scholarly journals Neural support of manual preference revealed by BOLD variations during right and left finger-tapping in a sample of 287 healthy adults balanced for handedness

2020 ◽  
Author(s):  
Nathalie Tzourio-Mazoyer ◽  
Loïc Labache ◽  
Laure Zago ◽  
Isabelle Hesling ◽  
Bernard Mazoyer
Keyword(s):  
Finger Tapping ◽  
Brain Areas ◽  
Left Hand ◽  
Left Handedness ◽  
Somatosensory Cortices ◽  
Hand Control ◽  
Left And Right ◽  
The Right ◽  
The Brain ◽  
Somatosensory Areas

AbstractWe have identified the brain areas involved in Manual Preference (MP) in 143 left-handers (LH) and 144 right-handers (RH)). First, we selected the pairs of homotopic regions of interest (hROIs) of the AICHA atlas with significant contralateral activation and asymmetry during the right-hand and the left-hand Finger-Tapping (FT) both in RH and LH. Thirteen hROIs were selected, including the primary and secondary sensorimotor, and premotor cortices, thalamus, dorsal putamen and cerebellar lobule IV. Both contralateral activations and ipsilateral deactivations (reversed for the cerebellum) were seen in primary motor and somatosensory areas, with stronger asymmetries when the preferred hand was used. Comparing the prediction of MP with different combinations of BOLD variations in these 13 hROIs, the differences between movement of the preferred hand versus that of the non-preferred hand within the contralateral and/or ipsilateral cortices of 11 hROIS performed best at explaining handedness distribution, Handedness is thus supported by: 1-between-hand variations of ipsilateral deactivations of hand primary sensorimotor and secondary somatosensory cortices and 2-variations in regions showing the same profile in left and right-handers during the right or left FT. The present study demonstrates that right and left-handedness are not based on mirrored organization of hand control areas.

Functional Overlap of Finger Representations in Human SI and SII Cortices

2001 ◽  
Vol 86 (4) ◽  
pp. 1661-1665 ◽  
Author(s):  
Cristina Simões ◽  
Markus Mertens ◽  
Nina Forss ◽  
Veikko Jousmäki ◽  
Bernd Lütkenhöner ◽  
...  
Keyword(s):  
Index Finger ◽  
Ring Finger ◽  
Middle Finger ◽  
Response Latencies ◽  
Left Hand ◽  
Tactile Stimuli ◽  
Somatosensory Cortices ◽  
Somatosensory Evoked Fields ◽  
Left And Right ◽  
The Right

We aimed to find out to what extent functional representations of different fingers of the two hands overlap at the human primary and secondary somatosensory cortices SI and SII. Somatosensory evoked fields (SEFs) were recorded with a 306-channel neuromagnetometer from 8 subjects. Tactile stimuli, produced by diaphragms driven by compressed air, were delivered to the fingertips in three different conditions. First, the right index finger was stimulated once every 2 s. Then two other stimuli were interspersed, in different sessions, to right- or left-hand fingers (thumb, middle finger, or ring finger) between the successive right index finger stimuli. Strengths of the responses to right index finger stimuli were evaluated in each condition. Responses to right index finger stimuli were modeled by three current dipoles, located at the contralateral SI and the SII cortices of both hemispheres. The earliest SI responses, peaking around 65 ms, were suppressed by 18% ( P < 0.05) when the intervening stimuli were presented to the same hand; intervening stimuli to the other hand had no effect. The SII responses were bilaterally suppressed by intervening stimuli presented to either hand: in the left SII, the suppression was 39 and 42% ( P < 0.01) and in the right SII 67 and 72% ( P < 0.001) during left- and right-sided intervening stimuli, respectively. Left- and right-sided intervening stimuli affected similarly the SII responses and had no effect on the response latencies. The results indicate a strong and symmetric overlap of finger representations for both hands in the human SII cortices, and a weaker functional overlap for fingers of the same hand in the SI cortex.

Bilateral Writing Ability, Cerebral Organization, and Hand Posture

1979 ◽  
Vol 49 (3) ◽  
pp. 867-870
Author(s):  
Allan L. Combs ◽  
Dana A. Beezley ◽  
Gary M. Prater ◽  
Gerald F. Henning ◽  
Rhonda F. Cottrell
Keyword(s):  
Hand Position ◽  
Hand Posture ◽  
Writing Ability ◽  
Left Hand ◽  
Left And Right ◽  
The Right

Among a group of 12 persons selected for the ability to write with ease with either hand, none were found to write using a hooked hand posture with either the right or left hand. Tests of verbal and manipulospatial ability indicated a normal balance of these two types of abilities, usually associated with the left and right hemispheres. Findings are discussed in terms of implications for cerebral organization and hand position in writing.

