible mappings (see also Stephan & Koch, 2016). …”

“…An illustration of how a response-effect (R-E) task (i.e., output-input task) can be created from a stimulus-response (S-R) task (input-output task), reversing the order of procedure in the task in order to investigate modality compatibility (Greenwald, 1972; Stephan & Koch, 2010, 2011, 2016). …”

“…Recently, this notion of ideomotor compatibility was reexamined as modality-specific compatibility in the context of a sequential task switching paradigm (Schäffner, Koch, & Philipp, 2016; Stephan & Koch, 2010 , 2011, 2016). Stephan and Koch (2010) instructed participants to switch between two spatial S-R tasks.…”