scholarly journals The “right” side of sleeping: laterality in resting behaviour of Aldabra giant tortoises (Aldabrachelys gigantea)

2021 ◽  
Author(s):  
Caterina Spiezio ◽  
Camillo Sandri ◽  
Flavien Joubert ◽  
Marie-May Muzungaile ◽  
Selby Remy ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Botanical Garden ◽  
The Body ◽  
Brain Lateralization ◽  
Righting Response ◽  
Resting Behaviour ◽  
Head Positioning ◽  
Human Care ◽  
The Right ◽  
Free Ranging

AbstractAlthough some studies investigated lateralization in reptiles, little research has been done on chelonians, focusing only on few behaviours such as righting response and escape preference. The aim of this study was to investigate lateralization in Aldabra giant tortoises (Aldabrachelys gigantea), focusing on asymmetrical positioning of the limbs and the head during resting behaviour, called sleep-like behaviour, involving both wild tortoises and individuals under human care. Subjects of the study were 67 adult Aldabra tortoises (54 free ranging on Curieuse, 13 under human care in Mahè Botanical Garden). For each tortoise observed during sleep-like behaviour, we recorded the position of the head (on the left, on the right or in line with the body midline) and we collected which forelimb and hindlimb were kept forward. Moreover, the number of subjects in which limbs were in a symmetrical position during the sleep-like behaviour was recorded. Based on our results, the number of tortoises with asymmetrical position of head and limb was higher (head: 63%; forelimbs: 88%; hindlimbs: 70%) than the number of tortoises with symmetrical position of the head and the limb. Regarding the head, throughout the subjects found with the asymmetrical position of the head during sleep-like behaviour, tortoises positioning the head on the right (42%) were more than those sleeping with the head on the left (21%). We found a relationship between the position of the forelimbs and hindlimbs during sleep-like behaviour. We reported no differences between Mahè (under human care) and Curieuse (wild) tortoises. Findings of this preliminary study underlined traces of group-level lateralization in head positioning during the sleep-like behaviour, possibly due to a left-eye/right-hemisphere involvement in anti-predatory responses and threatening stimuli as reported in reptiles and other vertebrates. This study aims at adding data on brain lateralization, often linked to lateralized behaviours, in reptiles, especially in chelonians.

Head positioning control in a gravito-inertial field and in normal gravity

2004 ◽  
Vol 14 (4) ◽  
pp. 321-333
Author(s):  
Frédéric Sarès ◽  
Christophe Bourdin ◽  
Jean-Michel Prieur ◽  
Jean-Louis Vercher ◽  
Jean-Pierre Menu ◽  
...  
Keyword(s):  
Inertial Force ◽  
The Body ◽  
Body Axis ◽  
Positioning Control ◽  
Head Positioning ◽  
Subject Variability ◽  
Visual Frame ◽  
Vector Orientation ◽  
The Right ◽  
Within Subject Variability

The way in which the head is controlled in roll was investigated by dissociating the body axis and the gravito-inertial force orientation. Seated subjects (N = 8) were requested to align their head with their trunk, 30° to the left, 30° to the right or with the gravito-inertial vector, before, during (Per Rotation), after off-center rotation and on a tilted chair without rotation (Tilted). The gravito-inertial vector angle during rotation and the chair tilt angle were identical (17°). The subjects were either in total darkness or facing a visual frame that was fixed to the trunk. Both final error and within-subject variability of head positioning increased when the body axis and the gravito-inertial vector were dissociated (Per Rotation and Tilted). However, the behavior was different depending on whether the subjects were in the Tilted or Per Rotation conditions. The presentation of the visual frame reduced the within-subject variability and modified the perception of the gravito-inertial vector's orientation on the tilted chair. As head positioning with respect to the body and sensing of the gravito-inertial vector are modified when body axis and gravito-inertial vector orientation are dissociated, the observed decrease in performance while executing motor tasks in a gravito-inertial field may be at least in part attributed to the inaccurate sensing of head position.

