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Mechanisms of Practice-Related Reductions of Dual-Task Interferencewith Simple Tasks: Data and Theory

View Article: PubMed Central - PubMed

ABSTRACT

In dual-task situations, interference between two simultaneous tasks impairsperformance. With practice, however, this impairment can be reduced. To identifymechanisms leading to a practice-related improvement in sensorimotor dual tasks,the present review applied the following general hypothesis: Sources that impairdual-task performance at the beginning of practice are associated withmechanisms for the reduction of dual-task impairment at the end of practice. Thefollowing types of processes provide sources for the occurrence of thisimpairment: (a) capacity-limited processes within the component tasks, such asresponse-selection or motor response stages, and (b) cognitive control processesindependent of these tasks and thus operating outside of component-taskperformance. Dual-task practice studies show that, under very specificconditions, capacity-limited processes within the component tasks areautomatized with practice, reducing the interference between two simultaneoustasks. Further, there is evidence that response-selection stages are shortenedwith practice. Thus, capacity limitations at these stages are sources fordual-task costs at the beginning of practice and are overcome with practice.However, there is no evidence demonstrating the existence of practice-relatedmechanisms associated with capacity-limited motor-response stages. Further,during practice, there is an acquisition of executive control skills for animproved allocation of limited attention resources to two tasks as well as someevidence supporting the assumption of improved task coordination. These lattermechanisms are associated with sources of dual-task interference operatingoutside of component task performance at the beginning of practice and alsocontribute to the reduction of dual-task interference at its end.

No MeSH data available.


Panel A: Illustration of typical performance pattern (i.e., reactiontimes [RTs]) in the context of dual tasks of the psychologicalrefractory period (PRP) type. While performance in Task 1 is independentof the stimulus onset asynchrony (SOA), Task 2 performance is impairedwith decreasing SOSOA. The RTRT increase from long to short SOAsreflects the PRP effect. Panel B: Dual-task processing architectureaccording to the central bottleneck model (e.g., Pashler, 1994a) in PRP dual tasks with SO Amanipulations. Central response-selection (RS 1; RS 2) stages in Task 1and Task 2 are processed sequentially while perception (P1; P2) andresponse (R1; R2) stages are processed in parallel. Response selectionstages (e.g., in Task 2) are lengthened due to the manipulation of thecompatibility between stimuli and responses (McCann & Johnston, 1992) while perceptionstages are lengthened due to the manipulation of stimulus intensity(Pashler & Johnston,1989). In particular, extra time needed for the lengthenedperception stage in Task 2 can run in parallel to RS1 and is therebyabsorbed into the waiting time of RS 2 until RS 1 is completed.
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Figure 1: Panel A: Illustration of typical performance pattern (i.e., reactiontimes [RTs]) in the context of dual tasks of the psychologicalrefractory period (PRP) type. While performance in Task 1 is independentof the stimulus onset asynchrony (SOA), Task 2 performance is impairedwith decreasing SOSOA. The RTRT increase from long to short SOAsreflects the PRP effect. Panel B: Dual-task processing architectureaccording to the central bottleneck model (e.g., Pashler, 1994a) in PRP dual tasks with SO Amanipulations. Central response-selection (RS 1; RS 2) stages in Task 1and Task 2 are processed sequentially while perception (P1; P2) andresponse (R1; R2) stages are processed in parallel. Response selectionstages (e.g., in Task 2) are lengthened due to the manipulation of thecompatibility between stimuli and responses (McCann & Johnston, 1992) while perceptionstages are lengthened due to the manipulation of stimulus intensity(Pashler & Johnston,1989). In particular, extra time needed for the lengthenedperception stage in Task 2 can run in parallel to RS1 and is therebyabsorbed into the waiting time of RS 2 until RS 1 is completed.

Mentions: Dual-task situations of the psychological refractory period (PRP) type are oneof the most prominent situations to investigate processes that are sources ofdual-task costs and are located within simple component tasks (Pashler, 1984, 1994a; Pashler &Johnston, 1989, 1998; Schubert, 1999; Schubert et al., 2008; Telford, 1931; Welford,1952). In these dual-task situations, two tasks are presented in closesuccession with various time intervals between the onsets of the first andsecond task stimulus (i.e., variable stimulus onset asynchronies, SOAs), andparticipants are instructed to respond to Task 1 first. As illustrated in Figure 1A, the performance of the second task(Task 2) typically decreases (e.g., RTs increase) with decreasing SOA andincreasing task overlap. This performance decrease indicates dual-task costs andthus dual-task interference in the context of PRP dual tasks (i.e., the PRPeffect).