Stimulus–Response Compatibility for Vertically Oriented Stimuli and Horizontally Oriented Responses: Evidence for Spatial Coding

1995 ◽  
Vol 48 (2) ◽  
pp. 367-383 ◽  
Author(s):  
Daniel J. Weeks ◽  
Robert W. Proctor ◽  
Brad Beyak
Keyword(s):  
Spatial Coding ◽  
Left Hand ◽  
Response Location ◽  
Stimulus Response ◽  
Response Sets ◽  
Response Switch ◽  
Oriented Stimulus ◽  
Left And Right ◽  
Active Switch ◽  
The Right

It has previously been shown that, when stimuli positioned above or below a central fixation point (“up” and “down” stimuli) are assigned to left and right responses, the stimulus–response mapping up-left/down-right is more compatible than the mapping up-right/down-left for responses executed by the left hand in the left hemispace, but this relation is reversed for responses executed by the right hand in the right hemispace. In Experiment 1, each hand responded at locations in both hemispaces to dissociate the influence of hand identity from response location, and response location was found to be the determinant of relative compatibility. In Experiment 2 responses were made at the sagittal midline, and an inactive response switch was placed to the left or right to induce coding of the active switch as right or left, respectively. This manipulation of relative location had an effect similar to, although of lesser magnitude than, that produced by physically changing location of the response switch in Experiment 1. It is argued that these results are counter to predictions of a movement-preference account and consistent with the view that spatial coding underlies compatibility effects for orthogonally oriented stimulus and response sets.

scholarly journals Lateral comparisons using Fishman's skeletal maturation assessment

2014 ◽  
Vol 85 (3) ◽  
pp. 408-412 ◽  
Author(s):  
Abraham N. Safer ◽  
Peter Homel ◽  
David D. Chung
Keyword(s):  
Bone Development ◽  
Surgical Patients ◽  
Skeletal Maturation ◽  
Age And Gender ◽  
Left Hand ◽  
Right Hand ◽  
Significant Difference ◽  
Left And Right ◽  
And Gender ◽  
The Right

ABSTRACT Objective:  To assess lateral differences between ossification events and stages of bone development in the hands and wrists utilizing Fishman's skeletal maturation indicators (SMIs). Materials and Methods:  The skeletal ages of 125 subjects, aged 8 to 20 years, were determined with left and right hand-wrist radiographs using Fishman's SMI assessment. Each subject was also given the Edinburgh Handedness Questionnaire to assess handedness. The skeletal ages of both hand-wrist radiographs were analyzed against each other, handedness, chronologic age, and gender. Results:  There were no significant differences overall in right and left SMI scores (P  =  .70); 79% of all patients showed no difference in right and left SMI scores, regardless of handedness, gender, or age. However, when patients were categorized based on clinical levels of SMI score for the right hand-wrist, there was a significant difference (P  =  .01) between the SMI 1-3 group and the SMI 11 group. Subjects in the SMI 1-3 group were more likely to show a left &gt; right SMI score, while subjects in the SMI 11 group were likely to show a right &gt; left SMI score. Conclusion:  Although no significant overall lateral differences in SMI scores were noted, it may be advisable to obtain a left hand-wrist radiograph and/or additional diagnostic information to estimate completion of growth in young surgical patients.

Evaluation of Hand-Dominance on Manual Control of Aircraft

1996 ◽  
Vol 40 (2) ◽  
pp. 72-76 ◽  
Author(s):  
Valerie J. Gawron ◽  
James E. Priest
Keyword(s):  
Manual Control ◽  
Dominant Hand ◽  
Hand Dominance ◽  
Transport Aircraft ◽  
Left Hand ◽  
Tracking Tasks ◽  
Right Hand ◽  
Hand Control ◽  
Left And Right ◽  
Task Simulation

In the transport aircraft community the non-dominant hand control of aircraft is the norm. This historical precedence may be biasing the cockpit designs of the newer fly-by-wire aircraft which utilize a small sidestick controller rather than a wheel-column. Very little data are available to determine what effect non-dominant hand control using small throw controllers has on the pilot operator. To provide such data, a part-task simulation study was undertaken. Three different compensatory tracking tasks were performed with both left and right hand-controllers. Six right-hand dominant and three left-hand dominant subjects performed all three tasks, with both controllers. The results indicate that performance degraded and workload increased when the pilots were forced to use their non-dominant hand.