scholarly journals Asymmetrical Body Perception

2009 ◽  
Vol 20 (11) ◽  
pp. 1373-1380 ◽  
Author(s):  
Sally A. Linkenauger ◽  
Jessica K. Witt ◽  
Jonathan Z. Bakdash ◽  
Jeanine K. Stefanucci ◽  
Dennis R. Proffitt
Keyword(s):  
Right Hemisphere ◽  
The Body ◽  
Neural Representation ◽  
Many Body ◽  
Body Perception ◽  
Left Handed ◽  
Naturally Occurring ◽  
The Right ◽  
Cortical Representations ◽  
The Brain

Perception of one's body is related not only to the physical appearance of the body, but also to the neural representation of the body. The brain contains many body maps that systematically differ between right- and left-handed people. In general, the cortical representations of the right arm and right hand tend to be of greater area in the left hemisphere than in the right hemisphere for right-handed people, whereas these cortical representations tend to be symmetrical across hemispheres for left-handers. We took advantage of these naturally occurring differences and examined perceived arm length in right- and left-handed people. When looking at each arm and hand individually, right-handed participants perceived their right arms and right hands to be longer than their left arms and left hands, whereas left-handed participants perceived both arms accurately. These experiments reveal a possible relationship between implicit body maps in the brain and conscious perception of the body.

scholarly journals The End of the Line for a Brain-Damaged Model of Unilateral Neglect

1997 ◽  
Vol 9 (2) ◽  
pp. 171-190 ◽  
Author(s):  
Michael C. Mozer ◽  
Peter W. Halligan ◽  
John C. Marshall
Keyword(s):  
Right Hemisphere ◽  
Orientation Angle ◽  
Line Length ◽  
The Body ◽  
Line Bisection ◽  
Simple Task ◽  
Unilateral Neglect ◽  
Related Disorder ◽  
On Line ◽  
The Right

For more than a century, it has been known that damage to the right hemisphere of the brain can cause patients to be unaware of the contralesional side of space. This condition, known as unilateral neglect, represents a collection of clinically related spatial disorders characterized by the failure in free vision to respond, explore, or orient to stimuli predominantly located on the side of space opposite the damaged hemisphere. Recent studies using the simple task of line bisection, a conventional diagnostic test, have proven surprisingly revealing with respect to the spatial and attentional impairments involved in neglect. In line bisection, the patient is asked to mark the midpoint of a thin horizontal lie on a sheet of paper. Neglect patients generally transect far to the right of the center. Extensive studies of line bisection have been conducted, manipulating-among other factors-line length, orientation, and position. We have simulated the pattern of results using an existing computational model of visual perception and selective attention called MORSEL (Mozer, 1991). MORSEL has already been used to model data in a related disorder, neglect dyslexia (Mozer & Behrmann, 1990). In this earlier work, MORSEL was “lesioned” in accordance with the damage we suppose to have occurred in the brains of neglect patients. The same model and lesion can simulate the detailed pattern of performance on line bisection, including the following observations: (1) no consistent across-subject bias is found in normals; (2) transection displacements are proportional to line length in neglect patients; (3) variability of displacements is proportional to line length, in both normals and patients; (4) position of the lines with respect to the body or the page on which they are drawn has little effect; and (5) for lines drawn at different orientations, displacements are proportional to the cosine of the orientation angle. MORSEL fails to account for one observation: across patients, the variability of displacements for a particular line length is roughly proportional to mean displacement. Nonetheless, the overall fit of the model is sufficiently good that we believe MORSEL can be used as a diagnostic tool to characterize the specific nature of a patient's deficit, and thereby has potential down the line in therapy.

scholarly journals Intentional Supernumerary Motor Phantom Limb after Right Cerebral Stroke: A Case Report

