Learning of across- and within-task contingencies modulates partial-repetition costs in dual-tasking

2021 ◽  
Author(s):  
Lasse Pelzer ◽  
Christoph Naefgen ◽  
Robert Gaschler ◽  
Hilde Haider
Keyword(s):  
Dual Task ◽  
Discrimination Task ◽  
Experimental Approach ◽  
Feature Binding ◽  
Dual Tasking ◽  
Single Task ◽  
Task Set ◽  
Task Processing ◽  
Tone Discrimination ◽  
Task Sets

AbstractDual-task costs might result from confusions on the task-set level as both tasks are not represented as distinct task-sets, but rather being integrated into a single task-set. This suggests that events in the two tasks are stored and retrieved together as an integrated memory episode. In a series of three experiments, we tested for such integrated task processing and whether it can be modulated by regularities between the stimuli of the two tasks (across-task contingencies) or by sequential regularities within one of the tasks (within-task contingencies). Building on the experimental approach of feature binding in action control, we tested whether the participants in a dual-tasking experiment will show partial-repetition costs: they should be slower when only the stimulus in one of the two tasks is repeated from Trial n − 1 to Trial n than when the stimuli in both tasks repeat. In all three experiments, the participants processed a visual-manual and an auditory-vocal tone-discrimination task which were always presented concurrently. In Experiment 1, we show that retrieval of Trial n − 1 episodes is stable across practice if the stimulus material is drawn randomly. Across-task contingencies (Experiment 2) and sequential regularities within a task (Experiment 3) can compete with n − 1-based retrieval leading to a reduction of partial-repetition costs with practice. Overall the results suggest that participants do not separate the processing of the two tasks, yet, within-task contingencies might reduce integrated task processing.

scholarly journals Energy optimization during walking involves implicit processing

2021 ◽  
Vol 224 (17) ◽  
Author(s):  
Megan J. McAllister ◽  
Rachel L. Blair ◽  
J. Maxwell Donelan ◽  
Jessica C. Selinger
Keyword(s):  
Dual Task ◽  
Secondary Task ◽  
Discrimination Task ◽  
Energy Optimization ◽  
The Body ◽  
Step Frequency ◽  
Implicit Processing ◽  
Single Task ◽  
Optimization Task ◽  
Tone Discrimination

ABSTRACT Gait adaptations, in response to novel environments, devices or changes to the body, can be driven by the continuous optimization of energy expenditure. However, whether energy optimization involves implicit processing (occurring automatically and with minimal cognitive attention), explicit processing (occurring consciously with an attention-demanding strategy) or both in combination remains unclear. Here, we used a dual-task paradigm to probe the contributions of implicit and explicit processes in energy optimization during walking. To create our primary energy optimization task, we used lower-limb exoskeletons to shift people's energetically optimal step frequency to frequencies lower than normally preferred. Our secondary task, designed to draw explicit attention from the optimization task, was an auditory tone discrimination task. We found that adding this secondary task did not prevent energy optimization during walking; participants in our dual-task experiment adapted their step frequency toward the optima by an amount and at a rate similar to participants in our previous single-task experiment. We also found that performance on the tone discrimination task did not worsen when participants were adapting toward energy optima; accuracy scores and reaction times remained unchanged when the exoskeleton altered the energy optimal gaits. Survey responses suggest that dual-task participants were largely unaware of the changes they made to their gait during adaptation, whereas single-task participants were more aware of their gait changes yet did not leverage this explicit awareness to improve gait adaptation. Collectively, our results suggest that energy optimization involves implicit processing, allowing attentional resources to be directed toward other cognitive and motor objectives during walking.

scholarly journals ENERGY OPTIMIZATION DURING WALKING CAN BE A PRIMARILY IMPLICIT PROCESS

2020 ◽  
Author(s):  
Megan J. McAllister ◽  
Rachel L. Blair ◽  
J. Maxwell Donelan ◽  
Jessica C. Selinger
Keyword(s):  
Dual Task ◽  
Secondary Task ◽  
Discrimination Task ◽  
Energy Optimization ◽  
Step Frequency ◽  
Single Task ◽  
Attentional Resources ◽  
Optimization Task ◽  
Tone Discrimination ◽  
Explicit Process

