Age-related differences in corticospinal control during functional isometric contractions in left and right hands

2005 ◽  
Vol 99 (4) ◽  
pp. 1483-1493 ◽  
Author(s):  
Martin V. Sale ◽  
John G. Semmler
Keyword(s):  
Older Adults ◽  
Precision Grip ◽  
Silent Period ◽  
Isometric Contractions ◽  
Age Difference ◽  
Left Hand ◽  
Right Hand ◽  
Age Related ◽  
Left And Right ◽  
The Right

The purpose of the study was to examine age-related differences in electromyographic (EMG) responses to transcranial magnetic stimulation (TMS) during functional isometric contractions in left and right hands. EMG responses were recorded from the first dorsal interosseus muscle following TMS in 10 young (26.6 ± 1.3 yr) and 10 old (67.6 ± 2.3 yr) right-handed subjects. Muscle evoked potentials (MEPs) and silent-period durations were obtained in the left and right hands during index finger abduction, a precision grip, a power grip, and a scissor grip, while EMG was held constant at 5% of maximum. For all tasks, MEP area was 30% ( P < 0.001) lower in the left hand of old compared with young subjects, whereas there was no age difference in the right hand. The duration of the EMG silent period was 14% ( P < 0.001) shorter in old (150.3 ± 2.9 ms) compared with young (173.9 ± 3.0 ms) subjects, and the age differences were accentuated in the left hand (19% shorter, P < 0.001). For all subjects, the largest MEP area (10–12% larger) and longest EMG silent period (8–19 ms longer) were observed for the scissor grip compared with the other three tasks, and the largest task-dependent change in these variables was observed in the right hand of older adults. These differences in corticospinal control in the left and right hands of older adults may reflect neural adaptations that occur throughout a lifetime of preferential hand use for skilled (dominant) and unskilled (nondominant) motor tasks.

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.

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 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.

The Influence of Age and Work-Related Expertise on Fine Motor Control

GeroPsych ◽  
2012 ◽  
Vol 25 (4) ◽  
pp. 199-206 ◽  
Author(s):  
Solveig Vieluf ◽  
Jasmin Mahmoodi ◽  
Ben Godde ◽  
Eva-Maria Reuter ◽  
Claudia Voelcker-Rehage
Keyword(s):  
Motor Control ◽  
Precision Grip ◽  
Middle Finger ◽  
Fine Motor ◽  
Force Variability ◽  
Fine Motor Control ◽  
Left Hand ◽  
Work Related ◽  
Age Related ◽  
The Right

Age-related decline of fine motor control commences even in middle adulthood. Less is known, however, whether age-related changes can be postponed through continuous practice. In this study we tested how age and professional expertise influence fine motor control in middle-aged adults. Forty-eight right-handed novices and experts (35 to 65 years) performed submaximal precision grip force modulation tasks with index or middle finger opposing the thumb, either with the right hand or the left hand. Novices revealed expected age-related differences in all performance measures (force initialization, mean applied force, variability), whereas experts outperformed novices in all outcome measures. Expertise seems to contribute to maintaining manual skills into older age, as indicated by the age and expertise interaction for the force initialization.

Lateral Differences in Schematic Face Encoding during Dual-Task Performance with Increasing Levels of Difficulty

1989 ◽  
Vol 68 (3) ◽  
pp. 767-778 ◽  
Author(s):  
Teresa Wilcox ◽  
R. Harter Kraft
Keyword(s):  
Right Hemisphere ◽  
Memory Task ◽  
Interference Effects ◽  
Left Hand ◽  
Right Hand ◽  
Dual Task Performance ◽  
Hand Tapping ◽  
Left And Right ◽  
The Right ◽  
Verbal Production

20 normal, right-handed, familial dextral men performed (a) unimanual finger tapping, (b) encoding of schematic faces at three levels of difficulty (3, 5, and 7 faces), (c) verbal production, (d) concurrent tapping and verbal production, and (e) concurrent tapping and face encoding. Subsequent recognition of faces was disrupted more by concurrent left-hand tapping than by concurrent right-hand tapping, supporting both the hypothesis that the right hemisphere mediates face encoding in adults and Kinsbourne and Hicks' (1978) “functional cerebral distance principle.” Left- and right-hand tapping rate and variability were not asymmetrically affected by either verbal production or face encoding. While there was an increase in generalized interference effects on face encoding, the degree of asymmetry of the interference remained constant. In addition, as the difficulty of the memory task increased, variability of tapping rate decreased. This was discussed in terms of attention and automatic motor programming.

