scholarly journals Multisensory modulation of body ownership in mice

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Christine L Buckmaster ◽  
Julia E Rathmann-Bloch ◽  
Luis de Lecea ◽  
Alan F Schatzberg ◽  
David M Lyons
Keyword(s):  
Sex Differences ◽  
Tactile Stimulation ◽  
Fundamental Aspect ◽  
Body Ownership ◽  
Body Parts ◽  
Experimental Conditions ◽  
Healthy Humans ◽  
Evolutionarily Conserved ◽  
Human Brains ◽  
Multisensory Information

Abstract Body ownership is a fundamental aspect of self-consciousness that reflects more than the presence of physical body parts. As demonstrated by the rubber hand illusion (RHI), human brains construct body ownership experiences using available multisensory information. Experimental conditions similar to those that induce the RHI in humans have been recently adapted to induce the rubber tail illusion (RTI) in mice. Here, we show that the RTI is enhanced in both sexes of mice by repetitive synchronous stroking comprised of correlated visual and tactile stimulation of real and rubber tails compared to visual-only mimicked stroking conducted without tactile stimulation. The RTI also appears to be enhanced in female but not male mice by slow compared to fast stroking that reflects an interoceptive manipulation associated with affective touch in humans. Sex differences in slow stroking effects are exploratory and require replication in mice. Sex differences have not been reported for the RHI in healthy humans, but women rate slow stroking as more affectively pleasant compared to the ratings of men. Results suggest that the RHI in humans resembles aspects of the RTI in mice. Studies of mice may therefore provide neurobiological insights on evolutionarily conserved mechanisms of bodily self-consciousness in humans.

Behavioral measures of sensitization to repeated d-amphetamine: Preliminary data on sex differences in healthy humans

2016 ◽  
Vol 26 ◽  
pp. S265 ◽  
Author(s):  
A. Weidenauer ◽  
M. Bauer ◽  
L. Bartova ◽  
U. Sauerzopf ◽  
N. Praschak-Rieder ◽  
...  
Keyword(s):  
Sex Differences ◽  
Preliminary Data ◽  
Behavioral Measures ◽  
Healthy Humans

Sex differences in respiratory muscle activation patterns during high-intensity exercise in healthy humans

2018 ◽  
Vol 247 ◽  
pp. 57-60 ◽  
Author(s):  
Reid A. Mitchell ◽  
Michele R. Schaeffer ◽  
Andrew H. Ramsook ◽  
Sabrina S. Wilkie ◽  
Jordan A. Guenette
Keyword(s):  
Sex Differences ◽  
High Intensity ◽  
Respiratory Muscle ◽  
Muscle Activation ◽  
High Intensity Exercise ◽  
Activation Patterns ◽  
Muscle Activation Patterns ◽  
Healthy Humans

Contralateral coordination and retargeting of limb movements during scratching in the locust

1998 ◽  
Vol 201 (13) ◽  
pp. 2021-2032 ◽  
Author(s):  
T Matheson
Keyword(s):  
Nerve Cord ◽  
Tactile Stimulation ◽  
Schistocerca Gregaria ◽  
Limb Movements ◽  
Single Cycle ◽  
Experimental Conditions ◽  
The Subject ◽  
The Common ◽  
Peripheral Sensory ◽  
Stimulus Site

Locusts, Schistocerca gregaria, in common with many limbed vertebrates, can make directed scratching movements in response to tactile stimulation. For instance, stimulation of different sites on a wing elicits different movements that are accurately targeted so that the hindleg tarsus passes across the stimulus site. I have analysed these limb movements to define the ability of a locust to target stimulus sites correctly under a range of experimental conditions. In particular, I describe aspects of the behaviour that reveal possible neuronal pathways underlying the responses. These neuronal pathways will be the subject of further physiological analyses. Limb targeting during scratching is continuously graded in form; different patterns of movement are not separated by sharp transitions. The computation of limb trajectory takes into account the starting posture of the hindleg, so that different trajectories can be used to reach a common stimulus site from different starting postures. Moreover, the trajectories of the two hindlegs moving simultaneously from different starting postures in response to a single stimulus can be different, so that their tarsi converge onto the common stimulus site. Different trajectories can be used to reach a common stimulus site from the same start posture. Targeting information from a forewing is passed not only down the nerve cord to the ipsilateral hindleg but also across the nerve cord, so that the contralateral hindleg can also make directed movements. This contralateral transmission does not rely on peripheral sensory feedback. When the stimulus site moves during a rhythmical scratch, the targeting of subsequent cycles reflects this change. Both ipsilateral and contralateral hindlegs can retarget their movements. The trajectory of a single cycle of scratching directed towards a particular stimulus site can be modified after it has begun, so that the tarsus is redirected towards a new stimulus site.

scholarly journals Non-informative vision improves spatial tactile discrimination on the shoulder but does not influence detection sensitivity