AbstractGait adaptations, in response to novel environments, devices or changes to the body, can be driven by the continuous optimization of energy expenditure. However, whether energy optimization is primarily an implicit process—occurring automatically and with minimal cognitive attention—or an explicit process—occurring as a result of a conscious, attention-demanding, strategy—remains unclear. Here, we use a dual-task paradigm to test whether energy optimization during walking is primarily an implicit or explicit process. To create our primary energy optimization task, we used lower-limb exoskeletons to shift people’s energetically optimal step frequency to frequencies lower than normally preferred. Our secondary task, designed to draw explicit attention from the optimization task, was an auditory tone discrimination task. We found that adding this secondary task did not disrupt energy optimization during walking; participants in our dual-task experiment adapted their step frequency toward the optima by an amount similar to participants in our previous single-task experiment. We also found that performance on the tone discrimination task did not worsen when participants were optimizing for energetic cost; accuracy scores and reaction times remained unchanged when the exoskeleton altered the energy optimal gaits. Survey responses suggest that dual-task participants were largely unaware of the changes they made to their gait to optimize energy, whereas single-task participants were more aware of their gait changes yet did not leverage this explicit awareness to improve gait optimization. Collectively, our results suggest that energy optimization is primarily an implicit process, allowing attentional resources to be directed toward other cognitive and motor objectives during walking.Summary statementPeople can adapt to energy optimal walking patterns without being consciously aware they are doing so. This allows people to discover energetically efficient gaits while preserving attentional resources for other tasks.

scholarly journals Reduction of Dual-task Costs by Noninvasive Modulation of Prefrontal Activity in Healthy Elders

2016 ◽  
Vol 28 (2) ◽  
pp. 275-281 ◽  
Author(s):  
Brad Manor ◽  
Junhong Zhou ◽  
Azizah Jor'dan ◽  
Jue Zhang ◽  
Jing Fang ◽  
...  
Keyword(s):  
Older Adults ◽  
Dual Task ◽  
Cognitive Task ◽  
Brain Regions ◽  
Dual Tasking ◽  
Single Task ◽  
Novel Approach ◽  
Before And After ◽  
Improved Performance ◽  
Task Conditions

Dual tasking (e.g., walking or standing while performing a cognitive task) disrupts performance in one or both tasks, and such dual-task costs increase with aging into senescence. Dual tasking activates a network of brain regions including pFC. We therefore hypothesized that facilitation of prefrontal cortical activity via transcranial direct current stimulation (tDCS) would reduce dual-task costs in older adults. Thirty-seven healthy older adults completed two visits during which dual tasking was assessed before and after 20 min of real or sham tDCS targeting the left pFC. Trials of single-task standing, walking, and verbalized serial subtractions were completed, along with dual-task trials of standing or walking while performing serial subtractions. Dual-task costs were calculated as the percent change in markers of gait and postural control and serial subtraction performance, from single to dual tasking. Significant dual-task costs to standing, walking, and serial subtraction performance were observed before tDCS (p < .01). These dual-task costs were less after real tDCS as compared with sham tDCS as well as compared with either pre-tDCS condition (p < .03). Further analyses indicated that tDCS did not alter single task performance but instead improved performance solely within dual-task conditions (p < .02). These results demonstrate that dual tasking can be improved by modulating prefrontal activity, thus indicating that dual-task decrements are modifiable and may not necessarily reflect an obligatory consequence of aging. Moreover, tDCS may ultimately serve as a novel approach to preserving dual-task capacity into senescence.

scholarly journals Evidence for a multicomponent hierarchical representation of dual tasks

2020 ◽  
Author(s):  
Patricia Hirsch ◽  
Clara Roesch ◽  
Iring Koch
Keyword(s):  
Dual Task ◽  
Task Interference ◽  
Dual Tasks ◽  
Hierarchical Representation ◽  
Switch Costs ◽  
Task Processing ◽  
The Individual ◽  
Task Sets ◽  
Dual Task Interference ◽  
And Task

Abstract Recent dual-task studies observed worse performance in task-pair switches than in task-pair repetitions and interpreted these task-pair switch costs as evidence that the identity of the two individual tasks performed within a dual task is jointly represented in a single mental representation, termed “task-pair set.” In the present study, we conducted two experiments to examine (a) whether task-pair switch costs are due to switching cues or/and task pairs and (b) at which time task-pair sets are activated during dual-task processing. In Experiment 1, we used two cues per task-pair and found typical dual-task interference, indicating that performance in the individual tasks performed within the dual task deteriorates as a function of increased temporal task overlap. Moreover, we observed cue switch costs, possibly reflecting perceptual cue priming. Importantly, there were also task-pair switch costs that occur even when controlling for cue switching. This suggests that task-pair switching per se produces a performance cost that cannot be reduced to costs of cue switching. In Experiment 2, we employed a go/no-go-like manipulation and observed task-pair switch costs after no-go trials where subjects prepared for a task-pair, but did not perform it. This indicates that task-pair sets are activated before performing a dual task. Together, the findings of the present study provide further evidence for a multicomponent hierarchical representation consisting of a task-pair set organized at a hierarchically higher level than the task sets of the individual tasks performed within a dual task.

