Incremental Visual Occlusion During Split-Belt Treadmill Walking Has No Gradient Effect on Adaptation or Retention

2021 ◽  
pp. 003151252110503
Author(s):  
Amanda E. Stone ◽  
Adam C. Hockman ◽  
Jaimie A. Roper ◽  
Chris J. Hass
Keyword(s):  
Visual Field ◽  
Repeated Measures ◽  
Visual Information ◽  
Step Length ◽  
Group Differences ◽  
Lower Visual Field ◽  
Normal Vision ◽  
Locomotor Adaptation ◽  
Visual Occlusion ◽  
Length Standard

Split-belt treadmills have become an increasingly popular means of quantifying ambulation adaptability. Multiple sensory feedback mechanisms, including vision, contribute to task execution and adaptation success. No studies have yet explored visual feedback effects on locomotor adaptability across a spectrum of available visual information. In this study, we sought to better understand the effects of visual information on locomotor adaptation and retention by directly comparing incremental levels of visual occlusion. Sixty healthy young adults completed a split-belt adaptation protocol, including a baseline, asymmetric walking condition (adapt), a symmetric walking condition (de-adapt), and another asymmetric walking condition (re-adapt). We randomly assigned participants into conditions with varied visual occlusion (i.e., complete and lower visual field occlusion, or normal vision). We captured kinematic data, and outcome measures included magnitude of asymmetry, spatial and temporal contributions to step length asymmetry, variability of the final adapted pattern, and magnitude of adaptation. We used repeated measures and four-way MANOVAs to examine the influence of visual occlusion and walking condition. Participants with complete, compared to lower visual field visual occlusion displayed less consistency in their walking pattern, evident via increased step length standard deviation ( p = .007, d = 0.89), and compared to normal vision groups ( p = .003 d = 0.81). We found no other group differences, indicating that varying levels of visual occlusion did not significantly affect locomotor adaptation or retention. This study offers insight into the role vision plays in locomotor adaptation and retention with clinical utility for improving variability in step control.

scholarly journals Contributions of spatial and temporal control of step length symmetry in the transfer of locomotor adaptation from a motorized to a non-motorized split-belt treadmill

2019 ◽  
Author(s):  
Daniel L. Gregory ◽  
Frank C. Sup ◽  
Julia T. Choi
Keyword(s):  
Repeated Measures ◽  
Step Length ◽  
Treadmill Walking ◽  
The Body ◽  
Speed Ratio ◽  
Temporal Control ◽  
After Effects ◽  
Locomotor Adaptation ◽  
Length Difference ◽  
Motor Outputs

AbstractBackgroundLocomotor adaptation during motorized split-belt walking depends on independent processes for spatial and temporal control of step length symmetry. The unique mechanics of motorized split-belt walking that constrains two limbs to move at different speeds during double support may limit transfer of step length adaptations to new walking contexts.Research questionHow do spatial and temporal locomotor outputs contribute to transfer of step length adaptation from constrained motorized split-belt walking to unconstrained non-motorized split-belt walking?MethodsWe built a non-motorized split-belt treadmill that allows the user to walk at their own pace while simultaneously allowing the two belts to be self-propelled at different speeds. 10 healthy young participants walked on the non-motorized split-belt treadmill after an initial 10-minute adaptation on the motorized split-belt with a 2:1 speed ratio. Foot placement relative to the body and timing between heel strikes were calculated to determine spatial and temporal motor outputs, respectively. Separate repeated measures ANOVAs were used for step length difference and its spatial and temporal components to assess for transfer to the non-motorized treadmill.ResultsWe found robust after-effects in step length difference during transfer to non-motorized split-belt treadmill walking that were primarily driven by changes in temporal motor outputs. Conversely, residual after-effects observed during motorized tied-belt treadmill walking (post-transfer) were driven by changes in spatial motor outputs.SignificanceOur data showed decoupling of adapted spatial and temporal locomotor outputs during the transfer to non-motorized split-belt walking, raising the new possibility of using a non-motorized split-belt treadmill to target specific spatial or temporal gait deficits.

scholarly journals Lower visual field preference for the visuomotor control of limb movements in the human dorsomedial parietal cortex

2021 ◽  
Author(s):  
Teresa Maltempo ◽  
Sabrina Pitzalis ◽  
Martina Bellagamba ◽  
Sara Di Marco ◽  
Patrizia Fattori ◽  
...  
Keyword(s):  
Visual Field ◽  
Parietal Cortex ◽  
Visual Information ◽  
Visual Cues ◽  
Macaque Monkey ◽  
Systematic Investigation ◽  
Lower Visual Field ◽  
Limb Movements ◽  
Visuomotor Task ◽  
Foot Posture

