scholarly journals Mild Stroke Affects Pointing Movements Made in Different Frames of Reference

2021 ◽  
pp. 154596832198934
Author(s):  
Fariba Hasanbarani ◽  
Marc Aureli Pique Batalla ◽  
Anatol G. Feldman ◽  
Mindy F. Levin
Keyword(s):  
Degrees Of Freedom ◽  
Peripersonal Space ◽  
The Body ◽  
Frames Of Reference ◽  
Rehabilitation Programs ◽  
Spatial Frames Of Reference ◽  
Complex Process ◽  
Sensorimotor Impairment ◽  
Mild Stroke ◽  
Made In

Background Motor performance is a complex process controlled in task-specific spatial frames of reference (FRs). Movements can be made within the framework of the body (egocentric FR) or external space (exocentric FR). People with stroke have impaired reaching, which may be related to deficits in movement production in different FRs. Objective To characterize rapid motor responses to changes in the number of degrees of freedom for movements made in different FRs and their relationship with sensorimotor and cognitive impairment in individuals with mild chronic stroke. Methods Healthy and poststroke individuals moved their hand along the contralateral forearm (egocentric task) and between targets in the peripersonal space (exocentric task) without vision while flexing the trunk. Trunk movement was blocked in randomized trials. Results For the egocentric task, controls produced the same endpoint trajectories in both conditions (free- and blocked-trunk) by preserving similar shoulder-elbow interjoint coordination (IJC). However, endpoint trajectories were dissimilar because of altered IJC in stroke. For the exocentric task, controls produced the same endpoint trajectories when the trunk was free or blocked by rapidly changing the IJC, whereas this was not the case in stroke. Deficits in exocentric movement after stroke were related to cognitive but not sensorimotor impairment. Conclusions Individuals with mild stroke have deficits rapidly responding to changing conditions for complex reaching tasks. This may be related to cognitive deficits and limitations in the regulation of tonic stretch reflex thresholds. Such deficits should be considered in rehabilitation programs encouraging the reintegration of the affected arm into activities of daily living.

scholarly journals Spatial frames of reference and somatosensory processing: a neuropsychological perspective

1997 ◽  
Vol 352 (1360) ◽  
pp. 1401-1409 ◽  
Author(s):  
Giuseppe Vallar
Keyword(s):  
Right Hemisphere ◽  
Higher Order ◽  
The Body ◽  
Frames Of Reference ◽  
Neural Basis ◽  
Right Brain ◽  
Extrapersonal Space ◽  
Spatial Frames Of Reference ◽  
Posterior Parietal ◽  
Sensory Processes

In patients with lesions in the right hemisphere, frequently involving the posterior parietal regions, left–sided somatosensory (and visual and motor) deficits not only reflect a disorder of primary sensory processes, but also have a higher–order component related to a defective spatial representation of the body. This additional factor, related to right brain damage, is clinically relevant: contralesional hemianaesthesia (and hemianopia and hemiplegia) is more frequent in right brain–damaged patients than in patients with damage to the left side of the brain. Three main lines of investigation suggest the existence of this higher–order pathological factor. (i) Right brain–damaged patients with left hemineglect may show physiological evidence of preserved processing of somatosensory stimuli, of which they are not aware. Similar results have been obtained in the visual domain. (ii) Direction–specific vestibular, visual optokinetic and somatosensory or proprioceptive stimulations may displace spatial frames of reference in right brain–damaged patients with left hemineglect, reducing or increasing the extent of the patients’ ipsilesional rightward directional error, and bring about similar directional effects in normal subjects. These stimulations, which may improve or worsen a number of manifestations of the neglect syndrome (such as extrapersonal and personal hemineglect), have similar effects on the severity of left somatosensory deficits (defective detection of tactile stimuli, position sense disorders). However, visuospatial hemineglect and the somatosensory deficits improved by these stimulations are independent, albeit related, disorders. (iii) The severity of left somatosensory deficits is affected by the spatial position of body segments, with reference to the midsagittal plane of the trunk. A general implication of these observations is that spatial (non–somatotopic) levels of representation contribute to corporeal awareness. The neural basis of these spatial frames includes the posterior parietal and the premotor frontal regions. These spatial representations could provide perceptual–premotor interfaces for the organization of movements (e.g. pointing, locomotion) directed towards targets in personal and extrapersonal space. In line with this view, there is evidence that the sensory stimulations that modulate left somatosensory deficits affect left motor disorders in a similar, direction–specific, fashion.