Mechanisms of Practice-Related Reductions of Dual-Task Interferencewith Simple Tasks: Data and Theory
Panel A: Illustration of typical performance pattern (i.e., reactiontimes [RTs]) in the context of dual tasks of the psychologicalrefractory period (PRP) type. While performance in Task 1 is independentof the stimulus onset asynchrony (SOA), Task 2 performance is impairedwith decreasing SOSOA. The RTRT increase from long to short SOAsreflects the PRP effect. Panel B: Dual-task processing architectureaccording to the central bottleneck model (e.g., Pashler, 1994a) in PRP dual tasks with SO Amanipulations. Central response-selection (RS 1; RS 2) stages in Task 1and Task 2 are processed sequentially while perception (P1; P2) andresponse (R1; R2) stages are processed in parallel. Response selectionstages (e.g., in Task 2) are lengthened due to the manipulation of thecompatibility between stimuli and responses (McCann & Johnston, 1992) while perceptionstages are lengthened due to the manipulation of stimulus intensity(Pashler & Johnston,1989). In particular, extra time needed for the lengthenedperception stage in Task 2 can run in parallel to RS1 and is therebyabsorbed into the waiting time of RS 2 until RS 1 is completed.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5385484&req=5

Figure 1: Panel A: Illustration of typical performance pattern (i.e., reactiontimes [RTs]) in the context of dual tasks of the psychologicalrefractory period (PRP) type. While performance in Task 1 is independentof the stimulus onset asynchrony (SOA), Task 2 performance is impairedwith decreasing SOSOA. The RTRT increase from long to short SOAsreflects the PRP effect. Panel B: Dual-task processing architectureaccording to the central bottleneck model (e.g., Pashler, 1994a) in PRP dual tasks with SO Amanipulations. Central response-selection (RS 1; RS 2) stages in Task 1and Task 2 are processed sequentially while perception (P1; P2) andresponse (R1; R2) stages are processed in parallel. Response selectionstages (e.g., in Task 2) are lengthened due to the manipulation of thecompatibility between stimuli and responses (McCann & Johnston, 1992) while perceptionstages are lengthened due to the manipulation of stimulus intensity(Pashler & Johnston,1989). In particular, extra time needed for the lengthenedperception stage in Task 2 can run in parallel to RS1 and is therebyabsorbed into the waiting time of RS 2 until RS 1 is completed.
Mentions: Dual-task situations of the psychological refractory period (PRP) type are oneof the most prominent situations to investigate processes that are sources ofdual-task costs and are located within simple component tasks (Pashler, 1984, 1994a; Pashler &Johnston, 1989, 1998; Schubert, 1999; Schubert et al., 2008; Telford, 1931; Welford,1952). In these dual-task situations, two tasks are presented in closesuccession with various time intervals between the onsets of the first andsecond task stimulus (i.e., variable stimulus onset asynchronies, SOAs), andparticipants are instructed to respond to Task 1 first. As illustrated in Figure 1A, the performance of the second task(Task 2) typically decreases (e.g., RTs increase) with decreasing SOA andincreasing task overlap. This performance decrease indicates dual-task costs andthus dual-task interference in the context of PRP dual tasks (i.e., the PRPeffect).

View Article: PubMed Central - PubMed

ABSTRACT

In dual-task situations, interference between two simultaneous tasks impairsperformance. With practice, however, this impairment can be reduced. To identifymechanisms leading to a practice-related improvement in sensorimotor dual tasks,the present review applied the following general hypothesis: Sources that impairdual-task performance at the beginning of practice are associated withmechanisms for the reduction of dual-task impairment at the end of practice. Thefollowing types of processes provide sources for the occurrence of thisimpairment: (a) capacity-limited processes within the component tasks, such asresponse-selection or motor response stages, and (b) cognitive control processesindependent of these tasks and thus operating outside of component-taskperformance. Dual-task practice studies show that, under very specificconditions, capacity-limited processes within the component tasks areautomatized with practice, reducing the interference between two simultaneoustasks. Further, there is evidence that response-selection stages are shortenedwith practice. Thus, capacity limitations at these stages are sources fordual-task costs at the beginning of practice and are overcome with practice.However, there is no evidence demonstrating the existence of practice-relatedmechanisms associated with capacity-limited motor-response stages. Further,during practice, there is an acquisition of executive control skills for animproved allocation of limited attention resources to two tasks as well as someevidence supporting the assumption of improved task coordination. These lattermechanisms are associated with sources of dual-task interference operatingoutside of component task performance at the beginning of practice and alsocontribute to the reduction of dual-task interference at its end.

No MeSH data available.