2020 ◽  
Vol 238 (12) ◽  
pp. 2865-2875
Author(s):  
Fabrizio Leo ◽  
Sara Nataletti ◽  
Luca Brayda
Keyword(s):  
Tactile Stimulation ◽  
Detection Threshold ◽  
Receptive Fields ◽  
Judgment Task ◽  
The Body ◽  
Detection Sensitivity ◽  
Body Parts ◽  
Tactile Acuity ◽  
Tactile Stimuli ◽  
Numerosity Judgment

Abstract Vision of the body has been reported to improve tactile acuity even when vision is not informative about the actual tactile stimulation. However, it is currently unclear whether this effect is limited to body parts such as hand, forearm or foot that can be normally viewed, or it also generalizes to body locations, such as the shoulder, that are rarely before our own eyes. In this study, subjects consecutively performed a detection threshold task and a numerosity judgment task of tactile stimuli on the shoulder. Meanwhile, they watched either a real-time video showing their shoulder or simply a fixation cross as control condition. We show that non-informative vision improves tactile numerosity judgment which might involve tactile acuity, but not tactile sensitivity. Furthermore, the improvement in tactile accuracy modulated by vision seems to be due to an enhanced ability in discriminating the number of adjacent active electrodes. These results are consistent with the view that bimodal visuotactile neurons sharp tactile receptive fields in an early somatosensory map, probably via top-down modulation of lateral inhibition.

scholarly journals Altered visual feedback from an embodied avatar unconsciously influences movement amplitude and muscle activity

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Pierre Bourdin ◽  
Matteo Martini ◽  
Maria V. Sanchez-Vives
Keyword(s):  
Visual Feedback ◽  
Muscle Activity ◽  
Motor Performance ◽  
Muscular Activity ◽  
Arm Movement ◽  
Body Ownership ◽  
Immersive Virtual Reality ◽  
Body Parts ◽  
Elastic Band ◽  
Visual Inputs

AbstractEvidence suggests that the sense of the position of our body parts can be surreptitiously deceived, for instance through illusory visual inputs. However, whether altered visual feedback during limb movement can induce substantial unconscious motor and muscular adjustments is not known. To address this question, we covertly manipulated virtual body movements in immersive virtual reality. Participants were instructed to flex their elbow to 90° while tensing an elastic band, as their virtual arm reproduced the same, a reduced (75°), or an amplified (105°) movement. We recorded muscle activity using electromyography, and assessed body ownership, agency and proprioception of the arm. Our results not only show that participants compensated for the avatar’s manipulated arm movement while being completely unaware of it, but also that it is possible to induce unconscious motor adaptations requiring significant changes in muscular activity. Altered visual feedback through body ownership illusions can influence motor performance in a process that bypasses awareness.

Sex Differences in the Swordtail Xiphophorus hellerii Revealed by a New Method to Investigate Volumetric Data

2020 ◽  
Vol 95 (3-4) ◽  
pp. 127-138
Author(s):  
Michael H. Hofmann
Keyword(s):  
Sex Differences ◽  
Statistical Analysis ◽  
Relative Size ◽  
Volume Ratio ◽  
New Method ◽  
Brain Morphology ◽  
Body Parts ◽  
Swordtail Fish ◽  
Xiphophorus Hellerii ◽  
Matrix Volume

Comparing the relative volumes of body parts is a useful tool in morphology, but it is not trivial to do this in animals that differ in overall size. To account for scaling differences, a “reference size” has to be determined and the original absolute volumes have to be “corrected for” by this scaling reference. However, the outcome of a statistical analysis is greatly affected by this “reference size,” and it is practically impossible to determine the “overall size” of a structure independent of the changes in the relative size of the parts of it. Here, a new method is introduced to compare the relative volumes of parts that does not need a scaling reference. The method transforms the absolute part volumes into a ratio matrix (volume ratio transformation, VRT). The VRT is free of any scaling factors and can be used to compare groups of animals. This paper also reviews various other errors made frequently when comparing brain morphology between animals. Finally, the VRT is applied to investigate sex differences in the swordtail fish <i>(Xiphophorus hellerii)</i>, which show profound differences in the size of the valvula cerebelli.

scholarly journals The Role of Motor Learning on Measures of Physical Requirements and Motor Variability During Repetitive Screwing

2019 ◽  
Vol 16 (7) ◽  
pp. 1231 ◽  
Author(s):  
Tessy Luger ◽  
Robert Seibt ◽  
Monika Rieger ◽  
Benjamin Steinhilber
Keyword(s):  
Muscle Activation ◽  
Biceps Brachii ◽  
Extensor Digitorum ◽  
Body Parts ◽  
Triceps Brachii ◽  
Experimental Conditions ◽  
Motor Variability ◽  
Physical Requirement ◽  
Flexor Carpi Radialis ◽  
Arm Muscles