Dissociable Neural Effects of Task Order Control and Task Set Maintenance during Dual-task Processing

2008 ◽  
Vol 20 (4) ◽  
pp. 613-628 ◽  
Author(s):  
Christine Stelzel ◽  
Antje Kraft ◽  
Stephan A. Brandt ◽  
Torsten Schubert
Keyword(s):  
Dual Task ◽  
Parametric Design ◽  
Task Set ◽  
Task Order ◽  
Fmri Study ◽  
Addition Task ◽  
Dual Task Performance ◽  
Task Processing ◽  
Functional Relevance ◽  
And Task

The functional relevance of the lateral prefrontal cortex (lPFC) for the ability to process two tasks simultaneously has been debated extensively in previous studies that employed functional magnetic resonance imaging (fMRI) to investigate the neural correlates of dual-task processing. In the present fMRI study, we shed new light on this debate by directly comparing the lPFC activity changes for two cognitive functions commonly associated with dual-task performance: task order control and task set maintenance. We manipulated both functions in a 2 × 2 integrated parametric design. The fMRI data revealed a functional-neuroanatomical dissociation for the lPFC. Regions surrounding the inferior frontal sulcus and the middle frontal gyrus were exclusively associated with task order control but not with increased demands on task set maintenance during dual-task processing. The only lPFC region associated with task set maintenance was located in the left anterior insula. Outside the lPFC, we found dissociable regions for task order control and task set maintenance bilaterally in the premotor cortices with more rostral premotor activity for task order control and more caudal premotor activity for task set maintenance. In addition, task order control activated the intraparietal sulci bilaterally. Our data clearly suggest that task order control is a separable cognitive mechanism in dual-task situations that is related to activity changes in the lPFC and that can be dissociated from task set maintenance.

Combining Letter-Matching and Tone Discrimination: Evidence of Automatic Perceptual and Spatial Congruity Effects

1993 ◽  
Vol 46 (1) ◽  
pp. 161-180
Author(s):  
Duane J. Page ◽  
Jerry G. Ells
Keyword(s):  
Target Letter ◽  
Dual Task ◽  
Secondary Task ◽  
Discrimination Task ◽  
Letter Pair ◽  
Cost Benefit ◽  
Process Theory ◽  
Attentional Processes ◽  
Identical Letter ◽  
Tone Discrimination

Dual task and priming paradigms were combined to investigate the distinction between automatic and attentional processes. Subjects in two experiments performed a primed letter-matching and a tone discrimination task separately and concurrently. The interval between prime onset and letter pair (SOA) was varied from 50 to 500 msec. Cost-benefit analyses in Experiment 1 indicated that primes that matched target letter pairs began to facilitate performance at an SOA of 150 msec. Primes inhibited performance when they mismatched identical letter pairs at SOA 100. In the dual-task situation, the benefits of priming letter targets were reflected in probe latencies with no evidence of concurrent costs in tone latencies. Experiment 2 revealed that two tasks could be primed simultaneously as effectively as when each was primed alone. Findings are discussed in reference to Posner and Snyder's (1975a, 1975b) two-process theory of priming and the applicability of a secondary task technique.

Effects of Concurrent Manual Task Performance on Connected Speech Acoustics in Individuals With Parkinson Disease

2019 ◽  
Vol 62 (7) ◽  
pp. 2099-2117 ◽  
Author(s):  
Jason A. Whitfield ◽  
Zoe Kriegel ◽  
Adam M. Fullenkamp ◽  
Daryush D. Mehta
Keyword(s):  
Task Performance ◽  
Speech Production ◽  
Dual Task ◽  
Motor Task ◽  
Task Condition ◽  
Connected Speech ◽  
Speech Acoustics ◽  
Single Task ◽  
Manual Task ◽  
Task Conditions