AbstractVisual cues coming from the lower visual field (VF) play an important role in the visual guidance of upper and lower limb movements. A recently described region situated in the dorsomedial parietal cortex, area hPEc (Pitzalis et al. in NeuroImage 202:116092, 2019), might have a role in integrating visually derived information with somatomotor signals to guide limb interaction with the environment. In macaque, it has been demonstrated that PEc receives visual information mostly from the lower visual field but, to date, there has been no systematic investigation of VF preference in the newly defined human homologue of macaque area PEc (hPEc). Here we examined the VF preferences of hPEc while participants performed a visuomotor task implying spatially directed delayed eye-, hand- and foot-movements towards different spatial locations within the VF. By analyzing data as a function of the different target locations towards which upcoming movements were planned (and then executed), we observed the presence of asymmetry in the vertical dimension of VF in area hPEc, being this area more strongly activated by limb movements directed towards visual targets located in the lower compared to the upper VF. This result confirms the view, first advanced in macaque monkey, that PEc is involved in processing visual information to guide body interaction with the external environment, including locomotion. We also observed a contralateral dominance for the lower VF preference in the foot selective somatomotor cortex anterior to hPEc. This result might reflect the role of this cortex (which includes areas PE and S-I) in providing highly topographically organized signals, likely useful to achieve an appropriate foot posture during locomotion.

scholarly journals How Do Spatiotemporal Parameters and Lower-Body Stiffness Change with Increased Running Velocity? A Comparison Between Novice and Elite Level Runners

2019 ◽  
Vol 70 (1) ◽  
pp. 25-38 ◽  
Author(s):  
Felipe García-Pinillos ◽  
Amador García-Ramos ◽  
Rodrigo Ramírez-Campillo ◽  
Pedro Á. Latorre-Román ◽  
Luis E. Roche-Seruendo
Keyword(s):  
Repeated Measures ◽  
Step Length ◽  
Sine Wave ◽  
Group Differences ◽  
Lower Body ◽  
Step Frequency ◽  
Spatiotemporal Parameters ◽  
Elite Level ◽  
Acclimatization Period ◽  
High Level

Abstract This study aimed to examine the effect of running velocity on spatiotemporal parameters and lower-body stiffness of endurance runners, and the influence of the performance level on those adaptations. Twenty-two male runners (novice [NR], n = 12, and elite runners [ER], n = 10) performed an incremental running test with a total of 5 different running velocities (10, 12, 14, 16, 18 km/h). Each condition lasted 1 min (30 s acclimatization period, and 30 s recording period). Spatiotemporal parameters were measured using the OptoGait system. Vertical (Kvert) and leg (Kleg) stiffness were calculated according to the sine-wave method. A repeated measures ANOVA (2 x 5, group x velocities) revealed significant adaptations (p < 0.05) to increased velocity in all spatiotemporal parameters and Kvert in both NR and ER. ER showed a greater flight time (FT) and step angle (at 18 km/h) (p < 0.05), longer step length (SL) and lower step frequency (SF) (p < 0.05), whereas no between-group differences were found in contact time (CT) nor in the sub-phases during CT at any speed (p ≥ 0.05). ER also showed lower Kvert values at every running velocity (p < 0.05), and no differences in Kleg (p ≥ 0.05). In conclusion, lower SF and Kvert and, thereby, longer FT and SL, seem to be the main spatiotemporal characteristics of high-level runners compared to their low-level counterparts.

scholarly journals OPTIC FLOW IMPROVES SPATIAL GAIT FUNCTIONING ESPECIALLY IN MEDIOLATERAL DIRECTION

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S658-S658
Author(s):  
Farahnaz Fallahtafti ◽  
Hyeon Jung Kim ◽  
Jennifer M Yentes ◽  
Dawn Venema ◽  
Julie Blaskewicz Boron
Keyword(s):  
Older Adults ◽  
Optic Flow ◽  
Repeated Measures ◽  
Visual Information ◽  
Step Length ◽  
Step Width ◽  
Gait Performance ◽  
Double Support ◽  
Double Support Time ◽  
Support Time