Cortical Representation of Swallowing: A Modified Dual Task Paradigm

2002 ◽  
Vol 94 (3) ◽  
pp. 1029-1040 ◽  
Author(s):  
Stephanie K. Daniels ◽  
David M. Corey ◽  
Cristen L. Barnes ◽  
Nikki M. Faucheaux ◽  
Daniel H. Priestly ◽  
...  
Keyword(s):  
Dual Task ◽  
Right Hemisphere ◽  
Index Finger ◽  
Finger Tapping ◽  
Left Index Finger ◽  
Cortical Representation ◽  
Word Repetition ◽  
Dual Task Paradigm ◽  
Left And Right ◽  
The Right

It is unclear whether the cortical representation of swallowing is lateralized to the left cerebral hemisphere, right hemisphere, or bilaterally represented. As dysphagia is common in acute stroke, it is important to elucidate swallowing lateralization to facilitate earlier detection of stroke patients who may be at greater risk for dysphagia and aspiration. In this study, a modified dual task paradigm was designed to study laterality of swallowing in a group of 14 healthy, young, right-handed, male adults. The subjects were studied at baseline and with interference. Baseline conditions, performed separately, were continuous swallowing, finger tapping using the right and left index fingers, and word repetition. Interference tasks, including tapping with the right index finger, tapping with the left index finger, and word repetition, were completed with and without swallowing. Finger-tapping rate was measured, and x-ray samples of the swallowing task were taped to measure swallowing rate and volume swallowed. At baseline, the rate of tapping the right index finger was significantly faster than that of the left index finger. There was a significant decline in the tapping rates of both left and right index fingers with swallowing interference. The volume per swallow was significantly reduced during the interfering language task of silent repetition. These results offer partial support for a bilateral representation of swallowing as well as suggest an important left hemispheric contribution to swallowing. However, it cannot be concluded that the left hemisphere is more important than the right, as a comparable right hemisphere task was not studied.

scholarly journals Drawing with the Non-dominant Hand: Implications for the Study of Construction

1998 ◽  
Vol 25 (4) ◽  
pp. 306-309 ◽  
Author(s):  
Sherma Zacharias ◽  
Andrew Kirk
Keyword(s):  
Neurological Disease ◽  
Right Hemisphere ◽  
Normal Subjects ◽  
Elderly Subjects ◽  
Dominant Hand ◽  
Left Hand ◽  
Right Hand ◽  
Left And Right ◽  
The Right ◽  
Right And Left Hand

ABSTRACT:Background:Constructional impairment following left vs. right hemisphere damage has been extensively studied using drawing tasks. A confounding factor in these studies is that right-handed patients with left hemisphere damage (LHD) are often forced by weakness to use their non-dominant (left) hand or hemiparetic dominant hand. Qualitative differences in the drawing characteristics of left and right hand drawings by normal subjects have not previously been characterized. The present study was undertaken to determine the qualitative differences between left and right hand drawings of normal subjects.Methods:Thirty right-handed, elderly subjects without a history of neurological disease were asked to draw, from memory, seven objects using the right and left hand. Half of the subjects were randomly assigned to draw with the left hand first, and half the right hand first. Right and left hand drawings were compared using a standardized scoring system utilized in several previous studies of drawing in focal and diffuse neurological disease. Each drawing was scored on eighteen criteria. Right and left hand drawing scores were then compared using the t-test for paired samples or the Wilcoxon matched-pairs testResults:Drawings made using the left hand were found to be significantly simpler, more tremulous and of poorer overall quality than drawings made by the same subjects using the right hand.Conclusions:The deficits found in left versus right hand drawings of normals are similar to those found in patients with LHD, suggesting that much of the drawing impairment seen following LHD is due to an elementary motor disturbance related to use of the non-dominant hand.

scholarly journals Effects of tDCS Dose and Electrode Montage on regional cerebral blood flow and motor behavior

2021 ◽  
Author(s):  
Anant Shinde ◽  
Karl Lerud ◽  
Fanny Munsch ◽  
David C Alsop ◽  
Gottfried Schlaug
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Brain Regions ◽  
Regional Cerebral Blood ◽  
Left Hand ◽  
Motor Region ◽  
Left And Right ◽  
The Right ◽  
Sequence Performance