Purpose Prior investigations suggest that simultaneous performance of more than 1 motor-oriented task may exacerbate speech motor deficits in individuals with Parkinson disease (PD). The purpose of the current investigation was to examine the extent to which performing a low-demand manual task affected the connected speech in individuals with and without PD. Method Individuals with PD and neurologically healthy controls performed speech tasks (reading and extemporaneous speech tasks) and an oscillatory manual task (a counterclockwise circle-drawing task) in isolation (single-task condition) and concurrently (dual-task condition). Results Relative to speech task performance, no changes in speech acoustics were observed for either group when the low-demand motor task was performed with the concurrent reading tasks. Speakers with PD exhibited a significant decrease in pause duration between the single-task (speech only) and dual-task conditions for the extemporaneous speech task, whereas control participants did not exhibit changes in any speech production variable between the single- and dual-task conditions. Conclusions Overall, there were little to no changes in speech production when a low-demand oscillatory motor task was performed with concurrent reading. For the extemporaneous task, however, individuals with PD exhibited significant changes when the speech and manual tasks were performed concurrently, a pattern that was not observed for control speakers. Supplemental Material https://doi.org/10.23641/asha.8637008

THE RELIABILITY OF CLINICAL BALANCE TESTS UNDER SINGLE-TASK AND DUAL-TASK TESTING PARADIGMS IN UNINJURED ACTIVE YOUTH AND YOUNG ADULTS

2020 ◽  
Vol 15 (4) ◽  
pp. 487-500
Author(s):  
Thaer S. Manaseer ◽  
Jackie L. Whittaker ◽  
Codi Isaac ◽  
Kathryn Schneider ◽  
Mary Roduta Roberts ◽  
...  
Keyword(s):  
Young Adults ◽  
Dual Task ◽  
Single Task ◽  
Balance Tests ◽  
Youth And Young Adults

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&lt;0.001) executive function (Stroop interference score). tDCS+seated and sham+walking did not affect the dual-task cost to gait speed (p&gt;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.

Digital Biomarkers of Cognitive Frailty: The Value of Detailed Gait Assessment Beyond Gait Speed

Gerontology ◽  
2021 ◽  
pp. 1-10
Author(s):  
He Zhou ◽  
Catherine Park ◽  
Mohammad Shahbazi ◽  
Michele K. York ◽  
Mark E. Kunik ◽  
...  
Keyword(s):  
Older Adults ◽  
Steady State ◽  
Dual Task ◽  
Gait Speed ◽  
Stride Length ◽  
Cognitive Frailty ◽  
Single Task ◽  
Double Support ◽  
Gait Parameters ◽  
Digital Biomarkers

<b><i>Background:</i></b> Cognitive frailty (CF), defined as the simultaneous presence of cognitive impairment and physical frailty, is a clinical symptom in early-stage dementia with promise in assessing the risk of dementia. The purpose of this study was to use wearables to determine the most sensitive digital gait biomarkers to identify CF. <b><i>Methods:</i></b> Of 121 older adults (age = 78.9 ± 8.2 years, body mass index = 26.6 ± 5.5 kg/m<sup>2</sup>) who were evaluated with a comprehensive neurological exam and the Fried frailty criteria, 41 participants (34%) were identified with CF and 80 participants (66%) were identified without CF. Gait performance of participants was assessed under single task (walking without cognitive distraction) and dual task (walking while counting backward from a random number) using a validated wearable platform. Participants walked at habitual speed over a distance of 10 m. A validated algorithm was used to determine steady-state walking. Gait parameters of interest include steady-state gait speed, stride length, gait cycle time, double support, and gait unsteadiness. In addition, speed and stride length were normalized by height. <b><i>Results:</i></b> Our results suggest that compared to the group without CF, the CF group had deteriorated gait performances in both single-task and dual-task walking (Cohen’s effect size <i>d</i> = 0.42–0.97, <i>p</i> &#x3c; 0.050). The largest effect size was observed in normalized dual-task gait speed (<i>d</i> = 0.97, <i>p</i> &#x3c; 0.001). The use of dual-task gait speed improved the area under the curve (AUC) to distinguish CF cases to 0.76 from 0.73 observed for the single-task gait speed. Adding both single-task and dual-task gait speeds did not noticeably change AUC. However, when additional gait parameters such as gait unsteadiness, stride length, and double support were included in the model, AUC was improved to 0.87. <b><i>Conclusions:</i></b> This study suggests that gait performances measured by wearable sensors are potential digital biomarkers of CF among older adults. Dual-task gait and other detailed gait metrics provide value for identifying CF above gait speed alone. Future studies need to examine the potential benefits of gait performances for early diagnosis of CF and/or tracking its severity over time.

Sign in / Sign up

Export Citation Format

Share Document