scholarly journals Evaluating the energetics of entrainment in a human–machine coupled oscillator system

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ryan T. Schroeder ◽  
James L. Croft ◽  
John E. A. Bertram
Keyword(s):  
Central Pattern Generators ◽  
Metabolic Cost ◽  
The Body ◽  
Vertical Force ◽  
Wide Range ◽  
Metabolic Expenditure ◽  
Pattern Generators ◽  
Positive Work ◽  
Phase Relationships

AbstractDuring locomotion, humans sometimes entrain (i.e. synchronize) their steps to external oscillations: e.g. swaying bridges, tandem walking, bouncy harnesses, vibrating treadmills, exoskeletons. Previous studies have discussed the role of nonlinear oscillators (e.g. central pattern generators) in facilitating entrainment. However, the energetics of such interactions are unknown. Given substantial evidence that humans prioritize economy during locomotion, we tested whether reduced metabolic expenditure is associated with human entrainment to vertical force oscillations, where frequency and amplitude were prescribed via a custom mechatronics system during walking. Although metabolic cost was not significantly reduced during entrainment, individuals expended less energy when the oscillation forces did net positive work on the body and roughly selected phase relationships that maximize positive work. It is possible that individuals use mechanical cues to infer energy cost and inform effective gait strategies. If so, an accurate prediction may rely on the relative stability of interactions with the environment. Our results suggest that entrainment occurs over a wide range of oscillation parameters, though not as a direct priority for minimizing metabolic cost. Instead, entrainment may act to stabilize interactions with the environment, thus increasing predictability for the effective implementation of internal models that guide energy minimization.

scholarly journals The Role of Entrainment in Human Walking: Energy Minimization in Oscillating Environments

2020 ◽  
Author(s):  
Ryan Schroeder ◽  
James Croft ◽  
John Bertram
Keyword(s):  
Energy Minimization ◽  
Central Pattern Generators ◽  
Metabolic Cost ◽  
Vertical Force ◽  
Effective Implementation ◽  
Wide Range ◽  
Metabolic Expenditure ◽  
Pattern Generators ◽  
Phase Relationships

Abstract During locomotion, humans often entrain (i.e. synchronize) their steps to external oscillations: e.g. swaying bridges, tandem walking, bouncy harnesses, vibrating treadmills, exoskeletons. Previous studies have discussed the role of nonlinear oscillators (e.g. central pattern generators) in facilitating entrainment. However, the underlying benefits of entrainment are unknown. Given substantial evidence that humans prioritize economy during locomotion, we tested whether reduced metabolic expenditure accompanies human entrainment to vertical force oscillations, where frequency and amplitude were prescribed via a custom mechatronics system during walking. Although metabolic cost was not significantly reduced during entrainment, individuals who experienced negative work from oscillations had a higher cost than those who experienced positive work, and subjects generally selected phase relationships indicating the latter. It is possible that individuals use mechanical cues to infer energy cost and inform effective gait strategies. If so, an accurate prediction may rely on the relative stability of interactions with the environment. Our results suggest that entrainment is preferred over a wide range of oscillation parameters, though not as a direct priority for minimizing metabolic cost. Instead, entrainment may act to stabilize interactions with the environment, thus increasing predictability for the effective implementation of internal models that guide energy minimization.

Sensory regulation of quadrupedal locomotion: a top-down or bottom-up control system?

2012 ◽  
Vol 108 (3) ◽  
pp. 709-711 ◽  
Author(s):  
Yann Thibaudier ◽  
Marie-France Hurteau
Keyword(s):  
Control System ◽  
Central Pattern Generators ◽  
Top Down ◽  
Bottom Up ◽  
Sensory Inputs ◽  
Sensory Regulation ◽  
Before And After ◽  
Pattern Generators

Propriospinal pathways are thought to be critical for quadrupedal coordination by coupling cervical and lumbar central pattern generators (CPGs). However, the mechanisms involved in relaying information between girdles remain largely unexplored. Using an in vitro spinal cord preparation in neonatal rats, Juvin and colleagues ( Juvin et al. 2012 ) have recently shown sensory inputs from the hindlimbs have greater influence on forelimb CPGs than forelimb sensory inputs on hindlimb CPGs, in other words, a bottom-up control system. However, results from decerebrate cats suggest a top-down control system. It may be that both bottom-up and top-down control systems exist and that the dominance of one over the other is task or context dependent. As such, the role of sensory inputs in controlling quadrupedal coordination before and after injury requires further investigation.

