Overlapping Mental Operations in Serial Performance with Preview

1994 ◽  
Vol 47 (1) ◽  
pp. 161-191 ◽  
Author(s):  
Harold Pashler
Keyword(s):  
Dual Task ◽  
Response Selection ◽  
Response Duration ◽  
Task Set ◽  
Response Mapping ◽  
Stimulus Response ◽  
Manual Responses ◽  
First Response ◽  
Concurrent Performance ◽  
Response Selection Bottleneck

Dual-task research has revealed a response-selection bottleneck: response selection cannot occur simultaneously in two different tasks, though perceptual processing may overlap response selection (Welford, 1952; Pashler & Johnston, 1989). In serial performance with preview, the same task is performed repeatedly, but stimuli are available well before response. Does the dual-task bottleneck limit the rate of responding in this situation, despite the fact that task set need not change? Four experiments examined manual responses to letters, varying stimulus preview. Preview increased RTs for the first response and reduced the subsequent inter-response intervals (IRIs). Preview also reduced the effect of visual intensity and response duration on IRIs, whereas effects of stimulus-response mapping variables were unchanged. These results indicate that the response-selection bottleneck limits serial performance, just as it limits concurrent performance of two unrelated tasks. This implies that the response-selection bottleneck is not caused by the need to switch task set.

Locus of Backward Crosstalk Effects on Task 1 in a Psychological Refractory Period Task

2014 ◽  
Vol 61 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Yao-Ting Ko ◽  
Jeff Miller
Keyword(s):  
Dual Task ◽  
Refractory Period ◽  
Psychological Refractory Period ◽  
Response Selection ◽  
Stimulus Onset ◽  
Standard Response ◽  
Backward Crosstalk ◽  
Selection Stage ◽  
Prp Paradigm ◽  
Response Selection Bottleneck

Our performance on a task decreases when the task is in a dual-task situation than when it is in isolation. An important experimental setting for dual-task situation is the psychological refractory period (PRP) paradigm, and the dual-task performance decrements in the PRP paradigm are referred to as PRP interference. The standard response-selection bottleneck (RSB) models state that the response-selection stage of the second task (T2) cannot start until the response-selection stage of the first task (T1) finishes, resulting in the PRP interference. Contrary to the prediction of RSB models, several researchers have found T2’s modulations on T1’s performance, and have suggested that T1’s selection-related processes are affected by T2’s selection-related processes, referred to as backward crosstalk effects. The locus of backward crosstalk effects is not clear, however, because RTs were measured in most previous studies. By using semantically unrelated stimuli and responses and by measuring T1’s lateralized readiness potential, we examined the locus of backward crosstalk effects. We found that the interval between T1’s stimulus onset and the stimulus-locked LRP onset was affected, suggesting T2’s response selection starts before T1’s selection is complete. The present result provided electrophysiological evidence focusing on T1’s changes in favor of the hypothesis of parallel response selection in the PRP paradigm.

Localizing practice effects in dual-task performance

2007 ◽  
Vol 60 (6) ◽  
pp. 860-876 ◽  
Author(s):  
Jörg Sangals ◽  
Maria Wilwer ◽  
Werner Sommer
Keyword(s):  
Dual Task ◽  
Response Selection ◽  
Reaction Times ◽  
Stimulus Onset ◽  
Practice Effects ◽  
Stimulus Response ◽  
Central Processing ◽  
Dual Task Performance ◽  
Central Bottleneck ◽  
Task Processing

Practice effects on dual-task processing are of interest in current research because they may reveal the scope and limits of parallel task processing. Here we used onsets of the lateralized readiness potential (LRP), a time marker for the termination of response selection, to assess processing changes after five consecutive dual-task sessions with three stimulus onset asynchronies (SOAs) and priority on Task 1. Practice reduced reaction times in both tasks and the interference between tasks. As indicated by the LRP, the reduction of dual-task costs can be explained most parsimoniously by a shortening of the temporal demands of central bottleneck stages, without assuming parallel processing. However, the LRP also revealed a hitherto unreported early activation over the parietal scalp after practice in the short SOA condition, possibly indicating the isolation of stimulus–response translation from other central processing stages. In addition, further evidence was obtained from the LRP for a late motoric bottleneck, which is robust against practice.

