Manual Asymmetries in Aimed Movements

1989 ◽  
Vol 41 (3) ◽  
pp. 501-516 ◽  
Author(s):  
Eric A. Roy ◽  
Digby Elliott

Three hypotheses for the right-hand advantage in aiming movements were examined in these experiments: (1) the right-hand system is more efficient at processing visual information during the movement; (2) subjects make more use of visual information prior to movement initiation when using the right hand; (3) the right hand is less variable in generating force in initiating the pointing response as force demands increase. In the first experiment subjects pointed at a target located directly in front of them from two starting positions which defined short (25-cm) and long (35-cm) movements. The movements were made in three movement times, fast (150 to 249 msec), medium (250 to 349 msec) and slow (350 to 449 msec), under three vision conditions—full vision, and no vision (lights out) with immediate or delayed movement initiation. Performance was measured in movement time and accuracy in amplitude of movement. The results did not completely support any of the hypotheses regarding the right-hand advantage, although the left hand was generally more variable than the right. Also, variability increased with increases in movement length and decreases in movement time. The second experiment was designed to examine further the hypotheses regarding the right-hand advantage. In this experiment the same three visual conditions were used; however, subjects made only fast (<250-msec) movements. Also six rather than two starting positions were used. The increased variability of the left hand was observed again here. Further pointing accuracy with the left hand was more adversely affected in the no-vision delay condition. The implications of these results were discussed as they pertain to understanding the processes involved in visual aiming and the observed manual asymmetries.

1998 ◽  
Vol 86 (3) ◽  
pp. 967-975 ◽  
Author(s):  
Brian K. V. Maraj ◽  
Digby Elliott ◽  
James Lyons ◽  
Eric A. Roy ◽  
Tamara Winchester

Two experiments were conducted to examine manual asymmetries in a one-dimensional aiming task. In Exp. 1, 10 right-handed adults slid a computer mouse 13 cm on a graphics tablet with both the right and left hands to targets of 3 different diameters. Under these conditions, the movement time for the right hand was significantly faster as expected. In Exp. 2, subjects performed similar movements to move a cursor 13 cm on a computer monitor. Thus the study was identical except the stimulus-response mapping was indirect. In this situation, there were no significant differences for either movement time or movement error between hands despite these performance measures indicating that target aiming was more difficult in Exp. 2. Because increases in task difficulty generally result in a greater advantage for the right hand, as indicated by Todor & Smiley, 1985, the present studies suggest that superiority of the right hand in aiming tasks may be diminished when spatial translation is required. Perhaps the spatial translation requires greater involvement of the right hemisphere, a process associated with manual advantage for the left hand, previously suggested by Roy and MacKenzie.


2017 ◽  
Vol 14 (3) ◽  
pp. 1067-1074 ◽  
Author(s):  
Malihe Moones Tousi ◽  
Toktam Emami ◽  
Seyed Mojtaba Hoseini

ABSTRACT: The purpose of this study is to analyze the effect of practice orderwithdominant and non-dominant hand on acquisition, retention and transfer of basketball dribbling skills of female students at Ferdowsi University. The subjects were 20 female students of General Physical Education (19-24), who did not have any experiences in basketball with dominant right hand. They were randomly selected and equally assigned into two groups. The subjects practiced within the program for 4 weeks, 2 times a week and 45 minutes per session. Group A practiced with their dominant right hand for the first four sessions and then switched to their left hand for the second four sessions. Group B practiced reversely. The subjects were assessed by Slalom-Dribble-Test in pre-test and post-test. Retention and transfer tests were performed one week after the exercise was finished. The results showed that there was no significant difference between the two groups in acquisition of dribbling skill (p=0.053). Movement time has been significantly reduced from pre-test to post-test (p=0.00). The results showed better performance of the right hand compared to the left (p=0.042). Both groups had a shorter dribbling time with the right hand compared to the left hand in the post-test and retention test. There was no significant difference between two groups in transfer task (p = 0.16). The results indicate that practicing with dominant and non-dominant limbs in the initial motor learning seems to be important to improve performance of both limbs and to strengthen bilateral competence of the learners.