scholarly journals Pacification and Indigenous Struggles in Canada

2013 ◽  
Vol 9 (2) ◽  
Author(s):  
Tia Dafnos
Keyword(s):  
The Body ◽  
Access To Information ◽  
Security Threat ◽  
Front Line ◽  
Indigenous Resistance ◽  
The Public ◽  
Wide Range ◽  
Integral Role ◽  
Information Requests

Front-line police operations are deeply entwined with less visible activities – or practices not commonly identified as policing – that are carried out by a wide range of participants as strategies of settler-colonial pacification operating through the organizing logics of security and liberal legalism. Using open source texts and records obtained through access to information requests, this article unmaps some of the contemporary strategies employed by Canadian institutions to pacify Indigenous resistance. As a contribution to the body of work seeking to develop the politics of anti-security, the analysis disrupts the binary categories that animate security logic by examining the public order policing approach of the Ontario Provincial Police, the framing of Indigenous resistance as a security threat, and the integral role of Indian Affairs in securing the settler-state.

The Bodily Self

2018 ◽  
Author(s):  
José Luis Bermúdez
Keyword(s):  
Sense Of Self ◽  
The Body ◽  
The Self ◽  
Behavioral Sciences ◽  
Significant Contributor ◽  
Wide Range ◽  
Physical Objects ◽  
Selection Of

How can we be aware of ourselves both as physical objects and as thinking, experiencing subjects? What role does the experience of the body play in generating our sense of self? What is the role of action and agency in the construction of the bodily self? These questions have been a rich subject of interdisciplinary debate among philosophers, neuroscientists, experimental psychologists, and cognitive scientists for several decades. José Luis Bermúdez been a significant contributor to these debates since the 1990’s, when he authored The Paradox of Self-Consciousness (MIT Press, 1998) and co-edited The Body and the Self (MIT Press, 1995) with Anthony Marcel and Naomi Eilan. The Bodily Self is a selection of essays all focused on different aspects of the role of the body in self-consciousness, prefaced by a substantial introduction outlining common themes across the essays. The essays have been published in a wide range of journals and edited volumes. Putting them together brings out a wide-ranging, thematically consistent perspective on a set of topics and problems that remain firmly of interest across the cognitive and behavioral sciences.

Mimi Nichter, Fat talk: What girls and their parents say about dieting. Cambridge, MA: Harvard University Press, 2000. Pp. xi, 263. Hb $22.95.

2002 ◽  
Vol 31 (5) ◽  
pp. 811-815
Author(s):  
Mary Bucholtz
Keyword(s):  
Human Body ◽  
Harvard University ◽  
The Body ◽  
Fat Talk ◽  
Teenage Girls ◽  
Wide Range ◽  
Medical Anthropologist ◽  
The Relationship ◽  
Equal Interest

The relationship between language and the body has become an increasingly prominent area of research within linguistics and related disciplines. Some investigators of this question have examined how facts about the human body are encoded in linguistic structure, while others have explored the use of the body as a communicative resource in interaction. Surprisingly little, however, has been written about the role of language in constructing the body as a social object. In Fat talk, Mimi Nichter, a medical anthropologist, addresses this issue by examining the discourse of dieting among American teenage girls. Although language itself is not the center of the analysis, Nichter draws on a wide range of sociolinguistic research to investigate how the body is constructed through talk – a question that will be of equal interest to scholars of language, culture, and society.

