Relationships between cognitive factors and gait strategy during exoskeleton-augmented walking

2021 ◽  
Vol 65 (1) ◽  
pp. 211-215
Author(s):  
Aditi Gupta ◽  
Ryan McKindles ◽  
Leia Stirling
Keyword(s):  
Divided Attention ◽  
Individual Variation ◽  
Stride Length ◽  
Simon Task ◽  
Reaction Times ◽  
Cognitive Factors ◽  
Gait Stability ◽  
Gait Characteristics

Individual variation in exoskeleton-augmented gait strategy may arise from differences in cognitive factors, e.g., ability to respond quickly to stimuli or complete tasks under divided attention. Gait strategy is defined as different approaches to achieving gait priorities (e.g., walking without falling) and is observed via changes in gait characteristics like normalized stride length or width. Changes indicate shifting priorities like increasing stability or coordination with an exoskeleton. Relationships between cognitive factors and exoskeleton gait characteristics were assessed. Cognitive factors were quantified using a modified Simon task and a speed achievement task on a self-paced treadmill with and without a secondary go/no-go task. Individuals with faster reaction times and decreased ability to maintain a given speed tended to prioritize coordination with an exoskeleton over gait stability. These correlations indicate relationships between cognitive factors and individual exoskeleton-augmented gait strategy that should be further investigated to understand variation in exoskeleton use.

Metrics for quantifying cognitive factors that may underlie individual variation in exoskeleton use

2021 ◽  
Vol 65 (1) ◽  
pp. 216-220
Author(s):  
Aditi Gupta ◽  
Ryan McKindles ◽  
Leia Stirling
Keyword(s):  
Reaction Time ◽  
Task Performance ◽  
Individual Variation ◽  
Simon Task ◽  
Reaction Times ◽  
Cognitive Factors ◽  
System Operation ◽  
Subject Variability ◽  
Strategy Parameters ◽  
Outcome Metrics

Individual differences in adaptation to exoskeletons have been observed, but are not well understood. Kinematic, kinetic, and physiologic factors are commonly used to assess these systems. Parameters from experimental psychology and gait literature wereadapted to probe the lower extremity perception-cognition-action loop using measures of reaction times, gait task performance, and gait strategy. Parameters were measured in 15 subjects via two tasks: (1) a modified Simon task and (2) a speed-achievement task with secondary go/no-go cues on a self-paced treadmill. Outcome metrics were assessed for significantly different intra- versus inter-subject variability. Reaction time measures from the modified Simon task, as well two speed-achievement metrics and one gait-strategy characteristic we re found to show significant differenc es in intra- versus inter-subject variability. These results suggest that select cognitive factors may differentiate between individuals and be potential predictors for individual variation during exoskeleton system operation.

scholarly journals Hierarchical Task Analysis for Driving under Divided Attention

2019 ◽  
Vol 63 (1) ◽  
pp. 1744-1748 ◽  
Author(s):  
Xiaonan Yang ◽  
Jung Hyup Kim ◽  
Roland Nazareth
Keyword(s):  
Divided Attention ◽  
Task Analysis ◽  
Reaction Times ◽  
Cognitive Factors ◽  
Driver Assistance ◽  
Driver Assistance Systems ◽  
Hierarchical Task Analysis ◽  
Driving Behaviors ◽  
Driving Scenario ◽  
Assistance Systems

Although researchers have made various models of driving behavior, the behavior model under divided attention is not well studied. In this paper, the driver’s behavior differences under divided-attention were studied in a simulated driving environment. A driving scenario was developed to simulate hazards on the highway in dynamic driving conditions. Based on crash and non-crash cases through eye tracking videos from the experiment, Hierarchical task analysis (HTA) was conducted, and decomposed different complex driving behaviors into drivers’ perception, cognition, and decision. Also, their reaction times were compared by using the cognitive-perceptual model in GOMS. Through this study, different driving behaviors and corresponding cognitive factors, which contributed to a slower reaction were identified. The results from this study could be as a valuable input to develop advanced driver assistance systems which could provide smart collision warnings based on the driver’s attention.

scholarly journals Gait Characteristics under Imposed Challenge Speed Conditions in Patients with Parkinson’s Disease During Overground Walking