We investigated whether physical requirements and motor variability decreased over days in novices during a repetitive screwing task. Fifty-seven subjects performed one hour of repetitive screwing and fastening on three days, separated by 2–7 days. The average physical requirement and relative cycle-to-cycle variability (coefficient of variation, i.e., CV) were calculated from continuous recordings of electromyography of four arm muscles (biceps brachii, triceps brachii, flexor carpi radialis, extensor digitorum), forearm acceleration, and electrocardiography. Muscle activity levels, heart rate, and forearm acceleration decreased from day 1 to day 2 (range: ~4% to ~20%) and/or 3 (range: ~4% to ~28%). Not all muscles showed a similar pattern. Activity of the extensor digitorum and biceps brachii decreased already between days 1 and 2 (range: ~6% to ~13%), whereas activity of the flexor carpi radialis and triceps brachii decreased between days 1 and 3 (range: ~13% to ~20%). No changes in physical requirement were detected between days 2 and 3. Relative motor variability did not change across days, except that variability of forearm acceleration increased from day 1 to 3 (~5%). This study found consistent changes in physical requirements and indicated that several arm muscles show earlier decreases of muscular activity, like the extensor digitorum, compared to other body parts, like the flexor carpi radialis. Moreover, movement strategies may develop differently than muscle activation strategies, based on the different developments of physical requirements and motor variability. The development of physical requirements in industrial tasks is part of daily living and starts at task onset, highlighting the importance of task familiarization and the randomization of experimental conditions in scientific studies.

Sex differences in surface EMG interference pattern power spectrum

1994 ◽  
Vol 77 (5) ◽  
pp. 2163-2168 ◽  
Author(s):  
R. Cioni ◽  
F. Giannini ◽  
C. Paradiso ◽  
N. Battistini ◽  
C. Navona ◽  
...  
Keyword(s):  
Sex Differences ◽  
Power Spectrum ◽  
Surface Emg ◽  
Progressive Increase ◽  
Experimental Conditions ◽  
Spectral Parameters ◽  
Mean Values ◽  
Healthy Female ◽  
Power Frequency ◽  
Median Power Frequency

Sex differences in the spectral parameters of the surface electromyogram (EMG) power spectrum were studied during voluntary muscle contractions of different strength with rest in between. The influence of two different types of leads (unipolar and bipolar) on the values of the spectral parameters was also investigated under the same experimental conditions. The subjects were 15 healthy female and 15 healthy male volunteers. The relationship between the amplitude (root mean square) of the EMG and the force developed was not linear. The mean values of the median power frequency were lower in women than in men. With both types of lead, the increase in force was accompanied by a progressive increase in median power frequency in male and female subjects. The significant differences in spectral parameters observed in the two sexes are probably correlated with anatomic differences.

Selected Contribution: Ambient temperature for experiments in rats: a new method for determining the zone of thermal neutrality

2002 ◽  
Vol 92 (6) ◽  
pp. 2667-2679 ◽  
Author(s):  
Andrej A. Romanovsky ◽  
Andrei I. Ivanov ◽  
Yury P. Shimansky
Keyword(s):  
Ambient Temperature ◽  
Body Core Temperature ◽  
Body Parts ◽  
Experimental Conditions ◽  
Strong Negative Correlation ◽  
Liquid Crystal Thermography ◽  
Body Core ◽  
Definition Of ◽  
Operational Range ◽  
Rat Tail

There is a misbelief that the same animal has the same thermoneutral zone (TNZ) in different experimental setups. In reality, TNZ strongly depends on the physical environment and varies widely across setups. Current methods for determining TNZ require elaborate equipment and can be applied only to a limited set of experimental conditions. A new, broadly applicable approach that rapidly determines whether given conditions are neutral for a given animal is needed. Consistent with the definition of TNZ [the range of ambient temperature (Ta) at which body core temperature (Tc) regulation is achieved only by control of sensible heat loss], we propose three criteria of thermoneutrality: 1) the presence of high-magnitude fluctuations in skin temperature (Tsk) of body parts serving as specialized heat exchangers with the environment (e.g., rat tail), 2) the closeness of Tsk to the median of its operational range, and 3) a strong negative correlation between Tskand Tc. Thermocouple thermometry and liquid crystal thermography were performed in five rat strains at 13 Ta. Under the conditions tested (no bedding or filter tops, no group thermoregulation), the Ta range of 29.5–30.5°C satisfied all three TNZ criteria in Wistar, BDIX, Long-Evans, and Zucker lean rats; Zucker fatty rats had a slightly lower TNZ (28.0–29.0°C). Skin thermometry or thermography is a definition-based, simple, and inexpensive technique to determine whether experimental or housing conditions are neutral, subneutral, or supraneutral for a given animal.

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