What Spatial Frames of Reference are Used to Guide Off-Axis Aiming?

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 364-364
Author(s):  
P T Sowden ◽  
I R L Davies ◽  
S K Boyles ◽  
T J Simpson ◽  
L A Skinner
Keyword(s):  
Closed Loop ◽  
General Information ◽  
The Body ◽  
Frames Of Reference ◽  
Absolute Space ◽  
Laser Pointer ◽  
Spatial Frames Of Reference ◽  
Preliminary Model ◽  
Correction System ◽  
Aiming Performance

What spatial frames of reference are used to guide body centred actions such as pointing and aiming? Do observers learn to use body-scaled frames of reference with specific points of origin (eg hip vs shoulder)? Do they extrapolate general information about body scaling? Do they learn about the position of the body (and its individual parts) in absolute space? We investigated these questions using two kinds of aiming: off-axis aiming vs along-axis aiming. Subjects aimed a ‘gun’ (a laser pointer mounted at the end of a stick with a button at the other end) at various targets under three conditions. They practised aiming in one position for 60 ‘shots’ and then changed to a new position and completed another 60 shots. Transfer across position of ‘gun’ in absolute space, across position of body in absolute space, and across position of gun relative to body were assessed. Results suggested that off-axis aiming was controlled by a closed-loop error correction system requiring sight of results for learning to occur. Further, changes in the position of the body in absolute space (from kneeling to standing or vice versa) led to the worst aiming performance. Changes in gun position relative to the body or in absolute space had less effect on aiming accuracy, which suggests that it is not dependent on specific learned sensory - motor linkages. On the basis of these results we propose a preliminary model for off-axis training.

Representing utility and deploying the body

2020 ◽  
Vol 43 ◽  
Author(s):  
David Spurrett
Keyword(s):  
Functional Activity ◽  
Degrees Of Freedom ◽  
The Body ◽  
Target Article ◽  
Processing Demands ◽  
The Many

Abstract Comprehensive accounts of resource-rational attempts to maximise utility shouldn't ignore the demands of constructing utility representations. This can be onerous when, as in humans, there are many rewarding modalities. Another thing best not ignored is the processing demands of making functional activity out of the many degrees of freedom of a body. The target article is almost silent on both.

Individual Differences in the Flexibility of Peripersonal Space

2017 ◽  
Vol 64 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Samuel B. Hunley ◽  
Arwen M. Marker ◽  
Stella F. Lourenco
Keyword(s):  
Individual Differences ◽  
Peripersonal Space ◽  
The Body ◽  
Laser Pointer ◽  
Baseline Measure ◽  
Bisection Task ◽  
Defensive Function ◽  
Representational Space ◽  
Laser Condition ◽  
Line Bisection Task

Abstract. The current study investigated individual differences in the flexibility of peripersonal space (i.e., representational space near the body), specifically in relation to trait claustrophobic fear (i.e., fear of suffocating or being physically restricted). Participants completed a line bisection task with either a laser pointer (Laser condition), allowing for a baseline measure of the size of one’s peripersonal space, or a stick (Stick condition), which produces expansion of one’s peripersonal space. Our results revealed that individuals high in claustrophobic fear had larger peripersonal spaces than those lower in claustrophobic fear, replicating previous research. We also found that, whereas individuals low in claustrophobic fear demonstrated the expected expansion of peripersonal space in the Stick condition, individuals high in claustrophobic fear showed less expansion, suggesting decreased flexibility. We discuss these findings in relation to the defensive function of peripersonal space and reduced attentional flexibility associated with trait anxieties.