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2132 ◽  
Author(s):  
Myeounggon Lee ◽  
Changhong Youm ◽  
Byungjoo Noh ◽  
Hwayoung Park ◽  
Sang-Myung Cheon
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Stride Length ◽  
Motor Symptoms ◽  
Overground Walking ◽  
Gait Stability ◽  
Double Support ◽  
Gait Characteristics ◽  
Measurement Units ◽  
Walking Tests

Evaluating gait stability at slower or faster speeds and self-preferred speeds based on continuous steps may assist in determining the severity of motor symptoms in Parkinson’s disease (PD) patients. This study aimed to investigate the gait ability at imposed speed conditions in PD patients during overground walking. Overall, 74 PD patients and 52 age-matched healthy controls were recruited. Levodopa was administered to patients in the PD group, and all participants completed imposed slower, preferred, and faster speed walking tests along a straight 15-m walkway wearing shoe-type inertial measurement units. Reliability of the slower and faster conditions between the estimated and measured speeds indicated excellent agreement for PD patients and controls. PD patients demonstrated higher gait asymmetry (GA) and coefficient of variance (CV) for stride length and stance phase than the controls at slower speeds and higher CVs for phases for single support, double support, and stance. CV of the double support phase could distinguish between PD patients and controls at faster speeds. The GA and CVs of stride length and phase-related variables were associated with motor symptoms in PD patients. Speed conditions should be considered during gait analysis. Gait variability could evaluate the severity of motor symptoms in PD patients.

scholarly journals Limitations of Foot-Worn Sensors for Assessing Running Power

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 4952
Author(s):  
Tobias Baumgartner ◽  
Steffen Held ◽  
Stefanie Klatt ◽  
Lars Donath
Keyword(s):  
Time Use ◽  
Stride Length ◽  
Metabolic Cost ◽  
Running Economy ◽  
Accelerometer Data ◽  
Gait Characteristics ◽  
Significant Difference ◽  
Metabolic Costs ◽  
Ground Contact Time ◽  
Training Signal

Running power as measured by foot-worn sensors is considered to be associated with the metabolic cost of running. In this study, we show that running economy needs to be taken into account when deriving metabolic cost from accelerometer data. We administered an experiment in which 32 experienced participants (age = 28 ± 7 years, weekly running distance = 51 ± 24 km) ran at a constant speed with modified spatiotemporal gait characteristics (stride length, ground contact time, use of arms). We recorded both their metabolic costs of transportation, as well as running power, as measured by a Stryd sensor. Purposely varying the running style impacts the running economy and leads to significant differences in the metabolic cost of running (p < 0.01). At the same time, the expected rise in running power does not follow this change, and there is a significant difference in the relation between metabolic cost and power (p < 0.001). These results stand in contrast to the previously reported link between metabolic and mechanical running characteristics estimated by foot-worn sensors. This casts doubt on the feasibility of measuring running power in the field, as well as using it as a training signal.

Tussen Lezen En Luisteren

1992 ◽  
Vol 43 ◽  
pp. 27-38
Author(s):  
Ton Dijkstra
Keyword(s):  
Stimulus Onset Asynchrony ◽  
Divided Attention ◽  
Single Channel ◽  
Reaction Times ◽  
Race Model ◽  
Stimulus Onset ◽  
Sublexical Processing ◽  
Temporal Aspects ◽  
Onset Asynchrony ◽  
Processing Differences

Two divided attention experiments investigated whether graphemes and phonemes can mutually activate each other during bimodal sublexical processing. Dutch subjects reacted to target letters and/or speech sounds in single-channel and bimodal stimuli. In some bimodal conditions, the visual and auditory targets were congruent (e.g., visual A, auditory /a:/), in others they were not (e.g., visual U, auditory /a:/). Temporal aspects of cross-modal activation were examined by varying the stimulus onset asynchrony (SOA) of visual and auditory stimulus components. Processing differences among stimuli (e.g., the letters A and U) were accounted for by correcting the obtained bimodal reaction times by means of the predictions of an independent race-model. Comparing the results of the adapted congruent and incongruent conditions for each SOA, it can be concluded that (a) cross-modal activation takes place in this task situation; (b) it is bidirectional, i.e. it spreads from grapheme to phoneme and vice versa; and (c) it occurs very rapidly.