Valence Processing Bypassing the Response Selection Bottleneck?

2008 ◽  
Vol 55 (3) ◽  
pp. 203-211 ◽  
Author(s):  
Rico Fischer ◽  
Torsten Schubert
Keyword(s):  
Dual Task ◽  
Refractory Period ◽  
Psychological Refractory Period ◽  
Response Selection ◽  
Flanker Task ◽  
Capacity Limitations ◽  
Semantic Categories ◽  
Response Selection Bottleneck ◽  
Response Activation ◽  
Temporal Overlap

Abstract. The activation of semantic categories has often been claimed to occur in an attention-free, unconditionally automatic fashion (e.g., Bargh & Chartrand, 1999 ; Ferguson & Bargh, 2004 ). Using a dual-task procedure we tested whether the activation of valence categories is restricted by dual-task specific attentional limitations. For this reason we implemented a modified Eriksen-flanker task as Task 2 in a psychological refractory period paradigm. Participants were to judge the frequency of a tone in Task 1 and the valence of a target word in the presence of irrelevant flanker words in Task 2. Two different flanker categories ensured the activation of semantic categories instead of S-R based response activation. The most important result was an underadditive interaction between flanker congruency and the amount of temporal overlap between tasks that was independent of flanker type. Following the locus-of-slack logic, we interpret these findings as evidence for Task 2 processing parallel to bottleneck-stage processing in Task 1. This extends previous findings by showing that not only number categories ( Fischer, Schubert, & Miller, 2007 ; Oriet, Tombu, & Jolicouer, 2005 ), but also semantic valence categories can be activated despite dual-task capacity limitations.

Electrophysiological correlates of parallel response selection in dual-task performance

2010 ◽  
Author(s):  
Sandra J. Thomson ◽  
Matthew T. Mazurek ◽  
Judith M. Shedden ◽  
Scott Watter
Keyword(s):  
Task Performance ◽  
Dual Task ◽  
Response Selection ◽  
Dual Task Performance

scholarly journals Combining tDCS With a Motor-Cognitive Task to Reduce the Negative Impact of Dual-Tasking on the Gait of Older Adults

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 287-288
Author(s):  
Jeffrey Hausdorff ◽  
Nofar Schneider ◽  
Marina Brozgol ◽  
Pablo Cornejo Thumm ◽  
Nir Giladi ◽  
...  
Keyword(s):  
Older Adults ◽  
Virtual Reality ◽  
Executive Function ◽  
Dual Task ◽  
Gait Speed ◽  
Negative Impact ◽  
Virtual Reality Environment ◽  
Dual Tasking ◽  
Concurrent Performance ◽  
Dual Task Cost

Abstract The simultaneous performance of a secondary task while walking (i.e., dual tasking) increases motor-cognitive interference and fall risk in older adults. Combining transcranial direct current stimulation (tDCS) with the concurrent performance of a task that putatively involves the same brain networks targeted by the tDCS may reduce the negative impact of dual-tasking on walking. We examined whether tDCS applied while walking reduces the dual-task costs to gait and whether this combination is better than tDCS alone or walking alone (with sham stimulation). In 25 healthy older adults (aged 75.7±10.5yrs), a double-blind, within-subject, cross-over pilot study evaluated the acute after-effects of 20 minutes of tDCS targeting the primary motor cortex and the dorsal lateral pre frontal cortex during three separate sessions:1) tDCS while walking on a treadmill in a virtual-reality environment (tDCS+walking), 2) tDCS while seated (tDCS+seated), and 3) walking in the virtual-reality environment with sham tDCS (sham+walking). The complex walking condition taxed motor and cognitive abilities. During each session, single- and dual-task walking and cognitive function were assessed before and immediately after stimulation. Compared to pre-tDCS performance, tDCS+walking reduced the dual-task cost to gait speed (p=0.004) and other gait features (e.g., variability p=0.02), and improved (p<0.001) executive function (Stroop interference score). tDCS+seated and sham+walking did not affect the dual-task cost to gait speed (p>0.17). These initial findings demonstrate that tDCS delivered during challenging walking ameliorates dual-task gait and executive function in older adults, suggesting that the concurrent performance of related tasks enhances the efficacy of the neural stimulation and mobility.

Sign in / Sign up

Export Citation Format

Share Document