Central Resetting of Neuromuscular Steady States May Underlie Rhythmical Arm Movements

2006 ◽  
Vol 96 (3) ◽  
pp. 1124-1134 ◽  
Author(s):  
Ksenia I. Ustinova ◽  
Anatol G. Feldman ◽  
Mindy F. Levin
Keyword(s):  
Steady State ◽  
Muscle Activation ◽  
Central Pattern Generators ◽  
Steady States ◽  
The Body ◽  
Proprioceptive Reflexes ◽  
Natural Tendency ◽  
Equilibrium Configurations ◽  
Pattern Generators ◽  
State Configuration

Changing the steady-state configuration of the body or its segments may be an important function of central pattern generators for locomotion and other rhythmical movements. Thereby, muscle activation, forces, and movement may emerge following a natural tendency of the neuromuscular system to achieve the current steady-state configuration. To verify that transitions between different steady states occur during rhythmical movements, we asked standing subjects to swing one or both arms synchronously or reciprocally at ∼0.8 Hz from the shoulder joints. In randomly selected cycles, one arm was transiently arrested by an electromagnetic device. Swinging resumed after some delay and phase resetting. During bilateral swinging, the nonperturbed arm often stopped before resuming swinging at a position that was close to either the extreme forward or the extreme backward arm position observed before the perturbation. Oscillations usually resumed when both arms arrived at similar extreme positions when a synchronous bilateral pattern was initially produced or at the opposite positions if the initial pattern was reciprocal. Results suggest that a central generator controls both arms as a coherent unit by producing transitions between its steady state (equilibrium) positions. By controlling these positions, the system may define the spatial boundaries of movement. At these positions, the system may halt the oscillations, resume them at a new phase (as observed in the present study), or initiate a new motor action. Our findings are relevant to locomotion and suggest that walking may also be generated by transitions between several equilibrium configurations of the body, possibly accomplished by modulation and gating of proprioceptive reflexes.

SPECIES-SPECIFIC PATTERNS OF REFUGE USE IN FISH: THE ROLE OF METABOLIC EXPENDITURE AND BODY LENGTH

Behaviour ◽  
2000 ◽  
Vol 137 (7-8) ◽  
pp. 1113-1127 ◽  
Author(s):  
Graeme Ruxton ◽  
Jens Krause ◽  
David Cheng ◽  
Emma Kirkman
Keyword(s):  
Body Length ◽  
Gasterosteus Aculeatus ◽  
Relative Weight ◽  
Metabolic Cost ◽  
The Body ◽  
Weight Losses ◽  
Strong Trend ◽  
Relative Weight Loss ◽  
Metabolic Expenditure ◽  
Species Specific

AbstractBeing in a refuge has benefits in terms of predator avoidance and costs in terms of lost feeding opportunities. We investigated how the relative importance of these costs and benefits changes with increasing body length in two sympatric fish species, the minnow, Phoxinus phoxinus, and the stickleback, Gasterosteus aculeatus, which differ in their morphological anti-predator adaptations. Minnows were slower to emerge after taking refuge than sticklebacks, and spent less time outside it, which is consistent with the idea that minnows, which lack the morphological defences (such as spines) of sticklebacks, are more cautious of predators than the latter. Food-deprivation experiments indicated that the costs of missed feeding opportunities in terms of relative weight loss were lower for minnows than sticklebacks. Therefore hiding in a refuge comes at a lower metabolic cost for minnows than sticklebacks. Both species reduced their hiding time when food deprived and increased it following a predation threat. Furthermore, they both showed a strong trend for longer hiding periods and shorter exploration times outside the refuge with increasing body length. Our results suggest that in sticklebacks the body length-dependence of hiding times was a result of perceived predation risks being constant with increasing body length whereas relative weight losses decreased. Thus larger fish could metabolically afford to be more cautious. In minnows, both the predation risk and metabolic expenditure decreased with increasing body length suggesting that the longer hiding times in larger fish represented a trade-off between the two factors.

scholarly journals An autonomous tail-beating cycle period expressed by a region-specific swimming pattern generator in the Ciona larva

2021 ◽  
Author(s):  
Takashi Hara ◽  
Shuya Hasegawa ◽  
Yasushi Iwatani ◽  
Atsuo S. Nishino
Keyword(s):  
Central Pattern Generators ◽  
Sister Group ◽  
Pattern Generator ◽  
The Body ◽  
Periodic Pattern ◽  
Cycle Period ◽  
Swimming Pattern ◽  
Aquatic Vertebrates ◽  
Pattern Generators ◽  
Region 10