Introduction

2018 ◽  
Author(s):  
Nora Goldschmidt ◽  
Barbara Graziosi
Keyword(s):  
Material Culture ◽  
The Body ◽  
Specific Site ◽  
Entire Volume ◽  
The Third ◽  
Religious Significance ◽  
Classical Poetry ◽  
Life Of The Mind ◽  
The Mind ◽  
Made In

The Introduction sheds light on the reception of classical poetry by focusing on the materiality of the poets’ bodies and their tombs. It outlines four sets of issues, or commonplaces, that govern the organization of the entire volume. The first concerns the opposition between literature and material culture, the life of the mind vs the apprehensions of the body—which fails to acknowledge that poetry emerges from and is attended to by the mortal body. The second concerns the religious significance of the tomb and its location in a mythical landscape which is shaped, in part, by poetry. The third investigates the literary graveyard as a place where poets’ bodies and poetic corpora are collected. Finally, the alleged ‘tomb of Virgil’ provides a specific site where the major claims made in this volume can be most easily be tested.

scholarly journals Non-destructive handheld XRF study of archaeological composite silver objects—the case study of the late Roman Seuso Treasure

2021 ◽  
Vol 13 (5) ◽  
Author(s):  
Viktória Mozgai ◽  
Bernadett Bajnóczi ◽  
Zoltán May ◽  
Zsolt Mráv
Keyword(s):  
Fluorescence Analysis ◽  
The Body ◽  
High Quality ◽  
X Ray ◽  
Composite Objects ◽  
Mechanical Attachment ◽  
Non Destructive ◽  
Made In ◽  
Late Roman

AbstractThis study details the non-destructive chemical analysis of composite silver objects (ewers, situlas, amphora and casket) from one of the most significant late Roman finds, the Seuso Treasure. The Seuso Treasure consists of fourteen large silver vessels that were made in the fourth–early fifth centuries AD and used for dining during festive banquets and for washing and beautification. The measurements were systematically performed along a pre-designed grid at several points using handheld X-ray fluorescence analysis. The results demonstrate that all the objects were made from high-quality silver (above 90 wt% Ag), with the exception of the base of the Geometric Ewer B. Copper was added intentionally to improve the mechanical properties of soft silver. The gold and lead content of the objects shows constant values (less than 1 wt% Au and Pb). The chemical composition as well as the Bi/Pb ratio suggests that the parts of the composite objects were manufactured from different silver ingots. The ewers were constructed in two ways: (i) the base and the body were made separately, or (ii) the ewer was raised from a single silver sheet. The composite objects were assembled using three methods: (i) mechanical attachment; (ii) low-temperature, lead-tin soft solders; or (iii) high-temperature, copper-silver hard solders. Additionally, two types of gilding were revealed by the XRF analysis, one with remnants of mercury, i.e. fire-gilding, and another type without remnants of mercury, presumably diffusion bonding.

Some Experiments on the Extra-Corporeal Hatching of the Eggs of Ascaris suum

1939 ◽  
Vol 17 (2) ◽  
pp. 69-82 ◽  
Author(s):  
D. W. Fenwick
Keyword(s):  
Hydrochloric Acid ◽  
Digestive Tract ◽  
Sodium Carbonate ◽  
Ascaris Suum ◽  
The Body ◽  
Very Old ◽  
The Past ◽  
Pancreatic Fluid ◽  
Sand Cultures ◽  
Made In

Numerous attempts have been made in the past to induce the eggs of Ascaris suum to hatch outside the body of the host. Extra-corporeal hatching has been observed under a variety of conditions by different workers. Kondo (1920, 1922), Asada (1921) and others record hatching in water, charcoal and sand cultures. Wharton (1915) states that hatching will occur in alkaline digestive juices, while Martin (1913) records a similar phenomenon in pancreatic fluid. Many different explanations have been offered to explain this hatching. Wharton suggested that the interaction of algae and sand might have some effect. Ohba (1923), who found that hatching would occur in 0·2% hydrochloric acid and 0·2% sodium carbonate believed that extra-corporeal hatching was limited to very old cultures of eggs. Many workers are of the opinion that some stimulus normally present in the digestive tract is necessary for hatching.