1937 ◽  
Vol 57 (2) ◽  
pp. 224-226 ◽  
Author(s):  
Annie Zadoks-Jitta

From an old Italian collection there has come to Holland the bronze statuette here published, representing Poseidon as he is known to us from several marbles and bronzes and numerous Hellenistic and Roman coins. The god is shown leaning forward on his raised and bent right leg, his right forearm resting on his thigh, his left hand raised high. The statuette, which measures 17½ cm. in height, is in an excellent state of preservation; only the tops of the thumb and of three fingers of the right hand are missing; too vigorous cleaning has removed much of the patina; on the right side of the neck is a hole, probably a vent. The statuette is of very fine quality and excellent workmanship. In spite of its small size it is impressive and monumental, and strongly recalls a life-sized original; evidently this was a modelled, not a sculptured one; we have to think of a bronze statue. Coins of Demetrios Poliorketes, the figure on which shows exactly the same posture as our bronze, tell us that the right leg rested on a rock and the left hand held a trident.The most famous of this well-known type is the Lateran statue, which has been much discussed as to the authorship of its original. Unfortunately this is rather a bad example of a Roman copy, made in a very classicist taste, probably in the first half of the second century A.D.; moreover, it has been much restored. Helbig tells us that nose, left arm, both legs up to the knee, ship, dolphin and plinth are restored, while parts of the hair and beard are new.


1970 ◽  
Vol 30 (2) ◽  
pp. 615-630 ◽  
Author(s):  
Lilliane Lurcat ◽  
Irene Kostin

The Lurcat Test of Graphical Abilities was administered to 124 right-handed children between the ages of 4 and 10. Age trends were determined for the ability to reproduce the correct form of a curve, i.e., a cycloid or a spiral, when given (a) visual information alone, (b) both visual and kinesthetic information, and (c) kinesthetic information alone. Results for the right and left hands were determined separately. Age trends were examined, also, for the ability to reproduce the correct trajectory or orientation of these curves in the three situations mentioned above. Most of the development of these abilities in our sample seems to occur between the ages of 4 and 7. Reproducing cycloids with parallel rotations with both hands simultaneously while blindfolded seems to be related to laterality. In this situation, for 6- and 7-yr.-olds, the large majority of right-handed children correctly reproduce the rotation of the cycloid only with the right hand. The rotation produced by the left hand was found to be symmetrical rather than parallel to that produced by the right hand.


1946 ◽  
Vol 11 (1) ◽  
pp. 2-2

In the article “Infant Speech Sounds and Intelligence” by Orvis C. Irwin and Han Piao Chen, in the December 1945 issue of the Journal, the paragraph which begins at the bottom of the left hand column on page 295 should have been placed immediately below the first paragraph at the top of the right hand column on page 296. To the authors we express our sincere apologies.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Velarie Ansu ◽  
Stephanie Dickinson ◽  
Alyce Fly

Abstract Objectives To determine which digit and hand have the highest and lowest skin carotenoid scores, to compare inter-and-intra-hand variability of digits, and to determine if results are consistent with another subject. Methods Two subjects’ first(F1), second(F2), third(F3) and fifth(F5) digits on both hands were measured for skin carotenoids with a Veggie Meter, for 3 times on each of 18 days over a 37-day period. Data were subjected to ANOVA in a factorial treatment design to determine main effects for hand (2 levels), digits (4), and days (18) along with interactions. Differences between digits were determined by Tukey's post hoc test. Results There were significant hand x digit, hand x day, digit x day, and hand x digit x day interactions and significant simple main effects for hand, digit, and day (all P < 0.001). Mean square errors were 143.67 and 195.62 for subject A and B, respectively, which were smaller than mean squares for all main effects and interactions. The mean scores ± SD for F1, F2, F3, and F5 digits for the right vs left hands for subject A were F1:357.13 ± 45.97 vs 363.74 ± 46.94, F2:403.17 ± 44.77 vs. 353.20 ± 44.13, F3:406.76 ± 43.10 vs. 357.11 ± 45.13, and F5:374.95 ± 53.00 vs. 377.90 ± 47.38. For subject B, the mean scores ± SD for digits for the right vs left hands were F1:294.72 ± 61.63 vs 280.71 ± 52.48, F2:285.85 ± 66.92 vs 252.67 ± 67.56, F3:268.56 ± 57.03 vs 283.22 ± 45.87, and F5:288.18 ± 34.46 vs 307.54 ± 40.04. The digits on the right hand of both subjects had higher carotenoid scores than those on the left hands, even though subjects had different dominant hands. Subject A had higher skin carotenoid scores on the F3 and F2 digits for the right hand and F5 on the left hand. Subject B had higher skin carotenoid scores on F5 (right) and F1 (left) digits. Conclusions The variability due to hand, digit, and day were all greater than that of the 3 replicates within the digit-day for both volunteers. This indicates that data were not completely random across the readings when remeasuring the same finger. Different fingers displayed higher carotenoid scores for each volunteer. There is a need to conduct a larger study with more subjects and a range of skin tones to determine whether the reliability of measurements among digits of both hands is similar across the population. Funding Sources Indiana University.


Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 728
Author(s):  
Jessica McDonnell ◽  
Nicholas P Murray ◽  
Sungwoo Ahn ◽  
Stefan Clemens ◽  
Erik Everhart ◽  
...  