2021 ◽  
Vol 13 (1) ◽  
pp. 251-258
Author(s):  
Mai Yamada ◽  
Yoshimi Sasahara ◽  
Makiko Seto ◽  
Akira Satoh ◽  
Mitsuhiro Tsujihata
Keyword(s):  
Right Hemisphere ◽  
Premotor Cortex ◽  
Brain Mri ◽  
The Body ◽  
Phantom Limb ◽  
Cerebral Stroke ◽  
Emission Computed Tomography ◽  
Computed Tomography Images ◽  
Intention To Move ◽  
The Right

A 47-year-old right-handed man was admitted to our hospital for rehabilitation after right basal ganglion hematoma. On day 57, he noticed a supernumerary motor phantom limb (SPL) involving his right arm, originating at the level of the elbow. The most notable finding of his SPL was the motor characteristic. When the subject had the intention to move the upper paralyzed limb simultaneously with the trainer’s facilitating action, he said “there is another arm.” The intention to move the paralyzed arm alone or passive movement of the paralyzed arm did not induce the SPL. He showed a severe left sensorimotor impairment and mild hemineglect, but no neglect syndromes of the body (e.g., asomatognosia, somatoparaphrenia, personification and misoplegia, or anosognosia) were observed. Brain MRI demonstrated a hematoma in the right temporal lobe subcortex, subfrontal cortex, putamen, internal capsule, and thalamus. Single-photon emission computed tomography images showed more widespread hypoperfusion in the right hemisphere in comparison to the lesions on MRI. However, the premotor cortex was preserved. Our case is different from Staub’s case in that SPL was not induced by the intention to move the paralyzed limb alone; rather, it was induced when the patient intended to move the paralyzed limb with a trainer’s simultaneous facilitating action. The SPL may reflect that an abnormal closed-loop function of the thalamocortical system underlies the phantom phenomenon. However, despite the severe motor and sensory impairment, the afferent pathway from the periphery to the premotor cortex may have been partially preserved, and this may have been related to the induction of SPL.

scholarly journals Early Right Motor Cortex Response to Happy and Fearful Facial Expressions: A TMS Motor-Evoked Potential Study

2021 ◽  
Vol 11 (9) ◽  
pp. 1203 ◽  
Author(s):  
Sara Borgomaneri ◽  
Francesca Vitale ◽  
Simone Battaglia ◽  
Alessio Avenanti
Keyword(s):  
Motor Cortex ◽  
Facial Expressions ◽  
Right Hemisphere ◽  
Motor Evoked Potential ◽  
Corticospinal Excitability ◽  
The Body ◽  
Emotional Facial Expressions ◽  
Human Motor Cortex ◽  
Emotional Faces ◽  
The Right

The ability to rapidly process others’ emotional signals is crucial for adaptive social interactions. However, to date it is still unclear how observing emotional facial expressions affects the reactivity of the human motor cortex. To provide insights on this issue, we employed single-pulse transcranial magnetic stimulation (TMS) to investigate corticospinal motor excitability. Healthy participants observed happy, fearful and neutral pictures of facial expressions while receiving TMS over the left or right motor cortex at 150 and 300 ms after picture onset. In the early phase (150 ms), we observed an enhancement of corticospinal excitability for the observation of happy and fearful emotional faces compared to neutral expressions specifically in the right hemisphere. Interindividual differences in the disposition to experience aversive feelings (personal distress) in interpersonal emotional contexts predicted the early increase in corticospinal excitability for emotional faces. No differences in corticospinal excitability were observed at the later time (300 ms) or in the left M1. These findings support the notion that emotion perception primes the body for action and highlights the role of the right hemisphere in implementing a rapid and transient facilitatory response to emotional arousing stimuli, such as emotional facial expressions.

scholarly journals A transcallosal fiber system between homotopic inferior frontal regions supports complex linguistic processing

2016 ◽  
Author(s):  
Philipp Kellmeyer ◽  
Magnus-Sebastian Vry ◽  
Tonio Ball
Keyword(s):  
Right Hemisphere ◽  
Diffusion Tensor ◽  
The Body ◽  
Canonical Model ◽  
Stroke Recovery ◽  
Linguistic Processing ◽  
Fiber System ◽  
Affective Prosody ◽  
Left And Right ◽  
The Right