The relevance of therapeutic drug monitoring in plasma and erythrocytes in anti-cancer drug treatment

2004 ◽  
Vol 42 (11) ◽  
Author(s):  
Herlinde Dumez ◽  
Gunther Guetens ◽  
Gert De Boeck ◽  
Martin S. Highley ◽  
Robert A. A. Maes ◽  
...  
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Drug Monitoring ◽  
Drug Transport ◽  
Free Fraction ◽  
The Body ◽  
Cancer Drug ◽  
Therapeutic Drug ◽  
Anti Cancer ◽  
Plasma Compartment ◽  
Made In

AbstractTherapeutic drug monitoring generally focuses on the plasma compartment only. Differentiation between the total plasma concentration and the free fraction (plasma water) has been described for a number of limited drugs. Besides the plasma compartment, blood has also a cellular fraction which has by far the largest theoretical surface and volume for drug transport. It is with anti-cancer drugs that major progress has been made in the study of partition between the largest cellular blood compartment, i.e., erythrocytes, and the plasma compartment. The aim of the present review is to detail the progress made in predicting what a drug does in the body, i.e., pharmacodynamics including toxicity and plasma and/or red blood cell concentration monitoring. Furthermore, techniques generally used in anti-cancer drug monitoring are highlighted. Data for complex Bayesian statistical approaches and population kinetics studies are beyond the scope of this review, since this is generally limited to the plasma compartment only.

The locust jump. I. The motor programme

1977 ◽  
Vol 66 (1) ◽  
pp. 203-219
Author(s):  
W. J. Heitler ◽  
M. Burrows
Keyword(s):  
High Frequency ◽  
Tactile Stimulation ◽  
The Body ◽  
Flexor Muscle ◽  
Tactile Stimuli ◽  
Extensor Muscles ◽  
Trigger Activity ◽  
Three Stages ◽  
Motor Programme ◽  
Made In

A motor programme is described for defensive kicking in the locust which is also probably the programme for jumping. The method of analysis has been to make intracellular recordings from the somata of identified motornuerones which control the metathoracic tibiae while defensive kicks are made in response to tactile stimuli. Three stages are recognized in the programme. (1) Initial flexion of the tibiae results from the low spike threshold of tibial flexor motorneurones to tactile stimulation of the body. (2) Co-contraction of flexor and extensor muscles followa in which flexor and extensor excitor motoneurones spike at high frequency for 300-600 ms. the tibia flexed while the extensor muscle develops tension isometrically to the level required for a kick or jump. (3) Trigger activity terminates the co-contraction by inhibiting the flexor excitor motorneurones and simultaneously exciting the flexor inhibitors. This causes relaxation of the flexor muscle and allows the tibiae to extend. If the trigger activity does not occur, the jump or kick is aborted, and the tibiae remain flexed.

scholarly journals Enactive Emotion In Forensic Practice: The Application of Embodied Cognitive and Affective Science to Offender Rehabilitation Programs

2021 ◽  
Author(s):  
◽  
Max Davis
Keyword(s):  
Cognitive Skills ◽  
Emotional Experience ◽  
The Body ◽  
Specific Reference ◽  
Offender Rehabilitation ◽  
Cognition And Emotion ◽  
Rehabilitation Programs ◽  
Affective Science ◽  
Forensic Practice ◽  
Bodily Feeling

<p>In recent years, affective science has seen a shift in the understanding of emotion and its relationship to cognition. No longer is cognition viewed as the only significant factor in determining emotional experience, and as fundamentally distinct from bodily feeling. Rather than a linear causal relationship between one and the other, the philosophy and cognitive science of Enactivism suggests that the cognitive and emotional elements of experience, along with the body and surrounding environment, are constitutive of each other, and continuously influence each other in a dynamic, multidirectional manner to produce the experience of emotional patterns (Colombetti & Thompson, 2008). However, despite these advances in emotion theory, current rehabilitation programs such as the Reasoning and Rehabilitation (R&R, Ross et al., 2016) program continue to understand cognition and emotion as functionally distinct components of experience, with deficits conceptualised in mainly cognitive terms, and targeted through Cognitive Skills, which largely neglect the emotional elements of experience. This thesis explores how an enactivist understanding of emotion can be applied to offender rehabilitation programs, with specific reference to the R&R program. It is concluded that R&R and similar programs would benefit significantly from revisions to conceptualisations of cognitive deficits, and in treatment components, which should integrate emotional and cognitive techniques.</p>

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