The majority of the population identifies as right-hand dominant, with a minority 10.6% identifying as left-hand dominant. Social factors may partially skew the distribution, but it remains that left-hand dominant individuals make up approximately 40 million people in the United States alone and yet, remain underrepresented in the motor control literature. Recent research has revealed behavioral and neurological differences between populations, therein overturning assumptions of a simple hemispheric flip in motor-related activations. The present work showed differentially adaptable motor programs between populations and found fundamental differences in methods of skill acquisition highlighting underlying neural strategies unique to each population. Difference maps and descriptive metrics of coherent activation patterns showed differences in how theta oscillations were utilized. The right-hand group relied on occipital parietal lobe connectivity for visual information integration necessary to inform the motor task, while the left-hand group relied on a more frontal lobe localized cognitive based approach. The findings provide insight into potential alternative methods of information integration and emphasize the importance for inclusion of the left-hand dominant population in the growing conceptualization of the brain promoting the generation of a more complete, stable, and accurate understanding of our complex biology.


Südosteuropa ◽  
2019 ◽  
Vol 67 (2) ◽  
pp. 175-195
Author(s):  
Petru Negură

Abstract The Centre for the Homeless in Chișinău embodies on a small scale the recent evolution of state policies towards the homeless in Moldova (a post-Soviet state). This institution applies the binary approach of the state, namely the ‘left hand’ and the ‘right hand’, towards marginalised people. On the one hand, the institution provides accommodation, food, and primary social, legal assistance and medical care. On the other hand, the Shelter personnel impose a series of disciplinary constraints over the users. The Shelter also operates a differentiation of the users according to two categories: the ‘recoverable’ and those deemed ‘irrecoverable’ (persons with severe disabilities, people with addictions). The personnel representing the ‘left hand’ (or ‘soft-line’) regularly negotiate with the employees representing the ‘right hand’ (‘hard-line’) of the institution to promote a milder and a more humanistic approach towards the users. This article relies on multi-method research including descriptive statistical analysis with biographical records of 810 subjects, a thematic analysis of in-depth interviews with homeless people (N = 65), people at risk of homelessness (N = 5), professionals (N = 20) and one ethnography of the Shelter.


Cell Reports ◽  
2016 ◽  
Vol 17 (11) ◽  
pp. 2809-2810
Author(s):  
Jody C. Culham
Keyword(s):  

1987 ◽  
Vol 101 (2) ◽  
pp. 89-94
Author(s):  
J. Bruyn

AbstractOf the nine interpretations proposed for Rembraradt's history Painting of 1626 now at Leiden, none is really convincing. Il seems attractive to think of palamedes Condemned by Agamemncm as the subject because of its political significance in the year after the publication of Voredel's tragecty Palamedcs or Innocence Murdered, which denounced the execution of the Remonstrant leader Johan van Oldenbarnevelt in 1619. γet the scene depicted does not fit any episode frorn the Palamedes story. It appears rather to represent three young men appearing before a crowned figure who makes a pronouncement, probably one of magnanimity or clemency. It is conceivable that the subject was taken from Q. Curtius Rufus's Historiae Alexandri Magni Macedonis, ofwhich several editions, including translations into the vernacular, were published in Holland in the first decades of the 17th century. The episode in question was known to the young Rubens, but does not seem to have been illustrated by any other artist. At the beginning of the seventh book it is described how Alexander summoned before. him in the presence of the army two oj three brothers, who had been close friends of Philotas, a former, friend of his who had been executed for plotting against his life. The youngest brother, Poleinon, had panicked and fled but was caught and brought back at the very moment when Alexander had accused the brothers and the eldest, Amyntas, after having been released from his bonds and given a spear which he held in his left hand, had embarked on his szzccess ful defence. The appearance of Polemon infuriated the soldiers, but when he took the blame on himself and prrifessed his brothers' innocence, they were moved to tears. So too was Alexander who, prompted by their cries, absolved the brothers. This anecdote does at least explain some of the features of Rembrandt's scene. The young man standing on the right with his right hand raised as if swearing an oath would be the eloquent Amyntas with a spear in his left hand. Hidden behind him kneels the second brother, Simias, while Polemon, 'a young man just come to maturity and in the first bloom of his youth', has fallen on one knee in the foreground, underlining his emotional words with his right hand bressed to his heart. Alexander raises his sceptre in token of his absolution and some men in the background wave and shout from a socle they have climbed. Interpreted in this way, the scene coralains not a topical political allegory but, as would seem usual with history paintings, a message of a more general nature: the magnanimity of Alexander as an 'exemblum virtutis'.


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