title: Information continuity across the response selection bottleneck: early parallel Task 2 response activation contributes to overt Task 2 performance.
abstract: Several studies of dual-task performance have demonstrated Task 2 to Task 1 response priming (backward compatibility effects), indicating some degree of parallel response computation for concurrent tasks and suggesting that the well-established response selection bottleneck (RSB) model may be incomplete. However, the RSB might be considered to remain informationally intact if this early parallel Task 2 response information does not persist across the attentional shift between tasks to contribute to overt Task 2 performance. We used an adapted psychological refractory period paradigm with an additional early transient Task 2 stimulus to examine whether response information generated for Task 2 in parallel with overt Task 1 response selection could persist across the bottleneck to influence eventual overt Task 2 performance. After controlling for potential indirect effects of Task 1 processing stage variability propagating onto Task 2 reaction time via locus of slack effects, we observed reliable and consistent effects of early Task 2 response information facilitating Task 2 reaction times. These effects were observed only when the responses to both tasks of the dual-task pair were compatible, under both univalent and bivalent response mappings across tasks. These findings may represent evidence of a variably sensitive response gating or suppression mechanism in dual-task performance and support the idea that backward response compatibility effects represent transient informational influences on central response codes, rather than later postbottleneck response execution processes.
authors.affiliation: Department of Psychology, Neuroscience & Behaviour, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4K1, Canada. thomsosj@mcmaster.ca
authors.forename: Sandra J
authors.initials: SJ
authors.lastname: Thomson
authors.forename: Scott
authors.initials: S
authors.lastname: Watter
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D003118:Color Perception / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008960:Models, Psychological; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D012033:Refractory Period, Psychological / Q000502:physiology*; D055815:Young Adult