Swimming locomotion in aquatic vertebrates, such as fish and tadpoles, is expressed through orchestrated operations of central pattern generators. These parallel neuronal circuits are ubiquitously distributed and mutually coupled along the spinal cord to express undulation patterns accommodated to efferent and afferent inputs. While such sets of schemes have been shown in vertebrates, the evolutionary origin of those mechanisms along the chordate phylogeny remains unclear. Ascidians, representing a sister group of vertebrates, give rise to tadpole larvae that freely swim in seawater. In this study, we tried to locate the swimming pattern generator in larvae of the ascidian Ciona by examining locomotor ability of segmented body fragments. Our experiments demonstrated necessary and sufficient pattern generator activity in a short region (~10% of the body length as the longest estimation) including the trunk-tail junction but excluding most of the trunk and tail with major sensory apparatuses therein. Moreover, we found that these "mid-piece" body fragments express periodic tail beating bursts with ~20-s intervals without any exogenous stimuli. Comparisons among temporal patterns of tail beating bursts expressed by the mid-piece fragments and by whole larvae placed under different sensory conditions suggested that the presence of parts other than the critical mid-piece had effects to shorten swimming burst intervals, especially in the dark, and also to expand the variance in burst durations. We propose that Ciona larvae perform swimming as modified representations of autonomous and periodic pattern generator drives, which operate locally in the region of the trunk-tail junction.

scholarly journals Can the Center of Mass Reflect the Metabolic Expenditure?

2010 ◽  
Vol 16 (1) ◽  
pp. 16-21
Author(s):  
Ying ki FUNG ◽  
Tyzz yuang SHIANG
Keyword(s):  
Pulmonary Ventilation ◽  
Center Of Mass ◽  
Metabolic Cost ◽  
The Past ◽  
Transition Speed ◽  
Wide Range ◽  
Locomotion Pattern ◽  
Metabolic Expenditure ◽  
Analysis System ◽  
Preferred Transition Speed

LANGUAGE NOTE | Document text in English; abstract also in Chinese. In the past studies, the movement of center or mass (COM) was one of the descriptor to estimate the metabolic expenditure. However, the sensitivity of this method among the wide range speed, the locomotion pattern and during the Energetically Optimal Transition Speed (EOTS) is still unexplored. Hence that, the purpose of this investigation was to determine the metabolic and COM pattern differences between walk and run among the EOTS with a reflective marker motion analysis system and indirect pulmonary ventilation machine. The results showed that there is a metabolic intersection on two locomotion patterns (walk and run) between 100 and 125% Preferred Transition Speed (PTS), which coincides with the past EOTS studies, whereas, COM result showed that the variation of vertical COM displacement for running is significantly higher than walking among the entire tested speed. The pattern between the metabolic and COM variables is an inverse relation after the EOTS. Hence, the present investigator doubted that there would be a reliability problem for those instruments which use the COM displacement to estimate the metabolic cost or the intensity of physical activity among 5.15 to 9.82km/h for walk and run. 在過去的研究，身體質量中心移動常常被用作評估身體耗能的一種方法。可是這種方法在不同速度、動作型態及最佳轉換速度(EOTS)之可信範圍一直都沒有作出深入探討。因此本研究目的希望利用動作及生理分析系統對身體中心及身體耗能在兩種動作型態(走和跑)和在EOTS的情況底下的趨勢上作出分析及探討。結果顯示在兩個動作型態上在100及125%自然轉換速度情況下身體耗能出現交叉點(EOTS)，而此發現與過去EOTS之文獻相吻合，反之身體質量中心結果顯示，跑步在身體質量中心之穩定性在所有測試速度情況下都比走路有統計上之差異，跑步的垂直位移變異量明顯比走路大。由此可見身體耗能及身體質量中心變異量顯示出兩者在EOTS出現後是反比關係。因此本研究結果可推斷現在有利用身體質量中心變異量去推估身體耗能或身體活動量的儀器在速度5.15—9.82公里的情況底下可能會出現信度問題。

Sign in / Sign up

Export Citation Format

Share Document