AbstractWe used three dose levels (Sham, 2mA and 4mA) and two different electrode montages (unihemispheric or bihemispheric) to examine DOSE and MONTAGE effects on regional cerebral blood flow (rCBF) as a surrogate marker of neural activity, and on a finger sequence task, as a surrogate behavioral measure drawing on brain regions targeted by transcranial direct current stimulation (tDCS). We placed the anodal electrode over the right motor region (C4) while the cathodal or return electrode was placed either over a left supraorbital region (unihemispheric montage) or over the left motor region (C3 in the bihemispheric montage). Performance changes in the finger sequence task for both hands (left hand: p = 0.0026, and right hand: p = 0.0002) showed a linear tDCS dose response, but no effect of montage. rCBF in the the right hemispheric perirolandic area increased with dose under the anodal electrode (p = 0.027), while in the perirolandic ROI in the left hemisphere, rCBF showed a trend to increase with dose (p = 0.053), and significant effect of montage (p = 0.00004). The bihemispheric montage showed additional rCBF increases in frontomesial regions in the 4mA condition but not in the 2mA condition. Furthermore, we found correlations between rCBF changes in the right perirolandic region and improvements in the finger sequence task performance (FSP) for left and right hand. Our data support not only a strong direct tDCS dose effect for rCBF and FSP as surrogate measures of targeted brain regions, but also indirect effects on rCBF in functionally connected regions (e.g., frontomesial regions), particularly in the higher dose condition, and on FSP of the ipsilateral hand (to the anodal electrode). At higher dose and irrespective of polarity, a wider network of sensorimotor regions is positively affected by tDCS.Graphical AbstractHighlightstDCS-DOSE had linear effect on finger sequence performance for both handsrCBF changes in both perirolandic ROIs demonstrated tDCS-DOSE effects and left perirolandic ROI demonstrated tDCS-MONTAGE effects.Simulated current intensity in the left and right perirolandic ROI strongly correlated with the contralateral hand’s finger sequence performance.tDCS-Tolerability scores did not correlate with change in rCBF or finger sequence performance of the left hand.

scholarly journals Simultaneous Arterial and Venous Brain Infarctions in a Patient with COVID-19.

2021 ◽  
Author(s):  
Sonia Bermúdez ◽  
Paula Forero ◽  
Vanessa Salej ◽  
Silvia González ◽  
Jaime Toro
Keyword(s):  
Rt Pcr ◽  
Brain Images ◽  
Case Presentation ◽  
Cortical Vein ◽  
Left Hand ◽  
Brain Infarcts ◽  
Starting Point ◽  
Severity Of The Disease ◽  
The Right ◽  
The Brain

Abstract Introduction: Stroke is one of the manifestations of COVID-19 associated coagulopathy. Arterial infarcts are the most common presentation, however involvement of both arterial and venous irrigation is possible but rare. We report, what is, to our knowledge, the second case of concomitant arterial and venous brain thrombosis evidenced in magnetic resonance. Case presentation: A 62-year-old man presented with acute weakness of the left hand and lack of coordination in the left arm. Nine days earlier, he was positive for SARS-CoV-2 RT-PCR. The brain images revealed two subacute infarcts, one corresponding to the territory of the right middle cerebral artery, and the other in the right frontal cortical vein. Conclusion: The existence of both venous and arterial brain infarcts due to COVID-19 infection, has been previously reported once. Most of the cases of stroke are due to only arterial thrombosis, therefore this could be the starting point to start collecting data about simultaneous compromise in order to assess and compare outcomes, severity of the disease, among other variables.

scholarly journals Are left- and right-eye pupil sizes always equal?

2019 ◽  
Vol 12 (2) ◽  
Author(s):  
Gonca Gokce Menekse Dalveren ◽  
Nergiz Ercil Cagiltay
Keyword(s):  
Cognitive Load ◽  
Movement Analysis ◽  
Difficulty Level ◽  
Human Beings ◽  
Left Hand ◽  
Surgical Residents ◽  
Right Hand ◽  
Significant Difference ◽  
Left And Right ◽  
The Right

Eye movements provide very critical information about the cognitive load and behaviors of human beings. Earlier studies report that under normal conditions, the left- and right-eye pupil sizes are equal. For this reason, most studies undertaking eye-movement analysis are conducted by only considering the pupil size of a single eye or taking the average size of both eye pupils. This study attempts to offer a better understanding concerning whether there are any differences between the left- and right-eye pupil sizes of the right-handed surgical residents while performing surgical tasks in a computer-based simulation environment under different conditions (left hand, right hand and both hands). According to the results, in many cases, the right-eye pupil sizes of the participants were larger than their left-eye pupil sizes while performing the tasks under right-hand and both-hands conditions. However, no significant difference was found in relation to the tasks performed under left-hand condition in all scenarios. These results are very critical to shed further light on the cognitive load of the surgical residents by analyzing their left-eye and right-eye pupil sizes. Further research is required to investigate the effect of the difficulty level of each scenario, its appropriateness with the skill level of the participants, and handedness on the differences between the left- and right-eye pupil sizes.

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