Binding of Event Files in a (go/no-go) Simon Task With an Accessory Peripheral Signal

2009 ◽  
Vol 56 (2) ◽  
pp. 100-111 ◽  
Author(s):  
Kathleen Maetens ◽  
David Henderickx ◽  
Eric Soetens
Keyword(s):  
Simon Effect ◽  
Time Course ◽  
Simon Task ◽  
Reaction Times ◽  
Response Signal ◽  
Event File ◽  
Response Information ◽  
Event Files ◽  
Accessory Stimulus ◽  
Accessory Signal

To understand the relation between the Simon effect and the time course of relevant and irrelevant code activations, we presented the response signal before or simultaneously with a go/no-go signal in an accessory Simon task. A peripheral accessory signal could appear before, simultaneously with or after the go/no-go signal. We observed a Simon effect when the accessory signal was presented just before or simultaneously with the go signal, irrespective of the delay between response and go/no-go signal. The Simon effect reversed when the accessory signal was presented 150 ms after the go signal when response information was presented first and the participants had to make a go/no-go decision afterwards or when they had to select a response when the go signal appeared. The reversal did not occur when both decisions were required at the same time. Our data suggest that the integration and release of event files are involved in the occurrence of the reversal. Response activation induced by the accessory stimulus facilitates/interferes with the response when it is presented before the event file is integrated. When the accessory stimulus is presented after integration, the automatically activated response is inhibited, causing a delay in the corresponding reaction times.

scholarly journals Effects of age on inhibitory control are affected by task-specific features

2018 ◽  
Vol 71 (5) ◽  
pp. 1219-1233 ◽  
Author(s):  
Angela de Bruin ◽  
Sergio Della Sala
Keyword(s):  
Older Adults ◽  
Inhibitory Control ◽  
Processing Speed ◽  
Simon Task ◽  
Flanker Task ◽  
Reaction Times ◽  
Age Effects ◽  
Control Task ◽  
Younger Adults

Older adults have been argued to have impoverished inhibitory control compared to younger adults. However, these effects of age may depend on processing speed and their manifestation may furthermore depend on the type of inhibitory control task that is used. We present two experiments that examine age effects on inhibition across three tasks: a Simon arrow, static flanker and motion flanker task. The results showed overall slower reaction times (RTs) for older adults on all three tasks. However, effects of age on inhibition costs were only found for the Simon task, but not for the two flanker tasks. The motion flanker task furthermore showed an effect of baseline processing speed on the relation between age and inhibition costs. Older adults with slower baseline responses showed smaller inhibition costs, suggesting they were affected less by the flanker items than faster older adults. These findings suggest that effects of age on inhibition are task dependent and can be modulated by task-specific features such as the type of interference, type of stimuli and processing speed.

Cognitive inhibitory control in children following early childhood music education

2016 ◽  
Vol 21 (3) ◽  
pp. 303-315 ◽  
Author(s):  
Marie-Eve Joret ◽  
Filip Germeys ◽  
Yori Gidron
Keyword(s):  
Music Education ◽  
Executive Functions ◽  
Inhibitory Control ◽  
Simon Task ◽  
Musical Training ◽  
Economic Status ◽  
Reaction Times ◽  
Error Rates ◽  
Significant Group ◽  
Music Training

The relationship between music training and executive functions has remained inconsistent in previous studies, possibly due to methodological limitations. This study aims to investigate cognitive inhibitory control in children (9–12 years old) with and without musical training, while carefully considering confounding variables. To assess executive functions, the Simon task was used, measuring reaction times (RTs) and error rates on congruent and incongruent trials. Information on important variables such as bilingualism, socio-economic status (SES), music pedagogy and amount of musical training was collected through a parental questionnaire. Furthermore, verbal and non-verbal intelligence were assessed with validated tests to consider their effects as well. The results showed that the samples did not significantly differ in background variables. The analysis of the RT data on the Simon task revealed a significant group × congruency interaction, such that musically trained children showed a reduced magnitude of the congruency effect (RTs on incongruent trials – RTs on congruent trials) compared to non-musicians. To conclude, music training seems to be associated with enhanced cognitive inhibitory control in well-matched samples.

Sign in / Sign up

Export Citation Format

Share Document