Sequence Knowledge on When and What Supports Dual-Tasking.

Fang Zhao,Lisa Schneider,Hilde Haider,Eva Röttger,Roland Thomaschke,Robert Gaschler

doi:10.5334/joc.76

Abstract

The constraints in overlapping response selection have been established in dual-tasking studies with random sequence of stimuli and responses as well as random stimulus onset asynchrony (SOA). While this approach makes it possible to control for advance activation of upcoming stimuli or responses, it leaves open whether such preparatory processing can indeed influence dual-task performance. We investigated whether and how the sequence of stimuli and responses and the sequence of SOAs can be learned and used under dual-tasking. In each trial, participants (N = 28 in Experiment 1 and N = 30 in Experiment 2) were first presented with a random two-choice task followed by a four-choice Serial Reaction Time Task (SRTT), presented in a sequence of length four (position sequence). The SOA (timing) sequence also had length four. In test phases, one or both of the sequences were randomized. Results showed that both position and timing sequences were learned and supported dual-task performance, suggesting that predictive processing with respect to timing and identity of stimuli and responses can help to circumvent the response selection bottleneck constraints. Furthermore, in contrast to previous work on acquisition of interval sequences in single tasking, we found that the sequence of what (i.e. stimulus) and the sequence of when (i.e. interval between two tasks) contributed independently to performance.

Highlights

Despite being a massively parallel system, the brain is capable of producing precise serial output
Providing participants with a two-choice task with random stimulus sequence followed by a predictable stimulus in the Serial Reaction Time Task (SRTT) at a predictable interval, Experiment 1 targeted whether sequence knowledge could lead to advance preparation in dual-tasking
Our results suggest that participants could acquire sequence knowledge about stimulus and response positions in the SRTT and use this sequence knowledge for speeding up performance

Summary

Introduction

Despite being a massively parallel system, the brain is capable of producing precise serial output (as in playing an instrument or typing). This “problem of serial order” (Lashley, 1951) can be approached from different perspectives. Work on sequence learning (e.g., Schuck, Gaschler, & Frensch, 2012; Shin, 2008) and representations of serial order (e.g., Botvinick & Bylsma, 2005; Botvinick & Plaut, 2006) has dealt with representations and processes securing precision of serial output with respect to order and timing based on sequence knowledge. Work on the response selection bottleneck (Pashler, 1994) has dealt with the constraints that avoid parallel selection of responses despite parallel activation – for instance, when multiple stimuli are presented and multiple responses are required within the same trial. Early work has documented that responses of different tasks can be executed in temporally overlapping manner if they belong to different modalities (such as vocal and manual responses; cf. Pashler & Christian, 1994), while responding to two tasks with the same modality (e.g., two manual responses) can cause delays

Methods

Results

Conclusion