Abstract Instances where multiple tasks are completed simultaneously are considered high cognitive load situations (HCLS, also called dual-task), potentially affecting gait performance in older adults. Walking while talking is a common HCLS that requires additional cognitive resources. Optic flow (OF) provides visual information about speed and direction of self-motion, and thus, may ameliorate gait deficits under HCLS. This study aimed to identify the effect of HCLS, as well as OF, on gait performance in older adults. The HCLS included walking while talking on the phone, compared to walking alone. Fifteen older adults (70.86±4.7yrs) underwent four experimental conditions: walking alone with(1) and without OF(2), as well as walking while talking with(3) and without OF(4). Step width, step length, and double support time were measured and examined with 2(HCLS) x 2(OF) repeated-measures ANOVAs. There was a main effect of OF; step width was narrower with OF compared to without OF (p=0.048). For step length, there was a significant interaction between HCLS and OF (p=0.045). Without OF, there were no differences in step length; however, with OF step length was significantly longer when walking alone compared to when walking while talking (p=0.002). Double support time was not affected by HCLS or OF. Considering younger adults have longer and narrower steps compared to older adults, OF may have enhanced step width regardless of HCLS and step length when walking only. Using OF in training programs designed for older adults, could be a potential factor to improve spatial gait function, more so in the mediolateral direction.

scholarly journals Is there a lower visual field preference in object affordances? A registered report.

2022 ◽  
Author(s):  
Annie Warman ◽  
Stephanie Rossit ◽  
George Law Malcolm ◽  
Allan Clark
Keyword(s):  
Visual Field ◽  
Compatibility Effect ◽  
Visual Processing ◽  
Repeated Measures ◽  
Reaction Times ◽  
Object Identification ◽  
Spatial Compatibility ◽  
Lower Visual Field ◽  
Reach To Grasp ◽  
Stimulus Response

It’s been repeatedly shown that pictures of graspable objects can facilitate visual processing and motor responses, even in the absence of reach-to-grasp actions, an effect often attributed the concept of affordances, originally introduced by Gibson (1979). A classic demonstration of this is the handle compatibility effect, which is characterised by faster reaction times when the orientation of a graspable object’s handle is compatible with the hand used to respond, even when the handle orientation is task irrelevant. Nevertheless, whether faster RTs are due to affordances or spatial compatibility effects has been significantly debated. In the proposed studies, we will use a stimulus-response compatibility paradigm to investigate firstly, whether we can replicate the handle compatibility effect while controlling for spatial compatibility. Here, participants will respond with left- or right-handed keypresses to whether the object is upright or inverted and, in separate blocks, whether the object is red or green. RTs will be analysed using repeated-measures ANOVAs. In line with an affordance account, we hypothesise that there will be larger handle compatibility effects for upright/inverted compared to colour judgements, as colour judgements do not require object identification and are not thought to elicit affordances. Secondly, we will investigate whether the handle compatibility effect shows a lower visual field (VF) advantage in line with functional lower VF advantages observed for hand actions. We expect larger handle compatibility effects for objects viewed in the lower VF than upper VF, given that the lower VF is the space where actions most frequently occur.

scholarly journals Design of Electrode Placement for Presenting Phosphenes in the Lower Visual Field Based on Electric Field Simulation

2021 ◽  
Vol 11 (22) ◽  
pp. 10972
Author(s):  
Manami Kanamaru ◽  
Phan Xuan Tan ◽  
Eiji Kamioka
Keyword(s):  
Visual Field ◽  
Electric Field ◽  
Visual Information ◽  
Visually Impaired ◽  
Electrode Placement ◽  
Tool Electrode ◽  
Lower Visual Field ◽  
Support Tool ◽  
Field Simulation ◽  
The Right

Presenting visual information, called phosphenes, is a critical method for providing information on the position of obstacles for users of walking support tools for the visually impaired. A previous study has established a method for presenting phosphenes to the right, center, and left of the visual field. However, a method for presenting information on the position of obstacles around the feet using phosphenes, which is essential for the visually impaired, has not been clarified. Therefore, in this study, a method for presenting phosphenes in the lower visual field is presented, towards the aim of realizing a safe walking support tool. Electrode placement is proposed in this paper for the presentation of phosphenes to the right, center, and left of the lower visual field based on the electrode placement method used in the previous study, which presents the phosphene in three locations of the visual field. In addition, electric field simulation is performed, focusing on the electric field value on the eyeball surface, in order to observe whether the proposed electrode placement is able to stimulate the intended region. As a result, it is shown that the intended region on the eyeball surface can be stimulated locally with each of the proposed electrode placements.

scholarly journals Efficacy of the use of unaffected hand containment in unimanual intensive therapy to increase visuomotor coordination in children with hemiplegia: a randomized controlled pilot study

2021 ◽  
Vol 12 ◽  
pp. 204062232110012
Author(s):  
Rocío Palomo-Carrión ◽  
Elisabeth Bravo-Esteban ◽  
Sara Ando-La Fuente ◽  
Purificación López-Muñoz ◽  
Inés Martínez-Galán ◽  
...  
Keyword(s):  
Reaction Time ◽  
Upper Limb ◽  
Visual Information ◽  
Intensive Therapy ◽  
Action Planning ◽  
Reaction Time Task ◽  
Group Differences ◽  
Visuomotor Coordination ◽  
Therapy Program ◽  
Anticipatory Action