AbstractInferior frontal regions in the left and right hemisphere support different aspects of language processing. In the canonical model, left inferior frontal regions are mostly involved in processing based on phonological, syntactic and semantic features of language, whereas the right inferior frontal regions process paralinguistic aspects like affective prosody.Using diffusion tensor imaging (DTI) based probabilistic fiber tracking in 20 healthy volunteers, we identify a callosal fiber system connecting left and right inferior frontal regions that are involved in linguistic processing of varying complexity. Anatomically, we show that the interhemispheric fibers are highly aligned and distributed along a rostral to caudal gradient in the body and genu of the corpus callosum to connect homotopic inferior frontal regions.In light of converging data, taking previous DTI-based tracking studies and clinical case studies into account, our findings suggest that the right inferior frontal cortex not only processes paralinguistic aspects of language (such as affective prosody), as purported by the canonical model, but also supports the computation of linguistic aspects of varying complexity in the human brain. Our model may explain patterns of right hemispheric contribution to stroke recovery as well as disorders of prosodic processing. Beyond language-related brain function, we discuss how interspecies differences in interhemispheric connectivity and fiber density, including the system we described here, may also explain differences in transcallosal information transfer and cognitive abilities across different mammalian species.

scholarly journals Psychic Tonus, Body Schema and the Parietal Lobes: A Multiple Lesion Case Analysis

2007 ◽  
Vol 18 (2) ◽  
pp. 65-80 ◽  
Author(s):  
C. M. J. Braun ◽  
S. Desjardins ◽  
S. Gaudelet ◽  
A. Guimond
Keyword(s):  
Left Hemisphere ◽  
Right Hemisphere ◽  
Hemispheric Specialization ◽  
Body Schema ◽  
The Body ◽  
Parietal Lobes ◽  
Hemisphere Lesion ◽  
The Right ◽  
Internal Experience ◽  
And Behavior

The psychic tonus model (Braun and colleagues, 1999, 2002, 2003, 2006) states that the left hemisphere is a “booster” of internal experience and behavior in general, and that the right hemisphere is a “dampener”. Twenty-five patients with a “positive” extreme disturbance of body schema (somatoparaphrenia) and 37 patients with a “negative” disturbance of body schema (autotopagnosia or Gerstmann’s syndrome), all following a unilateral parietal lesion, were found in the literature and were analyzed to test predictions from Braun’s “psychic tonus” model. As expected, patients with a positive syndrome had a right hemisphere lesion significantly more frequently, and those with a negative syndrome had a left hemisphere lesion significantly more frequently. Thus the psychic tonus model of hemispheric specialization, previously supported with regard to psychomotor baseline, libido, talkativeness, memory, auditory and visual perceptual tonus, now incorporates the tonus of representation of the body (body schema) in the parietal lobes.

scholarly journals Behavioural lateralisation in reindeer

Rangifer ◽  
2002 ◽  
Vol 22 (1) ◽  
pp. 51 ◽  
Author(s):  
Yngve Espmark ◽  
Knut Kinderås
Keyword(s):  
Rangifer Tarandus ◽  
Right Hemisphere ◽  
Experimental Studies ◽  
Reindeer Husbandry ◽  
Average Group ◽  
Left And Right ◽  
The Right ◽  
Free Ranging ◽  
The Brain ◽  
Average Group Size