Absence of cross-limb transfer of performance gains following ballistic motor practice in older adults

2011 ◽  
Vol 110 (1) ◽  
pp. 166-175 ◽  
Author(s):  
Mark R. Hinder ◽  
Matthew W. Schmidt ◽  
Michael I. Garry ◽  
Timothy J. Carroll ◽  
Jeffery J. Summers
Keyword(s):  
Older Adults ◽  
Intracortical Inhibition ◽  
Young Group ◽  
Left Hand ◽  
Performance Improvements ◽  
Rehabilitation Programs ◽  
Right Hand ◽  
Motor Practice ◽  
The Right ◽  
Performance Gains

The phenomenon of cross-limb transfer, in which unilateral strength training can result in bilateral strength gains, has recently been tested for ballistic movements. Performance gains associated with repetitive motor practice, and the associated transfer, occur within a few minutes. In this study, young and older adults were trained to perform ballistic abductions of their dominant (right) index finger as quickly as possible. Performance was assessed bilaterally before, during, and after this training. Both groups exhibited large performance gains in the right hand as a result of training ( P < 0.001; young 84% improvement, older 70% improvement), which were not significantly different between groups ( P = 0.40). Transcranial magnetic stimulation revealed that the performance improvements were accompanied by increases in excitability, together with decreases in intracortical inhibition, of the projections to both the trained muscle and the homologous muscle in the contralateral limb ( P < 0.05). The young group also exhibited performance improvements as a result of cross-limb transfer in the left (untrained) hand ( P < 0.005), equivalent to 75% of the performance increase in the trained hand. In contrast, there were no significant performance gains in the left hand for the older group ( P = 0.23). This was surprising given that the older group exhibited a significantly greater degree of mirror activity than the young group ( P < 0.01) in the left first dorsal interosseus muscle (FDI) during right hand movements. Our findings suggest that older adults exhibit a reduced capacity for cross-limb transfer, which may have implications for motor rehabilitation programs after stroke.

scholarly journals Exploring the interactions among SNARC effect, finger counting direction and embodied cognition

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9155
Author(s):  
Giulia Prete ◽  
Luca Tommasi
Keyword(s):  
Embodied Cognition ◽  
Snarc Effect ◽  
Response Code ◽  
Numerical Processing ◽  
Left Hand ◽  
Right Hand ◽  
Finger Counting ◽  
Left And Right ◽  
The Right ◽  
Preferential Association

The Spatial Numerical Association of Response Code (SNARC) is the preferential association between smaller/larger magnitudes and left/right side, respectively. Some evidence suggest a link between SNARC and a left-to-right finger counting habit. We asked 268 participants to show how they use the hands to count from 1 to 10. By means of this ecological task, 80% of the sample use first the right hand (to count from 1 to 5) and the majority of them use a palm-up posture. In Experiment 2 (N = 46) right-starters were asked to categorize 1-to-5 magnitudes as even or odd, using the left and right hand. Stimuli were presented both as Arabic numbers and by means of left and right hand photographs in palm-up and palm-down posture. Results confirmed the expected SNARC effect in the Arabic condition. With hand images we found that right hand responses were better for larger than for smaller magnitudes (SNARC, mainly for left hand palm-up stimuli), showing that the SNARC can be generalized to different codes. Finally, the interactions between magnitudes and left/right hand images in palm-up and palm-down posture suggest that embodied cognition can influence numerical processing.

Editorial Note

1946 ◽  
Vol 11 (1) ◽  
pp. 2-2
Keyword(s):  
Editorial Note ◽  
Speech Sounds ◽  
Left Hand ◽  
Hand Column ◽  
Right Hand ◽  
Infant Speech ◽  
The Right

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.

scholarly journals Digit Variability in Carotenoid Scores Obtained with the Veggie Meter: A Pilot Study (P02-001-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Velarie Ansu ◽  
Stephanie Dickinson ◽  
Alyce Fly
Keyword(s):  
Indiana University ◽  
Left Hand ◽  
Funding Sources ◽  
Right Hand ◽  
Period Data ◽  
The Mean ◽  
The Right ◽  
Post Hoc ◽  
Main Effects ◽  
Mean Square Errors

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.

Sign in / Sign up

Export Citation Format

Share Document