Background: The capacity of children with hemiplegia to be engaged in anticipatory action planning is affected. There is no balance among spatial, proprioceptive and visual information, thus altering the affected upper limb visuomotor coordination. The objective of the present study was to assess the improvement in visuomotor coordination after the application of a unimanual intensive therapy program, with the use of unaffected hand containment compared with not using unaffected hand containment. Methods: A simple blind randomized clinical trial was realized. A total of 16 subjects with congenital infantile hemiplegia participated in the study with an age mean of 5.54 years old (SD:1.55). Two intensive protocols for 5 weeks of modified constraint-induced movement therapy (mCIMT) or unimanual therapy without containment (UTWC) were executed 5 days per week (2 h/day). Affected upper limb visuomotor coordination (reaction time, task total time, active range, dynamic grasp) was measured before–after intensive therapy using a specific circuit with different slopes (10°/15°). Results: Statistically significant inter-group differences were found after the intervention, with clinically relevant results for the mCIMT group not seen in UTWC, in the following variables: reaction time 10°slope ( p = 0.003, d = 2.44), reaction time 15°slope ( p = 0.002, d = 2.15) as well as for the task total time 10°slope ( p = 0.002, d = 2.25), active reach 10°slope ( p = 0.002, d = 2.7), active reach 15°slope ( p = 0.003, d = 2.29) and dynamic grasp 10°/15°slopes ( p = <0.001, d = 2.69). There were not statistically significant inter-group differences in the total task time with 15°slope ( p = 0.074, d = 1.27). Conclusions: The use of unaffected hand containment in mCIMT would allow improvements in the affected upper limb’s visuomotor coordination. Thus, it would favor clinical practice to make decisions on therapeutic approaches to increase the affected upper limb functionality and action planning in children diagnosed with infantile hemiplegia (4–8 years old).

Group Differences in Alcohol-Creativity Interactions

1994 ◽  
Vol 75 (3_suppl) ◽  
pp. 1635-1638 ◽  
Author(s):  
Geoff Lowe
Keyword(s):  
Body Weight ◽  
Repeated Measures ◽  
Group Differences ◽  
Placebo Condition ◽  
Significant Group ◽  
Social Drinkers ◽  
Alcohol Dose

A repeated-measures, balanced-order design was used to test for the effects of alcohol on creativity as measured by verbal forms of the Torrance Creativity Test. Social drinkers (8 men and 8 women) performed under 2 conditions, alcohol (dose = 0.83 ml ethanol/kg body weight) and a placebo. Significant group differences in the alcohol-creativity interaction were noted in that the performance of higher-scoring (in the placebo condition) subjects was impaired by alcohol whereas that of lower-scoring subjects was enhanced.

Systematic spatial patterns of the sense of familiarity: Hierarchical modelling based on eye-tracking experiments

2018 ◽  
Vol 72 (4) ◽  
pp. 832-846
Author(s):  
Kiyofumi Miyoshi ◽  
Hiroshi Ashida
Keyword(s):  
Working Memory ◽  
Visual Field ◽  
Spatial Patterns ◽  
Stimulus Type ◽  
Spatial Configuration ◽  
Long Term Memory ◽  
Lower Visual Field ◽  
Referential Process ◽  
Memory Theory ◽  
Spatial Configurations

Using different types of stimuli, such as pictures, horizontally written Japanese words, and vertically written Japanese words, this study investigated the spatial patterns of the sense of familiarity within the visual field. The perceptual asymmetry theory predicted that stimuli in the lower visual field would be processed more fluently and would therefore be perceived as more familiar. The working memory theory, originally proposed in space–number research, envisaged type-specific spatial patterns for different stimuli. Participants made old/new recognition memory judgements for stimuli, presented at random positions, while their eye movements were recorded. The observed spatial patterns changed according to the stimulus type (e.g., “more left = older” for horizontally written words and “upper = older” for vertically written words), and this flexibility is encapsulated by the working memory theory as follows: (a) stimulus-type-specific spatial configurations are encoded in long-term memory on the basis of one’s experience (e.g., vertically written words are empirically associated with the “upper = older” spatial configuration), (b) the presentation of a stimulus automatically cues the temporal activation of the associated spatial configuration in working memory, and (c) the referential process between the stimulus and configuration unconsciously affects the viewer’s sense of familiarity.

Sign in / Sign up

Export Citation Format

Share Document