Reindeer (Rangifer tarandus) kept in corrals or otherwise forced to clump typically start milling in response to stressing events. This behaviour is generally considered to have an antipredator effect. An inquiry on herd behaviour, to which 35 Norwegian reindeer husbandry districts responded, showed that 32 experienced that corralled rein¬deer consistently circled leftwards, whereas the remaining three reported consistently rightward circling. Regular monitoring of a reindeer herd in central Norway over a two-year period (1993-94), and experimental studies on a fraction of the same herd, revealed the following traits. Free-ranging reindeer showed no right- or left-turning preference during grazing or browsing, but when the reindeer were driven into corrals or forced to clump in the open they invariably rotated leftwards. The circling of corralled reindeer was triggered at an average group size of 20 to 25 animals, apparently independently of the age and sex of the animals. When they dug craters in the snow to reach food, the reindeer used their left foreleg significantly more often than their right. In 23 out of 35 reindeer, the right hemisphere of the brain was heavier than the left. However, in the sample as a whole, the weights of the left and right hemispheres did not differ significantly. Lateralised behaviour in reindeer is thought to be determined by natural and stress induced asymmetries in brain structure and hormonal activity. In addition, learning is probably important for passing on the behaviour between herd members and generations. Differences in lateralised behaviour between nearby herds are thought to be related primarily to different exposure to stress and learning, whereas genetical and environmental fac¬tors (e.g. diet), age structure and sex ratio are probably more important for explaining differences between distant pop¬ulations.

scholarly journals White Matter Integrity Correlates of the Reading Span

2021 ◽  
Author(s):  
Ekaterina V. Pechenkova ◽  
Yana R. Panikratova ◽  
Maria A. Fomina ◽  
Elena A. Mershina ◽  
Daria A. Bazhenova ◽  
...  
Keyword(s):  
Working Memory ◽  
White Matter ◽  
Right Hemisphere ◽  
Diffusion Tensor ◽  
Structural Connectivity ◽  
Verbal Working Memory ◽  
The Body ◽  
White Matter Integrity ◽  
Reading Span ◽  
The Right

Although working memory (WM) is crucial for intellectual abilities, not much is known about its brain underpinnings, especially the structural connectivity. We used diffusion tensor imaging (DTI) to look across the whole brain for the white matter integrity correlates of the individual differences in the reading span (verbal WM capacity during reading) in healthy adults. Right-handed healthy native Russian speakers (N = 67) underwent DTI on a 3T Philips Ingenia scanner. Verbal WM was assessed with the Daneman-Carpenter reading span test (Russian version). Fractional anisotropy maps from each participant were entered into the group tract-based spatial statistics analysis with the reading span as a covariate; the results were TFCE-corrected. After taking into account effects of age, sex, education and handedness, reading span positively correlated with the white matter integrity in multiple sites: the body, the genu and the splenium of corpus callosum; bilateral corona radiata (anterior, posterior, and superior); bilateral superior longitudinal fasciculus; several tracts in the right hemisphere only, including the internal and external capsule; bilateral superior parietal and frontal white matter. Although the left hemisphere is central for verbal processing, we revealed the important role of the right hemisphere white matter for the verbal WM capacity. Our finding indicates that larger verbal working memory span may originate from additional processing resources of the right hemisphere.

Are “Presences” Preferentially Felt along the Left Side of One's Body?

1994 ◽  
Vol 79 (3) ◽  
pp. 1200-1202 ◽  
Author(s):  
Peter Brugger
Keyword(s):  
Left Hemisphere ◽  
Right Hemisphere ◽  
Sense Of Self ◽  
Hemispheric Specialization ◽  
The Body ◽  
The Self ◽  
Brain Pathology ◽  
Healthy Individuals ◽  
Physical Presence ◽  
The Right

The “feeling of a presence” is the distinct awareness of the physical presence of somebody in the near extracorporeal space. Although fairly frequently confined to one side of the body, systematic documentation of the lateralization of the phenomenon has not yet been attempted. A brief tabular summary of 11 cases of the unilateral feeling of a presence in association with focal brain pathology (seven left-hemisphere lesions, four right-hemisphere lesions) shows lateralization to the left in five, to the right in six cases. The data, together with the scattered reports of unilaterally felt presences in patients with nonfocal brain pathology and in healthy individuals, do not support claims that the left hemispace is the preferred location. Any models of hemispheric specialization in the sense of self which are derived from observations of felt presences remain speculative. Nevertheless, clinicians are encouraged to document carefully all the unilateral aspects of the feeling of a presence as well as of other reduplicative phenomena involving the self.

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